Introduction:
India is a high prevalence country for tuberculosis and renal transplant recipients are at higher risk of developing TB (tuberculosis). It is estimated that about 40% of the Indian population is infected with Tubercle bacilli, the vast majority of whom have latent TB rather than TB disease. This study was undertaken to understand the incidence of tuberculosis after kidney transplantation
Methods:
Retrospective analysis of 616 patient records who underwent renal transplantation over 12 years, between 2005 to Nov 2023 were included in the study. Routine screening for latent TB with quantiferon TB test was done pre-transplant in this centre since 2018. Post transplant, patients were followed up and treated for active TB. Patients who had renal transplant 10 months or more prior to date of data collection were included, as median time of onset of TB post renal transplantation from previous studies was 9 months. TB was further classified as ‘confirmed’ if AFB smear, AFB culture or molecular test- CB-NAAT is positive, ‘probable’ if in the absence of microbiological test, clinical, radiological or pathological findings favour TB and improve with anti-tuberculous treatment. Incidence of active TB, site of infection, interval between transplant and occurrence of TB, underlying immune-suppression and outcome were studied.
Results:
Among 616 patients, 32 patients were lost to follow-up and 32 had died to due an etiology other than TB. 4 patients had latent TB diagnosed during pre transplant screening and were started on INH prophylaxis.18 had active TB among the 552 patients studied; the incidence being 3.26%.12 patients had confirmed TB, 6 had probable tuberculosis. 4 patients had developed TB within one year of transplantation, the longest time interval was 9 years. 5 had pulmonary TB, 12 had extra pulmonary TB and 1 had Disseminated TB. One had rejection 4 years prior to TB diagnosis, 3 had rejection 3 months, 2 and 7 years following TB diagnosis; steroid pulses or intensification of immune suppression were not found to be associated with occurrence of active TB. Combination regime that was commonly used was isoniazid, ethambutol, pyrazinamide and levofloxacin. One patient who was on rifampicin based regime developed rejection following low tacrolimus levels despite adjustment of dose. Rifampicin free regime was used in all patients who were on tacrolimus. Two patients expired 2 years following anti tuberculous treatment due to rejection and other infective complications, rest of them improved and had good outcome. None of the patients with latent TB started on INH prophylaxis have developed TB so far.
Conclusions:
The incidence of tuberculosis in renal transplant population studied is 3.26% which is lower as compared to other studies from India and Asia. Extra-pulmonary TB occurrence is common and can present in unusual sites like skin, bone etc. All treated patients had good outcome after TB treatment per se. Treatment of latent tuberculosis may prevent the occurrence of overt infection in this group of patients.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.