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BACKGROUND: Inborn errors of immunity (IEI) are rare diseases, which makes diagnosis a challenge. A better description of the initial presenting manifestations should improve awareness and avoid diagnostic delay. Although increased infection susceptibility is a well-known initial IEI manifestation, less is known about the frequency of other presenting manifestations.OBJECTIVE: We sought to analyze age-related initial presenting manifestations of IEI including different IEI disease cohorts.METHODS: We analyzed data on 16,486 patients of the European Society for Immunodeficiencies Registry. Patients with autoinflammatory diseases were excluded because of the limited number registered.RESULTS: Overall, 68% of patients initially presented with infections only, 9% with immune dysregulation only, and 9% with a combination of both. Syndromic features were the presenting feature in 12%, 4% had laboratory abnormalities only, 1.5% were diagnosed because of family history only, and 0.8% presented with malignancy. Two-third of patients with IEI presented before the age of 6 years, but a quarter of patients developed initial symptoms only as adults. Immune dysregulation was most frequently recognized as an initial IEI manifestation between age 6 and 25 years, with male predominance until age 10 years, shifting to female predominance after age 40 years. Infections were most prevalent as a first manifestation in patients presenting after age 30 years.CONCLUSIONS: An exclusive focus on infection-centered warning signs would have missed around 25% of patients with IEI who initially present with other manifestations.

Intrathecal production of kappa free light chains occurs in multiple sclerosis and can be measured using the kappa free light chain index. Kappa free light chain index values can be determined more easily than oligoclonal bands detection and seem more sensitive than the immunoglobulin (Ig)G index to diagnose multiple sclerosis. We assessed the value of oligoclonal bands, kappa free light chain index cut-offs 5.9, 6.6 and 10.61, and IgG index to diagnose multiple sclerosis with prospectively acquired data from a clinically isolated syndrome inception cohort. We selected patients with sufficient data to determine oligoclonal bands positivity, MRI dissemination in space and time, IgG index and sufficient quantities of paired CSF and blood samples to determine kappa free light chain indexes (n = 214). We used Kendall’s Tau coefficient to estimate concordance, calculated the number of additional diagnoses when adding each positive index to dissemination in space and positive oligoclonal bands, performed survival analyses for oligoclonal bands and each index with the outcomes second attack and 2017 MRI dissemination in space and time and estimated the diagnostic properties of oligoclonal bands and the different indexes for the previously mentioned outcomes at 5 years. Oligoclonal bands were positive in 138 patients (64.5%), kappa free light chain-5.9 in 136 (63.6%), kappa free light chain-6.6 in 135 (63.1%), kappa free light chain-10.61 in 126 (58.9%) and IgG index in 101 (47.2%). The highest concordance was between oligoclonal bands and kappa free light chain-6.6 (τ = 0.727) followed by oligoclonal bands and kappa free light chain-5.9 (τ = 0.716). Combining dissemination in space plus oligoclonal bands or kappa free light chain-5.9 increased the number of diagnosed patients by 11 (5.1%), with kappa free light chain-6.6 by 10 (4.7%), with kappa free light chain-10.61 by 9 (4.2%) and with IgG index by 3 (1.4%). Patients with positive oligoclonal bands or indexes reached second attack and MRI dissemination in space and time faster than patients with negative results (P < 0.0001 except IgG index in second attack: P = 0.016). In multivariable Cox models [adjusted hazard ratio (95% confidence interval)], the risk for second attack was very similar between kappa free light chain-5.9 [2.0 (0.9–4.3), P = 0.068] and kappa free light chain-6.6 [2.1 (1.1–4.2), P = 0.035]. The highest risk for MRI dissemination in space and time was demonstrated with kappa free light chain-5.9 [4.9 (2.5–9.6), P < 0.0001], followed by kappa free light chain-6.6 [3.4 (1.9–6.3), P < 0.0001]. Kappa free light chains-5.9 and -6.6 had a slightly higher diagnostic accuracy than oligoclonal bands for second attack (70.5, 71.1 and 67.8) and MRI dissemination in space and time (85.7, 85.1 and 81.0). Kappa free light chain indexes 5.9 and 6.6 performed slightly better than oligoclonal bands to assess multiple sclerosis risk and in terms of diagnostic accuracy. Given the concordance between oligoclonal bands and these indexes, we suggest using dissemination in space plus positive oligoclonal bands or positive kappa free light chain index as a modified criterion to diagnose multiple sclerosis.

