Tuberculosis in renal transplant recipients on various immunosuppressive regimens

Mycophenolate mofetil (MMF) and tacrolimus (TAC) are more potent than conventional immunosuppressive drugs, i.e. azathioprine, cyclosporin and prednisolone, and may be associated with an increase in the incidence of infections in the post-transplantation (post-tx) period. The aim of this study was to determine if the use of either or both of MMF and TAC for immunosuppression in renal transplant recipients increases the prevalence or modifies the clinical presentation of tuberculosis (TB), when compared with conventional therapy.

The medical records of 443 adult patients who received a kidney transplant between 1994 and 2002 were reviewed retrospectively. Comparisons were made between patients who had conventional immunosuppressive treatments (cyclosporin, azathioprine and prednisolone) or an alternative regimen (including MMF, TAC or both).

We found 20 patients (4.5%) to have post-tx TB. There were 13 cases of TB (age 38.9+/-10.6 years) among 328 patients who received conventional immunosuppressants (group I) (4.0%) and seven cases (age 24.2+/-7.4 years) among 115 (6.1%) who received an alternative immunosuppressive regimen (group II) (P>0.05). The patients in group II were younger than the patients in group I (P = 0.002). A significantly higher number of patients in group II developed TB within the first 6 months post-tx (P = 0.042). However, there was no significant difference between the two groups regarding clinical and radiographic presentations or outcomes.

Immunosuppression with TAC or MMF is associated with the development of TB earlier in the post-tx period and in younger patients.