the Management of Neutropenia in Pediatric Age Groups

Neutropenia is a reduction in the ANC below the lower limit of the normal range for the age and ethnic origin of the affected subject. It can be classified as congenital or acquired. Neutropenic individuals are at increased risk of infection. The greatest susceptibility of infection is seen with ANC below 500 /mm³. Real world data have shown that the work-up of patients with neutropenia is mostly based on the physicians’ experience and local practices rather than on the guided clinical and laboratory evidence. Thus, the diagnosis and monitoring of neutropenic patients remain varied and challenging.

This guideline focuses on the prevention and management of neutropenia in pediatric age groups.

After reviewing all the inclusion and exclusion criteria and quality appraisal results, the GDG/ GAG recommended using the following source original clinical practice guidelines (CPGs):

1.     Guideline for Managing Fever and Neutropenia in Pediatric Patients With Cancer and Hematopoietic Cell Transplantation Recipients: 2023 Update. ASCO (2023)

2.     The European Guidelines on Diagnosis and Management of Neutropenia in Adults and Children: A Consensus Between the European Hematology Association and the EuNet-INNOCHRON COST Action. EHA-EuNet-INNOCHRON (2023)

3.     Guideline for Antibacterial Prophylaxis Administration in Pediatric Cancer and Hematopoietic Stem Cell Transplantation. IDSA (2020)

4.     Guideline for the Management of Clostridium Difficile Infection in Children and Adolescents With Cancer and Pediatric Hematopoietic Stem-Cell Transplantation Recipients. ASCO (2018)

 

We conducted Adolopment for these guidelines: (Adoption, Adaptation, and Development)

         -          Adoption for most of the guideline recommendations.

         -          Development of Good Practice Statements

 

 

Recommendations and Good Practice Statements (GPS)

This version of the CPG includes recommendations and good practice statements on the following three sub-sections:

A. Diagnosis of Neutropenia in children

The guideline covers pediatric patients suffering from primary or secondary neutropenia.

This guideline emphasizes definitions of neutropenia in the different age groups with different etiopathogenesis as well as the criteria for the definition of febrile neutropenia.

B. Management of Neutropenia.

This section includes recommendations and good practice statements on first- and second-line investigations in cases of febrile and afebrile neutropenia. This section also highlights recommendations on the different pharmacological and non-pharmacological therapies for children with neutropenia.

 

C. Prevention of infections in children with neutropenia.

This section outlines the main lines and recommendations in preventing infections in children with neutropenia.

 

We can summarize the guidelines’ recommendations for the management of pediatric neutropenia in the following:

We recommend the use of the following definition of neutropenia

• The definition of neutropenia varies according to the patient’s ethnic origin and age. SoR: GPS
• At term neonates: Neutropenia is defined as an absolute neutrophil count (ANC) level of 2.5 × 10⁹/L for term/near-term neonates 72–240 hours following delivery. SoR: GPS
• In preterm newborns: Neutropenia is defined as an ANC level of 1.0 × 10⁹/L for preterm neonates. SoR: GPS
• Infants and Children: The widely accepted cutoff level of ANC for the definition of neutropenia in Caucasian newborns and infants up to the age of 1 year is 1.0 × 10⁹/L. SoR: GPS
• From the age of 1 year to adulthood the cutoff level for neutropenia is 1.5 × 10⁹/L. SoR: GPS

We recommend the use of the following classification of neutropenia (severity)

• Neutropenia is classified as mild when ANC is between 1.0 and 1.5 × 10⁹/L. SoR: GPS
• Moderate when ANC is 0.5 to 1.0 × 10⁹/L. SoR: GPS
• Severe when ANC is <0.5 × 10⁹/L. SoR: GPS
• The term agranulocytosis is used for severe neutropenia with ANC <0.2 × 10⁹/L. SoR: GPS

We recommend the use of the following classification of neutropenia (duration)

• Neutropenia is characterized as acute when duration is <3 months. SoR: GPS
• Chronic when duration is >3 months. SoR: GPS

We recommend the use of the following classification of neutropenia (etiology)

• An extended, pathogenesis-based classification categorizes neutropenia as congenital versus acquired and likely acquired. SoR: GPS

We recommend the use of the following congenital neutropenia and its classification

• Congenital neutropenia (CN) comprises a group of genetic diseases characterized by impaired production, differentiation, and survival of neutrophils in the bone marrow (BM), susceptibility to infections, and increased propensity to MDS/AML transformation. SoR: GPS
• CN can be further subclassified into disorders where neutropenia is the only abnormality and those where neutropenia is associated with extra-hematological manifestations, immunodeficiency/immune dysregulation, metabolic disorders and nutritional deficiencies, or as part of more complex BM failure syndromes. SoR: GPS
• The classification also takes into consideration the genes that have been identified as responsible for each CN subtype. SoR: GPS
• Individuals of African and Middle Eastern descent display normal ANCs in the range from 0.5 to 1.5 × 10⁹/L and less frequently even lower. SoR: GPS
• This variation, previously termed ethnic neutropenia, is usually inherited as an autosomal recessive trait associated with a polymorphism (rs2814778, −46T>C) in the GATA box in the promoter region of the ACKR1 gene (DARC). SoR: GPS
• In homozygosity (C/C), the polymorphism results in the absence of Duffy antigen expression specifically on red blood cells, a phenotype known as Duffy-null. SoR: GPS
• The guideline working group suggests the introduction of the term ACKR1/DARC-associated neutropenia (ADAN), instead of ethnic neutropenia, to emphasize the genetic rather than the ethnic basis of this entity. SoR: GPS

