Bacterial, Fungal and Viral Infections in Patients with Hematological Malignancies: Investigation of CMV Reactivation as a Risk Factor
Authors: Kocaman Mustafa , Tekin Kemal 
Published: August 2023

Reactivation of latent viruses such as human cytomegalovirus (CMV), as well as opportunistic infections associated with bacterial and fungal agents, cause serious clinical consequences in patients with hematological malignancies, which are characterized by both immunosuppressive drug use and functional and numerical disorders of immune system cells. In this study, it was aimed to investigate the association between CMV reactivation and the frequency of various simultaneous infections in adult patients with hematological malignancies. All CMV-DNA test results reported in the medical microbiology laboratory between November 2016 and February 2022 were retrospectively reviewed and the study group consisting of 270 adult patients with hematological malignancies was created. CMV-DNA follow-up results and clinical evaluations of these patients were examined and cases with CMV reactivation were determined. In the final stage, the possible association between CMV reactivation and the frequency of other infections identified by microbiological examination of patients' samples and radiological and clinical evaluations was investigated. Of 270 adult patients with hematological malignancies in the study group, 175 (64.8%) were male and 95 (35.2%) were female, and the mean age of the patients was 50.98 (±17.6). It was determined that 35.9% (97/270) of the patients had CMV reactivation during the follow-up period. The presence of 139 bacterial agents in 99 patients, 63 viral agents in 58 patients, and 56 fungal agents in 50 patients were determined. Bacterial infections were as follows according to the systems; 108 bacteremia (most frequently detected agent Escherichia coli; n=31, 28.7%), 21 urinary tract infections (most common cause E. coli; n=13, 61.9%), and 10 other bacterial infections. Fungal infections were as follows according to the systems; 36 respiratory tract infections (most common Aspergillus spp.; n=23, 63.9%), 6 fungemia (all Candida spp.), 14 other fungal infections (Candida spp.; n=11, and mucormycosis; n= 3). Viral infections were as follows, in order of frequency; hepatitis B (anti-HBc IgG seropositivity in 30 patients), COVID-19 (Coronavirus Disease-2019) in 14 patients, herpes simplex virus in 11 patients, herpes zoster in four patients, BK virus in three patients, and parvovirus B19 in one patient. CMV reactivation rates were found to be significantly higher in patients with fungal pneumonia, non-CMV viral reactivation, and bacterial bloodstream infection, p=0.046, p=0.003, and p=0.038, respectively. In the literature, CMV reactivation, risk factors associated with reactivation, and adverse clinical outcomes of CMV reactivation in patients with hematological malignancies have been investigated from many different aspects. However, additional pressures of CMV on the immune system and its negative effects on innate and adaptive immune responses and possible contributions of this situation to the development of other infections have not yet been studied in detail. We think that determining the possible effects of CMV reactivation on the development of opportunistic infections by comprehensive prospective studies may change antimicrobial therapy strategies in the management of CMV infections.