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[EN] Primary immunodeficiencies (PIDs) are rare, undiagnosed and potentially fatal diseases. Clinical manifestations of PID can be fatal or leave sequelae that worsen the quality of life of patients. Traditionally, the treatment of PIDs has been largely supportive, with the exception of bone marrow transplantation and, more recently, gene therapy. The discovering of new affected pathways, the development of new molecules and biologics, and the increasing understanding of the molecular basis of these disorders have created opportunities in PIDs therapy. This document aims to review current knowledge and to provide recommendations about the diagnosis and clinical management of adults and children with PIDs based on the available scientific evidence taking in to account current practice and future challenges. A systematic review was conducted, and evidence levels based on the available literature are given for each recommendation where available., [ES] Las inmunodeficiencias primarias (IDP) son unas enfermedades raras, frecuentemente infradiagnosticadas y potencialmente fatales. Las manifestaciones clínicas de las IDP pueden ser muy graves y ocasionar secuelas que empeoran la calidad de vida de los pacientes. Tradicionalmente, el tratamiento de las IDP ha sido fundamentalmente de soporte, con excepción del trasplante de progenitores hematopoyéticos y, más recientemente, la terapia génica. El descubrimiento de nuevos mecanismos patogénicos, el desarrollo de nuevas moléculas y fármacos biológicos y los avances en el conocimiento de las bases moleculares de estas enfermedades han abierto oportunidades para el tratamiento de esta afección. El objetivo de este documento es revisar el conocimiento actual y aportar recomendaciones para el diagnóstico y el tratamiento clínico de los pacientes adultos y pediátricos con IDP basado en la evidencia científica disponible y teniendo en cuenta la actual práctica y los retos futuros. Se realizó una revisión sistemática, que justifica los niveles de evidencia para cada recomendación.

Primary immune regulatory disorders (PIRD) are associated with autoimmunity, autoinflammation and/or dysregulation of lymphocyte homeostasis. Autoimmune lymphoproliferative syndrome (ALPS) is a PIRD due to an apoptotic defect in Fas-FasL pathway and characterized by benign and chronic lymphoproliferation, autoimmunity and increased risk of lymphoma. Clinical manifestations and typical laboratory biomarkers of ALPS have also been found in patients with a gene defect out of the Fas-FasL pathway (ALPS-like disorders). Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), we identified more than 600 patients suffering from 24 distinct genetic defects described in the literature with an autoimmune lymphoproliferative phenotype (ALPS-like syndromes) corresponding to phenocopies of primary immunodeficiency (PID) (NRAS, KRAS), susceptibility to EBV (MAGT1, PRKCD, XIAP, SH2D1A, RASGRP1, TNFRSF9), antibody deficiency (PIK3CD gain of function (GOF), PIK3R1 loss of function (LOF), CARD11 GOF), regulatory T-cells defects (CTLA4, LRBA, STAT3 GOF, IL2RA, IL2RB, DEF6), combined immunodeficiencies (ITK, STK4), defects in intrinsic and innate immunity and predisposition to infection (STAT1 GOF, IL12RB1) and autoimmunity/autoinflammation (ADA2, TNFAIP3,TPP2, TET2). CTLA4 and LRBA patients correspond around to 50% of total ALPS-like cases. However, only 100% of CTLA4, PRKCD, TET2 and NRAS/KRAS reported patients had an ALPS-like presentation, while the autoimmunity and lymphoproliferation combination resulted rare in other genetic defects. Recurrent infections, skin lesions, enteropathy and malignancy are the most common clinical manifestations. Some approaches available for the immunological study and identification of ALPS-like patients through flow cytometry and ALPS biomarkers are provided in this work. Protein expression assays for NKG2D, XIAP, SAP, CTLA4 and LRBA deficiencies and functional studies of AKT, STAT1 and STAT3 phosphorylation, are showed as useful tests. Patients suspected to suffer from one of these disorders require rapid and correct diagnosis allowing initiation of tailored specific therapeutic strategies and monitoring thereby improving the prognosis and their quality of life., his work was supported by grants from Fondo de Investigación Sanitaria (FIS-PI16/2053) to LA and LG-G. The project has been co-financed with FEDER funds. ML-N was co-financed by Fondo Social Europeo, Programa Operativo de empleo juvenil (YEI).

