Identification of Antibodies Against Neutrophil Surface Antigens in Two Iranian Patients with Autoimmune Neutropenia

Autoimmune neutropenia is a type of immune-mediated neutropenia, caused by antibody-induced neutrophil destruction. Here, we report two cases (a 3-year-old boy and a 9-year-old girl) with suspected autoimmune neutropenia. The presence of neutrophil antibodies in the sera of these two patients was investigated; using standard neutrophil antibody screening tests such as granulocyte immunofluorescence test (GIFT), granulocyte agglutination test (GAT), and lymphocyte immunofluorescence test (LIFT). A positive reactivity with two-panel cells was found in GIFT. No reactivities with panel cells were observed in GAT and LIFT. To the best of our knowledge, this is the first report for detecting the neutrophil reactive antibodies; using genotyped neutrophils in patients with autoimmune neutropenia in Iran. The final diagnosis of our patients was primary autoimmune neutropenia for the boy and autoimmune neutropenia associated with familial Mediterranean fever for the girl.

Alemtuzumab induced red cell aplasia and other immune cytopenias – not so ‘pure’

We report on the presentation and outcome of a 28-year-old female who developed red cell aplasia following alemtuzumab therapy for relapsing remitting multiple sclerosis. The patient also developed synchronous immune thrombocytopenia and immune neutropenia, but not aplastic anemia. This patient received high dose steroids, intravenous immunoglobulin (iv.Ig), rituximab, red cell transfusions, vincristine, G-CSF, cyclosporin and mycophenolate to treat the combination of cytopenias over a period of 6 months with subsequent improvement in bone marrow function. While alemtuzumab has several recognized autoimmune complications, little is known about the potential hematological side effects. The combination of red cell aplasia, immune thrombocytic purpura and autoimmune neutropenia has not previously been described in the literature following alemtuzumab immunotherapy and highlights the importance of monthly blood monitoring post alemtuzumab administration.

The Experience of the Cooperation in Science and Technology European Network for Innovative Diagnosis and Treatment of Chronic Neutropenias (COST EuNet-INNOCHRON) Action and the Sweden Experience in the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Era

Background-Aim: Infection from SARS-CoV-2 has emerged as new pathological entity within the global medical community. One of the earliest questions was in relation to the ability of the immunocompromised patients to clear the infection. In COST EuNet-INNOCHRON we were interested in the impact of SARS-CoV-2 infection in patients with different types of chronic neutropenia (CNP). The aim of the current study is to understand the impact of SARS-CoV-2 infection and to identify any possible characteristic patterns of the clinical course in patients with CNP. Patients and Methods: The COST EuNet-INNOCHRON Action in collaboration with the European Haematology Association - Scientific Working Group (EHA-SWG) on Granulocytes and Constitutional Marrow Failure Syndromes has conducted an online survey on SARS-CoV-2 infection in patients with CNP. The EuNet-INNOCHRON participants from different countries got access to an on-line platform fulfilling the General Data Protection Regulation (GDPR) and could register adult and paediatric CNP patients who had been infected by SARS-CoV-2 from March 2020 to June 2021. Data on demographic characteristics, type of CNP, patients' background and SARS-CoV-2 infection history (symptoms, laboratory features, radiological appearance, therapeutic approach and outcome) were collected. Results: Twenty-six patients with diagnosis of CNP, 7 males and 19 females were registered. Patient age distribution as follows: 16 patients >18 years old (y.o.)5 patients 5-18 y.o, 4 patients < 5 y.o whereas age was not available for one of the patients. Nine of the patients were diagnosed with idiopathic CNP, 7 patients with congenital neutropenia (6 of them with severe congenital neutropenia), 3 with secondary CNP, 2 with suspected autoimmune neutropenia of infancy (although antineutrophil Ab were negative), one with autoimmune neutropenia, one with drug induced neutropenia and 3 with other types of CNP. Twelve patients were on treatment with G-CSF and 6 patients had a history of previous viral or bacterial infections. Clonal Cytopenia(s) of Undetermined Significance (CCUS) was excluded in the eight patients who were investigated. Twenty-four out of 26 patients had positive PCR and one was found incidentally with positive antibodies for SARS-CoV-2. One more patient was symptomatic with history of close contact with SARS-CoV-2 infected family members. The commonest observed symptoms were fever >38 oC (19 patients), cough (10 patients), rhinorrhoea (10 patients), sore throat (6 patients), musculoskeletal pains (7 patients), taste/smell loss (5 patients), headache (5 patients), dyspnoea (4 patients), chest pain (one patient) and none of them had gastrointestinal symptoms. No other associated respiratory viral or bacterial infections were reported. Four patients who had one or more underlying conditions (immune deficiency, heart/respiratory/kidney disease) were admitted in hospital and needed anti SARS-CoV-2 treatment. Two of them had non-invasive ventilation and one of them needed admission in intensive care unit (ICU); both recovered. Another patient with Fallot's tetralogy needed mechanical ventilation in ICU and sadly passed away. No other deaths were observed. Deterioration of the pre-existing neutropenia was seen in two patients, two patients developed thrombocytopenia, one patient developed worsening lymphopenia and one anaemia. Twelve patients had chest X-ray and consolidation was found in two of them. All three patients who had chest CT scans were found with ground-glass changes. During the observation period (up to two months), no re-infection from SARS-CoV-2 was found. The Stockholm, Sweden experience is similar to the above data. One hundred fifty-four patients with CNP were followed up, for 10 months (March 1 to December 31, 2020) for SARS-CoV-2. Seventeen of these (i.e. 11 %) were infected. None needed hospitalization and there were no fatalities. Conclusion: Although the relative susceptibility of neutropenic patients to contract SARS-CoV-2 needs to be assessed with further studies, the clinical course and severity of SARS-CoV-2 infection doesn't seem to be worse in CNP patients (regardless the type of neutropenia and the need for GCSF treatment) compared to the general population. Also, like what has been observed in non-neutropenic patients, underlying comorbidities is a significant risk factor for severe disease and adverse outcome. Disclosures Dale: X4 Pharmaceuticals: Consultancy, Honoraria, Research Funding. Palmblad: Chiesi Ltd Sweden: Honoraria; Roche Sweden: Speakers Bureau; Chiesi Ltd Candada,: Honoraria.

