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Objective To assess the effect of the average adjusted global APS score (aGAPSS) over time on recurrence of clinical manifestations in APS patients through a retrospective longitudinal study. Material and methods The study included 200 patients with APS. The aGAPSS was calculated for each patient at baseline and on a yearly basis for either up to 6 years (minimum 3 years) or just before the clinical event in patients who experienced clinical recurrence. The mean score per patient was computed. In patients under vitamin K antagonists (VKA) the percentage of time spent within the therapeutic range (TTR) was calculated. Cox regression analysis was performed to determine the cut-off value of the aGAPSS with the strongest association with clinical recurrence. Results Higher average aGAPSS values were found in patients who experienced clinical recurrence in comparison to patients who did not [8.81 (95% CI 7.53, 10.08) vs 6.38 (95% CI 5.64, 7.12), P = 0.001], patients with thrombotic recurrence compared with patients with obstetric recurrence [9.48 (95% CI 8.14, 10.82) vs 4.25 (95% CI 0.85, 7.65), P = 0.006] and patients with arterial thrombosis compared with patients with venous thrombosis [10.66 (S.D. 5.48) vs 6.63 (S.D. 4.42), P = 0.01]. aGAPSS values >13 points were associated with the highest risk of recurrence in multivariate analysis [HR = 3.25 (95% CI 1.93, 5.45), P Conclusions Our data support the role of periodic (annual) monitoring of the aGAPSS score in predicting clinical recurrence in patients with APS.

To analyze the antiphospholipid antibody (aPL) persistence over time in patients with antiphospholipid syndrome (APS) and its association with clinical recurrence and to identify predictors of aPL persistence over time.200 patients with a diagnosis of APS and at least three follow-up aPL determinations were included. Persistent aPL profile was defined as the presence of lupus anticoagulant (LAC) and/or IgG/IgM anticardiolipin (aCL) and/or IgG/IgM anti-β2 glycoprotein-I (aβ2GPI) (99th percentile) antibodies in at least 66% of follow-up measurements. Multilevel mixed-effect generalized linear models with logit link were used.112 (56%) patients maintained persistent aPL profiles over time, while 88 (44%) were transient. Median follow-up time was 172.5 months. Follow-up time did not affect the odds of aPL persistence in multivariate analysis (p = 1.00). Baseline triple aPL positivity [OR 78 (95%CI 16.9-359.7, p 0.001)] and double aPL positivity [OR = 7.6 (95%CI 3.7-15.7, p 0.001)] correlated with persistent aPLs over time, while isolated LAC [OR = 0.26 (95% CI 0.08-0.49, p = 0.002)] or isolated IgG/IgM aCL [OR = 0.20 (95% CI 0.11-0.59, p = 0.004)] positivity, were predictors of transient aPL profile. Patients with persistent aPLs had higher rate of clinical recurrence in comparison to patients with transient aPLs [OR = 2.48 (95%CI 1.34-4.58, p = 0.003)].More than half of patients with baseline medium-high titer aPL positivity had persistent positive aPLs over time. Patients with persistent aPLs were more prone to present recurrence of clinical manifestations. Multiple aPL positivity increased the odds of a persistent aPL profile over time, while isolated LAC and aCL positivity decreased it.

Background and aims Recent studies have found an increase in the seroprevalence of hepatitis E virus (HEV) infection in patients with autoimmune hepatitis (AIH). We aimed to assess the prevalence of positive anti-HEV IgM and IgG, and HEV-RNA in a cohort of patients with AIH, to determine the impact of positive HEV serology on patient outcome, and to evaluate the role of hypergammaglobulinemia and positive autoantibodies in the presence of positive anti-HEV serology. Methods One hundred and five patients tested for HEV infection between 2014 and 2018 were included in the study: 50 with chronic AIH (more than 1 year on treatment), and 55 with an acute hepatitis (30 patients with acute AIH and 25 with non-AIH). Results Seroprevalence of HEV was higher in patients with acute AIH (17% vs 10% in patients with chronic AIH and 8% in patients with non-AIH). Patients with acute AIH and positive anti-HEV IgG were older (58 vs 40; P = .006), had higher IgG levels (27 g/dL vs 13 g/dL; P = .03) and antismooth muscle antibodies (ASMA) titres (1:160 vs 1:80; P = .045), and were more likely to have another autoimmune disease (60% vs 16%; P = .03). At the time of HEV testing, anti-HEV IgG positive patients had significantly higher serum IgG levels (17 g/L vs 11 g/L; P = .009), ANA (1:160 vs 1:60; P = .026) and ASMA titres (1:80 vs 1:40; P = .021). Conclusion Seroprevalence of HEV in patients with AIH in Catalonia does not differ from that of the general population. The higher HEV seroprevalence in patients with acute AIH with higher levels of gammaglobulins and high antibody titres suggest the presence of cross-reactivity between HEV and liver antigens.

