The value of second-generation gene sequencing in lung cancer immunotherapy with concurrent infections

Objective To observe the clinical characteristics of patients with lung cancer infection combined with immunotherapy, compare whether there is a difference in the detection of pathogens between the two groups of patients, and explore the diagnostic value of metagenomic next-generation sequencing (mNGS) for patients with lung cancer infection combined with immunotherapy. Methods Sixty-three patients with lung cancer co-infections were included in the First People's Hospital of Jingzhou City from December 2022 to April 2025, and were divided into 24 cases in the immunotherapy group and 39 cases in the non-immunotherapy group according to whether they were treated with immunotherapy or not, and underwent electron bronchoscopy and mNGS testing. We collected the detection of pathogens and various clinical information from the enrolled patients, explored the association between the infection characteristics and clinical characteristics of the patients in the two groups, and compared the detection of pathogens in the two groups. Results The CRP, PCT, IL-6, hospitalization days and hospitalization cost of patients in the immunotherapy group were higher than those in the non-immunotherapy group, and the differences were statistically significant (P < 0.05). In the immunotherapy group, 14 cases of bacteria, 14 cases of fungi, 9 cases of viruses and 18 cases of mixed infections were detected. In the non-immunotherapy group, 28 cases of bacteria, 25 cases of fungi, 14 cases of viruses and 28 cases of mixed infections were detected. The detection rate of fungal mixed infections was higher in the immunotherapy group (20.83%) than in the non-immunotherapy group (2.56%) (X ² =5.755, P=0.016), with the infection rate of Aspergillus terreus in the immunotherapy group significantly higher than that in the non-immunotherapy group (X ² =5.119, P=0.024). The differences in the detection rates of bacteria, virus and the rest of mixed infections were not statistically significant when compared with non-immunotherapy (P>0.05). Conclusion The incidence of mixed fungal infections increased after immunotherapy in lung cancer patients, in which the detection rate of Mycobacterium hyopneumoniae was significantly higher in the immunotherapy group than in the non-immunotherapy group. Bacterial infections were dominated by Mycobacterium tuberculosis complex, fungal infections were dominated by Aspergillus fumigatus and Pneumocystis japonicus, and viral infections were dominated by EBV. mNGS demonstrated good applicability in the population undergoing immunotherapy for lung cancer and had a greater impact on treatment.