Late Onset and Long Lasting Idiopathic and Autoimmune Neutropenia As Epiphenomena of Immune Dysregulation: Preliminary Data Study from the Italian Neutropenia Registry

INTRODUCTION: Idiopathic neutropenia (IN) of childhood is a benign, self-limiting disorder usually occurring in the first 3 years of life that differs from primary autoimmune neutropenia (AIN) because anti neutrophil antibodies are not detected on repeated indirect testing over time(1). Chronic idiopathic neutropenia (CIN) is a well characterized disorder of elderly with a peculiar immunological pattern(2). Pediatric AIN patients, with atypical features represented by longer disease duration (Long Lasting) or diagnosed later (Late Onset), were recently shown by our group to display a different immune-hematological profile vs typical primary AIN(3). Atypical pediatric IN subjects, i.e. diagnosed later or with longer disease duration, though occasionally reported, were never systematically investigated. In the present study we analyzed a cohort of young patients with atypical IN and AIN, diagnosed after the age of 3 years or with longer disease duration, aiming to identify an immunological signature that might predict their different outcome from classical AIN and IN of infancy. PURPOSE OF THE STUDY: to analyze a cohort of patients affected with AIN and IN rising > 3 years of age and with duration >12 months or rising <3 years of age but persisting over 36 months. MATERIALS AND METHODS: Clinical, immunological and genetic data (NGS panel of 160 immunodeficiency/disimmunity genes) of eligible patients were collected from the database of the Italian Neutropenia Registry. RESULTS: From 2005 to 2020, data from 46 patients (24F, 24 autoimmune and 22 Idiopathic Neutropenia) were retrieved. Median age at onset was 11.2 years (IQR13.2-16.7), median follow-up was 4.3 years (IQR 3.2-6.8). Neither autoimmunity nor additional cytopenias to neutropenia were present at onset. Cumulative incidence at 5 years of autoimmune manifestations (thyroiditis, arthritis, vitiligo, recurrent skin rash) was 11.8% (CI 95% 4.3-30). Throughout the follow up, infections occurred in 32/46 (70%) subjects and in only 16% were severe (meningitis, recurrent pneumonia, sepsis and pericarditis). Infections sites were upper respiratory (in 84% of subjects mouth and gums (47%), and skin (40%) ear (25%), lung (19%) and urinary tract (12%). Fever of unknown origin was detected in 40% of patients. Recurrent infections (more than 3/y) involved mouth (85%) and ear (88%). White Blood Cell, Absolute Neutrophil and Lymphocyte counts retrieved at the beginning of the study, in the middle and at the end of follow up are shown in Table 1. Leucocytes and Lymphocytes at the end of follow up were significantly lower than values seen at diagnosis (p < 0.001) whereas neutrophil count remained stable (p=ns). One third of the cohort had lower values than normal of CD19+ and CD3-CD56+CD16+ cells. B switched memory CD27+/IgD-/IgM- (in 94%) were lower, while marginal zone B lymphocytes CD27+/IgD+/IgM+ (62%) and Tγδ cells (70%) were increased than the normal population according to a pattern comparable to that described in chronic idiopathic neutropenia (CIN). Immunoglobulin serum levels (IgA, IgG and IgM) were below the normal value in 7.5% of the population, but specularly a small subset (7.5%) of IN showed an increase of IgM was seen, similar to what already descibed in adult CIN. The genetic study carried out in 32 patients showed in 5 (16%) pathogenic variants: of immunodeficit/dysregulation (2 TACI, 1 TINF2, 1 CARD11) and in 9 cases (28%) VUS in genes of the same groups (1CARD11, 4CASP10,1DDX41/SOCS1, 1TSR2/DCLRE1c, 1PIK3D, 1TERT/TACI). CONCLUSIONS: Atypical IN and AIN (of longer duration or occurring in advanced pediatric age) are different from those appearing in early infancy. They seem to display dysimmune/autoimmune features that is some case is proven to rely on a genetic dysimmune background. They might represent an anticipation of more complex autoimmune disorders which may fully manifest later in life. Interstingly these patients seem to share some features with CIN of adults. Definitive conclusions will be drawn by applying more comprehensive genetic nalysis (WES and WGS) on larger group of subjects. References: 1. Farruggia et al, Am J Hematol. 2019, 94:216-222 2. Mavroudi I et al, Clin Immunol. 2017 Oct;183:75-84 3. Fioredda F et al, Blood Adv 2020 Nov 24;4:5644-5649 Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Neutropenia in children: acquired neutropenia