Limfòcits b; Metilació de l'ADN; Genoma Linfocitos b; Metilación de ADN; Genoma B-lymphocytes; DNA methylation; Genome Activation-induced deaminase (AID) initiates antibody diversification in germinal center B cells by deaminating cytosines, leading to somatic hypermutation and class-switch recombination. Loss-of-function mutations in AID lead to hyper-IgM syndrome type 2 (HIGM2), a rare human primary antibody deficiency. AID-mediated deamination has been proposed as leading to active demethylation of 5-methycytosines in the DNA, although evidence both supports and casts doubt on such a role. In this study, using whole-genome bisulfite sequencing of HIGM2 B cells, we investigated direct AID involvement in active DNA demethylation. HIGM2 naïve and memory B cells both display widespread DNA methylation alterations, of which ∼25% are attributable to active DNA demethylation. For genes that undergo active demethylation that is impaired in HIGM2 individuals, our analysis indicates that AID is not directly involved. We demonstrate that the widespread alterations in the DNA methylation and expression profiles of HIGM2 naïve B cells result from premature overstimulation of the B-cell receptor prior to the germinal center reaction. Our data support a role for AID in B cell central tolerance in preventing the expansion of autoreactive cell clones, affecting the correct establishment of DNA methylation patterns. Spanish Ministry of Science, Innovation and Universities [SAF2017-88086-R to E.B.]; cofunded by FEDER funds/European Regional Development Fund (ERDF)—a way to build Europe. E.B is supported by Instituto de Salud Carlos III (ISCIII), Ref. AC18/00057, associated with i-PAD project (ERARE European Union program); P.L. and C.P. are supported by the German Cancer Aid project CO-CLL [70113869]; B.G. is funded by the Deutsche Forschungsgemeinschaft [GR1617/14-1/iPAD, SFB1160/2_B5, RESIST–EXC 2155–Project ID 390874280, CIBSS–EXC-2189–Project ID 390939984]; BMBF [GAIN 01GM1910A]. Funding for open access charge: Spanish Ministry of Science, Innovation and Universities [SAF2017-88086-R].

Monoallelic loss-of-function mutations in NFKB1 were recently recognized as the most common monogenic cause of common variable immunodeficiency (CVID). The prototypic clinical phenotype of NFKB1-deficient patients includes common CVID features, such as hypogammaglobulinaemia and sinopulmonary infections, plus other highly variable individual manifestations. Here, we describe a patient with a profound CVID phenotype and severe gastrointestinal manifestations, including chronic and recurrent diarrhoea. Using an NGS customized panel of 323 genes related to primary immunodeficiencies, we identified a novel monoallelic loss-of-function mutation in NFKB1 leading to a truncated protein (c.1149delT/p.Gly384Glu ∗ 48). Interestingly, we also found a rare variant in NOD2 previously associated with Crohn's disease (p.His352Arg). Our patient had hypogammaglobulinaemia with a small number of B cells, most of which were naive. The most noteworthy findings included marked skewing towards a Th1 phenotype in peripheral blood T cells and excessive production of proinflammatory cytokines (IL-1β, TNFα). The patient's 6-year-old daughter, a carrier of the NFKB1 mutation, is clinically asymptomatic, but has started to show cellular and molecular changes. This case of NFKB1 deficiency appears to be a combination of immunodeficiency and a hyperinflammatory state. The current situation of the patient's daughter provides a glimpse of the preclinical phase of the condition.

Primary immunodeficiency disorders (PIDs) are often associated with autoimmune disease due to the dysregulation of the immune system and distributed central and peripheral tolerance. In many inborn immune deficiencies, lymphocytes may be present but they are dysfunctional, allowing for the development of excessive autoreactivity skipping negative selection process and resultant autoimmune disease. This chapter summarizes the clinical approaches to the main immune dysregulations including hemophagocytic lymphohistiocytosis syndromes, autoimmunity with lymphoproliferation and autoimmunity without lymphoproliferation.

