Background Little is known about the prevalence and the clinically associated factors of low IgG and IgM levels in patients (pts) with RA.
Objectives To estimate the prevalence of low IgG and IgM levels in pts with RA and to investigate factors associated with low Ig
Methods This cross-sectional analysis evaluated Ig levels measured centrally at the time of enrollment in CERTAIN, a prospective comparative effectiveness study of biologics nested within CORRONA. Multivariate models (MV) evaluated factors associated with low Ig levels.
Results Characteristics for the 1151 enrollments were analyzed: 76% women, 86% Caucasian, 67% seropositive. The mean (±SD) age was 56.1 (±13.5) years, RA duration was 8.5 (±9.1) years and CDAI was 29.1 (±13.0). At the time of evaluation 35.7% of pts were biologic-naïve and 39.6% received prednisone in the last 6 months (34.8% of them ≤10mg/day). Low IgG (<700mg/dl) was noted in 76 (6.6%) pts and low IgM (<40mg/dl) in 63 (5.5%) pts. MV (Table 1) showed that pts with high disease activity were more likely to have low IgG. Prior exposure to biologics was not associated with low IgG or IgM. Instead, an opposite trend was suggested for prior exposure to TNF-α inhibitors. MV suggested that higher doses of prednisone are likely to be associated with low IgG levels and that seropositive pts are more likely to have normal Ig levels.
Conclusions High disease activity was associated with increased odds of low IgG. Effect of biologic agents, steroids and other factors on Ig levels, and clinical outcomes will be evaluated in a longitudinal analysis when CORRONA-CERTAIN is completed.
Disclosure of Interest: D. Pappas Employee of: Columbia University, Paid instructor for: Novartis, A. John Employee of: Genentech, Inc., J. Curtis Grant/research support from: Roche/Genentech, UCB, Janssen, CORRONA, Amgen, Pfizer, BMS, Crescendo, Abb Vie, Consultant for: Roche/Genentech, UCB, Janssen, CORRONA, Amgen, Pfizer, BMS, Crescendo, Abb Vie, J. Kremer Shareholder of: CORRONA, Employee of: CORRONA, W. Reiss Employee of: Genentech, Inc., A. Shewade Employee of: Genentech, Inc., G. Silverman Grant/research support from: NIH, ACR, RRF, Consultant for: Lilly, Genentech, Roche, Pfizer, Employee of: New York University, J. Greenberg Shareholder of: CORRONA, Consultant for: AstraZeneca, CORRONA, Novartis, Pfizer