Mycobacterial infections in solid organ transplantation

PURPOSE OF REVIEW: Tuberculosis and nontuberculous mycobacterial infections after solid organ transplantation can be associated with significant morbidity and mortality, and diagnosis and treatment are often challenging. This article reviews recent and relevant advances in the management of mycobacterial infections in the setting of solid organ transplantation. RECENT FINDINGS: The new interferon-γ release assays are more specific than the tuberculin skin test to detect latent tuberculosis infection because of lack of cross-reactivity with BCG and most nontuberculous mycobacterial infections. In immunosuppressed patients, however, these assays can give indeterminate results. A quantitative flow-cytometric method showed promising results by detecting T-cell reactivity toward tuberculosis antigens in transplant patients. The test results were not adversely affected by immunosuppression. Invasive nontuberculous mycobacterial infections are uncommon after lung transplantation, but the risk can increase if the infection is isolated prior to transplantation. Mycobacterium abscessus infections can present with pulmonary, cutaneous, and soft tissue involvement, which can be treated with a combination of antimicrobial therapy and surgical debridement in soft tissue involvement. SUMMARY: The new interferon-γ release assays are promising in diagnosing more accurately latent tuberculosis infection in solid organ transplantation patients, but indeterminate results can occur. Most tuberculosis and nontuberculous mycobacterial infections can be treated effectively with combination therapy, but optimal regimens are still undefined.