Implications of combined NOD2 and other gene mutations in autoinflammatory diseases.

NOD-like receptors (NLRs) are intracellular sensors associated with systemic autoinflammatory diseases (SAIDs). We investigated the largest monocentric cohort of patients with adult-onset SAIDs for coinheritance of low frequency and rare mutations in NOD2 and other autoinflammatory genes. Sixty-three patients underwent molecular testing for SAID gene panels after extensive clinical workups. Whole exome sequencing data from the large Atherosclerosis Risk in Communities (ARIC) study of individuals of European-American ancestry were used as control. Of 63 patients, 44 (69.8%) were found to carry combined gene variants in NOD2 and another gene (Group 1), and 19 (30.2%) were carriers only for NOD2 variants (Group 2). The genetic variant combinations in SAID patients were digenic in 66% (NOD2/MEFV, NOD2/NLRP12, NOD2/NLRP3, and NOD2/TNFRSF1A) and oligogenic in 34% of cases. These variant combinations were either absent or significantly less frequent in the control population. By phenotype-genotype correlation, approximately 40% of patients met diagnostic criteria for a specific SAID, and 60% had mixed diagnoses. There were no statistically significant differences in clinical manifestations between the two patient groups except for chest pain. Due to overlapping phenotypes and mixed genotypes, we have suggested a new term, "Mixed NLR-associated Autoinflammatory Disease ", to describe this disease scenario. Gene variant combinations are significant in patients with SAIDs primarily presenting with mixed clinical phenotypes. Our data support the proposition that immunological disease expression is modified by genetic background and environmental exposure. We provide a preliminary framework in diagnosis, management, and interpretation of the clinical scenario.

Genetic variations in NLRP3 and NLRP12 genes in adult-onset patients with autoinflammatory diseases: a comparative study.

Objectives: Cryopyrin-associated periodic syndrome or NLRP3-associated autoinflammatory disease (NLRP3-AID) and NLRP12-AID are both Mendelian disorders with autosomal dominant inheritance. Both diseases are rare, primarily reported in the pediatric population, and are thought to be phenotypically indistinguishable. We provide the largest cohort of adult-onset patients and compared these diseases and the gene variant frequency to population controls. Methods: A cohort of adult patients with AIDs were retrospectively studied. All underwent molecular testing for periodic fever syndrome gene panels after extensive and negative workups for systemic autoimmune and other related diseases. Patients were divided into Group 1- NLRP3-AID patients with NLRP3 variants (N=15), Group 2- NLRP12-AID with NLRP12 variants (N=14) and Group 3- both NLRP3 and NLRP12 (N=9) variants. Exome sequence data of two large control populations including the ARIC study were used to compare gene variant distribution and frequency. Results: All 38 patients were Caucasian with women accounting for 82%. Median age at diagnosis was 41 ± 23 years and the disease duration at diagnosis was 14 ± 13 years. We identified statistically significant differences between the groups, notably that gastrointestinal symptoms as well as evaluations for same were significantly more frequent in patients with NLRP12 variants, and headaches/dizziness were less common among the NLRP12 patients. Livedo reticularis was noted in four patients, exclusively among NLRP12 carriers. Over 50% of patients in Groups 1 and 2 carry low-frequency disease-associated variants, while the remaining carry rare variants. We unprecedently identified digenic variants, i.e., the coexistence of NLRP3 and NLRP12, which were either both low frequency or low frequency/rare. Allele frequencies of all variants identified in our cohort were either absent or significantly lower in the control populations, further strengthening the evidence of susceptibility of these variants to SAID phenotypes. Conclusion: Our comparative study shows that both NLRP3-AID and NLRP12-AID share similar clinical phenotypes, yet there are significant differences between them with regard to gastrointestinal and neurological symptoms. A spectrum of high to low genetic variations in both genes can contribute to SAID individually or in combination.

Polycystic ovary syndrome: epidemiologic assessment of prevalence of systemic rheumatic and autoimmune diseases.

BACKGROUND: Polycystic ovary syndrome (PCOS) causes anovulation and hyperandrogenism. Hormonal imbalance is known to contribute to systemic autoimmune diseases. OBJECTIVE: To examine the frequency of certain rheumatic diseases in PCOS. METHODS: This retrospective study utilized and analyzed electronic medical records from January 2004 through February 2020. A diagnosis of PCOS and specified rheumatic diseases was searched using ICD-9 and ICD-10 codes. A total of 754 adult patients with PCOS and 1,508 age- and body mass index-matched patients without PCOS were included. Frequencies of the rheumatic diseases were compared between PCOS and non-PCOS subjects or literature data. RESULTS: The prevalence of rheumatoid arthritis (RA) was found to be 2.25% (17/737) in the PCOS patients, numerically higher than 1.26% (19/1489) in the non-PCOS subjects. The difference was significant with a confidence level of 90% (1.04-3.15) but not at 95% with an odds ratio of 1.808 (95% CI = 0.934-3.4, p = 0.0747). When compared with the literature data from the US female population, the prevalence of RA in PCOS patients was significantly higher (2.25% vs. 1.40%, p < 0.0001). Among the autoimmune diseases examined, both systemic sclerosis (0.40% vs. 0.0%, p = 0.0369) and undifferentiated connective tissue disease (0.53% vs. 0.0%, p = 0.0123) were significantly more frequent in the PCOS patients than the non-PCOS. Additionally, PCOS patients had a significantly higher frequency of osteoarthritis than non-PCOS patients (5.44% vs. 2.92%, p = 0.0030) with an odds ratio of 1.913 (95% CI = 1.239-2.955). CONCLUSION: We have shown unprecedentedly that certain rheumatic diseases are more prevalent in PCOS. This study provides important insight into autoimmunity in association with PCOS. Key Points • Polycystic ovary syndrome is postulated to cause systemic autoimmune disease due to its hormonal imbalance. • We conducted the first epidemiologic assessment of the prevalence of systemic autoimmune diseases. • Certain autoimmune and rheumatic diseases are more prevalent in polycystic ovary syndrome.