Autoimmune lymphoproliferative syndrome (ALPS) is a primary immune regulatory disorder clinically defined by chronic and benign lymphoproliferation, autoimmunity and an increased risk of lymphoma due to a genetic defect in the FAS-FASL apoptotic pathway. Genetic defects associated with ALPS are germinal and somatic mutations in FAS gene, in addition to germinal mutations in FASLG, FADD, CASP8 and CASP10 genes. The accumulation of CD3+TCRαβ+CD4-CD8- double negative T-cells (DNT) is a hallmark of the disease and 20-25% of ALPS patients show heterozygous somatic mutations restricted to DNT in the FAS gene (ALPS-sFAS patients). Nowadays, somatic mutations in the FAS gene are detected through Sanger sequencing in isolated DNT. In this study, we report an ALPS-sFAS patient fulfilling clinical and laboratory ALPS criteria, who was diagnosed through NGS with a targeted gene panel using DNA from whole blood. Data analysis was carried out with Torrent Suite Software and variant detection was performed by both germinal and somatic variant caller plugin. The somatic variant caller correctly detected other six ALPS-sFAS patients previously diagnosed in the authors’ laboratories. In summary, this approach allows the detection of both germline and somatic mutations related to ALPS by NGS, avoiding the isolation of DNT as the first step. The reads of the somatic variants could be detected even in patients with DNT in the cut off limit. Thus, custom-designed NGS panel testing may be a faster and more reliable method for the diagnosis of new ALPS patients, including those with somatic FAS mutations (ALPS-sFAS).

X-linked Agammaglobulinemia is a primary immunodeficiency caused by mutations in BTK, a tyrosine kinase essential for B lymphocytes differentiation. Patients usually have very low or absent B lymphocytes and are not able to develop humoral specific responses. Here we present a boy, diagnosed with XLA due to a mutation on the promoter region of the gene, whose phenotype is characterised by low percentage of B cells, hypogammaglobulinemia, oscillating neutropenia, antibodies responses to some antigens after vaccination and IgE-mediated allergy. Additional technology as flow cytometry was needed to demonstrate the pathological status of the variant. We focus on the idea that XLA should be suspected in males with B lymphopenia and hypogammaglobulinemia, even if they make humoral specific responses. We also highlight the importance of sequencing BTK's promoter region, as mutations on it can be disease-causing., Genetics; Proteomics; Immunology; Immune disorder; Diagnostics; Primary immunodeficiencies; XLA; Promoter region; Flow cytometry; qPCR.

Use of adoptive immunotherapy with virus-specific T cells (VST) in patients with inborn errors of immunity prior to hematopoietic stem cell transplantation (HSCT) has been reported in few patients. We report our experience, reviewing all the cases previously reported. We report four children with inborn errors of immunity who received VST infusion in a pre-HSCT setting in two reference centers in Spain and review all inborn errors of immunity cases previously reported. Taking into account our four cases, nine children have been reported to receive VST prior to HSCT to date: 3 severe combined immunodeficiency, 2 CTPS1 deficiency, 1 dyskeratosis congenital, 1 ORAI1 deficiency, 1 Rothmund-Thomson syndrome, and 1 combined immunodeficiency without confirmed genetic defect. In four patients, immunotherapy resulted in clinical improvement, allowing to proceed to HSCT. In these cases, the infusion was started closely to viral diagnosis [mean time 28 days (IQR; 17–52 days)], and the VST was followed shortly thereafter by HSCT [mean time 28 days (IQR; 10–99 days)]. Viremia was controlled after HSCT in two cases (performed 7 and 36 days after the infusion). Multiple infusions were required in many cases. Five out of nine patients died before receiving HSCT. These patients presented with a prolonged and uncontrolled infection before VST administration [mean time from viral diagnosis to VST infusion was 176 days (IQR; 54–1687)]. In patients with inborn errors of immunity, the efficacy of VST for treating disseminated viral infections in pre-transplant settings seems to have a limited efficacy. However, this therapy could be used in a pre-emptive setting before severe viral disease occurs or closely to HSCT.

