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Background: Patients with terminal complement pathway deficiency (TPD) are susceptible to recurrent invasive meningococcal disease (IMD). Neisseria meningitidis (Nm) strains infecting these patients are poorly documented in the literature.Methods: We identified patients with TPD and available Nm strains isolated during IMD. We investigated the genetic basis of the different TPDs and the characteristics of the Nm strains.Results: We included 56 patients with C5 (n = 8), C6 (n = 20), C7 (n = 18), C8 (n = 9), or C9 (n = 1) deficiency. Genetic study was performed in 47 patients and 30 pathogenic variants were identified in the genes coding for C5 (n = 4), C6 (n = 5), C7 (n = 12), C8 (n = 7), and C9 (n = 2). We characterized 61 Nm strains responsible for IMD in the 56 patients with TPD. The most frequent strains belonged to groups Y (n = 27 [44%]), B (n = 18 [30%]), and W (n = 8 [13%]). Hyperinvasive clonal complexes (CC11, CC32, CC41/44, and CC269) were responsible for 21% of IMD cases. The CC23 predominates and represented 26% of all invasive isolates. Eleven of the 15 clonal complexes identified fit to 12 different clonal complexes belonging to carriage strains.Conclusions: Unusual meningococcal strains with low level of virulence similar to carriage strains are most frequently responsible for IMD in patients with TPD. [ABSTRACT FROM AUTHOR]

Among 143 patients with elastase, neutrophil-expressed (ELANE)-related neutropenia enrolled in the French Severe Chronic Neutropenia Registry, 94 were classified as having severe chronic neutropenia (SCN) and 49 with cyclic neutropenia (CyN). Their infectious episodes were classified as severe, mild or oral, and analysed according to their natural occurrence without granulocyte-colony stimulating factor (G-CSF), on G-CSF, after myelodysplasia/acute leukaemia or after haematopoietic stem-cell transplantation. During the disease's natural history period (without G-CSF; 1913 person-years), 302, 957 and 754 severe, mild and oral infectious events, respectively, occurred. Among severe infections, cellulitis (48%) and pneumonia (38%) were the most common. Only 38% of episodes were microbiologically documented. The most frequent pathogens were Staphylococcus aureus (37·4%), Escherichia coli (20%) and Pseudomonas aeruginosa (16%), while fungal infections accounted for 1%. Profound neutropenia (<200/mm 3 ), high lymphocyte count (>3000/mm 3 ) and neutropenia subtype were associated with high risk of infection. Only the p.Gly214Arg variant (5% of the patients) was associated with infections but not the overall genotype. The first year of life was associated with the highest infection risk throughout life. G-CSF therapy achieved lower ratios of serious or oral infectious event numbers per period but was less protective for patients requiring >10 µg/kg/day. Infections had permanent consequences in 33% of patients, most frequently edentulism., (© 2021 British Society for Haematology and John Wiley & Sons Ltd.)

Background: Coagulation disorders are common in patients with hemophagocytic lymphohistiocytosis (HLH), associated with an increased risk of bleeding and death. We aim to investigate coagulation disorders and their outcome implications in critically ill patients with HLH., Methods: We prospectively evaluated 47 critically ill patients with HLH (median age of 54 years [42-67]) between April 2015 and December 2018. Coagulation assessments were performed at day 1. Abnormal standard coagulation was defined as prothrombin time (PT) <50% and/or fibrinogen <2g/L. HLH aetiology was mostly ascribed to haematological malignancies (74% of patients)., Results: Coagulation disorders and severe bleeding events were frequent, occurring in 30 (64%) and 11 (23%) patients respectively. At day 1, median fibrinogen level was 2∙65g/L [1.61-5.66]. Fibrinolytic activity was high as suggested by increased median levels of D-dimers, fibrin monomers, PAI-1 (plasminogen activator inhibitor) and tPA (tissue plasminogen activator). Forty-one (91%) patients had a decreased ADAMTS13 activity (A Disintegrin-like And Metalloproteinase with ThromboSpondin type 1 repeats, member 13). By multivariable analysis, the occurrence of a severe bleeding (OR 3.215 [1.194-8.653], p = 0∙021) and SOFA score (Sepsis-Related Organ Failure Assessment) at day 1 (OR 1.305 per point [1.146-1.485], p<0∙001) were independently associated with hospital mortality. No early biological marker was associated with severe bleeding., Conclusions: Hyperfibrinolysis may be the primary mechanism responsible for hypofibrinogenemia and may also participate in ADAMTS13 degradation. Targeting the plasmin system appears as a promising approach in severe HLH-related coagulation disorders., Competing Interests: The authors have declared that no competing interests exist.