We recommend the use of the following causes of neutropenia in the neonatal period

• Females have ANC counts on average 2.0 × 10⁹/L higher than males. SoR: GPS
• ANC in capillary blood is on average 1.5–2.0 × 10⁹/L higher than in cord blood. SoR: GPS
• ANC is on average higher at altitude than at sea level. SoR: GPS
• Severe necrotizing enterocolitis in the newborn, especially if preterm, is frequently associated with transiently low ANCs. SoR: GPS
• Maternal tobacco smoking is associated with lower ANC. SoR: GPS
• Maternal chemotherapy results in neutropenia. SoR: GPS
• Maternal antiretroviral therapy results in neutropenia. SoR: GPS
• Maternal hypertension during pregnancy results in neutropenia. SoR: GPS
• Prenatal growth retardation is an independent risk factor for neutropenia. SoR: GPS
• Rh-hemolytic disease of the newborn is associated with neutropenia in about 50% of newborns. SoR: GPS
• Twin-twin transfusion syndrome: neutropenia always present in the donor twin. SoR: GPS
• Neutropenia is present in 67% of infants with asphyxia. SoR: GPS

 

Types of immune neutropenia specific to neonates

• AIN, which is unusual, but not impossible, at <1 month of age. SoR: GPS
• Neonatal alloimmune neutropenia (NAN): genetic mismatch for HNA polymorphism → maternal immunization → alloantibodies cross placenta → neutropenia in baby. SoR: GPS
• NAN secondary to maternal AIN (rarest form). SoR: GPS

Causes of acquired neutropenia

• Classified as primary/idiopathic (antineutrophil antibodies or unknown mechanisms). SoR: GPS
• Secondary due to infections, autoimmune diseases, drugs, nutritional deficiencies, hypersplenism, or hematologic diseases. SoR: GPS

Required points in history taking

• Patient history should include occurrence of infections and their frequency, type, severity, and need for hospitalization. SoR: GPS
• History of omphalitis, gingivitis, periodontitis, skin infections, abscesses, pneumonias, duration and response to antibiotics. SoR: GPS
• Presence of congenital malformations in the patient or family. SoR: GPS
• For adult patients: drug history, autoimmune disorders. SoR: GPS
• Detailed family history: ethnic origin, consanguinity, recurrent infections, neutropenia in family members, unexplained infant death or miscarriages. SoR: GPS
• Symptoms denoting autoimmune or other diseases. SoR: GPS
• History of chronic viral infections (hepatitis, HIV). SoR: GPS
• Careful inquiry about drug administration (including OTC, supplements, recreational drugs). SoR: GPS

➡️Required detailed clinical examination

• Careful clinical examination of skin, mucous membranes, respiratory tract, abdomen to exclude infection, lymphadenopathy, hepatosplenomegaly. SoR: GPS
• Examination should focus on growth, cognitive impairment, developmental delay, dysmorphism, nail/hair/skin abnormalities, bronchiectasis, hepatomegaly/splenomegaly, organ malformation, superficial veins, photophobia, nystagmus, albinism, neuropathy. SoR: GPS
• Cardiac function, enlarged lymph nodes, joint symptoms, autoimmune/metabolic/gastrointestinal/nutritional diseases should be considered. SoR: GPS

