Infectious complications after hematopoietic stem cell transplantation: current status and future perspectives in Korea

Cho, Sung-Yeon; Lee, Hyeon-Jeong; Lee, Dong-Gun

The incidence of PCP has been significantly reduced by trimethoprim/sulfamethoxazole prophylaxis in highrisk patients. High-risk patients who do not take prophylaxis or who show poor compliance with the drug regimen are the main populations at risk of PCP. In a systematic review and meta-analysis of non-HIV immunocompromised hosts (patients with acute leukemia and recipients of HSCT and solid organ transplant), the incidence of PCP was reduced by 91% (relative risk [RR], 0.09) in trimethoprim/sulfamethoxazole prophylaxis group compared with placebo [69, 70] . In addition, PCP-related mortality was significantly reduced by 83% (RR, 0.17). However, trimethoprim/sulfamethoxazole prophylaxis did not markedly reduce all-cause mortality in a hematology population [70] . Mortality rates remain very high in hematology patients (30% to 59%), particularly in HSCT recipients (48% to 70%), compared with 17% to 30% in patients with HIV infection [71] . Nevertheless, given the more severe course of PCP and the higher PCP-related mortality rates, trimethoprim/sulfamethoxazole prophylaxis can likely save lives in other www.kjim.org https://doi.org/10.3904/kjim.2018.036 immunocompromised groups as well. PCP should be prevented for at least 6 months or until the immunosuppressant is discontinued in allogeneic HSCT recipients [13, 48, 71] . Although the optimum duration of PCP prophylaxis is controversial, it is suggested to be continued for a period of time after the immunosuppressant is discontinued. In the setting of corticosteroid-containing regimens, prophylaxis should be continued while steroids are being weaned and/or for 6 weeks after their cessation [72] . With some chemotherapy regimens (i.e., alemtuzumab) consideration should be given to extended PCP prophylaxis for up to 12 months because of the high rate of late-onset PCP [73] . Table 4 summarizes the methods of preventing PCP after HSCT.