Prevalence and Clinical Characteristics of Rheumatoid Arthritis in an Inner City Population with Sickle Cell Disease.

Objectives: Rheumatoid arthritis (RA) has been rarely reported in association with sickle cell disease (SCD). Our study aimed to estimate the prevalence of RA in SCD population and to describe the clinical characteristics of RA associated with SCD.

Methods: Retrospective chart review of SCD and RA patients followed at 2 large urban hospitals. Seven RA/SCD patients were identified and compared to age and sex matched cohort of SCD only and of RA only group. All patients were Black.

Results: There were 739 SCD cases, seven (0.94%) met ACR criteria for RA (SCD-RA), 411 cases were RA only group. Mean age was significantly higher in SCD-RA compared to the entire population of SCD and RA (41.7 ± 3.9 (± SEM) vs. 33.26 ± 0.47, vs. 61.39 ± 0.79, p<0.01). SCD-RA patients had lower hemoglobin (g/dl) when compared to the age and sex matched SCD or RA only patients (7.4 ± 0.49 vs. 8.3 ± 0.60 vs. 11 ± 0.59, p <0.01) respectively. There were no significant differences in laboratory and treatment approach between SCD-RA and RA only groups, except for the radiographic evidence of periarticular osteopenia and greater difficulty in the activities of daily living (ADL) among SCD-RA cohort, compared to the age and sex matched RA cohort (p=0.01).

Conclusion: In contrast to older reports, the prevalence of RA among SCD patients in our study (0.94%) was similar to that reported in the general population (0.5-1%) and was to be associated with difficulty in ADL and periarticular osteopenia. Since RA manifests at an older age, our reported prevalence is likely explainable by improved survival of SCD patients due to enhanced medical care and the advent of hydroxyurea as a major therapeutic breakthrough for SCD.