Hemolytic anemia following intravenous immunoglobulins in children with PIMS-TS: Two case reports.

This is the first case report on two children presenting with immediate and severe hemolytic anemia following the administration of high-dose intravenous immunoglobulins (IVIGs) in the context of pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS). Hemolytic anemia was described as a significant decrease in hemoglobin and an increase in lactate dehydrogenase after the second administration of high-dose IVIGs was performed. Both patients were found to have AB blood group. One of our patients showed massive pallor, weakness, and inability to walk in association with hemolysis. However, in both cases, the anemia was self-limiting and transfusion of red blood cells was not required: both patients recovered without persistent impact. Nonetheless, we aim to draw attention to this widely unknown adverse effect of IVIG, especially in the context of PIMS-TS. We suggest determining the patient's blood group prior to high-dose IVIG infusion and replacing the second IVIG through high-dose steroids or anticytokine therapy. Using IVIGs containing lower titers of specifically anti-A or anti-B antibodies to avoid isoagglutinin-caused hemolytic anemia is desirable; however, the information is not routinely available.

Use of gene expression profiling to identify candidate genes for pretherapeutic patient classification in acute appendicitis.

BACKGROUND: Phlegmonous and gangrenous appendicitis represent independent pathophysiological entities with different clinical courses ranging from spontaneous resolution to septic disease. However, reliable predictive methods for these clinical phenotypes have not yet been established. In an attempt to provide pathophysiological insights into the matter, a genomewide gene expression analysis was undertaken in patients with acute appendicitis. METHODS: Peripheral blood mononuclear cells were isolated and, after histological confirmation of PA or GA, analysed for genomewide gene expression profiling using RNA microarray technology and subsequent pathway analysis. RESULTS: Samples from 29 patients aged 7-17 years were included. Genomewide gene expression analysis was performed on 13 samples of phlegmonous and 16 of gangrenous appendicitis. From a total of 56 666 genes, 3594 were significantly differently expressed. Distinct interaction between T and B cells in the phlegmonous appendicitis group was suggested by overexpression of T cell receptor α and ß subunits, CD2, CD3, MHC II, CD40L, and the B cell markers CD72 and CD79, indicating an antiviral mechanism. In the gangrenous appendicitis group, expression of genes delineating antibacterial mechanisms was found. CONCLUSION: These results provide evidence for different and independent gene expression in phlegmonous and gangrenous appendicitis in general, but also suggest distinct immunological patterns for the respective entities. In particular, the findings are compatible with previous evidence of spontaneous resolution in phlegmonous and progressive disease in gangrenous appendicitis.

Outcomes of mismatched and unrelated donor hematopoietic stem cell transplantation in Fanconi anemia conditioned with chemotherapy only.

Fanconi anemia (FA) is a genomic instability syndrome associated with bone marrow failure, myelodysplastic syndrome (MDS), and/or acute myeloid leukemia (AML) requiring hematopoietic stem cell transplantation (HSCT) to restore normal hematopoiesis. Although low-intensity fludarabine-based preparative regimens without radiation confer excellent outcomes in FA HSCTs with HLA-matched sibling donors, outcomes for FA patients with alternative donors are less encouraging, albeit improving. We present our experience with 17 FA patients who completed mismatched related or unrelated donor HSCT using a non-radiation fludarabine-based preparative regimen at Charité University Medicine Berlin. All patients engrafted; however, one patient had unstable chimerism in the setting of multi-viral infections that necessitated a stem cell boost to revert to full donor chimerism. Forty-seven percent of patients developed grade I acute graft-verus-host disease (aGVHD). No grade II-IV aGVHD or chronic graft-versus-host disease of any severity occurred. At a median follow-up of 30 months, 88 % of patients are alive with normal hematopoiesis. Two patients died of infections 4 months post-transplantation. These results demonstrate that short-term outcomes for FA patients with mismatched and unrelated donor HSCTs can be excellent using chemotherapy only conditioning. Viral reactivation, however, was a major treatment-related complication.

X-linked inhibitor of apoptosis (XIAP) deficiency: the spectrum of presenting manifestations beyond hemophagocytic lymphohistiocytosis.

