Interferon-gamma release assay screening before solid organ transplantation in a low-incidence country: a prospective single-center cohort study

The risk of tuberculosis is increased after solid organ transplantation (SOT) and associated with morbidity and mortality. Pre-transplantation screening and treatment for tuberculosis infection (TBI) is recommended. Aims of this prospective cohort study were determining the prevalence of positive pre-transplantation interferon-gamma release assays (IGRAs), risk factors for a positive result, and describe TBI management. We included SOT candidates from 2020 to 2023 at Rigshospitalet, Denmark with a pre-transplantation IGRA. Data were collected from records and the Danish Microbiology Database. Of 586 patients, 564 (96%) had a pre-transplantation IGRA. Twenty-two (4%) had positive, 537 (95%) negative, and 5 (1%) indeterminate results. Risk factors for a positive IGRA were diabetes (14/480 (3%) without diabetes, 8/84 (10%) with diabetes, aOR 3.07, 95% CI 1.14–7.78), birth in other low-incidence countries (4/24 (17%) vs. 8/463 (2%), aOR 10.14, CI 2.48–35.95) or medium-/high-incidence countries (10/77 (13%), aOR 8.22, CI 3.11–22.43), and alcohol use (aOR 2.75, CI 1.04–7.15). Seventeen patients had TBI; 16 (94%) treated with isoniazid for 6 months, one (6%) with rifampicin for 4 months; treatment discontinued in one case. In conclusion, IGRA screening coverage was high. Positive IGRAs were associated with birth in other low- or medium-/high-incidence countries, diabetes, alcohol use. TBI treatment was well tolerated.