Before the availability of gene therapy, bone marrow transplantation was the only available option for primary immunodeficiency diseases This case demonstrates that long-term follow up is required even when grafting is complete, as the complete recovery of cellular immunity and humoral function occurs only in 50–60% of patients Although partial immunity function is sufficient to prevent complications for some time, immunodeficiency may develop later in life due to the immunosenescence of the graft

Mutations in activation induced deaminase (AID) lead to hyper-IgM syndrome type 2 (HIGM2), a rare human primary antibody deficiency. AID-mediated cytosine deamination has been proposed as mediating active demethylation, although evidences both support and cast doubt on such a role. We here made use of HIGM2 B cells to investigate direct AID involvement in active DNA demethylation. HIGM2 naïve and memory B cells both display widespread DNA methylation defects, of which approximately 25% of these defects correspond to active events. For genes that undergo active demethylation that is impaired in HIGM2 individuals, we did not observe AID involvement but a participation of TET enzymes. DNA methylation alterations in HIGM2 naïve B cells are related to premature overstimulation of the B-cell receptor prior to the germinal center reaction. Our data supports a role for AID in B cell central tolerance in preventing the expansion of autoreactive cell clones, affecting the correct establishment of DNA methylation patterns.

Majority of patients with familial Mediterranean fever (FMF) become symptomatic before 10 years of age and up to 90% experience attacks before the age of 20

Background and aim To diagnose coeliac disease (CD) in individuals on a gluten free diet (GFD), we aimed to assess the utility of detecting activated γδ and CD8 T cells expressing gut-homing receptors after a short gluten challenge. Methods We studied 15 CD patients and 35 non-CD controls, all exposed to three days of gluten when following a GFD. Peripheral blood was collected before and six days after starting gluten consumption, and the expression of CD103, β7 and CD38 in γδ and CD8 T cells was assessed by flow cytometry. Determination of IFN-γ and IP-10 was performed by means of ELISPOT and/or Luminex technology. Results We observed both γδ and CD8 T cells coexpressing CD103, β7hi and CD38 in every patient with CD on day six, but only in one control. The studied CD8 T subpopulation was easier to detect than the γδ subpopulation. Increased IFN-γ and IP-10 levels after challenge were observed in patients with CD, but not in controls. Conclusion A short three-day gluten challenge elicits the activation of CD103+ β7hi CD8+ T cells in CD. These cells can be detected by flow cytometry in peripheral blood, opening new possibilities for CD diagnosis in individuals on a GFD.

FLC is a recognized biomarker used for monitoring response and outcome of patients with amyloidosis and oligosecretory and non-secretory MM. Nevertheless, the role of FLC in the early prediction of response to the treatment in patients with gammopathies has not been fully ascertained. Against this background, we have evaluated the relationship between early FLC detection and the achievement of a deep and prolonged response after the end of the treatment in a series of patients diagnosed with MM and homogeneously treated in a single institution. Eighty-six newly diagnosed patients with MM between 2011 and January 2018 at the University Hospital Vall d'Hebron treated front-line with a bortezomib-based scheme were retrospectively analyzed. All patients had FLC levels measured by the Freelite® nephelometric assay at diagnosis, after the 2nd cycle of therapy, and at the end of treatment. Different parameters related to the FLC measurement were evaluated: normalization of the involved FLC (iFLC), ratio of involved/uninvolved FLCs (R_FLC)95% compared to the baseline, and normalization of the ratio Kappa/lambda FLC (R_K/L). The predictive value of these parameters on the response after chemotherapy treatment was evaluated by using the Pearson´s exact test, and their impact on outcomes was analyzed by Kaplan Meier method using the long rank test for comparisons. The median age of the series at diagnosis was 69 years old (45-89). Forty-seven patients (55%) were considered candidate for autologous hematopoietic stem cell transplantation, therefore receiving induction treatment with the VTD combination (bortezomib-talidomide-dexametasone). In contrast, 39 patients (45%) were not candidate for autologous transplantation and were treated with MPV (melfalan-prednisone-bortezomib). The involved Ig was IgG in 54.7% of cases, IgA in 18.6%, IgD in 1.2% and IgM in 1.2%. Twenty-four percent of patients were diagnosed with MM of light chains (12% kappa and 12% lambda), whereas only 3 patients were diagnosed as having a oligosecretory MM. Twenty-nine percent of the cases were ISS III, 33% had increased serum LDH levels, and 79% showed immunoparesis. The kappa FLC mean at diagnosis was 1603.61 mg/dL (0.06 -36100 mg/dL) and lambda FLC was 1104 mg/dL (0.05-26500 mg/dL). Kappa FLC mean after 2nd cicle was of 192.14 mg/dL (1,61-6430 mg/dL) and lambda FLC was 61.41 mg/dL (0.05-1434 mg/dL). Thrirty-seven percent of patients obtained a profound response (≥VGPR) after the 2nd cycle of therapy, being this percentage increased to 63% of patients at the end of the chemotherapy treatment. Alongside this, the normalization of the iFLC was observed after the 2nd cycle of treatment in 44% of patients, the normalization of the R_K/L in 42%, R_FLC95% was observed in 57% of patients. The great majority (80-87%) of patients attaining the normalization of any of these parameters after the 2nd cycle experienced a response ≥VGPR at the end of the treatment (table 1). With a median follow-up of 28.2 months (7-84 months), the overall PFS of the series was of 26.7 months. Of note, median PFS was of 40.3 months for patients who achieved the normalization of the iFLC after the 2nd cycle vs. 24.6 months for those who did not (p=0.047) (figure 1). Moreover, PFS was 27.3 months for those who had R_FLC95% exhibited a trend for a longer PFS (40.3 vs. 23.5 months) (p=0.09), as those patients with normalization of R_K/L who presented a PFS of 40.3 vs. 26.5 months (p=0.099). In conclusion, patients with normalization of different parameters related to FLC at 2 months of the onset of treatment exhibit a deeper and prolonged response to bortezomib-based chemotherapies, suggesting that this assessment could be of paramount interest in the early prediction of outcomes in patients with MM receiving treatment. Therefore, early FLC determinations should be incorporated into prospective clinical trials to validate these observations. Disclosures No relevant conflicts of interest to declare.