Generalized lymphatic anomaly (GLA) is a vascular disorder characterized by diffuse or multifocal lymphatic malformations (LMs). The etiology of GLA is poorly understood. We identified four distinct somatic PIK3CA variants (Glu542Lys, Gln546Lys, His1047Arg, and His1047Leu) in tissue samples from five out of nine patients with GLA. These same PIK3CA variants occur in PIK3CA-related overgrowth spectrum and cause hyperactivation of the PI3K–AKT–mTOR pathway. We found that the mTOR inhibitor, rapamycin, prevented lymphatic hyperplasia and dysfunction in mice that expressed an active form of PIK3CA (His1047Arg) in their lymphatics. We also found that rapamycin reduced pain in patients with GLA. In conclusion, we report that somatic activating PIK3CA mutations can cause GLA, and we provide preclinical and clinical evidence to support the use of rapamycin for the treatment of this disabling and deadly disease.

During the clinical workup of an adolescent male with chronic active EBV disease, it was noted that natural killer (NK) cells of this individual did not express the Fc-receptor CD16A (Fig 1, A). The index patient, born to nonconsanguineous parents, was first seen when he was 11 years old, and an extended workup revealed persistently high levels of EBV-encoded small RNA (EBER) DNA in peripheral blood and multiple-organ infiltration with EBV-positive T lymphocytes including an IgA- and EBV-positive interstitial nephritis that eventually led to renal failure (see Case Report and Table E1 in this article’s Online Repository at www.jacionline.org)., This work was supported by grants SAF2014-58752-R and SAF2017-83265-R to H.T.R. and grant SAF2016-80363-C2-2-R to C.V. (Spanish Science agency/European Regional Development Fund, European Union, AEI/FEDER, EU). The group of M.V.-G. has also received funding from the Spanish Ministry of Science and Innovation (grant nos. RTC-2017-6379-1 and RTI2018-093569-B-I00 [MCIU/AEI/FEDER, EU]) and the regional government of Madrid (grant no. S2017/BMD-3733-2). The group of M.V.-G. also belongs to the research network TENTACLES (RED2018-102411-T) funded by the Spanish Ministry of Science. A.P.P. and A.B.M. acknowledge PhD studentships funded by the National Secretary of Higher Education, Science, Technology and Innovation (SENESCYT, Ecuador) and Spanish Ministry of Economy and Competitivity (MINECO), respectively (SVP-2014-068263). M.M. was supported by grant GCB15152947MELE from Fundación de la Asociación Española contra el Cáncer. Work in the laboratory of H.H. is supported by Infect-ERA grant TANKACY, BMBF 031L0090, and German Research Foundation (DFG) grant HE2526/9-1. E.L.G. has grants from the Spanish Association Against Cancer (AECC) and Carlos III Health Institute (grant no. PI16/01605). C.A.B. acknowledges support from the National Institutes of Health (grant no. DP2AI11219301).

Autoimmune lymphoproliferative syndrome is a primary immunodeficiency caused by variants in FAS-mediated apoptosis related genes and is characterized by lymphadenopathy, splenomegaly and autoimmunity. A total of six different variants in CASP10 have been described as potential causative of disease, although two of them have recently been considered polymorphisms. The high allele frequency of these variants in healthy population in addition to the broad clinical spectrum of the disease difficult the interpretation of their pathogenicity. Here, we describe the clinical and analytical findings of three new patients carrying variants in CASP10 and summarize 12 more cases from the literature. Autoimmune cytopenias, adenopathies and increment of TCRαβ+CD4-CD8- cells have been the most common findings, being possibly the FAS-mediated apoptosis pathway the pathogenic mechanism of this disease. The clinical impact and the consequences of CASP10 variants are not fully elucidated, therefore the description of new cases will contribute to solve this issue.

