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Background and Objectives: Human neutrophil antigens (HNAs) are categorized into five systems: HNA-1 to HNA-5. Given the importance of neutrophils in immunity, we sought to create awareness of the role of HNA diagnostic services in managing immune neutropenia and transfusion-related acute lung injury. To provide health communities all around the world with access to these services, we conducted a survey to create a directory of these HNA diagnostic services., Materials and Methods: An Excel table-based survey was created to capture information on the laboratory's location and was emailed to 55 individuals with known or possible HNA investigation activity. The collected data were then summarized and analysed., Results: Of contacted laboratories, the surveys were returned from 23 (38.2%) laboratories; 17 have already established HNA diagnostic (of them 12 were regular participants of the International Granulocyte Immunobiology Workshop [ISBT-IGIW]), 4 laboratories were in the process of establishing their HNA investigation and the remaining 2 responder laboratories, did not conduct HNA investigations. In established laboratories, investigation for autoimmune neutropenia (infancies and adults) was the most frequently requested, and antibodies against HNA-1a and HNA-1b were the most commonly detected., Conclusion: The directory of survey respondents provides a resource for health professionals wanting to access HNA diagnostic services. The present study offers a comprehensive picture of HNA diagnostics (typing and serology), identifying weak points and areas for improvement for the first time. Identifying more laboratories involved in HNA diagnostics with limited access to international societies in the field will globally improve HNA diagnostics., (© 2023 Institute of Clinical Immunology and Transfusion Medicine and The Authors. Vox Sanguinis published by John Wiley & Sons Ltd on behalf of International Society of Blood Transfusion.)

Introduction: Neutropenia is a relatively common finding in medical practice and the medical approach requires a gradual and pertinent diagnostic procedure as well as adapted management., Areas Covered: The area of chronic neutropenia remains fragmented between diverse diseases or situations. Here physicians involved in different aspects of chronic neutropenia gather both the data from medical literature till the end of May 2021 and their experience to offer a global approach for the diagnosis of chronic neutropenia as well as their medical care., Expert Opinion: In most cases, the neutropenia is transient, frequently related to a viral infection, and not harmful. However, neutropenia can be chronic (i.e. >3 months) and related to a number of etiologies, some clinically benign, such as so-called 'ethnic' neutropenia. Autoimmune neutropenia is the common form in young children, whereas idiopathic/immune neutropenia is a frequent etiology in young females. Inherited neutropenia (or congenital neutropenia) is exceptional, with approximately 30 new cases per 10 6 births and 30 known subtypes. Such patients have a high risk of invasive bacterial infections, and oral infections. Supportive therapy, which is primarily based on daily administration of an antibiotic prophylaxis and/or treatment with granulocyte-colony stimulating factor (G-CSF), contributes to avoiding recurrent infections.

Purpose: Neonatal immune neutropenia is observed in rare cases in newborns from mothers with idiopathic or autoimmune neutropenia, secondary to passive transfer of maternal granulocyte auto-antibodies., Methods: We performed a literature review and report four supplementary cases from the French registry of neutropenia., Results: Only 14 cases (11 mothers, 14 newborns) have been reported. Granulocyte aggregation (GAT) and granulocyte indirect immunofluorescence test (GIFT) are the recommended laboratory procedures for antibody detection. Monoclonal antibody-specific immobilization of granulocyte antigens (MAIGA)-confirmed antibody specificity. Antibody detection in newborns is not generally possible owing to extreme neutropenia. In half of the cases autoantibodies against neutrophils (AAN) were positive in maternal sera (7 out of 11). In some newborns tested, IgG + AAN were also positive, with disappearance in parallel of spontaneous neutrophil count improvement. No correlation between maternal type of AAN and titer and neonatal neutropenia can be established. Neutropenia resolved spontaneously between 2 weeks and 4 months. Infections in newborns were observed in 43% of cases, with no deaths reported. Granulocyte colony-stimulating factor (G-CSF) was administered to some newborns (5 out of 14) in the case of infections. Low-dose G-CSF administered to childbearing women during pregnancy could be proposed to prevent neutropenia in newborns., Conclusions: From the few cases reported so far it is impossible to draw any conclusions regarding frequency, risk factors, and outcome, but the overall prognosis for newborns seems good. Because it can be associated with potentially severe neonatal infections, autoimmune neutropenia in childbearing mothers should be closely monitored in collaboration with gynecologists and pediatricians.

Severe chronic primary neutropenia (CPN) is a rare entity, and long-term outcome and risk factors for infections in severe CPN adults have not been described to date. We report the characteristics and outcomes of 108 severe adult CPN patients enrolled in a multi-institutional observational study. Severe CPN adults were mostly female (78%), and median age at diagnosis was 28.3 years. Diagnosis was fortuitous in 62% of cases. The median absolute neutrophil count (ANC) at diagnosis was 0.4 × 10(9)/L, and median ANC without granulocyte colony-stimulating factor (G-CSF) during follow-up was 0.5 × 10(9)/L. Twenty-three of 66 (34.8%) evaluable patients had neutrophil autoantibodies, and 6 of 47 (12.8%) a T-cell clone. The presence of neutrophil autoantibodies or T-cell clone was not associated with any specific clinical or biological characteristics. No death or hematologic malignancies occurred, and 44 severe bacterial infections were reported in 27 patients with a median follow-up of 8.3 years. Fifty patients received G-CSF either sporadically (n = 24) or continuously (n = 26) and responded (96%). Nineteen patients received immunosuppressive therapies: overall response (OR) was 41%, and median duration of response was 3 months. At diagnosis, the only predictive factor for the occurrence of severe bacterial infections was an ANC count below 0.2 × 10(9)/L (OR, 0.76). Severe CPN in adults is characterized by a female predominance and a benign outcome with a low rate of severe bacterial infections and no secondary malignancies. G-CSF is efficient and well tolerated but is not required in a majority of patients., (© 2015 by The American Society of Hematology.)

Diagnosis of autoimmune neutropenia (AIN) in infants is important, because it allows the exclusion of more severe forms of neutropenia that have an increased risk for leukemia. AIN is characterized by chronic neutropenia, which spontaneously resolves within several months to a few years, and mild infections. Diagnosis is confirmed by the presence of antibodies directed against neutrophil antigens. The human neutrophil antigen (HNA) system is a polymorphic system, which includes five antigen groups with different polymorphisms. In AIN, antibodies are mostly directed against HNA-1 (or against a specific allele of HNA-1) and HNA-4. Here, we present a series of 116 infants with AIN. We observed that anti-neutrophil antibodies were present in 60% cases; directed against HNA-1a in 73% of cases. In addition, we showed there was a bias in the HNA allele distribution in these infants because the frequency of the HNA-1a allele was greater in comparison with controls., (© 2011 John Wiley & Sons A/S.)

Autoimmune neutropenias (AIN) are classically divided into primary AIN and secondary AIN. The latter are associated with autoimmune disorders, hematologic malignancies, primary immune deficiencies, drug exposure or infections. In this review we will focus on the major aetiologies of AIN, their differential diagnosis, the various methods in biological diagnosis, and the treatment., (Copyright © 2010 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.)

Abstract: Autoimmune neutropenias (AIN) are classically divided into primary AIN and secondary AIN. The latter are associated with autoimmune disorders, hematologic malignancies, primary immune deficiencies, drug exposure or infections. In this review we will focus on the major aetiologies of AIN, their differential diagnosis, the various methods in biological diagnosis, and the treatment. [ABSTRACT FROM AUTHOR]