Riesgo de enfermedad tuberculosa en pacientes con artritis reumatoide / Tuberculosis risk in patients with rheumatoid arthritis

RESUMEN

Antecedentes Los estudios sobre riesgo de enfermedad tuberculosa (ET) en artritis reumatoide (AR) en pacientes no usuarios de terapia biológica son controversiales. Objetivo: Evaluar AR como factor de riesgo independiente para ET. Diseño: Estudio de cohortes no concurrente. Lugar Red asistencial Hospital Guillermo Almenara Irigoyen, Lima-Perú, hospital docente. Participantes Pacientes con AR no usuarios de terapia biológica. Intervenciones Una cohorte de pacientes con AR no usuarios de terapia biológica (cumplimiento de criterios 1987 del ACR) fue pareada por edad y género con una cohorte control (pacientes con trastornos no inmunológicos). Se realizó una entrevista personal. El seguimiento para la cohorte AR se inició en el diagnostico de AR y culminó en el momento de la entrevista o en el diagnóstico de ET (los controles fueron seguidos el mismo periodo de tiempo). Se calculó la densidad de incidencia (DI) para ET en cada cohorte y el riesgo relativo (RR). La probabilidad de ET de acuerdo al tiempo de enfermedad fue comparada mediante curvas de Kaplan Meier. Se aplicó un modelo de Cox para ajustar drogas y patologías predisponentes (hazard ratio -HR). Principales medidas de resultados: Enfermedad tuberculosa en pacientes con artritis reumatoide. Resultados: La cohorte AR y los controles (667 y 664 pacientes, respectivamente) tuvieron 6 940,75 y 6 666,53 personas-año de seguimiento. La edad al diagnóstico...

ABSTRACT

Background: Studies on tuberculosis (TB) risk in patients with rheumatoid arthritis (RA) non-users of biological therapy show contradictory results. Objetives To determine RA as independent risk factor for TB. Design: Non concurrent cohort study. Setting: Guillermo Almenara Asistential Net, Lima-Peru, a teaching hospital. Participants: Biological therapy non-users RA patients. Interventions: RA patients fulfilled the ARA 1987 diagnosis criteria and were biological therapy non-users. Control group was paired by age and sex to RA patients. Patients in control groups had non immunological disorders. Clinical information was completed by interviews. RA patients follow-up was started at the time of diagnosis and ended at the time of interview and/or TB diagnosis. Density incidence (DI) was found for each cohort and TB relative risk (RR) was calculated. To evaluate time length to TB evolution a Kaplan Meier curve was graphed and compared both groups with log-rank test. Drugs and predisposing TB pathologies were analyzed. Main outcome measures: Tuberculosis in patients with rheumatoid arthritis. Results: Six hundred and seventy six out of 808 RA patients and 664 controls qualified for inclusion criteriaÆs. RA and control groups reached 6 940,75 and 6 666,53 follow-up patients-year, respectively. RA cohort mean age was 46,65 at RA diagnosis. Only 29,7 per cent of RA patients had a positive tuberculin reaction. Fifteen TB cases were identified in the RA cohort and 8 at the control group, yielding a mean DI of 216,1/100 000 and 122,1/ 100 000 patients-year respectively. TB RR was 1,8 (IC 95 per cent=0,8- 4,2), and after adjusting drugs and co-morbidity the HR was 1,69 (IC 95 per cent =0,26-10,93). Statistically significant difference was not found with Kaplan Meier curves comparison (p=0,19). Conclusions: We did not find a higher risk of rheumatoid arthritis patients to develop tuberculosis.