Prevalence of latent tuberculosis before biotherapy initiation in rheumatoid arthritis and spondyloarthritis: data from the Moroccan biotherapy registry.

Before the initiation of biotherapy in the treatment of rheumatic diseases, it is highly recommended for the patients to be screened for latent tuberculosis infection (LTBI). The objective of this study is to identify the prevalence of LTBI among patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA) before the initiation of biologic therapy in the Moroccan biotherapy registry (RBSMR). A cross sectional study was conducted using the baseline data of the Moroccan biotherapy registry. Tuberculin skin test or IGRA test or both tests were done before starting anti-TNF treatment for screening LTBI. The comparisons between positive and negative LTBI patients according to rheumatic disease were examined using categorical comparisons. 259 patients were included in this study.94 patients had RA and 165 had SpA. The mean age of the RA patients was 50.49 ± 11.82 years with a majority of females (84%). The mean age for the SpA patients was 36 ± 13.7 years with a majority of males (67.3%). The prevalence of LTBI in the RBSMR was 21.6%. This prevalence was at 24.8% in SpA patients, while it was at 15.9% for RA patients. After the comparison between positive and negative LTBI patients according to rheumatic disease, no demographic, clinical, or therapeutic characteristics were statistically associated with LTBI. This study found that in an endemic TB country like Morocco, a high prevalence of patients with SpA and RA had LTBI, and that RA patients had a lower prevalence than SpA patients.