Beijing Da Xue Xue Bao Yi Xue Ban. 2026 Jun 18;58(3):624-630.
ABSTRACT
OBJECTIVE: To delineate differences in lymphocyte subset expression between patients with infectious pneumonia and immune-related interstitial lung disease (IRILD), to assess the immune status across distinct pneumonia types, and to provide novel laboratory markers through immunological profiling to effectively differentiate pneumonias.
METHODS: A total of 78 patients sequentially enrolled from Peking University People’ s Hospital between January 2023 and March 2024 were stratified into three groups: 27 with infectious pneumonia, 27 with isolated immune-related interstitial lung disease (IRILD), and 24 with IRILD complicated by infection. Fifty age-matched healthy individuals undergoing routine physical examinations during the same period served as controls. Peripheral lymphocyte subsets were quantified in all subjects by multiparametric flow cytometry.
RESULTS: There was no statistically significant difference in age between the pneumonia patients and the healthy control group in this study (P>0.05). Analysis of laboratory parameters revealed that compared with the IRILD group, the infectious pneumonia group demonstrated significantly elevated levels of neutrophils, C-reactive protein, procalcitonin (PCT), erythrocyte sedimentation rate (ESR), D-dimer, and fibrinogen (P < 0.05), while the IRILD with superimposed infection group exhibited significantly increased levels of PCT, ESR, and immunoglobulin G (P < 0.05). At the lymphocyte subset level, compared with the control group, the infectious pneumonia group exhibited significantly decreased counts of T cells, B cells, natural killer (NK) cells, CD4+T cells, and the CD4+/CD8+ ratio (P < 0.05). Similarly, compared with the control group, the IRILD group showed significantly reduced counts of T cells, B cells, CD4+T cells, and the CD4+/CD8+ ratio (P < 0.05). Furthermore, compared with the control group, the IRILD-with-infection group demonstrated significantly lower counts of T cells, B cells, NK cells, CD4+T cells, and CD8+T cells (P < 0.05). Compared with the IRILD group, the infectious pneumonia group had a significantly lower NK cell count (P < 0.05). Additionally, compared with the IRILD group, the IRILD-with-infection group displayed significantly reduced counts of NK cells and CD8+T cells (P < 0.05).
CONCLUSION: The study revealed significant variations in lymphocyte subset profiles among the distinct pneumonia groups, providing novel insights with potential diagnostic value for differentiating between pneumonia types.
PMID:42287059
