Prolonged acquired neutropenia in children

Case series: Congenital enterovirus infection-associated haemophagocytic lymphohistiocytosis and subsequent neutropaenia

Congenital enterovirus infection can be associated with a pro-inflammatory state triggering haemophagocytic lymphohistiocytosis (HLH). Enteroviruses are also known to cause transient neutropenia in healthy children. Two infants presented with temperature instability, lethargy, thrombocytopaenia, hepatosplenomegaly and evidence of hyperinflammation in the setting of perinatal maternal rash and household contacts with gastrointestinal symptoms. Whilst HLH was successfully treated in both, protracted neutropenia persisted. Immune dysregulation with enterovirus in the neonatal period can provoke the generation of autoantibodies to hematologic cells giving rise to conditions such as autoimmune neutropenia. Sustained neutropaenia, after resolution of secondary infectious forms of HLH, requires investigation for underlying aetiologies.

Chronic Neutropenia in Childhood: Laboratory and Clinical Features

OBJECTIVES

To describe the clinical characteristics of patients with chronic neutropenia.

METHODS

Data of 36 patients with chronic neutropenia, who were followed up in the authors' clinic between May 2013 and May 2020, were analyzed retrospectively. Patients were diagnosed based on their clinical and laboratory characteristics.

RESULTS

A total of 36 patients (23 females, 13 males) were included in the study. The mean age at diagnosis was 9.85 ± 9.17 mo while the mean follow-up time was 21.83 ± 20.03 mo. The mean absolute neutrophil count (ANC) at admission was 462.5 ± 388.8 cells/mm³ (median = 375 cells/mm³), and the lowest and highest ANC mean was 241.2 ± 262.1 cells/mm³ (median = 125 cells/mm³), and 1362.9 ± 1127.9 cells/mm³ (median = 925 cells/mm³), respectively. Idiopathic neutropenia was found in 28 (77.8%) patients, autoimmune neutropenia in 6 (16.7%) patients, and congenital neutropenia in 2 (5.6%) patients. Neutrophil normalization was observed in 19 (52.8%) of the patients.

CONCLUSIONS

Chronic neutropenia is a heterogeneous picture that presents with different clinical symptoms in childhood. The cause of neutropoenia in children is usually benign and resolves spontaneously but especially in those with severe neutropoenia genetic examination should be performed.

Etiological causes and prognosis in children with neutropenia

OBJECTIVE

Neutropenia is defined as an absolute neutrophil count (ANC) below 1500/mm³ in the peripheral blood and is a common condition in childhood. In this study, underlying etiological causes and prognoses in children in follow-up due to neutropenia were analyzed to form a guide for physicians working in primary health care institutions.

METHODS

The medical records of pediatric patients who were followed up as an inpatients or outpatients due to neutropenia between October 2014 and October 2017 were reviewed retrospectively.

RESULTS

A total of 94 patients were included in the study with a median age of 24 (8-77) months. The median ANC at the time of admission was 600 (300-970)/mm³. The ANC was 0-500/mm³ in 34 patients (36.2%), 500-1000/mm³ in 36 patients (38.3%), and 1000-1500/mm³ in 24 patients (25.5%). Of the total, 43 patients (45.7%) were followed up as inpatients and 51 (54.3%) were followed as outpatients. Fifty-five patients (58.5%) were diagnosed with post-infectious neutropenia. The most common focus of infection was the upper respiratory airway (38.4%). The etiological cause could not be identified in 23 (24.6%) patients, neutropenia developed during drug use in 6 patients (6.3%), 5 patients (5.3%) were diagnosed with Vitamin B12 deficiency (Vitamin B12 level: 168 [129-174] pg/ml, the levels were studied in 48 patients), 2 patients (2%) were diagnosed with chronic benign neutropenia, 1 patient (1.1%) was diagnosed with immune deficiency, 1 patient (1.1%) was diagnosed with autoimmune lymphoproliferative syndrome, and 1 patient (1.1%) was diagnosed with hemophagocytic lymphohistiocytosis secondary to a previous infection. No patient was diagnosed with congenital neutropenia. A total of 91 patients (96.8%) recovered from the neutropenia. Neutropenia did not improve in 3 patients (3.2%). One patient was lost due to infection.