Background: Human encephalitis represents a medical challenge from a diagnostic and therapeutic point of view. We investigated the cause of 2 fatal cases of encephalitis of unknown origin in immunocompromised patients., Methods: Untargeted metatranscriptomics was applied on the brain tissue of 2 patients to search for pathogens (viruses, bacteria, fungi, or protozoans) without a prior hypothesis., Results: Umbre arbovirus, an orthobunyavirus never previously identified in humans, was found in 2 patients. In situ hybridization and reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) showed that Umbre virus infected neurons and replicated at high titers. The virus was not detected in cerebrospinal fluid by RT-qPCR. Viral sequences related to Koongol virus, another orthobunyavirus close to Umbre virus, were found in Culex pipiens mosquitoes captured in the south of France where the patients had spent some time before the onset of symptoms, demonstrating the presence of the same clade of arboviruses in Europe and their potential public health impact. A serological survey conducted in the same area did not identify individuals positive for Umbre virus. The absence of seropositivity in the population may not reflect the actual risk of disease transmission in immunocompromised individuals., Conclusions: Umbre arbovirus can cause encephalitis in immunocompromised humans and is present in Europe., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Purpose: Patients with primary immunodeficiency (PID) are at risk of serious complications. However, data on the incidence and causes of emergency hospital admissions are scarce. The primary objective of the present study was to describe emergency hospital admissions among patients with PID, with a view to identifying "at-risk" patient profiles., Methods: We performed a prospective observational 12-month multicenter study in France via the CEREDIH network of regional PID reference centers from November 2010 to October 2011. All patients with PIDs requiring emergency hospital admission were included., Results: A total of 200 admissions concerned 137 patients (73 adults and 64 children, 53% of whom had antibody deficiencies). Thirty admissions were reported for 16 hematopoietic stem cell transplantation recipients. When considering the 170 admissions of non-transplant patients, 149 (85%) were related to acute infections (respiratory tract infections and gastrointestinal tract infections in 72 (36%) and 34 (17%) of cases, respectively). Seventy-seven percent of the admissions occurred during winter or spring (December to May). The in-hospital mortality rate was 8.8% (12 patients); death was related to a severe infection in 11 cases (8%) and Epstein-Barr virus-induced lymphoma in 1 case. Patients with a central venous catheter (n = 19, 13.9%) were significantly more hospitalized for an infection (94.7%) than for a non-infectious reason (5.3%) (p = 0.04)., Conclusion: Our data showed that the annual incidence of emergency hospital admission among patients with PID is 3.4%. The leading cause of emergency hospital admission was an acute infection, and having a central venous catheter was associated with a significantly greater risk of admission for an infectious episode.

Heterozygous germline GATA2 mutations strongly predispose to leukemia, immunodeficiency, and/or lymphoedema. We describe a series of 79 patients (53 families) diagnosed since 2011, made up of all patients in France and Belgium, with a follow up of 2249 patients/years. Median age at first clinical symptoms was 18.6 years (range, 0-61 years). Severe infectious diseases (mycobacteria, fungus, and human papilloma virus) and hematologic malignancies were the most common first manifestations. The probability of remaining symptom-free was 8% at 40 years old. Among the 53 probands, 24 had missense mutations including 4 recurrent alleles, 21 had nonsense or frameshift mutations, 4 had a whole-gene deletion, 2 had splice defects, and 2 patients had complex mutations. There were significantly more cases of leukemia in patients with missense mutations (n=14 of 34) than in patients with nonsense or frameshift mutations (n=2 of 28). We also identify new features of the disease: acute lymphoblastic leukemia, juvenile myelomonocytic leukemia, fatal progressive multifocal leukoencephalopathy related to the JC virus, and immune/inflammatory diseases. A revised International Prognostic Scoring System (IPSS) score allowed a distinction to be made between a stable disease and hematologic transformation. Chemotherapy is of limited efficacy, and has a high toxicity with severe infectious complications. As the mortality rate is high in our cohort (up to 35% at the age of 40), hematopoietic stem cell transplantation (HSCT) remains the best choice of treatment to avoid severe infectious and/or hematologic complications. The timing of HSCT remains difficult to determine, but the earlier it is performed, the better the outcome., (Copyright© 2018 Ferrata Storti Foundation.)

