Abstract:

Objective To investigate the predictive value of CD3⁺/CD4⁺T lymphocyte level and neutrophil to lymphocyte ratio （NLR） in radiation pneumonia. Methods The data of 87 patients with locally advanced non-operative non-small cell lung cancer admitted to our hospital from March 2018 to October 2023 were retrospectively analyzed. Among them， 43 cases had radiation pneumonia and 44 cases did not have radiation pneumonia. The changes in T lymphocyte subsets and NLR before and after radiotherapy were compared between the two groups. The diagnostic value of T lymphocyte subsets and NLR in lung cancer radiation pneumonia after radiotherapy was analyzed， the correlation between T lymphocyte subsets and NLR and the grade severity of radiation pneumonia was analyzed， and the ROC curve of T lymphocyte subsets and NLR in predicting lung cancer radiation pneumonia after radiotherapy was drawn， and the AUC area was calculated. Results The levels of CD3⁺T lymphocytes and CD4⁺T lymphocytes in the post-radiotherapy group were significantly lower than those before radiotherapy and those without radiotherapy （P < 0.05）. The NLR in the post-radiotherapy group was significantly higher than that before radiotherapy and those without radiotherapy （P < 0.05）. The sensitivity， specificity， accuracy， negative predictive value， and positive predictive value of the combined diagnosis of CD3⁺T lymphocytes， CD4⁺T lymphocytes， and NLR were higher than those of NLR and higher than those of CD4⁺T lymphocytes and CD3⁺T lymphocytes. The changes of CD3⁺T lymphocyte and CD4⁺T lymphocyte levels were negatively correlated with grade severity of radiopneumonia （P < 0.05）， while the changes of NLR were positively correlated with grade severity of radiopneumonia （P < 0.05）. Combined detection of CD3⁺T lymphocytes， CD4⁺T lymphocytes， and NLR predicted that the AUC area of lung cancer after radiotherapy was 0.924， which was larger than that of CD3⁺T lymphocytes， CD4⁺T lymphocytes， and NLR alone. Conclusion The combined detection of CD3⁺T lymphocytes， CD4⁺T lymphocytes， and NLR has an ideal value in the diagnosis and prediction of radiation pneumonia after radiotherapy for locally advanced non-small cell lung cancer， and can be used as an indicator for early diagnosis and prevention of radiation pneumonia.

Key words: CD3⁺T lymphocytes, CD4⁺T lymphocytes, neutrophil to lymphocyte ratio, radiation pneumonia, non-small cell lung cancer