Cho SY, et al. Infect Chemother. 2014 Mar;46(1):1-12. http://dx.doi.org/10.3947/ic.2014.46.1.1

Cytomegalovirus (CMV) infection after hematopoietic stem cell transplantation (HSCT) is one of the critical infectious complications related to host immune recovery. The spectrum of CMV infection is quite extensive, from asymptomatic CMV reactivation presenting mainly as CMV DNAemia to fatal CMV diseases involving gut, liver, lungs, or brain. In addition to organ involvement, CMV reactivation can exert indirect effects such as immunosuppression or graft failure that may result in the development of concurrent infectious complications. Currently, preemptive therapy, which is based on PCR-based monitoring of CMV from blood, is a mainstay enabling improvement in CMV-related outcomes. During the past decades, new antiviral drugs, clinical trials for prophylaxis in high-risk groups, and vaccines for preventing CMV infection have been introduced. In addition, data for immunologic monitoring and adoptive immunotherapy have also been accumulated. Here, we review the current status and recent updates in this field, with future perspectives including immunotherapy in HSCT recipients.

Stenotrophomonas maltophilia causes serious infections in immunocompromised hosts. Here, we analyzed the clinical characteristics of S. maltophilia bloodstream infection (BSI) in patients with hematologic malignancies and evaluated in vitro synergistic effects of antimicrobial combinations. We retrospectively reviewed all consecutive episodes of S. maltophilia BSIs in adult hematologic patients from June 2009 to May 2014, with in vitro susceptibility and synergy tests using high-throughput bioluminescence assay performed for available clinical isolates. Among 11,004 admissions during 5-year period, 31 cases were identified as S. maltophilia BSIs. The incidence rate of S. maltophilia BSI was 0.134 cases/1,000 patient-days. Overall and attributable mortality of S. maltophilia BSI was 64.5% and 38.7%, respectively. Severe neutropenia (adjusted hazard ratio [HR] 5.24, p =0.013), shock at the onset of BSI (adjusted HR 6.05, p <0.001), and pneumonia (adjusted HR 3.15, p =0.017) were independent risk factors for mortality. In vitro susceptibilities to ceftazidime, levofloxacin, ticarcillin-clavulanic acid (TIM) and trimethoprim-sulfamethoxazole (SXT) were 11.1%, 44.0%, 40.7%, and 88.9%, respectively. MIC50/MIC90 for moxifloxacin and tigecycline were 1/4 mg/L and 4/8 mg/L. The 50% and 90% fractional inhibitory concentrations (FIC50/FIC90) of clinical isolates against a combination of SXT and TIM were 0.500/0.750. For SXT plus levofloxacin or moxifloxacin, FIC50/FIC90 were 0.625/1.000 and 0.625/0.625, respectively. S. maltophilia BSIs show high mortality, which is related to severe neutropenia, shock, and S. maltophilia pneumonia. Based upon drug susceptibility testing, the primary treatment of choice for S. maltophilia BSIs should be SXT in hematologic patients, rather than quinolones, with combination therapies including SXT serving as a feasible treatment option.

Hyeyoung Lee , M.D., Ji Hyeong Ryu , B.S., Hye-Sun Park , M.S., Ki Hyun Park , M.S., Hyunjoo Bae , B.S., Sojeong Yun , B.S., Ae-Ran Choi , B.S., Sung-Yeon Cho , M.D., Chulmin Park , Ph.D., Dong-Gun Lee , M.D., Jihyang Lim , M.D., Jehoon Lee , M.D., Seungok Lee , M.D., Soyoung Shin , M.D., Haeil Park , M.D., and Eun-Jee Oh , M.D.. Ann Lab Med 2019;39:566-71. https://doi.org/10.3343/alm.2019.39.6.566

Hematopoietic stem cell transplantation (HSCT) is a treatment for hematologic malignancies, immune deficiencies, or genetic diseases, ect. Recently, the number of HSCTs performed in Korea has increased and the outcomes have improved. However, infectious complications account for most of the morbidity and mortality after HSCT. Post-HSCT infectious complications are usually classified according to the time after HSCT: pre-engraftment, immediate post-engraftment, and late post-engraftment period. In addition, the types and risk factors of infectious complications differ according to the stem cell source, donor type, conditioning intensity, region, prophylaxis strategy, and comorbidities, such as graft-versushost disease and invasive fungal infection. In this review, we summarize infectious complications after HSCT, focusing on the Korean perspectives.

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has become an important cause of community-onset urinary tract infections. We aimed to evaluate the efficacy of non-carbapenem antibiotics for acute pyelonephritis (APN) due to ESBL-producing E. coli. We conducted a retrospective cohort study of patients with community-onset APN due to ESBL-producing E. coli at a single centre in Korea from 2007 to 2013. Outcomes included both microbiological and clinical failure. To adjust for non-random assignment of antibiotics, the propensity score method of inverse probability of treatment weighting and a multivariable analysis using Cox proportional hazards modelling were employed to estimate the efficacy of non-carbapenem antibiotics as compared with carbapenems. Of 152 eligible patients, 85 (55.9%) received carbapenems and 67 (44.1%) received non-carbapenems. Non-carbapenem antibiotics used in this cohort included aminoglycosides (n = 30), β-lactam/β-lactamase inhibitors (n = 13), fluoroquinolones (n = 12) and trimethoprim/sulfamethoxazole (n = 5). Microbiological failure was observed in 16 patients receiving carbapenems (16/83, 19.3%) versus 4 patients receiving non-carbapenem (4/67, 6.0%). After weighting, the risk of microbiological failure was similar between the two groups [weighted hazard ratio (HR) 0.99; 95% CI 0.31–3.19]. In a multivariable regression analysis combined with weights, the estimate did not change (weighted adjusted HR 0.96; 95% CI 0.41–2.27). The clinical failure rate was also similar in the two groups (weighted HR 1.05; 95% CI 0.24–4.62). These results suggest that non-carbapenem antibiotics were as effective as carbapenems as definitive therapy for treating community-onset APN caused by ESBL-producing E. coli if they are active in vitro.