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1.
Vox Sang ; 118(9): 763-774, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37608544

ABSTRACT

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.


Subject(s)
Neutropenia , Neutrophils , Adult , Humans , Granulocytes , Antibodies , Surveys and Questionnaires
2.
Lupus ; 31(14): 1816-1823, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36177950

ABSTRACT

OBJECTIVE: The aim of the study was to describe clinical and biological characteristics and thrombotic relapses of patients diagnosed with antiphospholipid syndrome (APS) after the age of 65 years, in comparison with patients diagnosed with APS before 65. METHODS: This retrospective multicenter study was performed to 2005 from 2017 and included patients diagnosed with APS after the age of 65 years, in accordance with Sydney criteria. We compared these patients with APS patients diagnosed before the age of 65 years, and with control thrombotic patients older than 65 years. RESULTS: Fifty-eight APS patients over the age of 65 years were compared to 127 APS patients aged less than 65 and to 58 controls. In elderly APS versus younger APS, there was a male predominance (58.6% vs 36.2% p = .001); myocardial infarction and lower limb deep vein thrombosis (LLDVT) were more frequent in elderly, respectively, 12.1% versus 1.6% (p = .005), and 44.8% versus 29.9% (p = .048). Anticardiolipin antibody (aCL) IgM was more frequently found in old patients compared to younger patients (33.9% vs 18.1%, p = .02), contrary to lupus anticoagulant (LAC) (52.8% vs 66.9%, p = .02). Older patients were more often diagnosed with single positive APS (82.8% vs 59.8% p = .002). The thrombotic relapse free survival was lower in elderly APS patients (p = .044) compared to younger APS. Elderly APS patients had more recurrent arterial and venous thrombosis (p = .03) and had poorer overall survival (p = .004) than elderly controls. CONCLUSION: In this study, APS was different in patients aged more than 65 years, with a male predominance and more myocardial infarctions and LLDVT at diagnosis. Single antiphopholipid positivity and aCL IgM were more frequent in older patients. Older patient with APS had more thrombotic recurrence during follow-up. Compared to elderly controls, elderly APS patients had more thrombosis recurrences and poorer survival.


Subject(s)
Antiphospholipid Syndrome , Lupus Erythematosus, Systemic , Thrombosis , Venous Thrombosis , Humans , Male , Aged , Female , Antiphospholipid Syndrome/diagnosis , Antibodies, Anticardiolipin , Lupus Coagulation Inhibitor , Venous Thrombosis/epidemiology , Recurrence , Immunoglobulin M
3.
Expert Rev Hematol ; 14(10): 945-960, 2021 10.
Article in English | MEDLINE | ID: mdl-34486458

ABSTRACT

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 106 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.


Subject(s)
Bacterial Infections , Neutropenia , Antibiotic Prophylaxis/adverse effects , Child , Child, Preschool , Congenital Bone Marrow Failure Syndromes , Female , Granulocyte Colony-Stimulating Factor/therapeutic use , Humans , Neutropenia/diagnosis , Neutropenia/etiology , Neutropenia/therapy
4.
Int J Neonatal Screen ; 7(3)2021 Jul 12.
Article in English | MEDLINE | ID: mdl-34287257

ABSTRACT

After it was demonstrated in 2005 that T cell receptor excision circle (TREC) quantification for dried blood spot (DBS) samples on Guthrie cards is an effective means of SCID screening and following several pilot studies, the practice was formally recommended in the US in 2010. More and more countries have adopted it since then. In France, before the health authorities could recommend adding SCID to the list of five diseases that were routinely screened for, feasibility and cost-effectiveness studies had to be conducted with a sufficiently large cohort of neonates. We carried out three such studies: The first sought to verify the effectiveness of the assay. The second, DEPISTREC, evaluated the feasibility of universal SCID screening in France and assessed the clinical benefit and economic advantage it would provide. Through the third study, NeoSKID, still under way and to continue until recommendations are issued, we have been offering SCID screening in the Pays de la Loire region of France. This review briefly describes routine newborn screening (NBS) and management of primary immunodeficiency diseases (PIDs) in France, and then considers the lessons from our studies and the status of SCID screening implementation within the country.

