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

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.

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.

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).

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