Background: Survival of children with combined immunodeficiency is strongly related to patient’s age and clinical situation at the time of hematopoietic stem cell transplantation (HSCT). We describe the clinical features before HSCT or enzyme replacement therapy (ERT) in a cohort of children treated in a National Reference Unit. Methods: A retrospective study of children with CIDs treated in our Hospital during a 20-year period (1995–2014) was performed, analyzing their clinical situation before HSCT/ERT. Results: Thirty-one children were included. Risk factors such as family history or consanguinity were present in 35% of cases, but only 3 children (9%) were initially studied because of family history. Median ages at clinical onset, diagnosis and HSCT/ERT were 3.3, 5.6 and 8.1 months, respectively. All patients had lymphopenia before HSCT/ERT. At the time of admission to our unit, 68% of cases had abnormal lung auscultation, 72% were malnourished, 45% reported chronic gastroenteritis and 35% had hepatosplenomegaly. Before HSCT/ERT, respiratory infections and sepsis episodes were documented in 80% and 42% of cases, respectively. In 23% of children, a viral systemic infection was confirmed. The mortality rate was 35%, and 72% of children who died had Gram-negative bacterial sepsis or a viral infection. Conclusions: The present study shows the characteristics and outcome of children with CIDs in the absence of neonatal screening. Although all our patients had lymphopenia and most of them had suffered relevant infections or had a positive family history, these factors were not identified early. Respiratory and systemic viral infections were the main source of infection with important implications in clinical outcome. Our results highlight the importance of the implementation of neonatal screening, to improve survival rates.

14 p.-5 fig.-5 tab., Supported by grants SAF2014-58752-R and SAF2017-83265-R (to H.T.R.), SAF2017-83785-R (to A.D.-S.; MINECO/AEI/FEDER, UE), and a PhD studentship to A.B.M. (MINECO, SVP-2014-068263). E.L.-G. has grants from the Spanish Association Against Cancer (AECC) and Carlos III Health Institute PI16/01605).

BACKGROUND: Postzygotic de novo mutations lead to the phenomenon of gene mosaicism. The 3 main types are called somatic, gonadal, and gonosomal mosaicism, which differ in terms of the body distribution of postzygotic mutations. Mosaicism has been reported occasionally in patients with primary immunodeficiency diseases (PIDs) since the early 1990s, but its real involvement has not been systematically addressed. OBJECTIVE: We sought to investigate the incidence of gene mosaicism in patients with PIDs. METHODS: The amplicon-based deep sequencing method was used in the 3 parts of the study that establish (1) the allele frequency of germline variants (n = 100), (2) the incidence of parental gonosomal mosaicism in families with PIDs with de novo mutations (n = 92), and (3) the incidence of mosaicism in families with PIDs with moderate-to-high suspicion of gene mosaicism (n = 36). Additional investigations evaluated body distribution of postzygotic mutations, their stability over time, and their characteristics. RESULTS: The range of allele frequency (44.1% to 55.6%) was established for germline variants. Those with minor allele frequencies of less than 44.1% were assumed to be postzygotic. Mosaicism was detected in 30 (23.4%) of 128 families with PIDs, with a variable minor allele frequency (0.8% to 40.5%). Parental gonosomal mosaicism was detected in 6 (6.5%) of 92 families with de novo mutations, and a high incidence of mosaicism (63.9%) was detected among families with moderate-to-high suspicion of gene mosaicism. In most analyzed cases mosaicism was found to be both uniformly distributed and stable over time. CONCLUSION: This study represents the largest performed to date to investigate mosaicism in patients with PIDs, revealing that it affects approximately 25% of enrolled families. Our results might have serious consequences regarding treatment and genetic counseling and reinforce the use of next-generation sequencing-based methods in the routine analyses of PIDs. ispartof: JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY vol:143 issue:1 pages:359-368 ispartof: location:United States status: published