Background: Recurrence of immunoglobulin (Ig)A nephropathy (rIgAN) is a growing cause of kidney allograft dysfunction. This study was aimed at investigating factors associated with rIgAN and the subsequent progression to end-stage renal disease (ESRD). Methods: Retrospective study including consecutive patients with IgA nephropathy (IgAN) who received a kidney transplant in our center between 1992 and 2016 and had a renal biopsy by clinical indication. The date of detection of chronic kidney disease (CKD) 5 was used as renal outcome. Results: Eighty-six kidney transplants were performed in patients with IgAN, 38 (44%) were from living donors (related n = 26). rIgAN was diagnosed in 23 allografts (27%). Renal function and proteinuria at the end of the follow-up period were worst in the rIgAN patients compared to those without rIgAN (2.2 vs. 1.4 mg/dL, p = 0.014, and 1.16 vs. 0.49 g/day, p = 0.005, respectively). Risk of rIgAN and progression to CKD 5 decreased with patient’s age (hazard ratio [HR] 0.95, 95% CI 0.92–0.98, p = 0.002, and HR 0.97, 95% CI 0.83–0.97, p = 0.008 per year, respectively). Patients with rIgAN had a higher risk of progression to CKD 5 (HR 6.7, 95% CI 1.3–35.7, p = 0.025). Full donor-recipient mismatch in the human leukocyte antigen (HLA)-B loci decreased the risk of rIgAN (HR 0.22, 95% CI 0.06–0.76, p = 0.017). Conclusions: rIgAN was an independent risk factor for ESRD after renal allograft. Younger age increased the risk of rIgAN and CKD 5. Conversely, HLA-B mismatching was a potential protective factor for rIgAN of this glomerular disease.

Background and Aims Anti-glomerular basement membrane (anti-GBM) disease is an aggressive and rare glomerulopathy characterized by rapidly progressive loss of kidney function, leading to end stage kidney disease (ESKD) in a significant amount of cases. The main objective of our study was to determine whether anti-GBM titer correlated with the rate of activity in renal biopsy and long-term kidney survival in patients with anti-GBM, hence identifying patients who would potentially benefit from more intensive treatments. Method A retrospective analysis was performed on the cases of anti-GBM from our center that had both a positive biopsy and serology, from 2007 to 2019. Epidemiological data, anti-GBM levels on admission, kidney function at admission, discharge and follow-up, treatment and kidney biopsy findings were collected. All biopsies were reevaluated by a single, blinded pathologist and nephrologist. Based on a recent study by van Daalen et al, a chronicity and activity histopathological score was developed. The score was divided in glomerular and interstitial sections. In the glomerular section, a sclerotic pattern (>50% of glomeruli) was given 0 points in activity and 3 in chronicity, a mixed pattern was given 1 point in activity and chronicity, and a crescentic pattern (>50% with cellular crescents) was given 3 points in activity and 0 in chronicity. In the interstitial section, the presence of fibrosis and atrophy was given between 0 and 3 points in chronicity and the presence of tubulitis or interstitial infiltrate were given points in activity (0 to 1 and 0 to 3 respectively). The presence of neutrophils in the infiltrate was given one extra point in activity. Spearman correlation was performed between anti-GBM levels and our biopsy score. Results Twelve cases were identified, with a median Anti-GBM titer at admission of 292 U/mL (IQR 40-1517). Ten patients were treated with cyclophosphamide, 1 with rituximab plus cyclophosphamide and 1 with only rituximab. All patients received treatment with metilprednisona and plasma exchange with a median number of sessions of 8 (range: 6-12). Only one patient was not in ESKD during follow-up (35 months), so correlation with long-term kidney survival could not be performed. On the other hand, high antibody titers correlated with more activity on biopsy (correlation coefficient 0.592, p= 0.042) and less chronicity (correlation coefficient -0.657, p= 0.02). Conclusion These results suggest that patients who present with higher titers have more acute inflammation and less chronicity in renal parenchima, and therefore could benefit from more intensive treatment that changes the natural history of this aggressive disease. It would be interesting to study this score in larger and multicentric cohorts in order to produce more definitive conclusions.

Monogenic autoinflammatory diseases (AIFD) are rare disorders characterized by an uncontrolled increase of the systemic inflammatory response, which is caused by mutations in genes involved in inflammatory pathways. Over the last few years, new genes and proteins responsible for new monogenic AIFD have been identified and a substantial improvement in their treatment has been achieved. Monogenic AIFD manifestations typically begin during childhood, but they can also occur in adults. Compared to pediatric patients, adults usually present with a less severe disease and fewer long-term complications. In addition, patients with adult-onset disease carry low-penetrance mutations more often than pathogenic variants. A late-onset of AIFD may be occasionally associated with the presence of somatic mutations. In this study, we review the most frequent monogenic AIFD, and others recently described, which may occur during adulthood.

