Factors Predisposing to Active Tuberculosis in Dialysis Patients

Background. The aim of our study was to identify risk factors for developing active tuberculosis in regular haemodialysis patients (Dps). Methods. A 36-month follow-up of 272 Dps, in S/W Greece, where all new cases of active TB were detected. Eligible Dps were tested with tuberculin (Mantoux skin test), in a 2-step manner. Specific Relative Risks (RR) for TB was calculated considering subjects from the general population as a reference group at the end of the studied period. The independent effect of age, BMI, diabetes, tuberculin reactivity, healed tuberculosis evidences on chest X-ray and dialysis stage was determined using Cox’s proportional hazard model. Results. Dps presented a multi-fold higher RR for TB [74.5(95% [CI] 58.65-113.6, P <0.001)] as compared to the aged matched background population. Elderly Dps (Adjusted/RR 25.3, P<0.02), diabetics (Adj/RR 25.3, P<0.03), underweighted (Adj/RR 72.3, P<0.001), tuberculin responders (Adj/RR 41.4, P<0.03), Dps with fibrotic residuals on chest x-ray (Adj./RR 82.3, P<0.03) and those treated for <12 months (Adj/RR 110.0, P<0.001), presented significantly higher specific RRs for TB even after allowing for the effect of the other studied risk factors. Conclusion. TST positivity, the existence of predisposing risk factors and/or chest X-ray findings, will guide the diagnosis of latent TB infection and the selection of those DPs who warrant preventive chemoprophylaxis. To optimize the benefit the later would be commenced upon entering a chronic dialysis program.