Early infectious complications after autologous hematopoietic cell transplantation for multiple myeloma

The spectrum of infectious complications in autologous hematopoietic cell transplant recipients (AHCT) with multiple myeloma has not been well described in the recent era of novel agent induction and improved supportive care.

We conducted a retrospective cohort study of 413 adult myeloma AHCT recipients at our institution from 2007-2016 to describe the cumulative incidence and risk factors for various infections and FN occurring within the first 100 days after AHCT. Additionally, landmark analysis was done among 404 patients who survived at least 100 days after transplant admission to estimate the association of infections with subsequent non-relapse mortality (NRM), overall survival (OS), and relapse-free survival (RFS).

Cumulative incidences (95% CI) of infection events by day 100 were: FN 43% (38-48), any infection 21% (17-25), bacterial 17% (14-21), viral 4% (3-7) and fungal 1% (0.5-3), central line-associated blood stream infection 3% (2-6), and Clostridium difficile colitis 6% (4-8). Patients with infection had a longer initial transplant hospitalization (median 17 vs 16 days, P < 0.01), more readmissions (31% vs 8%, P < 0.01), and spent more days in hospital in first 100 days (median 18 vs 16 days, P < 0.01). A 100-day mortality was low and similar between groups (2% vs 1%, P = 0.28). In landmark analysis of 404 100-day survivors, OS was worse among patients with early infections (hazard ratio 1.54 [1.03-2.30], P = 0.03), although there was no difference in NRM and RFS.

Notwithstanding advances in supportive care, early infectious complications remain a relevant source of morbidity and require attention in myeloma AHCT recipients.