Juvenile idiopathic arthritis (JIA) is a complex rheumatic disease with both autoimmune and autoinflammatory components. Recently, familial cases of systemic-onset JIA have been attributed to mutations in LACC1/FAMIN. We describe three affected siblings from a Moroccan consanguineous family with an early-onset chronic, symmetric and erosive arthritis previously diagnosed as rheumatoid factor (RF)-negative polyarticular JIA. Autozygosity mapping identified four homozygous regions shared by all patients, located in chromosomes 3, 6 (n:2) and 13, containing over 330 genes. Subsequent whole exome sequencing identified two potential candidate variants within these regions (in FARS2 and LACC1/FAMIN). Genotyping of a cohort of healthy Moroccan individuals (n: 352) and bioinformatics analyses finally supported the frameshift c.128_129delGT mutation in the LACC1/FAMIN gene, leading to a truncated protein (p.Cys43Tyrfs*6), as the most probable causative gene defect. Additional targeted sequencing studies performed in patients with systemic-onset JIA (n:23) and RF-negative polyarticular JIA (n: 44) revealed no pathogenic LACC1/FAMIN mutations. Our findings support the homozygous genotype in the LACC1/FAMIN gene as the defect underlying the family here described with a recessively inherited severe inflammatory joint disease. Our evidences provide further support to the involvement of LACC1/FAMIN deficiency in different types of JIA in addition to the initially described systemic-onset JIA., The authors would like to thank the CRG Genomics Unit for assistance with whole exome sequencing. This work has been partially funded by: CERCA Programme/Generalitat de Catalunya (JIA, XE, SO), the PERIS program of the Generalitat de Catalunya grant SLT002/16/00310 (RR), the Spanish Ministry of Economy and Competitiveness co-financed by European Regional Development Fund (ERDF) grant SAF2015-68472-C2-1-R (JIA), the Instituto de Salud Carlos III/Transnational Research Projects on Rare Diseases (JIA) grant AC15/00027, the Spanish Society of Pediatric Rheumatology (JIA), the Secretaria d’Universitats i Recerca del Departament d’Economia grant 2009-SGR-1502 (XE) and the European Union Seventh Framework Programme (FP7/2007-2013) grant agreement no. 262055 (XE). We also acknowledge support of the Spanish Ministry of Economy and Competitiveness (MEIC) to the EMBL partnership, ‘Centro de Excelencia Severo Ochoa’.

Objective Gain-of-function NLRP3 mutations cause cryopyrin-associated periodic syndrome (CAPS), with gene mosaicism playing a relevant role in the pathogenesis. This study was undertaken to characterize the genetic cause underlying late-onset but otherwise typical CAPS. Methods We studied a 64-year-old patient who presented with recurrent episodes of urticaria-like rash, fever, conjunctivitis, and oligoarthritis at age 56 years. DNA was extracted from both unfractionated blood and isolated leukocyte and CD34+ subpopulations. Genetic studies were performed using both the Sanger method of DNA sequencing and next-generation sequencing (NGS) methods. In vitro and ex vivo analyses were performed to determine the consequences that the presence of the variant have in the normal structure or function of the protein of the detected variant. Results NGS analyses revealed the novel p.Gln636Glu NLRP3 variant in unfractionated blood, with an allele frequency (18.4%) compatible with gene mosaicism. Sanger sequence chromatograms revealed a small peak corresponding to the variant allele. Amplicon-based deep sequencing revealed somatic NLRP3 mosaicism restricted to myeloid cells (31.8% in monocytes, 24.6% in neutrophils, and 11.2% in circulating CD34+ common myeloid progenitor cells) and its complete absence in lymphoid cells. Functional analyses confirmed the gain-of-function behavior of the gene variant and hyperactivity of the NLRP3 inflammasome in the patient. Treatment with anakinra resulted in good control of the disease. Conclusion We identified the novel gain-of-function p.Gln636Glu NLRP3 mutation, which was detected as a somatic mutation restricted to myeloid cells, as the cause of late-onset but otherwise typical CAPS. Our results expand the diversity of CAPS toward milder phenotypes than previously reported, including those starting during adulthood.

Objective Blau syndrome is characterized by noncaseating granulomatous arthritis, dermatitis, and uveitis, and results from gain-of-function NOD2 mutations. This study was undertaken to identify the genetic cause of the disease in a family with 3 members with Blau syndrome. Methods We studied a family with 3 affected members across 2 consecutive generations. The children's symptoms started early (at 6 and 7 months of age) and included polyarthritis, dermatitis, uveitis, and fever. In contrast, the father's symptoms started later (at 22 years of age) and included noncaseating granulomatous dermatitis and uveitis. We analyzed the NOD2 gene in all patients by both the Sanger method of DNA sequencing and amplicon-based deep sequencing using an Ion Torrent PGM platform. Results Sanger chromatograms revealed the heterozygous c.1001G>A transition in both children, which resulted in the p.Arg334Gln mutation that causes Blau syndrome. In contrast, the father's chromatograms revealed a small peak of adenine at the c.1001 position, suggesting the presence of a somatic NOD2 mutation. To evaluate this hypothesis, we performed amplicon-based deep sequencing using DNA from different tissues, which confirmed a variable degree (0.9–12.9%) of somatic NOD2 mosaicism. The previous detection of the NOD2 mutation in his daughters strongly suggests the presence of gonosomal (somatic plus gonadal) NOD2 mosaicism in the father. Comparative analyses with Blau syndrome patients carrying the germline p.Arg334Gln NOD2 mutation revealed late onset of the disease, a mild inflammatory phenotype, and an absence of complications in patients with NOD2 mosaicism. Conclusion This is the first description of gonosomal NOD2 mosaicism as the cause of intrafamilial recurrence of Blau syndrome. Our findings also indicate that Blau syndrome includes more diverse and milder phenotypes than previously described.