CONCLUSION

Etiological cause can be shown in approximately 75% of neutropenic children. The most common etiological cause is infection. Drug use, nutritional deficiencies, and chronic benign neutropenia are less common causes of neutropenia. The clinical course is largely benign and the mortality rate is very low.

Congenital Cytomegalovirus and Autoimmune Neutropenia: Cause or Coincidence?

BACKGROUND

Congenital cytomegalovirus (CCMV) accounts for high rates of infant morbidity and mortality. Neutropenia is a common finding in CCMV infection, of which the age of presentation overlaps with autoimmune neutropenia (AIN). AIN represents one of the most common forms of chronic neutropenia in childhood.

METHODS

A literature search exploring biologic associations between CCMV and AIN was conducted: PubMed (MEDLINE), Ovid and Web of Science. We further describe 2 cases of concurrent CCMV and AIN. Both cases were confirmed with the indirect granulocyte immunofluorescence test and alternative etiologies for neutropenia excluded.

RESULTS

Our 2 patients represent confirmed cases of AIN in infants with CCMV. One patient demonstrated neutropenia while undergoing treatment with Valganciclovir, while the other was never treated. With interruption of Valganciclovir in infant A, neutrophil counts (ANC) did not improve and upon resumption of treatment ANC remained static.

CONCLUSIONS

Further studies examining a possible biologic link between CCMV and AIN are advocated for. We encourage clinicians to actively consider AIN in the differential diagnosis of all infants with CCMV presenting with neutropenia.

The stage-specific impairment of granulopoiesis in people living with HIV/AIDS (PLWHA) with neutropenia

Neutropenia and impaired functions were common manifestation in antiretroviral therapy (ART) in both naïve and experienced PLWHA. Granulopoiesis can be divided into two phases: lineage determination and committed granulopoiesis. However, stage-specific impairment of granulopoiesis in PLWHA with neutropenia remains unclear. A total of 48 ART-naïve and 49 ART-experienced PLWHA from 2016 to 2018 were recruited and divided into non-, mild-, and moderate-to-severe-neutropenia groups according to their neutrophil counts. The bone marrow aspirates and peripheral blood were collected and analyzed by multicolor flow cytometry for granulocyte subsets, hematopoietic stem/progenitor cells (HSPC), apoptosis, and emigration and retention of different subsets. Compared with healthy donors, the percentages of circulating segmented neutrophils were significantly decreased along with an increase of immature neutrophils in both groups. ART-naïve patients with moderate to severe neutropenia exhibited decreased proportion and accelerated apoptosis of relative mature segmented neutrophils. In contrast, ART-experienced patients with neutropenia displayed decreased proportion of granulocyte macrophage progenitors, indicating a defect at a stage of lineage determination. Meanwhile, ART-experienced patients with neutropenia also the expression of CXCR4 segmented neutrophils, suggesting an increased retention of segmented neutrophils inn the bone marrow. ART-naïve patients with neutropenia is caused by increased apoptosis of relatively differentiated neutrophils at committed granulopoiesis, whereas impaired lineage determination and enhanced retention of segmented neutrophils contribute to in ART-experienced patients.

Autosomal Recessive Agammaglobulinemia Due to a Homozygous Mutation in PIK3R1

The role of class IA phosphoinositide 3 kinases (PI3Ks) in immune function and regulation continues to expand with the identification of greater numbers of genetic variants. This case report is the second reported case of a homozygous premature stop codon within the PIK3R1 gene leading to autosomal recessive agammaglobulinemia. The proband, born to consanguineous parents, presented at 10 months of age with a history of oropharyngeal petechiae and bleeding from the mouth, gums, and tear ducts. Initial investigations revealed thrombocytopenia, neutropenia and the absence of B cells. Further genetic testing via a custom next-generation sequencing panel confirmed the presence of a homozygous mutation in PIK3R1, c.901 C>T, a premature stop codon at amino acid position 301. Given their many roles in immune regulation, recessive mutations in the PlK3R1 gene should be considered in infants presenting with hypogammaglobulinemia or agammaglobulinemia, particularly in the setting of parental consanguinity.

