Gene polymorphisms in the NALP3 inflammasome are associated with interleukin-1 production and severe inflammation: Relation to Common Inflammatory Diseases?
2008 (English)In: Arthritis and Rheumatism, ISSN 0004-3591, E-ISSN 1529-0131, Vol. 58, no 3, 888-894 p.Article in journal (Refereed) Published
Objective: NALP3, ASC, and TUCAN are components of the NALP3 inflammasome, which triggers caspase 1-mediated interleukin-1β (IL-1β) release. Activating mutations in the gene encoding NALP3 (NLRP3) have recently been linked to familial periodic fever syndromes. We undertook this study to determine whether a patient with arthritis and antibiotic-resistant fever carried mutations in the genes encoding the NALP3 inflammasome.
Methods: Genetic analysis of NLRP3 and the gene encoding TUCAN (CARD-8) was performed on genomic DNA from the patient and from a population-based collection of DNA (806 subjects). For in vitro studies of IL-1β production and caspase 1 activity, blood was obtained from the patient at different time points after administration of anakinra, an IL-1 receptor antagonist, as well as from 5 healthy age- and sex-matched control subjects.
Results: Mutation analysis of the patient's genes encoding NALP3, ASC, and TUCAN revealed variations in the NLRP3 (Q705K) and CARD-8 (C10X) genes. The allele frequencies of these single-nucleotide polymorphisms (SNPs) in the population were 6.5% and 34%, respectively. The elevated activity of caspase 1 and the high levels of IL-1β measured in samples from the patient returned to normal levels after treatment with anakinra.
Conclusion: Our results indicate that the patient's symptoms were due to elevated levels of IL-1β, since treatment with anakinra effectively abolished the symptoms. The compound SNPs may explain the increased IL-1β levels and inflammatory symptoms observed, but further studies are needed to reveal a functional relationship. The prevalence of the polymorphisms (4% of the population carry both SNPs) in the general population may suggest a genetic predisposition for common inflammatory disorders.
Place, publisher, year, edition, pages
2008. Vol. 58, no 3, 888-894 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-19048DOI: 10.1002/art.23286OAI: oai:DiVA.org:liu-19048DiVA: diva2:222837