X-linked inhibitor of apoptosis (XIAP) deficiency caused by mutations in BIRC4 was initially described in patients with X-linked lymphoproliferative syndrome (XLP) who had no mutations in SH2D1A. In the initial reports, EBV-associated hemophagocytic lymphohistiocytosis (HLH) was the predominant clinical phenotype. Among 25 symptomatic patients diagnosed with XIAP deficiency, we identified 17 patients who initially presented with manifestations other than HLH. These included Crohn-like bowel disease (n=6), severe infectious mononucleosis (n=4), isolated splenomegaly (n=3), uveitis (n=1), periodic fever (n=1), fistulating skin abscesses (n=1) and severe Giardia enteritis (n=1). Subsequent manifestations included celiac-like disease, antibody deficiency, splenomegaly and partial HLH. Screening by flow cytometry identified 14 of 17 patients in our cohort. However, neither genotype nor protein expression nor results from cell death studies were clearly associated with the clinical phenotype. Only mutation analysis can reliably identify affected patients. XIAP deficiency must be considered in a wide range of clinical presentations.

[Interdisciplinary AWMF guideline for the diagnostics of primary immunodeficiency]. / Interdisziplinäre AWMF-Leitlinie zur Diagnostik von primären Immundefekten (S2k).

BACKGROUND: Primary immunodeficiencies are potentially life-threatening diseases. Over the last years, the clinical phenotype and the molecular basis of an increasing number of immunological defects have been characterized. However, in daily practice primary immunodeficiencies are still often diagnosed too late. Considering that an early diagnosis may reduce morbidity and mortality of affected patients, an interdisciplinary guideline for the diagnosis of primary immunodeficiencies was developed on behalf of the Arbeitsgemeinschaft Pädiatrische Immunologie (API) and the Deutsche Gesellschaft für Immunologie (DGfI). METHODS: The guideline is based on expert opinion and on knowledge from other guidelines and recommendations from Germany and other countries, supplemented by data from studies that support the postulated key messages (level of evidence III). With the contribution of 20 representatives, belonging to 14 different medical societies and associations, a consensus-based guideline with a representative group of developers and a structured consensus process was created (S2k). Under the moderation of a representative of the Association of the Scientific Medical Societies in Germany (AWMF) the nominal group process took place in April 2011. RESULTS: The postulated key messages were discussed and voted on following a structured consensus procedure. In particular, modified warning signs for primary immunodeficiencies were formulated and immunological emergency situations were defined.

Hyperbilirubinemia and rapid fatal hepatic failure in severe combined immunodeficiency caused by adenosine deaminase deficiency (ADA-SCID).

Adenosin deaminase (ADA) deficiency is the cause for Severe Combined Immunodeficiency (SCID) in about 15% of patients with SCID, often presenting as T (-)B (-)NK (-)SCID. Treatment options for ADA-SCID are enzyme replacement, bone marrow transplantation or gene therapy. We here describe the first patient with ADA-SCID and fatal hepatic failure despite bone marrow transplantation from a 10/10 HLA identical related donor. As patients with ADA-SCID may be at yet underestimated increased risk for rapid hepatic failure we speculate whether hepatitis in ADA-SCID should lead to the immediate treatment with enzyme replacement by pegylated ADA.

Delayed onset of (severe) combined immunodeficiency (S)CID (T-B+NK+): complete IL-7 receptor deficiency in a 22 months old girl.

BACKGROUND: Usually IL-7 receptor deficiency presents as (T-B+NK+) (Severe) Combined Immunodeficiency (SCID) within the first six months of life. All published IL-7R-deficient patients so far have been diagnosed and received stem cell transplantation within the first year of life. PATIENT AND METHODS: We present a female patient born to non-consanguineous German parents with delayed manifestation. She presented with superinfected dermatitis at 6 months of life and developed a first pneumonia at age 9 months. On admission to our department at 22 months the patient presented with severe T cell lymphopenia. PNEUMOCYSTIS JIROVECI pneumonia was diagnosed from broncho-alveolar lavage fluid. RESULTS: Sequencing of IL7RA in the patient revealed compound heterozygous mutations. FACS analysis showed no expression of IL-7 receptor alpha-chain on the patient's lympho- and monocytes. The patient successfully received haematopoietic stem cell transplantation from a 9/10 matched unrelated donor at age 24 months. CONCLUSION: [corrected] Despite almost absent T cell functions clinical symptoms occurred late compared to previously published patients. Thus even in patients with moderate clinical symptoms and delayed onset a (T-B+NK+) (Severe) Combined Immunodeficiency ((S)CID)) due to missing IL-7 receptor signalling must be considered.

[Genetic predisposition and children infectious disease]. / Prédisposition génétique et infections de l'enfant.

The classic primary immunodeficiencies confer predisposition to multiple infectious diseases. However since ten years severe pediatric infections which were idiopathic have now molecular explanation. Indeed, defects in several genes confer a predisposition to infection with specific pathogenes in otherwise healthy individuals. These children present a new kind of hereditary immunodeficiency with severe and/or recurrent infections caused by only one microorganisms family, in opposition of others patients with "classic" primary immunodeficiency.