Immune neutropenias of infancy and childhood

BACKGROUND

Anti-neutrophil antibodies are a well-recognized cause of neutropenia, producing a potential increase in risk of infection: in the majority of patients antibodies react against antigens located on the IgG Fc receptor type 3b (FcRIIIb), but other target antigens have been identified.

DATA SOURCES

In this review the most important papers of auto and alloimmune neutropenias of infancy and childhood were analyzed. PubMed, Google Scholar and Thompson ISI Web of Knowledge were searched for identifying relevant papers.

RESULTS

Primary autoimmune neutropenia of infancy is mostly a benign condition with self-limited course, whereas isolated alloimmune neonatal neutropenia or secondary autoimmune neutropenia may be occasionally complicated by severe infections.

CONCLUSION

Granulocyte colony stimulating factor is an effective therapy for patients affected by all types of autoimmune and alloimmune neutropenia, even though most of them do not need any therapy.

Chronic Neutropenia in Childhood: Experience From a Single Center

Chronic neutropenia (CN) is defined as neutropenia that persists for >3 months; it is caused by a heterogeneous group of diseases in children. The aim of the present study was to evaluate the significance and clinical manifestations of CN in children at a single children's hospital. Between October 2004 and April 2014, CN patient data were evaluated retrospectively. Thirty-one patients were assessed in this study. Thirteen of them (41.9%) were younger than 12 months of age at initial diagnosis. There was no difference in the absolute number of neutrophils at diagnosis between the children aged younger than 12 months and those aged 12 months and older at CN onset. Twenty-two of the patients (70.9%) were diagnosed during treatment for acute infections. A total of 11 patients (35.5%) were hospitalized because of recurrent infections. Most of the recurrent infections occurred in the lungs (81.8%). Congenital neutropenia (CoN) was identified in 14 patients (45.1%). Eight of 14 patients (57.1%) required granulocyte-colony stimulating factor treatment, and none of them experienced adverse effects from this treatment. Fifteen patients (48.3%) were diagnosed with idiopathic neutropenia. Comparison between the idiopathic and CoN groups revealed no differences in age, the absolute number of neutrophils, or the presence of infection at diagnosis; however, differences were detected in sex and the rate of spontaneous recovery from neutropenia. Ten of the patients (32.2%) experienced spontaneous recovery from neutropenia during a follow-up period of 7 to 52 months. In current study, we found a higher CoN ratio in the CN patients compared with previous reports, which may be due to the high rate of consanguineous marriages in our country. However, the finding of CN requires several laboratory investigations, prolonged follow-up, and advanced molecular analysis, and its etiology can remain idiopathic.

Pathogenesis of Severe Neutropenia in Patients With Primary Human Herpesvirus 6B Infection

BACKGROUND

Although myelosuppression caused by human herpesvirus 6B (HHV-6B) reactivation in transplant recipients has been extensively investigated, the pathophysiological mechanisms of severe neutropenia in primary HHV-6B infection remain unclear.

PROCEDURE

Fifty-four patients with primary HHV-6B infection were evaluated. Hematological examinations and blood sampling were conducted on days 1-4 (pre) and 5-10 (post) after the onset of illness. Severe neutropenia was defined as a neutrophil count less than 500 cells/μL. Patient characteristics, clinical data, and cytokines and chemokines levels were compared between the patients with (n = 16) and without (n = 38) severe neutropenia.

RESULTS

Severe neutropenia was detected in samples that were collected between days 5 and 10 after illness. Significantly lower platelet counts (pre, P = 0.048; post, P = 0.032) and regulated on activation, normal T cell expressed and secreted levels (post, P = 0.007) were detected in the patients with neutropenia. Aspartate aminotransferase levels (P = 0.008), and interferon γ-inducible protein-10 (P < 0.0001), monocyte chemoattractant protein-1 (P = 0.005), and monokine induced by interferon γ (P = 0.011) levels were significantly higher in post samples collected from the patients with neutropenia. No differences were observed in any patient characteristics and serum cytokines levels. No bacterial infections were detected during the observation period.