Generalized lymphatic anomaly (GLA) is a vascular disorder characterized by diffuse or multifocal lymphatic malformations (LMs). Here, Rodriguez-Laguna et al. report that somatic activating PIK3CA mutations can cause GLA, and we provide preclinical and clinical evidence to support the use of rapamycin for the treatment of GLA., Generalized lymphatic anomaly (GLA) is a vascular disorder characterized by diffuse or multifocal lymphatic malformations (LMs). The etiology of GLA is poorly understood. We identified four distinct somatic PIK3CA variants (Glu542Lys, Gln546Lys, His1047Arg, and His1047Leu) in tissue samples from five out of nine patients with GLA. These same PIK3CA variants occur in PIK3CA-related overgrowth spectrum and cause hyperactivation of the PI3K–AKT–mTOR pathway. We found that the mTOR inhibitor, rapamycin, prevented lymphatic hyperplasia and dysfunction in mice that expressed an active form of PIK3CA (His1047Arg) in their lymphatics. We also found that rapamycin reduced pain in patients with GLA. In conclusion, we report that somatic activating PIK3CA mutations can cause GLA, and we provide preclinical and clinical evidence to support the use of rapamycin for the treatment of this disabling and deadly disease.

Background The role of viruses in children with respiratory tract infections and humoral immunodeficiencies has hardly been studied. We have evaluated these infections in children with humoral immunodeficiencies who required immunoglobulin replacement therapy, considering their relationship with symptoms, lung function, bacterial co‐infection, and outcomes. Methods We conducted a prospective case‐control study during a 1‐year period, including children with humoral immunodeficiencies receiving immunoglobulin replacement therapy. For each patient, at least one healthy family member was included. Respiratory samples for viral detection were taken every 1‐3 months, and in case of respiratory tract infections. Symptoms questionnaires were filled biweekly. Spirometry and sputum culture were performed in every episode. Results Sixty‐six episodes were analyzed in 14 patients (median age 12 years; IQR 7‐17), identifying 18 respiratory viruses (27.3%), being rhinovirus the most frequently isolated one (12/18; 66%). Positive viral episodes were associated with clinical symptoms (89% vs 43%), more frequent antibiotic treatment (44% vs 15%) or hospital admission (22% vs 0%) than negative ones. Patients with positive viral detection showed impaired lung function, with lower FEV1 and FVC values. Conclusions In our experience, viral respiratory tract infections can cause significant respiratory symptoms and impaired lung function, in children with HID, despite immunoglobulin replacement therapy. These patients could benefit from the monitoring of viral infections, as these may be a gateway for ongoing lung damage.

Heterotrimers composed of B cell CLL/lymphoma 10 (BCL10), mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), and caspase recruitment domain-containing (CARD) family adaptors play a role in NF-κB activation and have been shown to be involved in both the innate and the adaptive arms of immunity in murine models. Moreover, individuals with inherited defects of MALT1, CARD9, and CARD11 present with immunological and clinical phenotypes. Here, we characterized a case of autosomal-recessive, complete BCL10 deficiency in a child with a broad immunodeficiency, including defects of both hematopoietic and nonhematopoietic immunity. The patient died at 3 years of age and was homozygous for a loss-of-expression, loss-of-function BCL10 mutation. The effect of BCL10 deficiency was dependent on the signaling pathway, and, for some pathways, the cell type affected. Despite the noted similarities to BCL10 deficiency in mice, including a deficient adaptive immune response, human BCL10 deficiency in this patient resulted in a number of specific features within cell populations. Treatment of the patient's myeloid cells with a variety of pathogen-associated molecular pattern molecules (PAMPs) elicited a normal response; however, NF-κB-mediated fibroblast functions were dramatically impaired. The results of this study indicate that inherited BCL10 deficiency should be considered in patients with combined immunodeficiency with B cell, T cell, and fibroblast defects.

International audience; Reported synonymous substitutions are generally non-pathogenic, and rare pathogenic synonymous variants may be disregarded unless there is a high index of suspicion. In a case of IL7 receptor deficiency severe combined immunodeficiency (SCID), the relevance of a non-reported synonymous variant was only suspected through the use of additional in silico computational tools, which focused on the impact of mutations on gene splicing. The pathogenic nature of the variant was confirmed using experimental validation of the effect on mRNA splicing and IL7 pathway function. This case reinforces the need to use additional experimental methods to establish the functional impact of specific mutations, in particular for cases such as SCID where prompt diagnosis can greatly impact on diagnosis, treatment, and survival.

