Clinical characteristics of patients with both anti‐U1RNP and anti‐centromere antibodies

Abstract

Objective: To clarify the clinical characteristics of patients having both anti‐U1RNP antibodies (anti‐U1RNP) and anti‐centromere antibodies (ACA) in comparison to subjects having either anti‐U1RNP or ACA alone.

Subjects and methods: One hundred and fifty‐six subjects who had anti‐U1RNP and/or ACA were enrolled. They were classified into three groups: anti‐U1RNP alone group (n = 64); ACA alone group (n = 82); and anti‐U1RNP+ACA group (n = 10). The anti‐U1RNP alone and ACA alone groups were also divided into the low‐titre and the high‐titre subgroups, respectively. The frequencies of the specific clinical findings and laboratory data were compared among the groups or subgroups.

Results: The frequencies of persistent proteinuria or lupus nephritis (LN, 50.0%) and primary biliary cirrhosis (PBC, 30.0%) in the anti‐U1RNP+ACA group were higher than that in the anti‐U1RNP alone group (17.2%, p<0.01; 3.1%, p = 0.075; respectively). The frequencies of systemic lupus erythematosus (SLE, 60.0%), persistent proteinuria or LN (50.0%), anti‐Ro (70.0%), and anti‐La (30.0%) in the anti‐U1RNP+ACA group were higher than those in the ACA alone group (11.0%, p<0.01; 4.9%, p<0.001; 23.2%, p<0.01; and 6.1%, p = 0.085; respectively). The frequency of systemic sclerosis (SSc) in the high‐titre subgroup (30.0%) was higher than that in the low‐titre subgroup (11.8%) in the anti‐U1RNP alone group, without significance (p = 0.072). The frequency of interstitial pneumonia in the high‐titre subgroup (26.8%) was higher than that in the low‐titre subgroup (2.4%) in the ACA alone group (p<0.01).

Conclusions: The clinical characteristics of patients with anti‐U1RNP+ACA were clarified in comparison to subjects having either anti‐U1RNP or ACA alone.