CONCLUSIONS

Chemokines may play an important role in the pathogenesis of severe neutropenia in patients with primary HHV-6B infection.

[Fortuitously discovered neutropenia in children: diagnosis and follow-up]

Neutropenia seems to be quite frequent in current pediatric practice and can confuse the clinician since it may result from a severe cause. The aim of this study was to provide a prospective description of episodes of neutropenia in children to assess its clinical relevance in a general pediatric cohort consulting and/or hospitalized in a French university hospital. In this prospective observational and monocentric study conducted from April 2012 to April 2013, we included all the patients under 18 years of age who presented neutropenia (defined as an absolute neutrophil count [ANC] below 1×10(9)/L before 1 year of age and below 1.5×10(9)/L beyond) on a whole blood count (WBC) performed in our hospital. Patients treated with chemotherapy were not included. Medical records were regularly checked for at least 1 year after inclusion, and clinical and biological data were collected prospectively to compare transient episodes of neutropenia (<3 months) with persistent episodes of neutropenia (>3months). Of 55,018 consultations and 13,967 hospitalizations (chemotherapy excluded), 8966 blood counts were performed and 250 episodes of neutropenia were found in 238 patients. Data concerning clinical progression were available in 195 cases of which 136 had at least one subsequent WBC. Two hundred thirty-one episodes corresponded to new episodes, while neutropenia preexisted before inclusion in the others. The median follow-up was 12.8 months. Most episodes of neutropenia occurred in children <2 years of age (52%), with a median age of 22.2 months. Mean ANC was 0.943×10(9)/L (±0.340) and a few episodes of neutropenia were below 0.5×10(9)/L (9.2%). Neutropenia persisted more than 3 months in only 13.2% of cases. When neutropenia was below 0.5×10(9)/L, it significantly persisted (RR=3.08; 95% CI [1.31-7.22]). Other factors associated with persistent neutropenia were thrombocytopenia, monocytopenia, a CRP more than 70mg/L, significant abnormality on the clinical exam, and age over 24 months. However, multivariate analysis showed that only an ANC below 0.5×10(9)/L was significantly associated with persistence. While etiology could not be determined in 32% of cases, neutropenia resulted mostly from infectious causes (37.8%), with other causes being more anecdotal. The majority of infectious episodes of neutropenia were viral (90.3%). Like other studies, this investigation suggests that most episodes of neutropenia concern young children, are transient, are benign and often due to infectious diseases. Although it may not reflect the medullar stock or the real capacity of neutrophils to fight bacterial infections, it seems that neutropenia below 0.5×10(9)/L is more likely to persist and be complicated, as previous studies also suggest. To conclude, neutropenia is not exceptional in children and, even if it often results from viral infections and mostly evolves favorably, the clinician should closely monitor these patients, especially when neutrophils are below 0.5×10(9)/L.

The epidemiology, clinical course and outcome of febrile cytopenia in children

AIM

Transient infectious neutropenia of mild-to-moderate severity is common and resolves spontaneously within weeks. This was the first prospective study of the whole spectrum of febrile cytopenia in noncancer patients followed-up for 2 years. It aimed to assess its aetiology, duration and outcome.

METHODS

We evaluated 116 children with febrile cytopenia aged 4 ± 3.8 years, admitted to a paediatric ward over 2 years, using inflammatory markers, cultures and serological tests.

RESULTS

An infectious agent was identified in 74 (63.8%) cases: 44.8% viral, 11.2% bacterial and 7.8% parasitic. One cell line was affected in 26.7% of patients and ≥2 cell lines in 73.3%. Cytopenia was transient in 82.75% of cases and chronic in 17.24%. The transient cytopenia subgroups - exhibited differences in severity (mild in bacterial cases and moderate in viral and parasitic cases, p = 0.018) and the number of affected cell lines, (predominantly two in viral and bacterial cases and pancytopenia in parasitic cases, p = 0.001). Chronic patients had severe cytopenia (p = 0.004) with ≥2 cell lines affected, while transient patients had mild-to-moderate cytopenia, with 1-3 cell lines affected.

