# Clinical Presentation, Risk Factors and Outcome of Non-Tuberculous Mycobacteria Infection in Hematopoietic Stem-Cell Transplantation: A Multinational Case-Control Study

## TL;DR

This study examines non-tuberculous mycobacteria infections in stem-cell transplant patients, finding prior non-NTM infections and corticosteroid use as risk factors.

## Contribution

The study identifies risk factors and clinical features of NTM disease in hematopoietic stem-cell transplant recipients through a multinational case-control design.

## Key findings

- Prior non-NTM infection and corticosteroid therapy are significant risk factors for NTM disease.
- Mycobacterium avium complex and rapidly growing mycobacteria are the most common species identified.
- NTM disease is associated with a 28% all-cause mortality rate among transplant recipients.

## Abstract

The clinical and microbiological features of infection due to non-tuberculous mycobacteria (NTM) after hematopoietic stem-cell transplantation (HSCT) remain poorly understood.

We performed a retrospective, multinational case-control study that included HSCT recipients (≥12 years) diagnosed with NTM disease between January 2008 and December 2018. Controls were HSCT recipients with no evidence of NTM disease, matched (1:2 ratio) by participating center and post-transplant survival. Logistic regression on matched pairs was used to investigate risk factors for NTM disease.

We included 25 cases of NTM disease. The most common HSCT type was allogeneic from unrelated donor (72.0%) after myeloablative conditioning (76.0%). Predominant hematological conditions were acute myelogenous leukemia (28.0%) and myelodysplastic syndrome (24.0%). Most patients (88.0%) had previously received immunosuppressive therapy. The most common species identified were Mycobacterium avium complex (64.0%) and rapidly growing mycobacteria (20.0%). Most patients (68.0%) had pulmonary disease. All but one received antimycobacterial therapy for a median of 267.5 days. Macrolides (83.3%), rifamycins (58.3%) and ethambutol (62.5%) were the most commonly used drugs. Four patients (16.7%) developed adverse events requiring therapy discontinuation. All-cause and attributable mortality rates were 28.0% and 4.0%, respectively. One patient experienced relapse after 464 days. Diagnosis of a non-NTM infection (adjusted odds ratio [aOR]: 3.11; 95% confidence interval [95% CI]: 1.25–7.78) and corticosteroid therapy (aOR: 2.88; 95% CI: 1.16–7.17), both within the previous 90 days, were associated with NTM disease.

NTM disease is a serious complication among heavily immunocompromised HSCT recipients associated with prior non-NTM infection and corticosteroid therapy.

In this multicenter case–control study, we investigated the clinical, radiological, and microbiological characteristics of non-tuberculous mycobacterial (NTM) infection in hematopoietic stem-cell transplant recipients, as well as associated risk factors and clinical outcomes. A prior diagnosis of non-NTM infection and the use of corticosteroid therapy within the preceding 90 days were identified as factors associated with the development of this rare but potentially severe complication.

Graphical AbstractThis graphical abstract is also available at Tidbit: https://tidbitapp.io/tidbits/clinical-presentation-risk-factors-and-outcome-of-non-tuberculous-mycobacteria-infection-in-hematopoietic-stem-cell-transplantation-a-multinational-case-control-study?utm_campaign=tidbitlinkshare&utm_source=IO

This graphical abstract is also available at Tidbit: https://tidbitapp.io/tidbits/clinical-presentation-risk-factors-and-outcome-of-non-tuberculous-mycobacteria-infection-in-hematopoietic-stem-cell-transplantation-a-multinational-case-control-study?utm_campaign=tidbitlinkshare&utm_source=IO