Monogenic autoinflammatory diseases (AIFD) are rare disorders characterized by an uncontrolled increase of the systemic inflammatory response, which is caused by mutations in genes involved in inflammatory pathways. Over the last few years, new genes and proteins responsible for new monogenic AIFD have been identified and a substantial improvement in their treatment has been achieved. Monogenic AIFD manifestations typically begin during childhood, but they can also occur in adults. Compared to paediatric patients, adults usually present with a less severe disease and fewer long-term complications. In addition, patients with adult-onset disease carry low-penetrance mutations more often than pathogenic variants. A late-onset of AIFD may be occasionally associated with the presence of somatic mutations. In this study, we review the most frequent monogenic AIFD, and others recently described, which may occur during adulthood.

Aparició en l'adult; Malalties autoinflamatòries; Variants de baixa penetrància Aparición en el adulto; Enfermedades autoinflamatorias; Variantes de baja penetrancia Adult onset; Autoinflammatory diseases; Low-penetrance variants Background: Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is an autosomal-dominant autoinflammatory disease caused by mutations in the TNFRSF1A gene. R92Q, a low-penetrance variant, is usually associated with a milder TRAPS phenotype than structural or pathogenic mutations. No studies differentiating R92Q-related disease in patients with pediatric and adult onset have been performed to date. Objective: To analyze clinical features and disease outcomes in patients diagnosed with TRAPS associated with R92Q variant and to investigate differences between patients with pediatric and adult disease onset. Methods: A retrospective review of patients with R92Q-related disease from four reference centers for autoinflammatory diseases was performed. Clinical and laboratory features, family history of autoinflammatory diseases, treatments received, and outcomes during follow-up were recorded and separately analyzed in pediatric and adult patients. Our results were included in the analysis with other reported pediatric and adult R92Q-related disease series. Results: Our series encompassed 18 patients (9 females and 9 males) with R92Q variant. In 61% of patients, disease onset occurred during infancy and in 39%, during adulthood, with a median diagnostic delay of 5 years and a follow-up of 5.4 years. A positive family history of autoinflammatory disease was detected in 28% of patients. All patients presented with febrile recurrent episodes. Other common symptoms included arthralgia/arthritis (61%), myalgia (39%), asthenia/fatigue (44%), abdominal pain (39%), headache (33%), odynophagia (33%), skin rash (28%), and chest pain (22%). During attacks, 80% of patients increased acute phase reactants levels. No patient had developed amyloidosis during the study period. At the end of follow-up, 28% of patients were asymptomatic and treatment free, 50% were receiving non-steroidal anti-inflammatory drugs or glucocorticoids on demand, and 22% were being treated with biologic agents. When differences between pediatric and adult patients were globally analyzed, adults tended to have longer attacks duration and presented more frequently with chest pain and headache, while abdominal pain, vomiting, cervical adenitis, and pharyngitis predominated in pediatric patients. No differences in outcomes and treatment requirements were observed in both age groups. Conclusion: This study has contributed to characterize R92Q-related disease by identifying trends in disease phenotypes depending on the age at disease onset. This study has been supported by Ministerio de Economía y Competitividad (SAF 14/57708-R) and co-funded by Fondo Europeo de Desarrollo Regional (FEDER), Unión Europea, and Una manera de hacer Europa (JH-R).

Celiac disease (CD) is a complex autoimmune disorder caused by ingestion of gluten in genetically susceptible individuals. Different genetic risk factors have been identified, but virtually all patients are human leukocyte antigen (HLA)-DQ2 and/or HLA-DQ8 positive. We describe a new, fast, accurate and simple real-time polymerase chain reaction (PCR)-based assay for the genotyping and homozygosity analysis of the CD-related HLA alleles. The assay overcomes the major limitations of protocols currently in use, allowing HLA-DQ2/DQ8 genotyping by using only three real-time PCR reactions. For the appraisal of DQ2 homozygosity, only one more reaction is needed. These reactions are easily automated and suitable for large screening studies in diagnostic procedures, as it is demonstrated by their successful application in our HLA diagnostic laboratory. Finally, we assessed the clinical relevance of this real-time PCR-based assay by studying a cohort of fully characterized patients. As expected, all CD patients had at least one of the CD-associated alleles, and the highest CD risk was indicated by the presence of the HLA-DQ2.5 heterodimer (HLA-DQA1*05-DQB1*02) with HLA-DQB1*02 in homozygosity.

