Immune biomarkers for predicting postoperative pneumonia following hip fracture surgery.

OBJECTIVE

Abnormalities of lymphocyte subsets have been observed in patients with pneumonia. This study investigated the diagnostic efficiency of lymphocyte subsets in the detection of early-stage postoperative pneumonia (POP) among older patients undergoing hip fracture surgery.

METHODS

A total of 576 patients with hip fracture were recruited and analyzed for lymphocyte subsets on the first postoperative day.

RESULTS

The incidence of POP was 10.6% (61/576) from March 2016 to December 2023. The area under the curve for the percentage of CD8+ HLA-DR+ T cells was higher than that of CD4+ T and CD4+ CD45RA+ T cells. A high percentage of CD8+ HLA-DR+ T cells was significantly associated with an increased occurrence of POP. The positive findings remained significant after adjusting for confounding factors. Among the multiple complications, patients with diabetes tended to have higher percentages of CD8+ HLA-DR+ T cells.

CONCLUSIONS

The percentage of CD8+ HLA-DR+ T cells had a good predictive value for detecting early-stage POP. Multi-center prospective studies with larger sample sizes are needed to verify this finding.