Rheumatoid arthritis subjects have impaired IL-17A-dependent anti-microbial peptide induction, but preserved oral immunity to Candida albicans. (A), (B)Candida albicans colonization in the oral cavity. Saliva (25 μl) from the indicated cohorts was analyzed for endogenous C. albicans colonization by plating on yeast peptone dextrose (YPD) agar in triplicate and performing colony enumeration. Data are presented as (A) the percent of each cohort that exhibited any oral colonization or (B) the number of colony-forming units (CFU) in each cohort (Fischer’s exact test and Mann–Whitney U test, respectively). (C) Rheumatoid arthritis (RA) subjects exhibit reduced salivary β-defensin 2 (BD2) levels. BD2 in saliva from the indicated cohorts was determined by enzyme-linked immunosorbent assay (Student’s t test). (D) RA subjects show intact salivary candidacidal activity. Salivary Candida killing was determined by centrifuging saliva to remove endogenous microbes and incubating the spun fraction with 106C. albicans (reference strain CAF2-1) for 1 hour at 37°C. Triplicate samples were plated on YPD for colony enumeration and killing is indicated as the percentage of a PBS control (Student’s t test).
Bishu et al. Arthritis Research & Therapy 2014 16:R50 doi:10.1186/ar4480