Research article

Risk factors for tuberculosis in dialysis patients: a prospective multi-center clinical trial

Antonios I Christopoulos¹ , Athanasios A Diamantopoulos² , Panagiotis A Dimopoulos³ , Demetrios S Goumenos⁴ and George A Barbalias⁵

¹School of Health & Wellfare Professions - Department of Nursing, Higher Technological-Educational Institute, Patra, Greece

²Department of Nephrology of "St. Andrew" General State Hospital, Patra, Greece

³Department of Radiology, University Hospital Rio, Patra, Greece

⁴Departent of Nephrology, University Hospital Rio, Patra, Greece

⁵Department of Urology, University Hospital Rio, Patra, Greece

author email corresponding author email

BMC Nephrology 2009, 10:36doi:10.1186/1471-2369-10-36

Published:	7 November 2009

Abstract

Background

Profound alterations in immune responses associated with uraemia and exacerbated by dialysis increase the risk of developing active tuberculosis (TB) in chronic haemodialysis patients (HDPs). In the current study, was determined the impact of various risk factors on TB development. Our aim was to identify which HDPs need anti-TB preventive therapy.

Methods

Prospective study of 272 HDPs admitted, through a 36-month period, to our institutions. Specific Relative Risk (RR) for TB was estimated, considering age matched subjects from the general population as reference group. Entering the study all patients were tested with tuberculin (TST). Using Cox's proportional hazard model the independent effect of various risk factors associated with TB development was estimated.

Results

History of TB, dialysis efficiency, use of Vitamin D supplements, serum albumin and zinc levels were not proved to influence significantly the risk for TB, in contrast to: advanced age (>65 years), BMI, diabetes mellitus, tuberculin reactivity, healed TB lesions on chest X-ray and time on dialysis. Elderly (>70 years old) HDPs (Adjusted RR 25.3, 95%CI 20.4-28.4, P < 0.02), diabetics (Adj.RR 25.3, 95%CI 17.2-21.1, P < 0.03), underweighted (Adj.RR 72.3, 95%CI 65.2-79.8 P < 0.001), tuberculin responders (Adj.RR 41.4, 95%CI 37.9-44.8, P < 0.03), HDPs with fibrotic lesions on chest x-ray (Adj.RR 82.3, 95%CI 51.3-95.5, P < 0.03) and those treated with haemodialysis for < 12 months (Adj.RR 110.0, 95%CI 97.4-135.3, P < 0.001), presented significantly higher specific RR for TB even after adjusting for the effect of the remaining studied risk factors.

Conclusion

The above mentioned factors have to be considered by the clinicians, evaluating for TB in HDPs. Positive TST, the existence of predisposing risk factors and/or old TB lesions on chest X-ray, will guide the diagnosis of latent TB infection and the selection of those HDPs who need preventive chemoprophylaxis.