• Febrile neutropenia (FN) is defined as an oral temperature of >38.3°C or two consecutive readings of >38.0°C for 2 h and an ANC of <0.5 × 10⁹/L or expected to fall below 0.5 × 10⁹/L. SoR: GPS
• A.5.a. Approach to investigate children with neutropenia
• Patients with acute neutropenia, particularly in the presence of symptoms/signs of infection, may require immediate investigation and even hospitalization depending on the severity of neutropenia and symptoms. SoR: GPS
• For patients with chronic, isolated neutropenia without a phenotype suggestive of any underlying CN syndrome, a flowchart of basic investigation is recommended. SoR: GPS
• If the initial evaluation does not suggest ADAN, nor postinfectious or drug-induced neutropenia, the first level of investigation, possibly adjusted to the availability of the recommended tests. SoR: GPS
• A.5.b. First and second lines of investigations for children with neutropenia
• First-line investigations: Complete blood count (CBC)s, peripheral blood (PB) smear. SoR: GPS
• Biochemistry tests including liver and kidney function, c-reactive protein (CRP). SoR: GPS
• Vitamin B12 and folate. SoR: GPS
• Virology antibody screening (i.e., HepB, HepC, HIV, EBV, and CMV). SoR: GPS
• Thyroid hormones (FT3, FT4, TSH), antithyroid antibodies (anti-TG and anti-TPO). SoR: GPS
• Antineutrophil antibodies by granulocyte immunofluorescence test (GIFT) and/or granulocyte agglutination test (GAT). SoR: GPS
• Immunoglobulin levels and flow cytometric analysis of PB lymphocyte subsets. SoR: GPS
• Additional investigation in children: flow cytometric analysis of CD3+TCRα/β+CD4-CD8- (double negative) PB T lymphocytes. SoR: GPS
• Second-line investigations: CBCs in family members, serial blood counts twice a week over a period of 6 weeks to exclude CyN, copper; ceruloplasmin, anti-tissue transglutaminase IgA, deamidated gliadin peptide antibodies IgA/IgG and pancreatic isoamylase. SoR: GPS
• Additional investigation in children: rheumatoid factor (RF), antinuclear antibody (ANA), extractable nuclear antigen (ENA), and double stranded DNA (ds-DNA). SoR: GPS
• In children, young adults, and considered for adults: genetic investigations. SoR: GPS
• A.5.c. Confirming the diagnosis of congenital neutropenia
• Following negative results of first-level investigation, all patients with SCN and recurrent infections and/or family history of severe neutropenia and typical anomalies should undergo genetic work-up using multigene next generation sequencing (NGS) methods. SoR: GPS
• Patients with congenital neutropenia may have positive anti-neutrophil antibodies. In case of severe infections patients should in spite positive antibodies undergo genetic testing. SoR: GPS
• Family history or clinical findings may suggest another specific neutropenia-associated gene to be sequenced (e.g., TAZ, G6PC3, SBDS). SoR: GPS
• A targeted NGS panel including all genes known to be mutated in CN (>30) is a reasonable first step that provides uniform sequencing coverage for all genes of interest and requires simpler bioinformatics analysis. SoR: GPS
• The choice of genes within the panel should include not only all those that strictly cause neutropenia when mutated but also genes resulting in diseases in which neutropenia is a secondary feature; whole exome sequencing (WES) can also be used in cases where no mutations were detected in a panel. SoR: GPS
• A.5.d. Diagnosing cyclic neutropenia
• Complete blood counts (CBC) in family members, serial blood counts twice or thrice a week over a period of 6 weeks to exclude CyN. SoR: GPS
• A.5.e. Diagnosing autoimmune neutropenia
• Antineutrophil antibody testing should be performed as first-line investigation in both children and adults. SoR: GPS
• Indirect granulocyte immunofluorescence test (GIFT) is recommended as a first-line assay in reference laboratories. SoR: GPS
• A positive GIFT in combination with laboratory tests and clinical picture can support diagnosis of autoimmune neutropenia (AIN) but does not exclude the diagnosis of other types of neutropenia. SoR: GPS
• With a negative indirect GIFT, if the clinical suspicion of AIN remains high, GIFT should be repeated several times. SoR: GPS
• A.5.f. Family screening in genetically proven congenital neutropenia
• Following identification of the responsible gene(s), Sanger sequencing is also recommended for mutation screening of the members of affected families. SoR: GPS
• Multigene NGS or WES ideally should include patient and parental DNA (trio analysis). SoR: GPS
• A.5.g. Role of bone marrow examination
• Diagnostic BM with morphology, cytogenetics, and NGS of genes related to myeloid malignancies should be performed: In pediatric patients with severe and moderate chronic neutropenia with the exception of patients with primary AIN with positive anti-granulocyte antibodies and drug-induced neutropenia. SoR: GPS
• Patients with congenital neutropenia may have positive antibody test. SoR: GPS
• In patients with suggested AIN but negative granulocyte antibody test, if patients suffer from recurrent infections. SoR: GPS
• In any patients before G-CSF treatment. SoR: GPS
• Repeated BM follow-up should be performed in patients with decreasing ANC or additional changes in other blood cell counts (e.g., anemia and thrombocytopenia) or erythrocyte indices. SoR: GPS
• A.5.h. Role of flow cytometry
• FC is an important tool in the diagnosis of neutropenia associated with PID syndromes such as ALPS, CVID, and HIGM syndrome. SoR: GPS
• Assessment of a PNH clone by FC testing is also recommended. SoR: GPS
• Flow FISH is recommended when a telomere biology disorder is suspected. SoR: GPS
• A.5.i. Role of genetic testing
• Genetic diagnosis is important to confirm the diagnosis of CN, estimate the risk for MDS/AML, support stem cell donor selection for patients, and family counseling. SoR: GPS
• When the clinical picture, inheritance, or bone marrow features (i.e., block at the promyelocyte stage) are indicative of a specific gene mutation, single-gene analysis by Sanger sequencing technique could be applied. SoR: GPS
• For CN where the clinical picture does not suggest a specific genetic cause, we recommend the use of NGS techniques such as multigene panels or targeted WES. SoR: GPS
• For patients for whom a genetic cause is not identified by the above methods, WGS and RNA-sequencing may be powerful diagnostic tools. SoR: GPS
• NGS analysis of bone marrow or peripheral blood for acquired somatic variants is recommended for patients with chronic neutropenia. SoR: GPS
• Screening for known mutations is recommended in family members. SoR: GPS
• It is important to validate germline mutations mainly in fibroblasts or hair follicles keratinocytes (cells from buccal swab are less indicated for possible blood contamination), in the presence of leukemic blasts in PB. SoR: GPS
• A.5.j. Initial evaluation for children presenting with fever and neutropenia (ASCO 2023)
• Adopt a validated risk stratification strategy and incorporate it into routine clinical management. SoR: Strong
• Obtain blood cultures at the onset of FN from all lumens of central venous catheters. SoR: Strong
• Consider obtaining peripheral blood cultures concurrent with central venous catheter cultures. SoR: Conditional
• Consider urinalysis and urine culture in patients where a clean-catch, mid-stream specimen is readily available. SoR: Conditional
• Obtain chest radiography only in patients with respiratory signs or symptoms. SoR: Strong
• Treatment of Neutropenia
• B.1. Treatment of infection in patients with fever and non-severe neutropenia
• Individuals with an ANC >1.0 × 10⁹/L can be managed as per those with normal ANC. SoR: GPS
• B.2. Treatment of fever and neutropenia (FN)
• Infants with primary AIN should be excluded from these recommendations, since ANC is not indicative of infectious risk in these patients. SoR: GPS
• Low-risk FN
• Consider initial or step-down outpatient management if the infrastructure is in place to ensure careful monitoring and follow-up. SoR: Conditional
