Infectious Complications in Patients With Multiple Myeloma After High-Dose Chemotherapy Followed by Autologous Stem Cell Transplant: Nationwide Study of the Infectious Complications Study Group of the Polish Adult Leukemia Group

Background. Multiple myeloma (MM) has become a chronic disease in majority of patients, and remission consolidation with autologous hematopoietic stem cell transplant (ASCT) remains the backbone of treatment in transplant-eligible patients. Objective. The aim of this multicenter cross-sectional nationwide retrospective study was to evaluate the epidemiology, etiology, and outcome of infections in patients with MM undergoing ASCT in 13 Polish transplant centers, carried out on behalf of the Infectious Complications Study Group of the Polish Adult Leukemia Group. Methods. A total number of consecutive 1374 patients with MM treated in Polish adult transplant centers from 2012 to 2014 were followed for infectious complications up to day +100 after ASCT in nationwide study. Results. Altogether 490 infection episodes in 336 patients (49% male, aged 21-72 years) were reported, including 145 episodes of neutropenic fever (103 patients) and 34 episodes of clinically documented infections (CDIs) (27 patients). Among microbiologically confirmed infections there were 251 episodes of bacterial infections (180 patients), 42 episodes of fungal infections (38 patients), and 18 episodes of viral infections (17 patients). The overall incidence of infections reached 13.1% for bacterial, 3.6% for fungal, and 1.3% for viral infections. There were 16 cases of infection-related deaths after ASCT (1.2%). The mortality risk factors included multidrug-resistant bacteria etiology (odds ratio [OR], 3.5; P = .033), coexistence of bacterial and fungal infection (OR, 6.3; P = .002), and CDI (OR, 5.5; P = .007). Conclusion. ASCT in patients with MM was connected with low risk of life-threatening infections. However, multidrug-resistant bacteria bacterial etiology, mixed etiology, and CDI increased the risk of fatal outcome.