CONCLUSION

Childhood febrile cytopenia is usually transient, of mild-to-moderate severity, and resolves spontaneously, but patients with severe cytopenia affecting ≥2 cell lines need further evaluation and follow-up.

Diagnosis and management of primary autoimmune neutropenia in children: insights for clinicians

Autoimmune neutropenia of infancy (AIN), also called primary autoimmune neutropenia, is a disease in which antibodies recognize membrane antigens of neutrophils, mostly located on immunoglobulin G (IgG) Fc receptor type 3b (FcγIIIb receptor), causing their peripheral destruction. It is the most frequent type of neutropenia in children under 3-4 years of age and in most cases shows a benign, self-limited course. The diagnosis is based on evidence of indirect antineutrophil antibodies, whose detection frequently remains difficult. In this review we have analyzed the literature regarding AIN and present our personal experience in diagnosis and management.

Etiology, clinical outcome, and laboratory features in children with neutropenia: analysis of 104 cases

BACKGROUND

Neutropenia is not uncommon in childhood. The aim of our study was to analyze the underlying causes of neutropenia and to evaluate its clinical significance in a series of children referred to our center.

METHODS

One hundred and four consecutive children with neutropenia were enrolled in this study. Clinical and laboratory features were analyzed.

RESULTS

The majority of patients (63.5%) showed chronic neutropenia. Among all chronic forms, the most frequent was chronic idiopathic neutropenia (CIN), followed by autoimmune neutropenia (AIN). Congenital neutropenia was identified in 6 patients. Acute neutropenia was mainly due to infections. Overall, at the time of first detection, neutropenia was more frequently severe or moderate. One-third of our patients who presented with severe neutropenia were ultimately diagnosed with a post-infectious acute form. Conversely, nearly half patients with CIN, AIN, or congenital neutropenia showed moderate/mild neutropenia at onset. Among patients with AIN and CIN, nearly half recovered between 7 months and 46 months and approximately one-fourth experienced infectious episodes during follow-up. No significant difference was noticed in terms of mean ANC between patients with and without remission, neither between patients with and without infections.

CONCLUSIONS

Our study confirms the great etiological heterogeneity of neutropenia in children. We could not demonstrate a correlation between ANC level at onset and the underlying disorder, nor a correlation between mean ANC and duration of neutropenia or infectious episodes during follow-up. Neutropenia remains a disease of concern to pediatricians, requiring several laboratory investigations, prolonged follow-up, and, in few cases, advanced molecular methods.

Neutropenia during HIV infection: adverse consequences and remedies

Neutropenia frequently occurs in patients with Human immunodeficiency virus (HIV) infection. Causes for neutropenia during HIV infection are multifactoral, including the viral toxicity to hematopoietic tissue, the use of myelotoxic agents for treatment, complication with secondary infections and malignancies, as well as the patient's association with confounding factors which impair myelopoiesis. An increased prevalence and severity of neutropenia is commonly seen in advanced stages of HIV disease. Decline of neutrophil phagocytic defense in combination with the failure of adaptive immunity renders the host highly susceptible to developing fatal secondary infections. Neutropenia and myelosuppression also restrict the use of many antimicrobial agents for treatment of infections caused by HIV and opportunistic pathogens. In recent years, HIV infection has increasingly become a chronic disease because of progress in antiretroviral therapy (ART). Prevention and treatment of severe neutropenia becomes critical for improving the survival of HIV-infected patients.

Transient neutropenia in children with febrile illness and associated infectious agents: 2 years' follow-up