• Consider oral antibacterial therapy administration if the patient is able to tolerate this route of administration reliably. SoR: Conditional
• High-risk FN
• Use monotherapy with an antipseudomonal β-lactam, a fourth-generation cephalosporin or a carbapenem as empiric antibacterial therapy in pediatric high-risk FN. SoR: Strong
• Reserve addition of a second anti-Gram-negative agent or a glycopeptide for patients who are clinically unstable, when a resistant infection is suspected, or for centers with a high rate of resistant pathogens. SoR: Strong
• Ongoing management – Modification of treatment
• In patients who are responding to initial empiric antibacterial therapy, discontinue double coverage for Gram-negative infection or empiric glycopeptide (if initiated) after 24–72 hours if there is no specific microbiologic indication to continue combination therapy. SoR: Strong
• Do not broaden the initial empiric antibacterial regimen based solely on persistent fever in patients who are clinically stable. SoR: Strong
• In patients with persistent fever who become clinically unstable, escalate the initial empiric antibacterial regimen to include coverage for resistant Gram-negative, Gram-positive and anaerobic bacteria. SoR: Strong
• Ongoing management – Cessation of treatment
• In both high-risk and low-risk FN patients who have been clinically well and afebrile for at least 24 hours, discontinue empiric antibacterial therapy if blood cultures remain negative at 48 hours if there is evidence of marrow recovery. SoR: Strong
• In patients with low-risk FN who have been clinically well and afebrile for at least 24 hours, consider discontinuation of empiric antibacterial therapy if blood cultures remain negative at 48 hours despite no evidence of marrow recovery. SoR: Conditional
• B.3. Treatment of severe chronic neutropenia
• Use of G-CSF
• Patients usually need life-time treatment. SoR: GPS
• The therapeutic target (ANC ≥1.0 × 10⁹/L and ≤5.0 × 10⁹/L) is considered achievable with a G-CSF starting dose of 5 μg/kg/d, but the individual variability of the response may require modifications of the subsequent doses. SoR: GPS
• It is suggested to increase G-CSF over 2 weeks up to doubling initial dose if ANC remain <1.0 × 10⁹/L and to reduce G-CSF if ANC reach >5.0 × 10⁹/L. SoR: GPS
• Maintain the initial dose if the target ANC (≥1.0 × 10⁹/L and ≤5.0 × 10⁹/L) is achieved and increase by 2.5 μg/kg/day every 5–7 days if ANC remains <1.0 × 10⁹/L. N.B: Depending on clinical situation and known underlying genotype doubling of G-CSF may be indicated up to 50 µg/kg/day to evaluate G-CSF response. SoR: GPS
• Experts agreed on the non-superiority of lenograstim vs. filgrastim as the number of infections was similar in patients treated with the two preparations. SoR: GPS
• The use of pegylated G-CSF in neutropenia has been rarely reported in pediatric age. SoR: GPS
• Hematopoietic stem cell transplantation (HSCT)
• Strong indications for HSCT include: (1) Established transformation to MDS/Acute Leukemia or bone marrow dysplastic features with high-risk acquired cytogenetic abnormalities (monosomy 7, trisomy 8, trisomy 21) or with a combination of acquired leukemia-associated somatic mutations (e.g., RUNX1, ASXL1, SETBP1). CSF3R mutations alone are not an indication of HSCT. (2) CN due to mutations carrying an intrinsic high risk of leukemic transformation per se, i.e., GATA2 mutations, high-risk ELANE mutations, or clones with biallelic TP53 mutations in SDS. (3) No response to G-CSF (doses >20 mcg/kg/d to reach ANC of 1.0 × 10⁹/L), poor response to G-CSF (doses between 10 and 20 mcg/kg/d failing to reach ANC of 1.0 × 10⁹/L) or poor control of infection irrespective of the G-CSF dose. Potential indications: adequate management of infections with G-CSF at “intermediate doses” (10–15 mcg/kg/d) with availability of a healthy HLA-identical sibling or HLA identical matched donor. Weak indication: G-CSF response at doses up to 10 μg/kg/d, good tolerability and compliance to daily subcutaneous injections, infections control, and unavailability of HLA matched donors. SoR: GPS
• B.4. Treatment of cyclic neutropenia (CyN)
• In cyclic neutropenia (CyN) G-CSF treatment has been shown to shorten the degree and the duration of neutropenia conferring the patients a better quality of life. For these reasons, the long-term pattern of treatment was considered adequate to CyN. SoR: GPS
• This has to be intended as a life-time treatment not to be performed daily but only during the lowest levels of neutrophils in cycling periods of neutropenia. SoR: GPS
• Usually, patients affected by CyN need lower G-CSF doses (median 2.4 μg/kg/day) than SCN patients. A starting dose of 1–3 μg/kg/d should maintain ANC around 1.5 × 10⁹/L; for lower counts the dosage may be increased up to two-fold within 2–4 weeks. Given the ANC fluctuations it is suggested to calculate the final G-CSF dose after a number of observations. SoR: GPS
• Daily administration during neutropenia is more appropriate than the intermittent schedule. Initial suggested dose during neutropenic periods is 2 μg/kg/day. If ANC target is not achieved, increases of 2 μg/kg/d every neutropenic phase are recommended. SoR: GPS
• The panel recommends the use of G-CSF in severe CN and in CyN, particularly in those patients with recurrent or severe infections. The panel considers ANC over 1.0 × 10⁹/L as the protective threshold against infections. For CyN, a lower nadir may be accepted. In CyN, G-CSF doses may be lower than in severe CN. The standard dose should be ≤3 mcg/kg/d continuously. G-CSF may be also given every other day. Dosage may be adjusted to avoid nadir <0.5 × 10⁹/L and clinical conditions such as mouth ulcers, fevers, or infections. SoR: GPS
• B.5. Treatment of idiopathic neutropenia (IN)
• In the majority of cases, IN requires an on-demand treatment only during infections or surgery. In these patients an initial dose of 1–2 μg/kg/d is considered sufficient to achieve goal ANC. SoR: GPS
• Some patients with a diagnosis of IN may have severe and/or recurrent infections and may require long-term treatment. A starting dose (1–2 μg/kg/die) of G-CSF can be sufficient to achieve the goal ANC and a rhythm of 2–3 times/week may ensure protective values of neutrophils. SoR: GPS
• B.6. Treatment of autoimmune neutropenia (AIN)
• G-CSF
• The use of G-CSF in AIN is generally necessary only in case of severe infections and therefore the on-demand treatment is considered appropriate. Some forms of AIN may have severe and/or recurrent infections requiring a long-term treatment. SoR: GPS
• An initial low dose of G-CSF (1–2 mg/kg/die) to be subsequently adjusted. SoR: GPS
• Other treatment modalities
• Various immune-regulating drugs (e.g., cyclosporine, methotrexate, low-dose cyclophosphamide) have been used in refractory cases, but overall efficacy has not been determined. SoR GPS
• G-CSF
• The use of G-CSF in AIN is generally necessary only in case of severe infections and therefore the on-demand treatment is considered appropriate. Some forms of AIN may have severe and/or recurrent infections requiring a long-term treatment. SoR: GPS
• An initial low dose of G-CSF (1–2 mg/kg/die) to be subsequently adjusted. SoR: GPS
• Other treatment modalities
• Various immune-regulating drugs (e.g., cyclosporine, methotrexate, low-dose cyclophosphamide) have been used in refractory cases, but overall efficacy has not been determined. SoR: GPS
• In case of an underlying immune dysregulation/deficiency, particularly in childhood, more targeted treatments (e.g., mycophenolate mofetil and rapamycin) may be used. SoR: GPS
• The role of rituximab (and other antibodies to CD20) is well established as effective treatment for many autoimmune disorders. However, its role as treatment for AIN is unclear. SoR: GPS
• Pediatric patients actively receiving cytotoxic chemotherapy. Down Syndrome. Children with immune deficiency. Patient with Central venous catheter. Compromise of mucosal barriers (e.g. mucositis, typhlitis). Myelosuppression. Children with hematologic malignancies have an increased risk relative to children with solid tumors (SoR: GPS)