Assembly of the NLRP3 inflammasome activates caspase-1 and mediates the processing and release of the leaderless cytokine IL-1β and thereby serves a central role in the inflammatory response and in diverse human diseases. Here we found that upon activation of caspase-1, oligomeric NLRP3 inflammasome particles were released from macrophages. Recombinant oligomeric protein particles composed of the adaptor ASC or the p.D303N mutant form of NLRP3 associated with cryopyrin-associated periodic syndromes (CAPS) stimulated further activation of caspase-1 extracellularly, as well as intracellularly after phagocytosis by surrounding macrophages. We found oligomeric ASC particles in the serum of patients with active CAPS but not in that of patients with other inherited autoinflammatory diseases. Our findings support a model whereby the NLRP3 inflammasome, acting as an extracellular oligomeric complex, amplifies the inflammatory response.

International audience; MyD88 is a key downstream adapter for most Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs). MyD88 deficiency in mice leads to susceptibility to a broad range of pathogens in experimental settings of infection. We describe a distinct situation in a natural setting of human infection. Nine children with autosomal recessive MyD88 deficiency suffered from life-threatening, often recurrent pyogenic bacterial infections, including invasive pneumococcal disease. However, these patients were otherwise healthy, with normal resistance to other microbes. Their clinical status improved with age, but not due to any cellular leakiness in MyD88 deficiency. The MyD88-dependent TLRs and IL-1Rs are therefore essential for protective immunity to a small number of pyogenic bacteria, but redundant for host defense to most natural infections.

Cryopyrin-associated periodic syndromes (CAPS) usually start during infancy as an urticarial-like rash and a marked acute phase response, with additional manifestations appearing during its evolution. The aim of this study was to expand the clinical diversity of CAPS by the description of novel atypical features.Clinical data were collected from patients' medical charts. Sanger sequencing analyzed NLRP3. Response to anti-IL-1 blockade was evaluated by clinical assessments and by measurements of laboratory parameters.Seventeen patients from two families (A and B), carrying the p.Ala439Thr and p.Arg260Trp NLRP3 mutations respectively, were enrolled. The disease was unexpectedly atypical in all members of Family A, with a 16-year-old asymptomatic carrier, and onset in adulthood associated with absence of skin lesions in four affected members. Surprisingly, one patient from each family suffered from severe haemorrhagic cystitis due to AA amyloidosis in the urinary bladder. Members of Family B displayed a classical phenotype, with two patients suffering from olfactive disorders.Our evidence suggests that CAPS may occasionally be presented as a late-onset, recurrent inflammatory disease without urticarial-like rash. In some patients, AA amyloidosis in strange locations like urinary bladder may complicate the clinical course. The response to IL-1 blockade in these atypical CAPS was similar to that described in classical forms. Consequently, we suggest that CAPS should be included in the differential diagnosis of adult patients with unexplained, recurrent inflammatory diseases, and once confirmed, the early initiation of anti-IL-1 blockade will probably prevent the development of life-threatening complications.

Gain-of-function NLRP3 mutations cause cryopyrin-associated periodic syndrome (CAPS), with gene mosaicism playing a relevant role in the pathogenesis. This study was undertaken to characterize the genetic cause underlying late-onset but otherwise typical CAPS.We studied a 64-year-old patient who presented with recurrent episodes of urticaria-like rash, fever, conjunctivitis, and oligoarthritis at age 56 years. DNA was extracted from both unfractionated blood and isolated leukocyte and CD34+ subpopulations. Genetic studies were performed using both the Sanger method of DNA sequencing and next-generation sequencing (NGS) methods. In vitro and ex vivo analyses were performed to determine the consequences that the presence of the variant have in the normal structure or function of the protein of the detected variant.NGS analyses revealed the novel p.Gln636Glu NLRP3 variant in unfractionated blood, with an allele frequency (18.4%) compatible with gene mosaicism. Sanger sequence chromatograms revealed a small peak corresponding to the variant allele. Amplicon-based deep sequencing revealed somatic NLRP3 mosaicism restricted to myeloid cells (31.8% in monocytes, 24.6% in neutrophils, and 11.2% in circulating CD34+ common myeloid progenitor cells) and its complete absence in lymphoid cells. Functional analyses confirmed the gain-of-function behavior of the gene variant and hyperactivity of the NLRP3 inflammasome in the patient. Treatment with anakinra resulted in good control of the disease.We identified the novel gain-of-function p.Gln636Glu NLRP3 mutation, which was detected as a somatic mutation restricted to myeloid cells, as the cause of late-onset but otherwise typical CAPS. Our results expand the diversity of CAPS toward milder phenotypes than previously reported, including those starting during adulthood.

Mevalonate kinase deficiency (MKD) is a recessively-inherited autoinflammatory condition caused by loss-of-functionMVK mutations. This gene encodes for the enzyme mevalonate kinase (MVK), which catalyzes a crucial step of the biosynthetic pathway of cholesterol and isoprenoids. The partial deficiency of enzymatic activity causes the Hyper-IgD and periodic fever syndrome (HIDS), whereas it complete deficiency provokes the Mevalonic Aciduria (MA).

