Mycobacterium tuberculosis in solid organ transplantation: incidence before and after expanded isoniazid prophylaxis.

BACKGROUND: The risk of tuberculosis is increased in solid organ transplantation. Rates remain high in developed and developing countries. We developed protocols to better identify transplant recipients at risk of tuberculosis and initiate interventions to prevent tuberculosis.

OBJECTIVES: Report tuberculosis incidence in solid-organ transplant recipients and the results of expanded isoniazid prophylaxis in deceased-donor renal transplantation.

DESIGN: Retrospective cohort study, comparing two time periods.

SETTING: Large transplantation center in a WHO-medium endemicity country for tuberculosis.

METHODS: In a cohort of all solid-organ transplant recipients performed between 2003 and 2012, tuberculosis-free transplantation follow-up is used for incidence calculation. Rates of tuberculosis in renal transplant recipients are compared before and after implementation of expanded isoniazid prophylaxis.

MAIN OUTCOME MEASURE(S): Active tuberculosis post-transplantation.

RESULTS: Of 1966 solid-organ transplant recipients (kidney: 1391, liver: 426, heart: 114, lung: 35), 20 recipients (1.02%) developed tuberculosis. Twelve cases (60%) developed tuberculosis within one year of transplantation. The incidence was 248 cases per 100 000 transplant-years. The proportion of transplant recipients (incidence of tuberculosis per 100 000 transplant-years) for specific organs were kidney 0.58% (127), liver 1.88% (594), heart: 1.75% (570), and lung 5.71% (4750). In the survival analysis, lung transplant recipients had significantly higher rates of tuberculosis compared to recipients of kidneys from living donors (P=.0001) with a rate ratio of 45.3 (95% CI: 7-313). Mortality was 5% among tuberculosis patients. After implementing expanded isoniazid prophylaxis among deceased-donor kidney recipients, no tuberculosis occurred in 177 recipients, compared to 3 out of 155 (2%) recipients before implementation.

CONCLUSIONS: Rates of tuberculosis among our solid transplant recipients are decreasing. Universal iso-niazid prophylaxis in transplant recipients could reduce transplant-associated tuberculosis in endemic areas.

LIMITATIONS: Donor data on tuberculosis exposure and prevention and tuberculosis prevention efforts before referral to our center are not available for all patients.