Counts of T-lymphocyte subsets and prognosis of severe influenza A / 医学研究生学报

ABSTRACT

Objective Influenza A (FluA) poses a serious threat to human health due to its high infectivity, viral variation and rapid progression. This study aimed to analyze the characteristics of T-lymphocyte subsets in patients with severe FluA and their role in the prognosis of the disease. Methods We collected the clinical data on 80 cases of severe FluA treated in our Department of Respiratory and Critical Diseases from January 2018 to May 2019, which were divided into a death group (n = 25) and a survival group (n = 55) based on 28-day survival after admission. Thirty-one of the patients were co-infected with other pathogens at admission, of whom 11 died and 20 survived within 28 days after admission. We compared the clinical characteristics, general laboratory results and T-lymphocyte subsets (CD3+T, CD4+T and CD8+T cells) between different groups and analyzed the factors influencing the prognosis of the disease using logistic regression and multivariate COX regression analyses. Results Compared with the patients in the survival group, those in the death group showed significantly decreased counts of lymphoid, CD3+T, CD4+T and CD8+T cells, albumins and globulins (P < 0.05), but increased levels of procalcitonin, blood urea nitrogen, serum creatinine and serum glutamic-oxaloacetic transaminase (P < 0.05). CD3+T, CD4+T and CD8+T cells and albumins were remarkably decreased in the co-infection death group in comparison with the co-infection survival group (P < 0.05). The area under the ROC curve for the count of CD4+T cells was 0.728 (95% CI 0.605-0.850), with the best cut-off value of 1.70 × 108/L, a sensitivity of 80% and a specificity of 64%. The 28-day survival rate was significantly higher in the patients with CD4+T cells ≥ 1.70×108/L than in those with CD4+T cells < 1.70×108/L (83% vs 41%, P < 0.05). COX regression analysis showed age, respiratory failure and alanine transaminase to be the risk factors while the count of CD4+T cells (RR = 0.740, 95% CI 0.572-0.958) to be a preventive factor for the death of the patients within 28 days after admission (P < 0.05). Conclusion The count of T-lymphocytes are closely correlated to the prognosis of severe FluA and the patients with a decreased count of CD4+T cells have a higher risk of death within 28 days after admission. The count of CD4+T cells can predict the 28-day prognosis of severe FluA.