Introduction Autoinflammatory diseases (AID) are usually diagnosed during the pediatric age. However, adult-onset disease or diagnosis during adulthood has been occasionally described. Objectives To assess the clinical and genetic characteristics of adult patients diagnosed with an AID in an adult referral center for AID. Methods We retrospectively evaluated clinical and genetic features of adult patients (≥ 16 years) diagnosed with an AID or referred after AID diagnosis to the Clinical Unit of AID, at the Department of Autoimmune Diseases, Hospital Clinic of Barcelona, from 2008 to 2014. Results During the study period, a genetic study for suspected AID was requested to 90 patients at the Department of Autoimmune Diseases. A final diagnosis of monogenic AID was achieved in 17 patients (19% of patients tested). Five additional cases were diagnosed with periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome and 10 patients with AID were referred from other adult departments. Finally, a total of 32 patients with AID were finally diagnosed or monitored in our Clinical Unit. These included 12 (37.5%) familial Mediterranean fever, 6 (18.8%) tumour necrosis factor-receptor associated periodic syndrome, 8 (25%) cryopirin-associated periodic syndromes (Muckle–Wells syndrome [MWS] or overlap familial cold-associated periodic syndrome/MWS), 1 (3.1%) mevalonate kinase deficiency, and 5 (15.6%) PFAPA. Clinical evidence of disease-onset during childhood and adulthood was observed in 15 (47%) and 17 (53%) patients, respectively. Overall, the final diagnosis was obtained after a delay of a mean of 12 years (range 0–47 years). Compared to children, adult patients with AID in our series presented more frequently with non-severe manifestations and none of them developed amyloidosis during follow-up. Adult patients also carried higher proportion of low-penetrance mutations or polymorphisms and all genetic variants were presented in heterozygosis or as heterozygous compounds. Conclusions Adult disease-onset or delayed diagnosis of AID during adulthood is associated with milder disease phenotypes, and seem to be driven by mild genotypes, with predominant presence of low-penetrance mutations or polymorphisms.

To the Editor: Blau syndrome (BS) is a dominant inherited autoinflammatory disease caused by gain-of-function NOD2 mutations and characterized by the triad of granulomatous arthritis, dermatitis, and uveitis.1 We identified a 17-year-old patient with a clinical diagnosis of BS (see pedigree in Fig 1, A, and a complete clinical description in this article’s Online Repository at www.jacionline.org). Sanger NOD2 sequencing using DNA from total leukocytes did not detect disease-causing mutations (Fig 1, B). A careful analysis of Sanger chromatograms revealed at c.1001 position (Ref Seq: {"type":"entrez-nucleotide","attrs":{"text":"NM_022162.1","term_id":"11545911","term_text":"NM_022162.1"}}NM_022162.1) a very small peak of adenine associated with a subtle decrease in the wild-type allele (Fig 1, C). This potential c.1001G>A transition might provoke the appearance of the p.Arg334Gln NOD2 variant, which is a well-known BS-causing mutation.1–4 A selective allele amplification was reasonably ruled out by the heterozygous c.802C>T transition in the same amplicon (Fig 1, D), which is a common polymorphism of the gene (rs2066842; allele frequency of 13% in the 1000 Genomes Project Phase 1). These data suggested the presence of a somatic NOD2 mosaicism. To address this issue, we performed targeted deep NOD2 sequencing using DNA extracted from hematological and nonhematological tissues (see this article’s Methods section in the Online Repository at www.jacionline.org). These analyses detected the p.Arg334Gln NOD2 mutation in all analyzed samples, with variable frequencies (4.9% to 11.0%) depending on the cells’ origin (Table I). The NOD2 mutation was not detected in the patient’s parents, confirming its de novo nature. FIG 1 A, Family’s pedigree. B, Genomic organization of the NOD2 gene (top) and scheme of the pair of primers designed to analyze the exon 4 (below) (green arrows represent the pair primers used for PCR amplification and Sanger sequencing, while white ... TABLE I Summary of NOD2 genotyping performed in different family members The patient’s phenotype was compared with those detected in patients with BS carrying germline NOD2 mutations. Differences were detected only in the joint involvement, which included the number of affected joints (oligoarthritis in our patient in place of polyarthritis in most patients with germline mutations), the type of affected joints (absence of involvement of small joints in our patient), and the absence of tenosynovitis and joint deformities in our patient (see Table E1 in this article’s Online Repository at www.jacionline.org). Genetic mosaicism describes an individual with 2 or more cell types with different genotypes that derive from the same zygote. This implies the occurrence of de novo, postzygotic mutational event(s) that may occur either during embryogenesis or after birth.5 Somatic mosaicism has been extensively studied in cancer, but its role in Mendelian inherited diseases has scarcely been reported. The arrival of next-generation sequencing technologies is providing evidence of its relevance in this field. Among the monogenic autoinflammatory diseases, somatic mosaicism has been well established in cryopyrinopathies and in stimulator of interferon genes-associated vasculopathy with onset in infancy.6–8 In the present work, the use of next-generation sequencing technologies enabled us to detect a well-known NOD2 mutation as a somatic mutation at low frequencies in all analyzed tissues. To our knowledge, this evidence represents the first description of somatic NOD2 mosaicism in the pathogenesis of BS, thus expanding the number of monogenic diseases in which this mechanism can play an important role. This evidence also enabled us to confirm the BS diagnosis and support the idea that a de novo mutational event affecting the NOD2 gene occurred in this patient, probably at an early stage during embryogenesis because tissues from different embryonal layers are equally affected. The involvement of somatic NOD2 mosaicism in BS may have relevant clinical consequences. During the past few years, the clinical diversity of BS has increased as the number of diagnosed patients has increased. Thus, we currently know that some patients never developed some of the symptoms of the classical triad, whereas other patients developed symptoms beyond the triad.4,9 The phenotype of the patient described here resembles that detected in patients with BS affected exclusively with the triad, although differences in the articular involvement should be highlighted. Our patient developed seronegative oligoarthritis affecting exclusively large joints, with no tenosynovitis or joint deformities, whereas most patients with BS carrying germline NOD2 mutations suffered from polyarthritis (95% in the International BS Registry), always associated with tenosynovitis, involving both large and small joints, which often progressed to joint deformities (42.8% in the Spanish BS cohort).1,4,9 It could be speculated that the apparent less severe articular disease observed in our patient could be a direct consequence of the low-level somatic mosaicism. The description of the joint disease in novel patients carrying somatic NOD2 mosaicism will probably confirm or invalidate our observation. Sporadic patients with BS with negative NOD2 analysis have been previously reported.1,3 This scenario is similar to that previously described for cryopyrinopathies, in which the use of different genetic technologies finally detected somatic NLRP3 mosaicism.6,7 The evidence shown here supports the possibility that “mutation-negative” patients with BS could actually be carriers of somatic NOD2 mosaicism, and its definitive diagnosis probably relies on the use of novel genetic technologies. In our experience, targeted deep sequencing is probably the most efficient method to identify low-level mosaicism and will be the recommended method to address this issue in future studies. In addition, it could be hypothesized that the candidates in whom to evaluate the presence of somatic NOD2 mosaicism had probably been previously diagnosed with juvenile idiopathic arthritis (JIA), especially in the forms of systemic-onset and seronegative polyarthritis and oligoarthritis. Future studies with selected candidates from these JIA subgroups will provide evidence regarding the validity of this hypothesis. The tissue distribution of the mosaicism could vary between different patients and is often difficult to analyze comprehensively. The potential tranmission of the somatic mutation to the offspring relies on its presence in the germ cells. In the case of patients with BS with germline NOD2 mutation, this probability is 50%. In our patient, it was not possible to calculate this probability because, for ethical reasons, we were unable to analyze the degree of gonadal mosaicism. In the case that the vertical transmission occurred, the NOD2 mutation will be present at the first zygote. Consequently, the child will carry a germline mutation and it is conceivable that his or her phenotype will be even more severe than that observed in patients carrying a somatic mutation. In conclusion, the evidence described here shows for the first time the involvement of somatic NOD2 mosaicism in the pathogenesis of BS. This opens the possibility that this genetic mechanism underlies additional patients previously diagnosed as BS or as JIA. Because of the potential clinical consequences, further studies are needed to confirm this hypothesis.

