<i>HLA-DRB1</i> allele carrier frequency in RA patients and controls.

<p>RA: rheumatoid arthritis, OR: odds ratio, CI: confidence interval, <i>P</i>c: corrected <i>P</i> value, NS: not significant, RPE: relative predispositional effects. Allele carrier frequencies are shown in parenthesis (%). Association was tested by Fisher's exact test using 2×2 contingency tables. RPE were tested by sequential elimination of carriers of each of the alleles <i>DRB1*04:05, *13:02, *04:01, *09:01, *01:01, *14:06, *10:01, *04:10</i>, and <i>*11:01</i>. Allele groups SE, D70, I67, and S1 were as defined in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099453#s2" target="_blank">Materials and Methods</a> section. <i>DRB1</i> alleles encoding the DERAA were the same as <i>DRB1*13</i> (i.e. <i>*13:01</i> and <i>*13:02</i>).