• Personal protective equipment (gown, gloves. . .) in patients with contagious infection or colonization by multidrug resistant (MDR) microorganisms (SoR: GPS) Aseptic technique in central venous catheter (CVC) handling (SoR: GPS) Hand, surface and food preparation hygiene measures (SoR: GPS) Chlorhexidine gluconate (CHG) baths (CHB) involve cleansing the patient’s body each day with CHG‑impregnated wipes. Literature from pediatric patients with temporary CVCs inserted during critical care admissions suggests that CHB may have a role in reducing the rate of CLABSIs in these patients (SoR: GPS)

• Avoid contact with pets associated with a high risk: turtles, cat’s litter, stables and new pets. This does not apply to other pets that are correctly vaccinated, in regard to which the sole precaution is to avoid contact with their faeces (SoR: GPS) Prevention of IFI (high risk patients/situations) Avoid flowers and plants in hospital rooms and the bedroom of the patient. Hospital rooms with HEPA filters and positive pressure (>12 room air changes/h). Use of FPP2 masks in closed spaces without HEPA filters (except the usual place of residence, where ventilation, avoiding plants, moisture and construction work). Recommendation not supported by evidence: Avoid pools, especially public or indoor ones. Low bacteria diet not proven to reduce the incidence or severity of infection. Personal protective equipment for patients in absence of microbial isolation that justifies it (SoR: GPS)

• G‑CSF in patients with solid tumors receiving intensive chemotherapy, who need to maintain cytotoxic dose/chemotherapy intensity and/or with previous history of fever neutropenia (FN) (SoR: GPS) Annual vaccination against seasonal flu of patients and their household contacts and health care workers (SoR: GPS)