5.
Rev Infirm ; 68(255): 16-18, 2019 Nov.
Article in French | MEDLINE | ID: mdl-31757321

ABSTRACT

Leukaemia results from a malignant proliferation of cells in the bone marrow. The prognosis is defined by the disease's biological characteristics. Treatment is based on chemotherapy. In cases of high-risk leukaemia, an allograft may be proposed. The arrival of targeted therapies and immunotherapy has revolutionised the prognosis of the disease. The challenge of the next few years will be to define the place of these therapies.


Subject(s)
Bone Marrow Transplantation , Immunotherapy , Leukemia , Allografts , Humans , Leukemia/therapy , Prognosis
6.
Clin Immunol ; 202: 33-39, 2019 05.
Article in English | MEDLINE | ID: mdl-30946917

ABSTRACT

PURPOSE: Severe combined immunodeficiency (SCID) refers to a group of genetic disorders characterized by greatly compromised cellular and humoral immunity. Children with SCID are asymptomatic at birth, but they die from infections within the first months of life if not treated. Quantification of T-cell receptor excision circles is an extremely sensitive screening method for detecting newborns who may have SCID.The goal of the DEPISTREC study was to evaluate the feasibility of nationwide newborn screening for severe T-cell lymphopenia in France as well as its economic and clinical utility. METHODS: The test universally used for neonatal screening for SCID was the quantification of TRECs on Guthrie cards. We compared a group of 190,517 babies from 48 maternities across the country who underwent newborn SCID screening with a control group of 1.4 million babies out of whom 28 were diagnosed with SCID without such screening during the course of the study. RESULTS: Within the screening group, 62 babies were found to be lymphopenic, including three with SCID. The cost of screening ranged from 4.7€ to €8.15 per newborn. The average 18-month cost was €257,574 vs €204,697 in the control group. CONCLUSIONS: In this large-scale study, we demonstrate that routine SCID screening is feasible and effective. This screening offers the additional benefit of aiding in the diagnosis of non-SCID lymphopenia. Economic evaluation allowed us to calculate the cost per test. Newborn screening may also prevent death by SCID before any curative treatment can be administered. The difference in cost between screened and control children could not be ascertained because of the very low numbers and death of one of the children tested.


Subject(s)
Lymphopenia/diagnosis , Neonatal Screening/economics , Severe Combined Immunodeficiency/diagnosis , Costs and Cost Analysis , Dried Blood Spot Testing/economics , Female , France , Humans , Infant , Infant, Newborn , Lymphocyte Count , Lymphopenia/economics , Male , Receptors, Antigen, T-Cell/immunology , Severe Combined Immunodeficiency/economics , T-Lymphocytes/immunology
7.
J Clin Immunol ; 39(2): 200-206, 2019 02.
Article in English | MEDLINE | ID: mdl-30900095

ABSTRACT

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.


Subject(s)
Neutropenia , Pregnancy Complications, Hematologic , Adult , Autoantibodies/blood , Female , France , Granulocyte Colony-Stimulating Factor/administration & dosage , Granulocytes/immunology , Humans , Infant, Newborn , Infections/drug therapy , Infections/etiology , Leukocyte Count , Male , Mothers , Neutropenia/blood , Neutropenia/complications , Neutropenia/immunology , Pregnancy , Pregnancy Complications, Hematologic/blood , Pregnancy Complications, Hematologic/immunology
8.
J Clin Immunol ; 38(7): 778-786, 2018 10.
Article in English | MEDLINE | ID: mdl-30251145

ABSTRACT

Severe combined immunodeficiency (SCID) is characterized by a major T cell deficiency. Infants with SCID are asymptomatic at birth but die from infections in the first year of life if not treated. Survival rates are better for early treatment. SCID therefore meets criteria for newborn screening (NBS). T cell receptor excision circle (TREC) quantification is a reliable marker of T cell deficiency and can be performed using Guthrie cards. The DEPISTREC project was designed to study the feasibility, clinical utility, and cost-effectiveness of generalized SCID screening in France. About 200,000 babies from all over the country were screened at birth with a commercial kit. We determined assay performance and proposed a cutoff for classification of results. Our findings suggest that, given clearly established validation rules and decision-making procedures, the TREC assay is a suitably specific and sensitive method for high-throughput SCID screening. Clinical Trials: NCT02244450.


