IS HYPOCOMPLEMENTEMIA ASSOCIATED WITH WORSE PROGNOSIS IN RA?
- Oscar Cabrera-Marante, Spain
Abstract
Background and Aims
Hypocomplementemia in rheumatoid arthritis (RA) has been associated to higher inflammatory disease activity, more erosive disease and most frequent extra-articular involvement (such as pleuropulmonary complications, vasculitis, rheumatoid nodules or infection), being all of the above associations also related to seropositivity for rheumatoid factor (RF) or anti-CCP antibodies. Our objective is to explore if hypocomplementemia in RA independently of seropositivity is associated with a more aggressive disease.
Methods
We searched for patients with RA diagnosis and RF+ (>15 UI/mL) and hypocomplementemia C3 (<84 mg/dL) in 2017, as well as patients with RF+ but normal levels of C3 (>84 mg/dL) and C4 (>14 mg/dL) in the same period as controls. Demographic, biochemical, clinical ( and therapeutic were obtained from medical records. Differences between variables were analysed using Student-t or Chi-square tests.
Results
25 RA patients with RF+ and hypocomplementemia C3 (+/-C4) and 50 RA controls with RF+ and normal complement levels were identified. Basal characteristics (sex, age, disease duration) were similar in both groups. All biochemical, clinical and therapeutic variables were comparable between both groups except for higher levels of CRP in patients with hypocomplementemia (Table 1).
Conclusions
The present study does not find differences between patients with seropositive RA with low complement levels and those with normocomplementemia in terms of a more aggressive disease, cardiovascular comorbidity or inflammatory burden, except for higher CRP levels. This findings support that clinical associations of hypocomplementemia in RA are the same as those of RF seropositivity (to which it is associated).