• AML and relapsed ALL: Consider systemic antibacterial prophylaxis administration in children receiving intensive chemotherapy expected to result in severe neutropenia (absolute neutrophil count <500/µl for at least 7 days) (SoR: Conditional) Newly diagnosed ALL: Do not use systemic antibacterial prophylaxis routinely for children receiving induction chemotherapy (SoR: Conditional)

• Therapy not expected to result in severe neutropenia (ANC <500/µl for at least 7 days): Do not use systemic antibacterial prophylaxis (SoR: Strong) Autologous HSCT: Do not use systemic antibacterial prophylaxis routinely (SoR: Conditional) Allogeneic HSCT: Do not use systemic antibacterial prophylaxis routinely (SoR: Conditional)

• Levofloxacin is the preferred agent if systemic antibacterial prophylaxis is planned (SoR: Strong) If systemic antibacterial prophylaxis is planned; we suggest that administration be restricted to the expected period of severe neutropenia (absolute neutrophil count <500/μL) (SoR: Conditional)

• AML: Administer systemic antifungal prophylaxis to children and adolescents receiving treatment of AML that is expected to result in profound and prolonged neutropenia (SoR: Strong)

•  ALL (newly diagnosed and relapsed): Consider administering systemic antifungal prophylaxis to children and adolescents at high risk for invasive fungal disease (IFD) (SoR: Conditional)

• ALL (low risk): Do not routinely administer systemic antifungal prophylaxis (SoR: Strong) Other malignancies (lymphomas and solid tumors): Do not routinely administer systemic antifungal prophylaxis to children and adolescents with cancer at low risk for IFD, such as most pediatric patients with lymphomas and solid tumors (SoR: Strong)

• Allogeneic HSCT: Administer systemic antifungal prophylaxis pre‑engraftment and to those receiving systemic immunosuppression for GVHD (SoR: Strong)

• Autologous HSCT: We suggest that systemic antifungal prophylaxis not be used routinely (SoR: Strong) Mold‑active agent: In choosing a mold‑active agent, administer an echinocandin or a mold‑active azole (SoR: Strong) Amphotericin: Do not use amphotericin routinely as systemic antifungal prophylaxis (SoR: Strong) If systemic antifungal prophylaxis is warranted, consider administration during periods of observed or expected severe neutropenia. For allogeneic HSCT recipients, consider administration during systemic immunosuppression for GVHD treatment (SoR: Conditional)

• Do not use probiotics routinely for the prevention of CDI in children and adolescents with cancer and pediatric HSCT patients (SoR: Conditional) Use either oral metronidazole or oral vancomycin for the treatment of non‑severe CDI in children and adolescents with cancer and pediatric HSCT patients (SoR: Strong) Use oral vancomycin for the treatment of severe CDI in children and adolescents with cancer and pediatric HSCT patients (SoR: Strong) Do not use monoclonal antibodies routinely for the treatment of CDI in children and adolescents with cancer and pediatric HSCT patients (SoR: Strong)

• Risk for PJP pneumonia is highest in patients with leukemia and lymphoma, prophylaxis is also recommended for children with solid tumors undergoing chemotherapy that is likely to cause lymphopenia. Data in patients with HIV shows that the risk of PJP is highest in those with CD4 counts under 200 x106/L, and one study from the solid organ transplantation population found that odds of PJP infection were significantly increased when absolute lymphocyte count (ALC) was < 500 x106/L. Sulfamethoxazole (TMP‑SMX) is highly effective. For patients who do not tolerate TMP‑SMX, pentamidine, dapsone, and atovaquone are alternative options, Optimal duration of PJP prophylaxis is unknown. One guideline suggests continuing until 3 months after the end of therapy and normalization of lymphocyte count (SoR: GPS)

• Use cryotherapy for older, cooperative pediatric patients receiving treatment for cancer or undergoing HSCT who will receive short infusions of melphalan or 5‑fluorouracil (SoR: GPS) Consider using cryotherapy for older, cooperative pediatric patients receiving treatment for cancer or undergoing HSCT who will receive short infusions of chemotherapy associated with mucositis other than melphalan or 5‑fluorouracil (SoR: GPS) Do not administer palifermin routinely to pediatric patients with cancer receiving treatment for cancer or undergoing HSCT (SoR: GPS) Use intraoral photo‑biomodulation therapy in the red‑light spectrum (620–750 nm) for pediatric patients undergoing autologous or allogeneic HSCT and for pediatric patients who will receive radiotherapy for head and neck carcinoma (SoR: GPS) Consider using intraoral photo‑biomodulation therapy in the red‑light spectrum (620–750 nm) for pediatric patients who will receive radiotherapy for head and neck cancers other than carcinoma (SoR: GPS) Do not administer GCSFs to pediatric patients receiving treatment for cancer or undergoing HSCT for the purpose of mucositis prevention (SoR: GPS)

• The use of G‑CSF in in patients with solid tumors receiving intensive chemotherapy, who need to maintain cytotoxic dose/chemotherapy intensity and/or with previous history of FN reduces the duration of neutropenia (SoR: GPS)

• Annual vaccination against seasonal flu of patients and their household contacts and health care workers. Despite potential lack of efficacy in certain populations, the American Academy of Pediatrics and Center for Disease Control still recommend yearly influenza vacations in pediatric oncology patients based on potential benefit with low risk of reaction (SoR: GPS)