Subject(s)
Severe Combined Immunodeficiency/diagnosis , Biological Assay , Biomarkers , Clinical Decision-Making , Cost-Benefit Analysis , Disease Management , France/epidemiology , Humans , Infant , Infant, Newborn , Neonatal Screening , Public Health Surveillance , Reagent Kits, Diagnostic , Receptors, Antigen, T-Cell/metabolism , Reproducibility of Results , Severe Combined Immunodeficiency/epidemiology , Severe Combined Immunodeficiency/immunology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism
11.
J Crohns Colitis ; 12(2): 258-261, 2018 Jan 24.
Article in English | MEDLINE | ID: mdl-28961694

ABSTRACT

Azathioprine is commonly used in Crohn's disease. It has been administered to many pregnant women over many years without significant side effects. However, pancytopenia and severe combined immune deficiency-like disease have been reported in infants whose mothers received azathioprine throughout pregnancy. Moreover, myelotoxicity has been described in patients being treated with azathioprine and having a low or absent thiopurine S-methyl transferase [TPMT] activity.Here, we describe the case of a newborn girl found to be highly lymphopenic [< 300 CD3+ T cells] after a positive newborn screening for severe combined immuno deficiency. The clinical examination was normal. The mother was treated with azathioprine throughout her pregnancy, without any reduction of the dose. It was shown that the mother was heterozygous for the 3A [TPMT] activity mutation and that the baby was homozygous for the same mutation; 6-thioguanine nucleotides were high (744 pmol/8.108 red blood cells [RBC]) in the mother and detectable in the infant [177 pmol/8.108 RBC].Although rare, this case illustrates the potential grave consequences of unsuspected TPMT homozygosity in a newborn of a mother receiving thiopurines during pregnancy. Because of the severity of the risk for the newborn, consideration should be given to performing maternal genetic testing and newborn routine blood count in cases of thiopurine treatment during pregnancy.


Subject(s)
Azathioprine/adverse effects , Crohn Disease/drug therapy , Immunosuppressive Agents/adverse effects , Lymphopenia/chemically induced , Pregnancy Complications/drug therapy , Prenatal Exposure Delayed Effects/chemically induced , Crohn Disease/genetics , Female , Homozygote , Humans , Infant, Newborn , Lymphopenia/genetics , Methyltransferases/genetics , Mutation , Pregnancy
12.
Blood ; 126(14): 1643-50, 2015 Oct 01.
Article in English | MEDLINE | ID: mdl-26261239

ABSTRACT

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.


Subject(s)
Neutropenia/blood , Neutropenia/pathology , Adult , Autoantibodies/blood , Female , Granulocyte Colony-Stimulating Factor/therapeutic use , Humans , Immunosuppressive Agents/therapeutic use , Male , Neutropenia/drug therapy
13.
Clin Immunol ; 161(2): 103-9, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26187144

ABSTRACT

Autosomal recessive human ZAP70 deficiency is a rare cause of combined immunodeficiency (CID) characterized by defective CD4 T cells and profound CD8 T cell lymphopenia. Herein, we report two novel patients that extend the molecular genetics, the clinical and functional phenotypes associated with the ZAP70 deficiency. The patients presented as infant-onset CID with severe infections caused by varicella zoster virus and live vaccines. Retrospective TCR excision circle newborn screening was normal in both patients. One patient carried a novel non-sense mutation (p.A495fsX75); the other a previously described misense mutation (p.A507V). In contrast to CD4 T cells, the majority of the few CD8 T cells showed expression of the ZAP70-related tyrosine kinase SYK that correlated with residual TCR signaling including calcium flux and degranulation. Our findings highlight the differential requirements of ZAP70 and SYK during thymic development, peripheral homeostasis as well as effector functions of CD4 and CD8 T cells.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Intracellular Signaling Peptides and Proteins/immunology , Protein-Tyrosine Kinases/immunology , Receptors, Antigen, T-Cell/immunology , Severe Combined Immunodeficiency/immunology , ZAP-70 Protein-Tyrosine Kinase/deficiency , CD4-Positive T-Lymphocytes/immunology , Child, Preschool , Humans , Immunologic Deficiency Syndromes/immunology , Infant , Male , Mutation/immunology , Retrospective Studies , Signal Transduction/immunology , Syk Kinase , ZAP-70 Protein-Tyrosine Kinase/immunology
14.
J Allergy Clin Immunol ; 135(6): 1589-93, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25840725

