Genetically determined NLRP3 inflammasome activation associates with systemic inflammation and cardiovascular mortality.

AIMS: Inflammation plays an important role in cardiovascular disease (CVD) development. The NOD-like receptor protein-3 (NLRP3) inflammasome contributes to the development of atherosclerosis in animal models. Components of the NLRP3 inflammasome pathway such as interleukin-1ß can therapeutically be targeted. Associations of genetically determined inflammasome-mediated systemic inflammation with CVD and mortality in humans are unknown. METHODS AND RESULTS: We explored the association of genetic NLRP3 variants with prevalent CVD and cardiovascular mortality in 538 167 subjects on the individual participant level in an explorative gene-centric approach without performing multiple testing. Functional relevance of single-nucleotide polymorphisms on NLRP3 inflammasome activation has been evaluated in monocyte-enriched peripheral blood mononuclear cells (PBMCs). Genetic analyses identified the highly prevalent (minor allele frequency 39.9%) intronic NLRP3 variant rs10754555 to affect NLRP3 gene expression. rs10754555 carriers showed significantly higher C-reactive protein and serum amyloid A plasma levels. Carriers of the G allele showed higher NLRP3 inflammasome activation in isolated human PBMCs. In carriers of the rs10754555 variant, the prevalence of coronary artery disease was significantly higher as compared to non-carriers with a significant interaction between rs10754555 and age. Importantly, rs10754555 carriers had significantly higher risk for cardiovascular mortality during follow-up. Inflammasome inducers (e.g. urate, triglycerides, apolipoprotein C3) modulated the association between rs10754555 and mortality. CONCLUSION: The NLRP3 intronic variant rs10754555 is associated with increased systemic inflammation, inflammasome activation, prevalent coronary artery disease, and mortality. This study provides evidence for a substantial role of genetically driven systemic inflammation in CVD and highlights the NLRP3 inflammasome as a therapeutic target.

Capnocytophaga canimorsus Septicemia With Sepsis-Induced Coagulopathy and Endocarditis.

Capnocytophaga canimorsus is a rare cause of serious infections with a high mortality of 10% to 30%. It is usually found in the oral cavity of cats and dogs and can cause severe sepsis in immunocompromised patients. An 81-year-old female Caucasian patient presented with C. canimorsus sepsis after a dog bite in her finger three days before presentation to our emergency department. She initially was presented to us with sepsis, thrombopenia, and schistocytes in her laboratory findings, suggesting the differential diagnoses of the multiple subtypes of thrombotic microangiopathy. She was admitted to the medical intensive care unit of the University Hospital of Saarland because of septic shock with circulatory insufficiency. The patient received plasmapheresis, antibiotics, and dialysis, under which she improved significantly. The fingertip of the affected finger developed necrosis and had to be amputated. Furthermore, the patient was diagnosed with a mitral valve endocarditis, a very rare complication of C. canimorsus infection. It was treated conservatively with antibiotics and was no longer detectable 8 weeks after the diagnosis. Surgical intervention was not needed. The case describes well that it is still difficult to distinguish between thrombotic thrombocytopenic purpura (TTP), disseminated intravascular coagulation (DIC), and sepsis-induced coagulopathy (SIC), especially in the early phases of acute disease, especially in C. canimorsus-induced sepsis.