Incidence and risk factors of opportunistic infections after autologous stem cell transplantation: a nationwide, population-based cohort study in Korea.

Several guidelines classify autologous stem cell transplantation (ASCT) as a low to intermediate risk group for infection. In a nationwide population-based study, using the Korean Health Insurance Review and Assessment Service database, patients with lymphoma and multiple myeloma (MM) who underwent ASCT from 2002 to 2016 were retrospectively analyzed. Cumulative incidence rates (CIRs) and risk factors of opportunistic infections were investigated. CIRs of fungal, Varicella zoster virus (VZV), cytomegalovirus (CMV), and Pneumocystis jirovecii infections in lymphoma were 7.9%, 16.0%, 7.4%, and 5.1%, respectively, and CIRs in MM were 6.3%, 19.1%, 4.2%, and 5.6%, respectively. Fungal infection was significantly higher in patients with previous infection (Hazard ratio (HR) 2.003, p = 0.005) in lymphoma. Incidence of CMV infection was significantly higher in patients with prior CMV infection: HR 4.920, p < 0.001 (lymphoma); HR 3.022, p = 0.030 (MM). VZV infection was significantly lower in patients receiving prophylaxis: HR 0.082, p < 0.001 (lymphoma); HR 0.096, p < 0.001 (MM). For P. jirovecii infection, busulfex and melphalan conditioning (HR 1.875, p = 0.032) and previous P. jirovecii infection (HR 4.810, p < 0.001) had a higher incidence in MM. Patients who underwent ASCT should receive VZV prophylaxis and prophylaxis for fungal and P. jirovecii may be considered in patients with previous same infection.