Celiac disease (CD) is a complex immune-related disease with a very strong genetic component. Multiple genetic findings over the last decade have added to the already known MHC influence numerous genetic variants associated to CD susceptibility. Currently, it is well-established that 6 MHC and 39 non-MHC loci, including a higher number of independent genetic variants, are associated to disease risk. Moreover, additional regions have been recently implicated in the disease, which would increase the number of involved loci. Together, the firmly described genetic variants account for roughly 31% of CD heritability, being 25% explained by the MHC influence. These new variants represent markers of disease risk and turn the identification of the causal genes and the causal variants inside the associated loci, as well as their precise biological role on the disease, into a major challenge in CD research. Numerous studies have been developed with this aim showing the high impact of risk variants on gene expression. These studies also indicate a central role of CD4(+) T cells in CD pathogenesis and point to B cells as important players, which is in accordance with the key steps highlighted by the immunological models of pathogenesis. We comprehensively summarize the current knowledge about the genetic architecture of CD, characterized by multiple low-risk variants located within diverse loci which are most likely affecting genes with immune-related functions. These findings are leading to a better understanding of CD pathogenesis and helping in the design of new treatments. The repertoire of potential drug targets for CD has largely broadened last years, bringing us closer to get alternative or complementary treatments to the life-long gluten-free diet, the only effective treatment so far. Epigenetics and microbiota are emerging as potent factors modulating disease risk and putatively affecting disease manifestation, which are also being explored as therapeutic targets.

Recent findings demonstrate the common genetic basis for many immune-mediated diseases, and consequently, the partially shared pathogenesis. We collected these findings and reviewed the extension of these overlaps to other disease characteristics. Two autoimmune diseases were selected that also share the specific target organ, the bowel. The etiology and immunopathogenesis of both conditions characterized by chronic intestinal inflammation, inflammatory bowel disease (IBD) and celiac disease (CeD), are not completely understood. Both are complex diseases with genetics and environment contributing to dysregulation of innate and adaptive immune responses, leading to chronic inflammation and disease. CeD constitutes a particular disease because the main environmental and genetic triggers are largely known. IBD comprises two main clinical forms, Crohn's disease and ulcerative colitis, which most likely involve a complex interplay between some components of the commensal microbiota and other environmental factors in their origin. These multifactorial diseases encompass a broad spectrum of clinical phenotypes and ages of onset, although the clinical presentation often differs depending on childhood or adult onset, with greater heterogeneity commonly observed in adults.