Tuberculosis incidence in solid organ transplant recipients in Europe: A multicenter TBnet cohort study

Background: Solid organ transplant (SOT) recipients face elevated tuberculosis risk, yet optimal prevention strategies in low- to medium-incidence regions remain unclear. Methods: We conducted a multicenter retrospective cohort study of adult SOT recipients transplanted between 2007 and 2012 at 15 European centers, with follow-up through 2018. The primary outcome was microbiologically confirmed post-transplant tuberculosis. Incidence rates were calculated per 100,000 person-years; standardized incidence ratios (SIRs) used World Health Organization country-specific background rates. Cox models assessed risk factors. Results: Among 5805 patients (median age 51; 62.7% male; 73.9% renal transplants), 33.8% were tested for tuberculosis infection and 10.3% received tuberculosis preventive therapy (TPT). Over 33,785 person-years, 23 patients (0.4%) developed tuberculosis (68.0/100,000 person-years). Highest incidence occurred in patients with positive screening but no TPT (233.8/100,000). Incidence was higher in Southern vs. Central Europe (251.9 vs. 28.7/100,000), with pooled SIRs of 12.8 and 3.1, respectively. Tuberculosis risk was elevated among Southern European recipients (HR 22.9) and those with migration history (HR 2.7). Conclusion: Tuberculosis risk is increased in European SOT recipients. Regionally adapted prevention strategies, including targeted screening in low-incidence areas and universal screening in higher-incidence regions, are warranted.

Highlights: -Tuberculosis incidence in SOT recipients was 68/100,000 person-years across Europe. -Highest incidence in M. tuberculosis infected persons without preventive therapy. -Southern Europe showed 9-fold higher TB incidence than Central Europe. -Most tuberculosis cases occurred more than two years after transplantation. - Findings support region-specific TB screening and prevention strategies.