Familial cold autoinflammatory syndrome, Muckle-Wells syndrome (MWS), and chronic, infantile, neurological, cutaneous and articular (CINCA) syndrome are dominantly inherited autoinflammatory diseases associated to gain-of-function NLRP3 mutations and included in the cryopyrin-associated periodic syndromes (CAPS). A variable degree of somatic NLRP3 mosaicism has been detected in approximate to 35% of patients with CINCA. However, no data are currently available regarding the relevance of this mechanism in other CAPS phenotypes. Objective To evaluate somatic NLRP3 mosaicism as the disease-causing mechanism in patients with clinical CAPS phenotypes other than CINCA and NLRP3 mutation-negative. Methods NLRP3 analyses were performed by Sanger sequencing and by massively parallel sequencing. Apoptosis-associated Speck-like protein containing a CARD (ASC)-dependent nuclear factor kappa-light chain-enhancer of activated B cells (NF-kappa B) activation and transfection-induced THP-1 cell death assays determined the functional consequences of the detected variants. Results A variable degree (5.5-34.9%) of somatic NLRP3 mosaicism was detected in 12.5% of enrolled patients, all of them with a MWS phenotype. Six different missense variants, three novel (p.D303A, p.K355T and p.L411F), were identified. Bioinformatics and functional analyses confirmed that they were disease-causing, gain-of-function NLRP3 mutations. All patients treated with anti-interleukin1 drugs showed long-lasting positive responses. Conclusions We herein show somatic NLRP3 mosaicism underlying MWS, probably representing a shared genetic mechanism in CAPS not restricted to CINCA syndrome. The data here described allowed definitive diagnoses of these patients, which had serious implications for gaining access to anti-interleukin 1 treatments under legal indication and for genetic counselling. The detection of somatic mosaicism is difficult when using conventional methods. Potential candidates should benefit from the use of modern genetic tools.

