Isoniazid Treatment to Prevent TB in Kidney and Pancreas Transplant Recipients Based on an Interferon-γ-releasing Assay: an Exploratory Randomized Controlled Trial

Background: We performed a randomized trial of isoniazid treatment based on interferon-γ-releasing assay (IGRA) in kidney transplant (KT) recipients in an intermediate-TB-burden country.

Methods: All adult patients admitted to a KT institute between June 2010 and May 2013 were enrolled. The IGRA (T-SPOT.TB assay) was performed on all patients, and isoniazid treatment was given to those with clinical risk factors for latent TB infection (LTBI). Patients with positive IGRA who had no clinical risk factors for LTBI were randomly assigned to isoniazid treatment or a control group. The development of TB after KT was monitored between June 2010 and November 2013. The primary endpoint was the development of TB.

Results: Of the 784 patients who had no clinical risk factors for LTBI, 445 (57%) gave negative results in the IGRA, 76 (10%) indeterminate results and 263 (33%) positive results. Of the latter, 131 were allocated to isoniazid treatment and 132 to the control group. Three (2%) of the control group developed TB, whereas none of the isoniazid treatment group developed TB (rate difference 1.22 per 100 person-years, P = 0.09). Of the 521 patients with negative or indeterminate IGRA results, 4 [0.8%, 0.43 per 100 person-years (95% CI 0.12-1.09)] developed TB after KT.

Conclusions: IGRA-based isoniazid treatment has a trend towards reducing TB development in KT recipients without clinical risk factors, but careful monitoring of TB development is needed in negative-IGRA KT recipients.