CASP1 and rheumatoid arthritis: To this end we performed immunoblotting in freshly isolated unstimulated whole blood cells and found that patients with active RA (n = 11) expressed higher intracellular levels of NLRP3 (p <0.008), ASC (p <0.003) and active caspase-1 (p <0.02) as compared to controls (n = 11) (Fig. 1a, b).