• Careful clinical examination of skin and mucous membranes, upper and lower respiratory tract and abdomen to exclude underlying infection, lymphadenopathy, and/or hepatosplenomegaly (SoR: GPS) Vital signs: temperature, heart rate, respiratory rate, blood pressure and oxygen saturation. Pediatric assessment triangle (early detection of sepsis). Review of systems, including neurologic assessment, perfusion, skin and mucosae (oral and perianal, avoid rectal palpation), any area with pain, scars, devices (SoR: GPS)

• In chronic neutropenia patients, we recommend performing CBC with differential WBC counts and morphological evaluation every 3–4 months (SoR: GPS) When approaching adulthood, CN patients should be transferred to a dedicated hematology specialist (SoR: GPS)

• Annual BM and cytogenetics follow‑up should be performed in patients with congenital BM failure syndromes independent of ANC and treatment with G‑CSF. undefined SCN (after extensive investigation) with G‑CSF treatment, may be considered (SoR: GPS) Repeated BM follow‑up should be performed in patients with decreasing ANC or additional changes in other blood cell counts (e.g., anemia and thrombocytopenia) or erythrocyte indices (SoR: GPS)

• Pediatric patients actively receiving cytotoxic chemotherapy. Down Syndrome. Children with immune deficiency. Patient with Central venous catheter. Compromise of mucosal barriers (e.g. mucositis, typhlitis). Myelosuppression. Children with hematologic malignancies have an increased risk relative to children with solid tumors (SoR: GPS)

• Personal protective equipment (gown, gloves. . .) in patients with contagious infection or colonization by multidrug resistant (MDR) microorganisms (SoR: GPS) Aseptic technique in central venous catheter (CVC) handling (SoR: GPS) Hand, surface and food preparation hygiene measures (SoR: GPS) Chlorhexidine gluconate (CHG) baths (CHB) involve cleansing the patient’s body each day with CHG‑impregnated wipes. Literature from pediatric patients with temporary CVCs inserted during critical care admissions suggests that CHB may have a role in reducing the rate of CLABSIs in these patients (SoR: GPS) Avoid contact with pets associated with a high risk: turtles, cat’s litter, stables and new pets. This does not apply to other pets that are correctly vaccinated, in regard to which the sole precaution is to avoid contact with their faeces (SoR: GPS) Prevention of IFI (high risk patients/situations) Avoid flowers and plants in hospital rooms and the bedroom of the patient. Hospital rooms with HEPA filters and positive pressure (>12 room air changes/h). Use of FPP2 masks in closed spaces without HEPA filters (except the usual place of residence, where ventilation, avoiding plants, moisture and construction work). Recommendation not supported by evidence: Avoid pools, especially public or indoor ones. Low bacteria diet not proven to reduce the incidence or severity of infection. Personal protective equipment for patients in absence of microbial isolation that justifies it (SoR: GPS)

• G‑CSF in patients with solid tumors receiving intensive chemotherapy, who need to maintain cytotoxic dose/chemotherapy intensity and/or with previous history of fever neutropenia (FN) (SoR: GPS) Annual vaccination against seasonal flu of patients and their household contacts and health care workers (SoR: GPS) 

• AML and relapsed ALL: Consider systemic antibacterial prophylaxis administration in children receiving intensive chemotherapy expected to result in severe neutropenia (absolute neutrophil count <500/µl for at least 7 days) (SoR: Conditional) Newly diagnosed ALL: Do not use systemic antibacterial prophylaxis routinely for children receiving induction chemotherapy (SoR: Conditional) Therapy not expected to result in severe neutropenia (ANC <500/µl for at least 7 days): Do not use systemic antibacterial prophylaxis (SoR: Strong) Autologous HSCT: Do not use systemic antibacterial prophylaxis routinely (SoR: Conditional) Allogeneic HSCT: Do not use systemic antibacterial prophylaxis routinely (SoR: Conditional)

• Levofloxacin is the preferred agent if systemic antibacterial prophylaxis is planned (SoR: Strong)

•  If systemic antibacterial prophylaxis is planned; we suggest that administration be restricted to the expected period of severe neutropenia (absolute neutrophil count <500/μL) (SoR: Conditional)

• AML: Administer systemic antifungal prophylaxis to children and adolescents receiving treatment of AML that is expected to result in profound and prolonged neutropenia (SoR: Strong) ALL (newly diagnosed and relapsed): Consider administering systemic antifungal prophylaxis to children and adolescents at high risk for invasive fungal disease (IFD) (SoR: Conditional) ALL (low risk): Do not routinely administer systemic antifungal prophylaxis (SoR: Strong) Other malignancies (lymphomas and solid tumors): Do not routinely administer systemic antifungal prophylaxis to children and adolescents with cancer at low risk for IFD, such as most pediatric patients with lymphomas and solid tumors (SoR: Strong) Allogeneic HSCT: Administer systemic antifungal prophylaxis pre‑engraftment and to those receiving systemic immunosuppression for GVHD (SoR: Strong)

• Autologous HSCT: We suggest that systemic antifungal prophylaxis not be used routinely (SoR: Strong)

• Mold‑active agent: In choosing a mold‑active agent, administer an echinocandin or a mold‑active azole (SoR: Strong)