Allergy to beta-lactam antibiotics is the most frequent cause of drug-induced immunological reactions, although the prevalence is not exactly known. IgE- and T-cell-dependent responses are the main mechanisms involved, although other immunological mechanisms can also participate, especially in haematological abnormalities, such as immune haemolytic anaemia or thrombocytopoenia. Aside from their frequency, the clinical entities reported nowadays have changed little since penicillin was first used. The variation in beta-lactams consumption through the year has modified the pattern and specificities of allergic reactions for IgE and T cell responses. Benzylpenicillin is no longer the beta-lactams most frequently prescribed and other chemical structures, with new or modified haptens, have progressively replaced it. This is relevant for the diagnostic evaluation and management of beta-lactam hypersensitivity.

La toxicidad pulmonar por amiodarona es un efecto secundario infrecuente pero que puede ser fatal en los pacientes tratados con este farmaco. En la actualidad, el principal problema es que no disponemos de la herramienta necesaria para predecir o detectar que pacientes la van a desarrollar. El KL-6 serico ha sido reconocido como un marcador de actividad de enfermedad intersticial pulmonar difusa. Presentamos el caso de una paciente que desarrollo toxicidad pulmonar por amiodarona con niveles elevados de este nuevo marcador. Se discute la utilidad clinica de esta nueva herramienta diagnostica.

Pulmonary toxicity is an infrequent but serious adverse event in patients treated with amiodarone. The main problem at present is that we lack the necessary tools to detect this event or predict which patients will develop pulmonary toxicity. Serum Krebs von den Lungen-6 (KL-6) has been previously recognized as a marker for the activity of diffuse interstitial lung disease. We describe a patient with pulmonary toxicity due to amiodarone with increased blood levels of this new marker, and discuss the clinical usefulness of this new diagnostic tool.

Summary Background Neuropeptides (NPs) may play an important role in the pathogenesis of atopic dermatitis (AD) by regulating immune responses and contributing to the cross-talk between the immune and nervous systems. Objectives To assess the ability of NPs to influence interleukin (IL)-13 and interferon (IFN)-γ production and the expression of the activation marker HLA-DR in skin memory T cells [cutaneous lymphocyte-associated antigen (CLA)+ T cells] from patients with AD with severe, chronic lesions and intense pruritus, and from nonatopic controls. Methods Cells were cultured in the presence and absence of different NPs, calcitonin gene-related peptide (CGRP), somatostatin (SOM) and substance P (SP). IL-13 and IFN-γ production and HLA-DR expression were measured in both CLA+ and CLA− T-cell subsets by flow cytometry. Results CGRP increased IL-13 production in peripheral blood mononuclear cells from patients with AD (P

Summary Background Heparins can induce delayed-type hypersensitivity (DTH) reactions mediated by specific T lymphocytes. However, the interaction between heparins and lymphocytes has not been sufficiently studied. Objectives To analyse the lymphocyte response to heparins using different types of antigen-presenting cells in patients with DTH reactions to these drugs. Methods We studied seven patients with DTH reactions to heparins diagnosed by delayed reading of intradermal skin testing (n = 5) or drug provocation test (n = 2) and nine tolerant controls. Biopsies were obtained from intradermal testing or during the acute reaction. Peripheral blood mononuclear cells were used to obtain T and B lymphocytes, monocytes and monocyte-derived dendritic cells (DC). T-lymphocyte proliferation was assayed by means of 3H-thymidine incorporation. Results Skin testing showed a high degree of cross-reactivity within low molecular weight heparins with good tolerance to sodium heparin, fondaparinux and lepirudin in most cases. The proliferative response was positive in six patients to most of the heparins tested with both monocytes and B cells (the classical lymphocyte transformation test) or immature DC as antigen-presenting cells, giving a higher response with DC. At a second evaluation 1 year later, the proliferative response was found only with DC, and mainly to the culprit drug. Conclusions A model using DC in the lymphocyte proliferation test is a more appropriate way to assess the immunological response in DTH to heparins; additionally, it can detect a response over a longer time. These findings may be useful for the diagnostic evaluation of drug reactions.