Neutropenia is defined as a reduction in the absolute neutrophil count (ANC) below 1,500 cells/mcl in the blood. Neutropenia is a common laboratory finding in children. It is important to distinguish transient and benign causes from severe congenital neutropenia. Neutropenia can be classified in asymptomatic (mild), moderate, and severe form, the susceptibility to infection depending on ANC. Neutropenia can be either acquired or congenital. Infection, drugs, and immune disorders are the most common acquired causes while congenital causes are rare and confined mostly to infants and children. Transient neutropenia often accompanies viral infections in children, manifested in the period of acute viremia. Young children are characterized by autoimmune neutropenia (AIN), which has a benign course and a favorable prognosis. Autoimmune neutropenia is characterized by a decrease in the number of neutrophils as a result of the destruction of neutrophils in the peripheral blood by antineutrophil antibodies. The duration of AIN is usually 3–5 years. This is a self-limiting disease that in most cases does not require treatment. Despite the benign course, serious infectious complications can occur. Treatment of myeloid growth factors should be started after a previous bone marrow aspiration biopsy in children with severe infections or requiring surgical intervention. High doses of intravenous immunoglobulin and corticosteroids may be effective in treating AIN in patients with life-threating infections. The danger to the patient depends on the etiology, ANC and bone marrow status. The risk of infections is significantly increased in patients with ACN less than 500 cells/μ1. The most common loci of infections include the oral mucosa, skin, perirectal area, perineum. Oral ulcers and gingivitis are characteristic signs of clinically significant neutropenia, requiring the exclusion of its congenital causes. Severe infections in patients with neutropenia are caused by pyogenic or intestinal bacteria and Candida species. It is important to distinguish between transient or benign causes and severe congenital neutropenia or neutropenia associated with serious haematological or systemic disease. Clarification of the cause of neutropenia is important for determining management and prognosis. No conflict of interest was declared by the author. Key words: neutropenia, children, immunodeficiency, autoimmune neutropenia.

Diagnosis and management of neutropenia in children: consensus audit of the “Associazione Italiana Ematologia Oncologia Pediatrica” (AIEOP) experts

SUMMARY Neutropenia is a generic term that indicates a reduction of neutrophils below the threshold for age and race. This condition encompasses a number of diseases with a wide range of duration and severity. In the present paper, the approach to diagnosis and treatment of neutropenia has been reviewed and implemented with the knowledge acquired during the last decade, by a group of experts, 10 years after the first publication. The diagnostic itinerary highlights the most important tools available to define the type of neutropenia and updates the list of genes causative of the disease. In addition, the present paper underlines the progresses towards a better definition of “primary autoimmune neutropenia” without remission which often hides different diseases. Moreover, indications on how to speed up neutropenia diagnosis and the indications to perform the bone marrow examination in the genetic forms, are given. The management and treatment of the “well-known” diseases and “special situations” are also reviewed giving literature derived and expert opinion-based suggestions tailored on the single patient/diagnosis.

Autoimmune neutropenia associated with influenza virus infection in childhood: a case report

Background Although neutropenia is relatively frequent in infants and children and is mostly a benign condition with a self-limited course, it can lead to life-threatening severe infections. Autoimmune neutropenia is a relatively uncommon hematological disorder characterized by the autoantibody-induced destruction of neutrophils. It is usually triggered by viral infections with very few documented cases after influenza virus. Case presentation An 8-month-old male infant presented at the emergency room with a 5-days history of fever up to 39.7 °C, cough and runny nose. In the blood test performed, severe neutropenia was diagnosed (neutrophils 109/μL). A nasopharyngeal aspirate revealed a positive rapid test for Influenza A. Serum antineutrophil antibodies were determined with positive results. Neutropenia targeted panel showed no mutations. Despite maintenance of severe neutropenia for 9 months the course was uneventful without treatment. Conclusions When severe neutropenia is diagnosed and confirmed, it is essential to rule out some potential etiologies and underlying conditions, since the appropriate subsequent management will depend on it. Although autoimmune neutropenia triggered by viral infections has been widely reported, it has seldom been reported after influenza infection. The benign course of the disease allows a conservative management in most cases.