Hypocomplementemia in XXXX --clinical and serological correlations.

@entity1 @entity627 @entity5442 @entity1333 @entity2631 @entity785
OBJECTIVE: Although complement fixation is not commonly thought to be part of the pathogenesis of @entity785 ( @entity785 ), hypocomplementemia has been associated with @entity785 . We hypothesized that hypocomplementemia in @entity785 might indicate the presence of overlap disease. We investigated if @entity785 @entity1 with hypocomplementemia had more features of overlap disease than those with normal complement levels. METHODS: Study subjects consisted of those enrolled in the Canadian @entity2631 Research Group Registry. @entity1 were divided into 2 groups: those with normal complement levels (normal C3 and C4) and those with hypocomplementemia (low C3 or C4). Evidence of overlap disease was defined as physician reports of other specific @entity627 . Autoantibodies were assayed. Differences in rates of concomitant diseases and in antibody profiles were compared between groups. RESULTS: Our study included 321 @entity1 (88% @entity1 , mean age 56 +/- 13 yrs, mean disease duration 11 +/- 9 yrs). Of these, 276 (86%) had normal complements and 45 (14%) had hypocomplementemia. @entity1 with hypocomplementemia were significantly more likely to have physician-reported inflammatory @entity5442 (27% vs 12%; p < 0.008) and @entity1333 (11% vs 2%; p < 0.011) than those with normal complement. There was also a trend toward more antichromatin antibodies (18% vs 9%; p = 0.051) in @entity1 with hypocomplementemia compared to normals. CONCLUSION: Hypocomplementemia may identify a particular subgroup of @entity785 @entity1 who have overlap disease.
