EuroFlow Standardized Approach to Diagnostic Immunopheneotyping of Severe PID in Newborns and Young Children

The EuroFlow PID consortium developed a set of flow cytometry tests for evaluation of patients with suspicion of primary immunodeficiency (PID). In this technical report we evaluate the performance of the SCID-RTE tube that explores the presence of recent thymic emigrants (RTE) together with T-cell activation status and maturation stages and discuss its applicability in the context of the broader EuroFlow PID flow cytometry testing algorithm for diagnostic orientation of PID of the lymphoid system. We have analyzed peripheral blood cells of 26 patients diagnosed between birth and 2 years of age with a genetically defined primary immunodeficiency disorder: 1

Hematopoietic stem cell transplantation for CD40 ligand deficiency: results from an EBMT/ESID-IEWP-SCETIDE-PIDTC Study

BACKGROUND: CD40 ligand (CD40L) deficiency, an X-linked primary immunodeficiency, causes recurrent sinopulmonary, Pneumocystis and Cryptosporidium infections. Long-term survival with supportive therapy is poor. Currently, the only curative treatment is hematopoietic stem cell transplantation (HSCT). OBJECTIVE: We performed an international collaborative study to improve patients' management, aiming to individualize risk factors and determine optimal HSCT characteristics. METHODS: We retrospectively collected data on 130 patients who underwent HSCT for CD40L deficiency between 1993-2015. We analyzed outcome and variables relevance with respect to survival and cure. RESULTS: Overall survival (OS), event-free survival (EFS) and disease-free survival (DFS) were 78.2%, 58.1% and 72.3% 5 years post-HSCT. Results were better in transplants performed ≥2000 and in children <10 years old at HSCT. Pre-existing organ damage negatively influenced outcome. Sclerosing cholangitis was the most important risk factor. After 2000, superior OS was achieved with matched donors. Use of myeloablative regimens and HSCT ≤2 years from diagnosis associated with higher OS and DFS. EFS was best with matched sibling donors, myeloablative conditioning (MAC) and bone marrow-derived stem cells. Most rejections occurred after reduced intensity or non-myeloablative conditioning, which associated with poor donor cell engraftment. Mortality occurred mainly early after HSCT, predominantly from infections. Among survivors who ceased immunoglobulin replacement, T-lymphocyte chimerism was ≥50% donor in 85.2%. CONCLUSION: HSCT is curative in CD40L deficiency, with improved outcome if performed before organ damage development. MAC is associated with better OS, EFS and DFS. Prospective studies are required to compare risks of HSCT with those of life-long supportive therapy

Occurrence of intestinal microsporidia in immunodeficient patients in Poland

Microsporidial infections may be asymptomatic in immunocompetent hosts, but can be severe and disseminated in HIV/AIDS patients, children, the elderly, or in immunocompromised individuals, including those with primary or medically-induced immunodeficiencies. 209 faecal samples were collected from 80 clinical patients, with or without abdominal symptoms, and tested for the presence of the parasites. Microsporidia were found in 10 of the 80 patients (12.5%) using trichrom staining of faecal smears and/or PCR. [i]Encephalitozoon[/i] intestinalis and 1 unidentified species were identified in 2 of the 32 children with primary immunodeficiencies (6%), presenting with diarrhoea, including one co-infection with [i]Cryptosporidium meleagridis[/i]. In the group of patients with medically-induced immunosuppression (transplant recipients), 8 of the 48 patients (17%) were tested positive for microsporidia. Thus, these pathogens should be taken into account when the other etiological agents cannot be found in diarrheic patients with PIDs or undergoing immunosuppressive treatment before or after transplantation. This article presents the results of the first epidemiological study on the ccurrence and prevalence of microsporidia in patients with primary and secondary immunodeficiency in Poland

A novel radiosensitive SCID patient with a pronounced G(2)/M sensitivity

V(D)J rearrangement in lymphoid cells involves repair of double-strand breaks (DSBs) through nonhomologous end joining (NHEJ). Defects in this process lead to increased radiosensitivity and severe combined immunodeficiency (RS-SCID). Here, a SCID patient, M3, is described witha-T-B+NK+ phenotype but without causative mutations in CD3 delta, epsilon, zeta or IL7R alpha, genes specifically involved in T cell development. Clonogenic survival of M3 fibroblasts showed an increased sensitivity to the DSB-inducing agents ionizing radiation and bleomycin, as well as the crosslinking compound, mitomycin C. We did not observe inactivating mutations in known NHEJ genes and results of various DSB-repair assays in G(1) M3 cells were indistinguishable from those obtained with normal cells. However, we found increased chromosomal radiosensitivity at the G(2) phase of the cell cycle. Checkpoint analysis indicated functional G(1)/S and intra-S checkpoints after irradiation but impaired activation of the "early" G(2)/M checkpoint. Together these results indicate a novel class of RS-SCID patients characterized by the specific absence of T lymphocytes and associated with defects in G(2)-specific DSB repair. The pronounced G(2)/M radiosensitivity of the RS-SCID patient described here, suggests a defect in a putative novel and uncharacterized factor involved in cellular DNA damage responses and T cell development. (C) 2009 Elsevier B.V. All rights reserved