Diagnosis of opportunistic infections in non-small cell lung cancer

Abstract

Aim. To investigate the species composition and frequency of opportunistic pathogens in cancer patients diagnosed with non-small cell lung cancer (NSCLC) receiving chemotherapeutic treatment at the Federal State Budgetary Institution National Medical Research Center of Oncology named after N. N. Blokhin of the Russian Ministry of Health.Materials and methods. A prospective open single-center study included a cohort of patients with locally advanced or metastatic NSCLC receiving drug antitumor therapy, aged 18 years and older. The study was observational in nature. The endpoint of this phase of the study was to determine the relative number of NSCLC patients with chronic infection (pneumocystis, herpes simplex virus (HSV) 1, HSV-2, cytomegalovirus (CMV), Epstein–Barr virus (EBV), human herpes virus type 6 (HHV-6) and their combinations).Results. Antibodies to herpes viruses and/or pneumocystis were detected in patients (n = 18) diagnosed with NSCLC in 100 % of cases. Antibody titers corresponding to active infection were more characteristic for EBV and CMV, with CMV infection markers more often registered in titers corresponding to the acute stage of the disease, and EBV – in the reactivation stage without obvious clinical manifestations. In most cases, mixed infection with different pathogens was determined: combination of HSV-1 + EBV + CMV was found in 55.5 % (n = 10) of NSCLC patients; HSV-1 + EBV + CMV + HHV-6 – in 33.3 % (n = 6) of cases, HSV-1 + HSV-2 + EBV + CMV – in 5.5 % (n = 1), HSV-1 + HSV-2 + EBV + CMV + HHV-6 also in 5.5 % (n = 1) of patients. During bronchoalveolar lavage examination, pneumocystis were detected in 3 (42.8 %) out of 7 examined patients.Conclusion. Based on the results of studies of a relatively small cohort of patients in the absence of clinical symptoms of infection in NSCLC patients, a high percentage of IgM and IgG antibodies, which are markers of opportunistic infections and their combinations, were detected. Pneumocystis was isolated from bronchoalveolar lavage in 42.8 % of cases. It is necessary to evaluate the results obtained in a larger number of patients to determine approaches to the prevention and treatment of opportunistic infections.