An interleukin-2-IgG-Fas ligand fusion protein suppresses delayed-type hypersensitivity in mice by triggering apoptosis in activated T cells as a novel strategy for immunosuppression.

BACKGROUND: Cell-mediated immune responses can be down-regulated by induction of apoptosis of immunoreactive lymphocytes. In the present study, we have tested the feasibility of a strategy for immunosuppression by the selective induction of apoptosis in activated, interleukin (IL)-2 receptor-positive lymphocytes, using a triple IL-2-IgG-FasL fusion protein. The IL-2-IgG-FasL fusion protein combines IL-2 for the selection of activated T cells, with the extracellular domain of the FasL molecule for inducing T-cell apoptosis. These components were separated by the Fc part of IgG1 serving as a spacer as well as for half-life prolongation. METHODS: The gene for the chimeric protein was created by fusing DNA sequences encoding for the three functional components: human IL-2, the Fc part of human IgG1, and the extracellular domain of murine FasL. When the fusion gene was expressed in murine J558L cells, we obtained soluble dimeric immunoglobulin-like proteins in the supernatant. After analyzing the function of the IL-2 and FasL portions individually in vitro, a delayed-type hypersensitivity (DTH) reaction to sheep red blood cells as model for cell-mediated immune responses was investigated to evaluate the IL-2-IgG-FasL-mediated immunosuppression in vivo. RESULTS: In vitro, the IL-2-IgG-FasL fusion protein supported IL-2-dependent proliferation of Fas-resistant CTLL-2 cells, whereas concanavalin A-T blasts were induced to undergo apoptosis by the FasL portion. In vivo, this fusion protein potently inhibited a murine DTH. This was associated with an increased rate of apoptosis in activated lymphocytes in the spleen, even at very low doses of the fusion protein. Furthermore, a second antigen challenge 10 days after IL-2-IgG-FasL treatment still failed to elicit a DTH response. CONCLUSION: The abrogation of a standard T cell-dependent immune response in vivo demonstrates that IL-2-IgG-FasL can be successfully exploited to trigger the death of deleterious T cells, presenting a potentially useful strategy in the management of autoimmune diseases and allotransplant rejections.

Vaccination with tumor cells engineered to secrete interleukin 2-immunoglobulin G fusion protein induces tumor rejection.

Here we provide proof that the injection of tumor cells engineered to secrete interleukin 2 (IL-2)-IgG chimeric proteins locally induces potent antitumor responses, which are more effective than tumor transfection with IL-2 alone. Murine plasmacytoma cells (J558L) were stably transfected with DNA coding for a human IL-2-IgG1 or a murine IL-2-IgG2b fusion protein and were injected s.c. into syngeneic BALB/c mice. Evaluation of tumor growth and rejection patterns showed that IL-2-IgG secretion by transfected J558L tumor cells induced their rejection in all animals tested, similar to the rejection of J558L cells engineered to secrete IL-2 alone, whereas treatment with parental cells was lethal. However, mice treated with IL-2-IgG-secreting J558L cells (human IL-2-IgG1 and murine IL-2-IgG2b) exhibited a significantly stronger tumor immunity against a later challenge with parental J558L cells than mice treated with IL-2-secreting tumor cells.

Perinatal hypoxia and bioelectric brain maturation of the newborn infant.

Bioelectric brain maturation of twenty infants who had suffered acute perinatal hypoxia (patients) was compared with that of twenty healthy newborns (controls). None of the patients had suffered any other pre- or perinatal complications that could have influenced the bioelectric brain maturation. All infants (postmenstrual age: 40--42 weeks) were subjected to a polygraphic recording. The patients were examined after the acute phase of their disease; all were in good clinical condition at the time of recording. Statistic evaluation revealed significantly retarded bioelectric brain maturation in the patient group. Furthermore, a more immature EEG pattern was found to correspond to greater extent of oxygen deprivation. The study shows: determination of bioelectric brain maturation can be used to obtain information about suffered hypoxia and extent of oxygen deprivation.

[Aicardi-syndrome (author's transl)]. / Das Aicardi-Syndrom

The main features of Aicardi's syndrome are infantile spasms, defects of the corpus callosum, chorioretinopathy, mental subnormality, characteristic EEG changes, vertebral anomalies, microphthalmos and colobomata. The disease affects only the female sex. 2 cases are described from our own experience.