Autosomal dominant deficiency of signal transducer and activator of transcription 3 (STAT3) is the main genetic etiology of hyper-immunoglobulin (Ig) E syndrome. We documented the molecular, cellular, and clinical features of 60 patients with heterozygous STAT3 mutations from 47 kindreds followed in France. We identified 11 known and 13 new mutations of STAT3. Low levels of interleukin (IL)-6-dependent phosphorylation and nuclear translocation (or accumulation) of STAT3 were observed in Epstein-Barr virus-transformed B lymphocytes (EBV-B cells) from all STAT3-deficient patients tested. The immunologic phenotype was characterized by high serum IgE levels (96% of the patients), memory B-cell lymphopenia (94.5%), and hypereosinophilia (80%). A low proportion of IL-17A-producing circulating T cells was found in 14 of the 15 patients tested. Mucocutaneous infections were the most frequent, typically caused by Staphylococcus aureus (all patients) and Candida albicans (85%). Up to 90% of the patients had pneumonia, mostly caused by Staph. aureus (31%) or Streptococcus pneumoniae (30%). Recurrent pneumonia was associated with secondary bronchiectasis and pneumatocele (67%), as well as secondary aspergillosis (22%). Up to 92% of the patients had dermatitis and connective tissue abnormalities, with facial dysmorphism (95%), retention of decidual teeth (65%), osteopenia (50%), and hyperextensibility (50%). Four patients developed non-Hodgkin lymphoma. The clinical outcome was favorable, with 56 patients, including 43 adults, still alive at the end of study (mean age, 21 yr; range, 1 mo to 46 yr). Only 4 patients died, 3 from severe bacterial infection (aged 1, 15, and 29 yr, respectively). Antibiotic prophylaxis (90% of patients), antifungal prophylaxis (50%), and IgG infusions (53%) improved patient health, as demonstrated by the large decrease in pneumonia recurrence. Overall, the prognosis of STAT3 deficiency may be considered good, provided that multiple prophylactic measures, including IgG infusions, are implemented.

The DEFI study has collected clinical data and biological specimens from kindreds with CVID. Patients with demonstrated parental consanguinity (cCVID group) were compared to patients without parental consanguinity (ncCVID). A total of 24 of the 436 patients with CVID had consanguineous parents. Age at first symptoms and age at diagnosis were comparable in the two groups. Some complications were more frequent in cCVID patients: splenomegaly (62.5% vs. 29%; p = 0.001), granulomatous disease (29% vs. 12%; p = 0.02), and bronchiectasis (58% vs. 29%; p = 0.003). A high incidence of opportunistic infections was also observed in this population (29% vs. 5%; p < 0.001). Distribution of B-cell subsets were similar in the two groups. Naïve CD4+ T cells were decreased in cCVID patients (15% vs. 28%; p < 0.001), while activated CD4 + CD95+ (88% vs. 74%; p = 0.002) and CD8 + HLA-DR + T cells (47% vs. 31%; p < 0.001) were increased in these patients when compared to ncCVID patients. Parental consanguinity is associated with an increased risk of developing severe clinical complications in patients with CVID. Most of these patients presented with severe T-cell abnormalities and should be considered with a diagnosis of late-onset combined immune deficiency (LOCID). Systematic investigation for parental consanguinity in patients with CVID provides useful information for specific clinical care and genetic screening.

Background: Common variable immunodeficiency (CVID) is a heterogeneous disorder characterized by recurrent infections and defective immunoglobulin production., Methods: The DEFI French national prospective study investigated peripheral T-cell and B-cell compartments in 313 CVID patients grouped according to their clinical phenotype, using flow cytometry., Results: In patients developing infection only (IO), the main B-cell or T-cell abnormalities were a defect in switched memory B cells and a decrease in naive CD4(+) T cells associated with an increase in CD4(+)CD95(+) cells. These abnormalities were more pronounced in patients developing lymphoproliferation (LP), autoimmune cytopenia (AC), or chronic enteropathy (CE). Moreover, LP and AC patients presented an increase in CD21(low) B cells and CD4(+)HLA-DR(+) T cells and a decrease in regulatory T cells., Conclusion: In these large series of CVID patients, the major abnormalities of the B-cell and T-cell compartments, although a hallmark of CVID, were only observed in half of the IO patients and were more frequent and severe in patients with additional lymphoproliferative, autoimmune, and digestive complications.