Analysis of Serum Immune Markers in Seropositive and Seronegative Rheumatoid Arthritis Among Sudanese Patients and the Relation Between the Serotype and Joint Involvement: A Cohort Study

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by inflammation of the synovial membrane. RA is classified as seropositive or seronegative, according to the absence or presence of primarily IgM RF, RF, and/or ACPA. The aim of this study is to identify the relationship between the serotype of rheumatoid arthritis and the level of ESR. METHODS AND MATERIALS: This is a descriptive, cross-sectional study done in Omdurman military hospital, Khartoum, Sudan. Conducted with 60 patients with RA, data were collected through a designated questionnaire which included demographic, age, gender, duration of the disease, laboratory finding. All the patients in the study were treated with conventional DMARDs and diagnosed according to the 2010 ACR/EULAR criteria; their disease activity status was assessed by DAS28/ESR. Data were analyzed using SPSS version 23. RESULTS: The study found that 91.7% of the patients were females, patients of age group between 36 and 50 years had the highest percentage at 38.3% followed by those between 51 and 70 years and the least age group between 20 and 35 years, 36.7% and 15%, respectively. Of all the patients 61.7% were found to be SPRA, while the remaining 38.3% were seronegative (SNRA). Altogether 55% of the patients had moderate disease activity, followed by 16.7% who had a remission, 15% had high disease activity and the remaining 13.3% had low disease activity. The metacarpophalangeal (MCP) joint was found to be the only joint that was significantly associated with DAS28 and its involvement was greater among seropositive patients. The most affected joints were found to be shoulders, knees, wrist, MCP, PIP and elbow, in that order. CONCLUSION: Females, middle-age group and shoulder joint were the most affected. Most RA was found to be SPRA, and the seropositive group was found to be more associated with high disease activity, while the seronegative group was associated with remission and low disease activity.