The aim of the study was to identify the relationship of acquired neutropenia with childhood infections and to assess its clinical course, complications, and outcome. Children admitted to two pediatric wards over a 4-year period with febrile neutropenia were prospectively investigated for underlying infections with inflammatory markers, cultures of body fluids, and serological tests. The study included 161 previously healthy children with febrile neutropenia/leukopenia aged (mean ± SD) 3.02 ± 3.86 years (range, 0.1-14). One hundred and thirty-six out of 161 patients (84.5 %) had transient neutropenia (TN), while in 25 patients, neutropenia was chronic (CN) and persisted for ≥180 days. An infectious agent was isolated in 98/161 (60.9 %) cases, in 68.4 % patients with TN, and in 20 % of those with CN (p = 0.001). Among the patients with CN, seven had positive antineutrophil antibodies (autoimmune neutropenia) and four were eventually diagnosed with hematological malignancy. In all age groups, TN was of short duration (<1 month), of mild to moderate severity, and was predominantly associated with viral infections. Two years after diagnosis, 143/161 children (88.8 %) were available for follow-up. One hundred and thirty-seven of 143 (95.8 %) had recovered completely, while the rest remained neutropenic. The latter patients had a benign course despite severe neutropenia. In conclusion, febrile neutropenia during childhood is usually transient, often following viral and common bacterial infections, without serious complications and in the majority of cases it resolves spontaneously. However, in a considerable percentage of patients, neutropenia is discovered incidentally during the course of an infection on the ground of an underlying hematological disease.

Pathogenesis and prognosis of neutropenia in infants and children admitted in a university children hospital in Egypt

This study aimed to assess the prevalence, severity, and etiology of neutropenia in infants and children admitted to a children's hospital in Egypt. A total of 200 patients with neutropenia were recruited from April 1, 2010 to September 30, 2010. Patients with a known hematological or immunological disease were excluded. Patients were followed till recovery or an underlying cause was uncovered. Viral serological analysis was done for patients with moderate/severe neutropenia, including cytomegalovirus (CMV); Epstein-Barr virus (EBV); hepatitis A, B, and C viruses; and HIV. Antineutrophil cytoplasmic antibody (ANCA) tested by enzyme immunoassay and bone marrow aspirate were done for prolonged neutropenia. The results revealed that neutropenia was mild in 90 (45%), moderate in 56 (28%), and severe in 54 (27%). Clinical diagnosis at admission was bronchopneumonia (38%), pyrexia of undetermined etiology (17%), bronchiolitis (13%), urinary tract infection (9%), acute gastroenteritis (8%), hepatitis (6.5%), and septicemia (5%). Patients with mild neutropenia recovered within 1 week. Among 110 patients with moderate/severe neutropenia, 80 (73%) recovered in <3 weeks. Predictors of prolonged neutropenia were age younger than 18 months (P < .01), absolute neutrophils count (ANC) < 500/mm(3) (P < .05), hemoglobin < 10 gm/dL (P < .05), and positive CMV serology (P < .01). CMV and EBV serology were positive in 34.5% and 7.3% of patients, respectively. ANCA was positive in 42.8% of patients with prolonged severe neutropenia. In conclusion, neutropenia is a frequent finding in Egyptian infants and children, usually mild and transient, and mainly associated with infection. CMV and EBV are associated with prolonged neutropenia. Immune neutropenia is a common cause of moderate/severe neutropenia in the first two years of life.

[Review and guidelines on the prevention, diagnosis and treatment of post-natal cytomegalovirus infection]

Postnatal cytomegalovirus (CMV) infection in the newborn can occur from exposure to maternal cervical secretions during birth, ingestion of breast milk, transfusion of blood products or transmission by body fluids of infected people. Breast milk is the main source of infection, given the high rate of CMV-positive mothers excreting CMV in milk. Freezing reduces the risk of CMV transmission by breastfeeding, although it does not eliminate it completely. Pasteurisation prevents such transmission, but it can alter the immunological properties of breast milk. Postnatal CMV infection is usually asymptomatic, as it normally results from viral reactivation in the mother, and the neonate is born with protective antibodies. However, in the very low birth weight premature infant the amount of transferred antibodies is smaller and a symptomatic infection can occur. Symptomatic post-natal CMV infection in the newborn typically causes hepatitis, neutropenia, thrombocytopenia or sepsis-like syndrome. Pneumonitis and enteritis are less common, but very characteristic. Diagnosis is based on urine virus detection at the time of onset of symptoms. Postnatal CMV infection in the newborn generally resolves spontaneously without antiviral treatment. Ganciclovir should be reserved for severe cases. Unlike congenital CMV disease, post-natal CMV infection in the preterm infant does not seem to be associated with hearing loss or abnormal neuro-development in long term follow-up.