Low Prevalence of Nodules in Rheumatoid Arthritis Patients in Kuwait: A Description and a Comparison of Patients from the Kuwait Registry for Rheumatic Diseases.

OBJECTIVES: To describe the prevalence of rheumatoid nodules (RN) in patients with rheumatoid arthritis (RA) and to compare their features with those of patients without RN.

SUBJECTS AND METHODS: Adult RA patients (n = 952) in the Kuwait Registry for Rheumatic Diseases from February 2013 to December 2015 were evaluated for RN. Demographic and serological features and disease activity and severity were obtained from the registry.

RESULTS: Of the 952 RA patients, 22 (2.3%) had RN and 930 (97.7%) did not. Age, sex, disease duration, smoking, and family history of an autoimmune rheumatic disease were similar. Obesity was more prevalent in the RN group, i.e. 11 (50%) vs. 326 (35.1%), p = 0.016. There was no difference in rheumatoid factor (RF) or anti-cyclic citrullinated peptide antibody positivity. Patients with RN had more sicca symptoms, i.e. 8 (36.4%) vs. 152 (16.3%), p = 0.025, a higher mean score on the visual analogue scale pain (3 ± 2.9 vs. 2 ± 2.7, p < 0.001), more tender joints (6.4 ± 8.8 vs. 4.2 ± 7.2, p = 0.001), a higher patient global assessment of disease activity (3.3 ± 2.7 vs. 2.3 ± 2.7, p < 0.001), and more deformities, i.e. 3 (13.6%) vs. 74 (8%), p = 0.034. The mean health assessment questionnaire score in RN patients was 1.1 versus 0.9 in patients without RN (p = 0.08). Patients with RN had a low disease activity (means: disease activity score [DAS-28], 3.02; clinical disease activity index, 7.7; and simple disease activity index, 10.4), similar to the other group. While the rates of methotrexate treatment were comparable, biologic therapy was administered more in patients with RN (i.e. 15 [68.2%] vs. 478 [51.4%], p < 0.001).

CONCLUSION: In Kuwait, the prevalence of RN is low among RA patients. Patients with and without RN are similar in terms of demographics and serologic features, except for more obesity. However, patients with RN have more sicca symptoms, joint deformities, and painful and tender joints. Disease activity scores are low with more frequent biologic therapy.