The type, clinical and microbiological properties of fungal agents of lung infections in febrile neutropenic patients

Purpose: Pulmonary infections are an important cause of morbidity and mortality in febrile neutropenic patients. The frequency of fungal agents is increasing among etiological agents. Fungal pneumonia is a rapidly progressing infection. Early diagnosis and treatment are important. The empirical treatment protocol applied in this patient group, the inability to perform invasive procedures, and the lack of diagnostic approaches make treatment much more complicated. The inability to provide specific antibacterial and antifungal medications and unnecessary and long term use of drugs bring problems such as waste of time, cost increase, drug side effects, and increase in morbidity. In this study, it was aimed to determine the type, clinical and microbiological characteristics of fungal agents in lung infections in febrile neutropenic patients. Materials and Methods: In this study, 77 serum and 28 bronchoalveolar lavage (BAL) samples were taken from 72 febrile neutropenic patients with pulmonary findings, who were followed up in the Division of Hematology and Oncology, the Department of Internal Medicine, Faculty of Medicine, Cukurova University between November 2015 and February 2017. Clinical findings and laboratory data of the patients were prospectively followed. Serum and BAL samples were subjected to culture, direct examination, galactomannan antigen test, and Aspergillus fumigatus and Pneumocystis jirovecii real time polymerase chain reaction assays. According to the criteria that have been prepared together by the European Organisation for Research and Treatment of Cancer and the Mycoses Study Group (EORTC/MSG), the patients were classified as definite (proven), highly probable, suspected invasive fungal infection (IFI), and non-invasive fungal infection (non-IFI). The sensitivity and specificity of GM antigen test and real-time PCR assay were calculated by the SPSS statistical software package version 19.0. The relationship between IFI development and risk factors for mortality and mortality was analyzed.Findings: The sensitivity of Aspergillus fumigatus real time PCR assay was higher in BAL than in serum. Moreover, Aspergillus fumigatus real time PCR assay using BAL samples had higher sensitivity than serum galactomannan assay and BAL galactomannan assay if the cut-off value was accepted as 0.5 ng/ml. However, the specificity of the PCR assay was as low as 14.3%. Only one patient's serum was found to be positive for Pneumocystis jiroveci. Factors such as chemotherapy regimens administered to the patients, antifungal therapy, level of neutropenia, and underlying disease had no effect on IFI development. All pulmonary findings except for the halo sign were not discriminative for infection (p:0.016). The use of antifungals prior to diagnostic procedures led to a statistically significant decrease in serum galactomannan levels (p:0.024). Result: In our study that examined lung findings for 77 episodes in 72 patients, 50 patients had evidence of infection. According to the EORTC/MSG definitions, 34 (44 %) patients were classified as proven and highly probable IFI. It was thought that the fact that the number of cases of proven infection was low and the number of cases of highly probable infection was high resulted from difficulty in obtaining evidence. It was concluded that the combined use of galactomannan and PCR tests in the diagnosis of invasive pulmonary aspergillosis would provide greater specificity and sensitivity than using one of them alone.