ABSTRACT

BACKGROUND: The inclusion of severe combined immunodeficiency (SCID) in a Europe-wide screening program is currently debated. OBJECTIVE: In making a case for inclusion in the French newborn screening program, we explored the costs incurred and potentially saved by early management of SCID. METHODS: For test costs, a microcosting study documented the resources used in a laboratory piloting a newborn screening test on Guthrie cards using the T-cell receptor excision circle quantification method. For treatment costs, patients with SCID admitted to the national reference center for primary immunodeficiency in France between 2006 and 2010 were included. Costs of admission were estimated from actual national production costs. We estimated the costs for patients who underwent early versus delayed hematopoietic stem cell transplantation (HSCT; age, ≤3 vs. >3 months, respectively). RESULTS: The unit cost of the test varied between €4.69 and €6.79 for 33,800 samples per year, depending on equipment use and saturation. Of the 30 patients included, 27 underwent HSCT after age 3 months. At 1 year after HSCT, 10 of these had died, and all 3 patients undergoing early transplantation survived. The medical costs for HSCT after 3 months were €195,776 (interquartile range, €165,884-€257,160) versus €86,179 (range, €59,014-€272,577) when performed before 3 months of age. In patients undergoing late transplantation, active infection contributed to high cost and poor outcome. CONCLUSION: Early detection of SCID could reduce the cost of treatment by €50,000-100,000 per case. Assuming a €5 unit cost per test, the incidence required to break even is 1:20,000; however, if the survival advantage of HSCT before 3 months is confirmed, universal screening is likely to be cost-effective.


Subject(s)
Biological Assay/economics , Cost-Benefit Analysis , Hematopoietic Stem Cell Transplantation/economics , Lymphopenia/diagnosis , Neonatal Screening/economics , Severe Combined Immunodeficiency/diagnosis , Early Diagnosis , Female , France , Health Care Costs , Humans , Infant , Infant, Newborn , Lymphopenia/economics , Lymphopenia/mortality , Lymphopenia/therapy , Male , Neonatal Screening/methods , Receptors, Antigen, T-Cell/analysis , Severe Combined Immunodeficiency/economics , Severe Combined Immunodeficiency/mortality , Severe Combined Immunodeficiency/therapy , Survival Analysis , T-Lymphocytes/immunology , T-Lymphocytes/pathology
15.
J Allergy Clin Immunol ; 135(3): 818-20.e4, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25420683
16.
Clin Nephrol ; 83(6): 357-62, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25345380

ABSTRACT

Kidney transplantation (KTx) is the treatment of choice for eligible patients suffering from anti-neutrophil cytoplasmic antibody(ANCA)-associated vasculitis (AAV) who are in clinical remission, regardless of ANCA status. With current immunosuppressive protocols, the recurrence rate of this primary disease in the kidney graft is low and is generally observed after the 1st year of transplantation, with a favorable outcome following conventional treatment. We report here two unusual observations of early (diagnosed within 2 weeks) and aggressive (graft failure despite therapy) recurrences in the kidney graft. These observations suggest that systematic induction by depleting antibodies and antibiotic prophylaxis may help prevent this rare but severe condition. In addition, we monitored these patients for the anti- lysosomal membrane protein-2 antibody (LAMP2ab) titers, but we found that LAMP2ab titers were not a surrogate marker of early recurrence if the LAMP2ab concentration was higher in AVV recipients before KTx. Finally, we must keep in mind that rare cases of early and aggressive recurrence ANCA-associated vasculitis on kidney graft are a challenge for early diagnosis and treatment.