Background Although the involvement of T cells in delayed reactions to drugs has been studied, little is known about the interaction between the drug and the antigen-presenting cells. Dendritic cells (DCs) are professional antigen-presenting cells essential for initiating T-cell responses. Their ability is regulated in a process known as maturation, by which they modulate the effector immune response. Objectives We studied the role of DCs in subjects who had a delayed-type hypersensitivity reaction to amoxicillin to assess the effect on the pattern of maturation and determine the capacity of DCs to activate T lymphocytes. Methods We examined the consequences of the interaction between monocyte-derived DCs, lymphocytes, and amoxicillin by means of phenotypic and functional studies, including endocytosis, proliferation, and cytokine production. Results Amoxicillin drove DCs from hypersensitive subjects to a phenotypic and functional semimature status, inducing a T-cell proliferation response. Conclusions In delayed reactions to amoxicillin, DCs play a relevant role in inducing the T-cell responses. These results are useful not only to understand the mechanism but potentially as a possible approach to diagnosis. Clinical implications A better understanding of T-cell and DC involvement in delayed-type hypersensitivity reactions is needed. This in vitro assay might provide clues to the diagnostic evaluation of patients allergic to penicillins.

OBJECTIVES Autoimmune enteropathy is a rare disorder of unknown pathogenesis, characterized by protracted diarrhea, villous atrophy, and enterocyte autoantibodies. Its association with extended inflammation of the whole gastrointestinal tract is termed as generalized autoimmune gut disorder (GAGD), generally a pediatric disease of difficult management due to its association with immunodeficiency. The aim of our work is to describe the mucosal immunological basis of an adult-onset case of GAGD. METHODS We studied an adult female with a severe inflammatory involvement of the gastrointestinal tract (stomach, small and large bowel, and liver) and antienterocyte autoantibodies. She had antibody deficiency and a predisposition to systemic autoimmunity. We analyzed, by immunohistochemistry and flow cytometry, the phenotypic and functional characteristics of her intestinal intraepithelial and lamina propria (LP) lymphocytes. RESULTS We observed the prominent and constant presence of an unusual CD4+alphaE/beta7- Tc subset in the jejunal epithelium. Signs of the lymphocyte activation as well as the prominent lymphoid TNF-alpha production observed in the rectal mucosa support the involvement of a cell-mediated pro-inflammatory response in the pathogenesis of GAGD. CONCLUSIONS We report the second case of an adult fulfilling all diagnostic criteria for GAGD. We propose that the activated LP CD4+ T lymphocytes, as well as those atypically located in the epithelium, may play a pathogenic role. The alphaE/beta7- IEL could constitute a diagnostic marker of intestinal autoimmunity in the cases when autoantibodies are not evidenced, and mucosal TNF-alpha might represent a novel therapeutic target in this severe disease.

Sarcoidosis is a rare multisystemic granulomatous disease. Pulmonary involvement is common in adults, but any organ can be affected.

Allergic drug reactions can be classified as immediate, accelerated or delayed. This classification usually correlates with the mechanism involved: immediate reactions are IgE mediated and delayed reactions are T cell dependent. We analyzed lymphocyte involvement in patients with these reactions by determining cell subpopulations, activation state and skin homing receptor expression (CLA) in blood and skin. Patients with immediate, accelerated and delayed reactions were evaluated during the acute phase and after resolution. Controls taking drugs were included. Phenotypic immunofluorescence analysis was done by flow cytometry in peripheral blood, and by immunohistochemistry in skin for delayed reactions. Forty-six patients were included, 17 with immediate reactions, 10 accelerated and 19 delayed. At the acute phase CLA was significantly increased in delayed reactions and HLA-DR in all three types of reaction. In the severest delayed reactions, Steven-Johnson/Lyell syndromes, the CD4 subsets were increased in peripheral blood and skin compared to maculopapular exanthemas and urticaria and HLA-DR when compared with urticaria. In maculopapular exanthemas CLA was significantly increased in peripheral blood and skin compared to urticaria and the severe reactions. We found that T-cells are implicated, besides delayed reactions, in immediate and accelerated reactions. In delayed reactions there is a parallelism between results found in skin and peripheral blood with a higher participation of CD4+ cells the more severe the reaction.