Cryopyrin-associated periodic syndromes (CAPS) are a group of dominantly inherited disorders caused by gain-of-function NLRP3 mutations. These disorders represent different degrees of severity of a same disease being familial cold autoinflammatory syndrome the milder form, Muckle-Wells syndrome an intermediate form and chronic infantile neurologic cutaneous and articular syndrome the severest form. Overlapping phenotypes among these diseases have been also reported. Here we describe two different Spanish families with atypical presentation for CAPS. The initial NLRP3 screening, which only included the analysis of exon 3, was negative. However, the complete gene analysis revealed two novel missense mutations in exon 1 and 8, respectively.

Cryopyrin-associated periodic syndromes (CAPS) usually present in early childhood as an urticaria-like skin rash associated with an increased inflammatory response, with additional manifestations (i.e. arthropathy, AA amyloidosis or deafness) typically restricted to certain phenotypes. CAPS are caused by dominantly inherited or de novogain-of-functionNLRP3 mutations. The introduction of next-generation sequencing (NGS) into clinics has revealed the important role of somatic NLRP3 mosaicism in these syndromes by means of its detection in a high proportion of patients who were apparently mutation-negative by Sanger sequencing. Thus, NGS technologies are becoming essential for routinely identifying the genetic cause of the suspected autoinflammatory disease.

Cryopyrin-associated periodic syndromes (CAPS) are rare autoinflammatory diseases caused by dominantly inherited or de novo gain-of-function NLRP3 mutations. They include familial cold autoinflammatory syndrome, Muckle-Wells syndrome and chronic infantile neurological, cutaneous and articular syndrome.1 The NLRP3 gene encodes cryopyrin, a key component of the cytosolic complex termed inflammasome, which generates the active form of interleukin (IL)-1s. Previous studies showed an uncontrolled IL-1s overproduction in CAPS, representing the basis from which to treat these patients with IL-1 blockade.1–3 The important role of somatic NLRP3 mutations in CAPS has been recently shown.4 However, as occurs in most Mendelian diseases, no data are available concerning the presence of low-level somatic NLRP3 mosaicism in parents of CAPS patients. To address this issue we performed massively parallel DNA …

We identified a consanguineous Moroccan family with three affected siblings diagnosed with rheumatoid factor-negative polyarticular juvenile idiopathic arthritis. They all suffered from an early-onset (2-4 years-old) chronic and symmetric polyarthritis affecting both large and small joints. The joint involvement was markedly erosive in two siblings, with the older sister requiring hip prosthetic replacement at the age of 18 years. None of the patients had fever, skin rash, uveitis or other extra-articular manifestations. Laboratory analyses revealed leukocytosis, thrombocytosis, severe anaemia, marked increase of inflammatory markers and negative results for rheumatoid factor, anti-nuclear antibodies and HLA-B27.

Monogenic autoinflammatory diseases are a group of genetic conditions characterized by a dysregulation of inflammatory response that include more than 20 diseases. Despite the fact that they are different clinical entities, several signs and symptoms are shared, making their differential diagnosis difficult. Moreover, in most cases, a definitive diagnosis is exclusively achieved by a positive genetic study. The need to analyze different genes makes this process costly in terms of both time and money. The arrival of next generation sequencing into clinics can overcome these problems.

Gene mosaicism describes an individual who has developed from a single zygote and has two or more cell types with distinct genotypes. Three major types of mosaicism have been described and are referred as gonadal, somatic and gonosomic mosaicism. They mainly differ on the body distribution of the somatic mutation and in their clinical consequences. The recent use of next-generation sequencing technologies is revealing the relevant role of gene mosaicism in various diseases other than cancer, including monogenic autoinflammatory diseases such as cryopyrinopathies and STING-associated vasculopathy with onset in infancy [1-3].

Systemic AA amyloidosis is a life-threatening complication of different chronic infectious and inflammatory diseases. The deposition of amyloid fibrils derived from the serum amyloid A (SAA) protein represents its pathological hallmark. A long lasting and increased serum level of SAA is a prerequisite to its development. The group of inherited autoinflammatory diseases includes different disorders consequence of a genetically-determined dysregulation of innate immune system. All these diseases are associated with a marked acute phase response. The incidence of AA amyloidosis varies widely among them, with the higher incidence in Muckle-Wells syndrome and in TNF receptor-associated periodic syndrome. Inversely, no cases of AA amyloidosis have been reported in some few inherited autoinflammatory diseases, including Blau syndrome, a dominantly-inherited disease caused by NOD2 mutations.

Loss-of-function mutations in the IL36RN gene define a novel recessively inherited autoinflammatory syndrome named deficiency of IL-36 receptor antagonist (DITRA). This genetically determined deficiency was first described in a subgroup of patients with generalized pustular psoriasis. It is a life-threatening condition characterized by recurrent episodes of severe skin inflammation, with pustule development, associated with fever, malaise, extracutaneous involvement, neutrophilia and a marked acute phase response.

Background Autoantibodies (Abs) to SSA/Ro recognize two ribonucleoproteins of 52and 60-kDa. Ro52 antigen is an E3ubiquitin-ligase. Anti-Ro52 Abs are present in patients with a broad spectrum of autoimmune diseases. Usually these Abs are in association with anti-Ro60 in lupus erythematosus (SLE) and Sjogren syndrome (SS). However, isolated anti-Ro52 is frequently present in inflammatory myositis.