Targeted next-generation sequencing in sepsis-associated lymphopenia: a concordance analysis with conventional microbiological testing.

OBJECTIVE

This study aimed to evaluate the concordance between targeted next-generation sequencing (tNGS) and conventional microbiological tests (CMT), and to investigate whether tNGS-CMT concordance varies with the degree of immune impairment in patients with sepsis-associated lymphopenia.

METHODS

Between October 2024 and March 2026, this study enrolled 93 patients with sepsis-associated lymphopenia who were treated at Peking Union Medical College Hospital and Beijing Chaoyang Hospital. Specimens from clinically suspected infection sites were collected from these patients, and both tNGS and CMT were performed. The detection rate, results, and turnaround time of the two methods were compared, and the association between host immune status, as indicated by lymphocyte subset counts, and tNGS-CMT concordance was examined.

RESULTS

Among the 93 tNGS tests, 80 were positive, while 211 of the 588 CMTs were positive. Comparison of the results revealed complete concordance between tNGS and CMT in 30 of 62 comparable cases (48.4%) and partial concordance in 16 of 62 cases (25.8%). Greater concordance between tNGS and CMT results was significantly associated with severe immune impairment, as indicated by lower CD4+ T-cell counts.

CONCLUSION

In patients with sepsis-associated lymphopenia, tNGS of specimens from multiple sites demonstrated a higher positivity rate and shorter turnaround time. Furthermore, patients with more severe immune impairment exhibited a higher tNGS-CMT concordance, as indicated by their lower CD4+ T-cell counts.