Subject(s)
Antibodies, Antineutrophil Cytoplasmic/analysis , Glomerulonephritis/etiology , Kidney Transplantation/adverse effects , Peroxidase/immunology , Female , Glomerulonephritis/immunology , Humans , Lysosomal-Associated Membrane Protein 2/immunology , Male , Middle Aged , Recurrence
17.
Scand J Infect Dis ; 46(5): 392-6, 2014 May.
Article in English | MEDLINE | ID: mdl-24716464

ABSTRACT

BACKGROUND: In recent years, the clinical use of interferon gamma release assays (IGRAs) has increased exponentially, while their indications remain controversial given difficulties in interpretation. Four indications were recommended by the French National Authority for Health (HAS) in 2006. We evaluated the utilization of the QuantiFERON-TB Gold In-Tube (QFT-IT) test over a 1-y period in a French university hospital and the impact of IGRA results in particular. METHODS: The QFT-IT tests requested in 2009 were analysed retrospectively, excluding those from the Occupational Health Department, the Regional Tuberculosis Centre, and rheumatology consultations for which the indications were clearly defined. RESULTS: Three hundred and sixty QFT-IT tests were analysed. The interpretation was frequently problematic given the inclusion of a significant proportion of patients over 80 y of age (11%), immunocompromised patients (43%), and patients with a known history of tuberculosis (6%). The indications failed to comply with HAS recommendations in 42% of cases (151/360), i.e. 14% of all QFT-IT tests in 2009. Thirty-seven percent of request forms were related to suspected pulmonary tuberculosis. In the case of a positive QFT-IT test, the clinical decision-making was changed in 58% of cases when the indications met the HAS recommendations, compared with only 16% if they did not (p < 0.005). CONCLUSION: When the indications do not meet the health authority recommendations, the diagnostic value of the IGRA remains limited.


Subject(s)
Interferon-gamma Release Tests/statistics & numerical data , Tuberculosis/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Female , France/epidemiology , Hospitals, University/statistics & numerical data , Humans , Interferon-gamma Release Tests/methods , Male , Middle Aged , Practice Guidelines as Topic , Retrospective Studies , Tuberculosis/epidemiology , Young Adult
19.
Pediatr Allergy Immunol ; 22(5): 494-6, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21771084

ABSTRACT

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.


Subject(s)
Autoimmune Diseases , Isoantibodies/blood , Isoantigens/genetics , Isoantigens/immunology , Neutropenia , Neutrophils/immunology , Autoimmune Diseases/genetics , Autoimmune Diseases/immunology , Child, Preschool , Female , Gene Frequency , Genotype , Humans , Infant , Isoantibodies/immunology , Male , Neutropenia/genetics , Neutropenia/immunology , Polymerase Chain Reaction/methods
20.
PLoS One ; 6(4): e18734, 2011 Apr 08.
Article in English | MEDLINE | ID: mdl-21494636

ABSTRACT

BACKGROUND: Dendritic cells (DC) and regulatory cells (Treg) play pivotal roles in controlling both normal and autoimmune adaptive immune responses. DC are the main antigen-presenting cells to T cells, and they also control Treg functions. In this study, we examined the frequency and phenotype of DC subsets, and the frequency and function of Treg from patients with ANCA-associated vasculitis (AAV). METHODOLOGY/PRINCIPAL FINDINGS: Blood samples from 19 untreated patients with AAV during flares and before any immunosuppressive treatment were analyzed, along with 15 AAV patients in remission and 18 age-matched healthy controls. DC and Treg numbers, and phenotypes were assessed by flow cytometry, and in vitro suppressive function of Treg was determined by co-culture assay. When compared to healthy volunteers, absolute numbers of conventional and plasmacytoid DC were decreased in AAV patients. During the acute phase this decrease was significantly more pronounced and was associated with an increased DC expression of CD62L. Absolute numbers of Treg (CD4(+)CD25(high)CD127(low/-) Tcells) were moderately decreased in patients. FOXP3 and CD39 were expressed at similar levels on Treg from patients as compared to controls. The suppressive function of Treg from AAV patients was dramatically decreased as compared to controls, and this defect was more pronounced during flares than remission. This Treg functional deficiency occurred in the absence of obvious Th17 deviation. CONCLUSION: In conclusion, these data show that AAV flares are associated with both a decrease number and altered phenotype of circulating DC and point to a role for Treg functional deficiency in the pathogenesis of AAV.


Subject(s)
Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/blood , Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/immunology , Dendritic Cells/pathology , T-Lymphocytes, Regulatory/pathology , Acute Disease , Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/pathology , Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/physiopathology , Case-Control Studies , Cell Count , Coculture Techniques , Flow Cytometry , Humans , Interleukin-17/metabolism , L-Selectin/metabolism , Middle Aged , Remission Induction , Th17 Cells/metabolism
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