Living donor and recipient screening for latent tuberculosis infection by tuberculin skin test and interferon-gamma releasing assay in a country with an intermediate burden of tuberculosis.

There are few data on donor screening for latent tuberculosis infection (LTBI) using the tuberculin skin test (TST) and interferon-gamma releasing assay (IGRA). In South Korea, most renal allografts involve living donors (average, 80%). Hence, we have an opportunity to evaluate donor and recipient screening for LTBI by TST and IGRA. All donors and recipients admitted for kidney transplantation during a 20-month period were evaluated prospectively by using TST and Mycobacterium tuberculosis-specific enzyme-linked immunosorbent spot (ELISPOT) assay. The study population consisted of 205 living donor-recipient pairs (≥16 years) including 15 (7%) who yielded indeterminate donor or recipient ELISPOT results. Of the 205 donors, 63 (31%) gave a positive TST ≥5 mm, 33 (16%) a positive TST ≥10 mm, and 96 (47%) a positive ELISPOT. Of the 205 recipients, 9 (5%) gave a positive TST ≥5 mm, 3 (2%) a positive TST ≥10 mm, and 79 (39%) had a positive ELISPOT. Of the 205 donor-recipient pairs, only 59 (29%) gave negative donor and recipient ELISPOT results and 139 (68%) negative donor and recipient TSTs (<5 mm) (P < 0.001). One third of donor-recipient pairs tends to be positive in the TST, and two thirds of the donor-recipient pairs tends to be positive in the ELISPOT. Given the high positive rate of LTBI obtained by screening donors, further studies on the clinical value of solid organ transplant donors with positive TST or ELISPOT and health economics analysis in countries with intermediate burden of TB are needed for policy decisions on isoniazid (INH) prophylaxis.