Table 1 RCAα haplotype frequencies in patients with pSS compared with controls
HaplotypepSS(2N = 230)Controls(2N = 196)OR (95% CI)p Value
AH180 (34.8%)46 (23.5%)2.1 (1.3,3.3)*0.002
AH225 (10.9%)27 (13.8%)1.3 (0.6,2.1)0.75
AH338 (16.5%)19 (9.7%)2.4 (1.3,4.4)0.006
Other87 (37.8%)104 (53.1%)1
Global test: χ2 = 14.6, df = 3, p = 0.002

  • There were three common RCAα block ancestral haplotypes, AH1, AH2 and AH3. “Other” haplotypes, with a frequency between 1 and 3%, were combined for analysis purposes. Both AH1 and AH3 frequencies were increased in patients with pSS relative to controls. This association was attributable to the Ro/La autoantibody-positive subgroup of patients with pSS and was not evident in the minority of patients with pSS who were autoantibody negative (2N = 38).