• Amphotericin: Do not use amphotericin routinely as systemic antifungal prophylaxis (SoR: Strong) If systemic antifungal prophylaxis is warranted, consider administration during periods of observed or expected severe neutropenia. For allogeneic HSCT recipients, consider administration during systemic immunosuppression for GVHD treatment (SoR: Conditional)

• Do not use probiotics routinely for the prevention of CDI in children and adolescents with cancer and pediatric HSCT patients (SoR: Conditional)

• Use either oral metronidazole or oral vancomycin for the treatment of non‑severe CDI in children and adolescents with cancer and pediatric HSCT patients (SoR: Strong)

• Use oral vancomycin for the treatment of severe CDI in children and adolescents with cancer and pediatric HSCT patients (SoR: Strong) Do not use monoclonal antibodies routinely for the treatment of CDI in children and adolescents with cancer and pediatric HSCT patients (SoR: Strong)

• Risk for PJP pneumonia is highest in patients with leukemia and lymphoma, prophylaxis is also recommended for children with solid tumors undergoing chemotherapy that is likely to cause lymphopenia. Data in patients with HIV shows that the risk of PJP is highest in those with CD4 counts under 200 x106/L, and one study from the solid organ transplantation population found that odds of PJP infection were significantly increased when absolute lymphocyte count (ALC) was < 500 x106/L. Sulfamethoxazole (TMP‑SMX) is highly effective. For patients who do not tolerate TMP‑SMX, pentamidine, dapsone, and atovaquone are alternative options, Optimal duration of PJP prophylaxis is unknown. One guideline suggests continuing until 3 months after the end of therapy and normalization of lymphocyte count (SoR: GPS)

• Use cryotherapy for older, cooperative pediatric patients receiving treatment for cancer or undergoing HSCT who will receive short infusions of melphalan or 5‑fluorouracil (SoR: GPS)

• Consider using cryotherapy for older, cooperative pediatric patients receiving treatment for cancer or undergoing HSCT who will receive short infusions of chemotherapy associated with mucositis other than melphalan or 5‑fluorouracil (SoR: GPS)

• Do not administer palifermin routinely to pediatric patients with cancer receiving treatment for cancer or undergoing HSCT (SoR: GPS)

• Use intraoral photo‑biomodulation therapy in the red‑light spectrum (620–750 nm) for pediatric patients undergoing autologous or allogeneic HSCT and for pediatric patients who will receive radiotherapy for head and neck carcinoma (SoR: GPS)

•  Consider using intraoral photo‑biomodulation therapy in the red‑light spectrum (620–750 nm) for pediatric patients who will receive radiotherapy for head and neck cancers other than carcinoma (SoR: GPS)

• Do not administer GCSFs to pediatric patients receiving treatment for cancer or undergoing HSCT for the purpose of mucositis prevention (SoR: GPS)

• The use of G‑CSF in in patients with solid tumors receiving intensive chemotherapy, who need to maintain cytotoxic dose/chemotherapy intensity and/or with previous history of FN reduces the duration of neutropenia (SoR: GPS)

• Annual vaccination against seasonal flu of patients and their household contacts and health care workers. Despite potential lack of efficacy in certain populations, the American Academy of Pediatrics and Center for Disease Control still recommend yearly influenza vacations in pediatric oncology patients based on potential benefit with low risk of reaction (SoR: GPS)

• Careful clinical examination of skin and mucous membranes, upper and lower respiratory tract and abdomen to exclude underlying infection, lymphadenopathy, and/or hepatosplenomegaly (SoR: GPS)

• Vital signs: temperature, heart rate, respiratory rate, blood pressure and oxygen saturation. Pediatric assessment triangle (early detection of sepsis). Review of systems, including neurologic assessment, perfusion, skin and mucosae (oral and perianal, avoid rectal palpation), any area with pain, scars, devices (SoR: GPS)

• In chronic neutropenia patients, we recommend performing CBC with differential WBC counts and morphological evaluation every 3–4 months (SoR: GPS) When approaching adulthood, CN patients should be transferred to a dedicated hematology specialist (SoR: GPS)

• Annual BM and cytogenetics follow‑up should be performed in patients with congenital BM failure syndromes independent of ANC and treatment with G‑CSF. undefined SCN (after extensive investigation) with G‑CSF treatment, may be considered (SoR: GPS) Repeated BM follow‑up should be performed in patients with decreasing ANC or additional changes in other blood cell counts (e.g., anemia and thrombocytopenia) or erythrocyte indices (SoR: GPS)

• The key markers of malignant transformation to MDS or leukemia in CN patients are the following: typical dysplastic features in PB (pseudo Pelger‑Huet anomaly, hypogranulation, hyper segmentation, reticulated nucleus, and ringed‑shaped nuclei) and BM (defective granulation, maturation arrest at myelocyte stage, and increase in monocytoid forms); cytogenetic abnormalities (e.g., CSF3R, RUNX1, and ASXL1); and high frequency of somatic mutations in leukemia‑associated driver genes. The most common chromosomal defects in patients with CN at the MDS stage are trisomy 21 and monosomy 7 (SoR: GPS)

➡️Guideline Registration

PREPARE (Practice guideline REgistration for transPAREncy), WHO Collaborating Center for Guideline Implementation and Knowledge Translation, EBM Center, University of Lanzhou, Lanzhou, China. Registration Number: PREPARE-2024CN145. Link: http://www.guidelines-registry.org/