Prevalence of positive ppd in a cohort of rheumatoid arthritis patients

The main objective of this study is to determine the prevalence of positive and anergic tuberculin skin test (ppd) in a rheumatoid arthritis cohort of patients (RA) and assess the association among ppd results and clinical and treatment variables. Patients with RA diagnosis were included. The ppd was done by Mantoux method. Positive result was considered when indurations were equal or greater than 5 mm. Anergic reaction was defined when the indurations was 0 mm. We included 105 patients (N = 105). The prevalence of positive ppd was 12.4% (n = 13), while the 87.6% (n = 92) presented a negative result. The 69.5% (n = 73) of the population were anergic to ppd. Patients with negative result received higher steroids dosages than patients with positive ppd (p < 0.04). In the multivariable model, the steroids dosage was a significant and independent predictor of negative ppd (p = 0.021, OR 0.72, 95% CI 0.55-0.95). Anergic and non-anergic patients were separated in groups, and a new analysis was done. The higher dosage of methotrexate was associated to tuberculine anergy (p = 0.025). In the multivariable model, the methotrexate dosage was a significant and independent predictor of tuberculine anergy (p = 0.005, OR 1.14, 95% CIs 1.04-1.24). In conclusion, in our cohort, the prevalence of positive ppd was lower than others studies. Among analyzed variables, the high steroid dose was a significant and independent predictor of negative ppd. The methotrexate treatment and dose were associated with ppd anergy.