Methods:

Single-center, prospective cohort study of 92 critically ill septic patients. Patients were categorized into febrile (≥ 38.0 C) and afebrile (< 38.0 C) groups based on temperature measurements within 24 hours of sepsis diagnosis. HLA-DR expression and LPS-induced TNF-α production were quantified on days 1–2, days 3–4, and days 6–8 after sepsis diagnosis. A repeated measures mixed models analysis was used to compare these markers between the two groups.

Results:

Forty-four patients (47.8%) developed a fever within 24 h of sepsis diagnosis. There were no significant differences in HLA-DR expression or LPS-induced TNF-α production between febrile and afebrile patients at any individual time point. However, HLA-DR expression significantly increased between days 1–2 and days 6–8 (median difference 8118 [IQR 1,662, 9,878] antibodies/cell, P= 0.002) in febrile patients, but not in afebrile patients (median difference 403 [− 3,382, 3,507] antibodies/cell, P= 0.25). Afebrile patients demonstrated higher 28-day mortality (37.5% vs 18.2%) and increased acquisition of secondary infections (35.4% vs. 15.9%).

Conclusions:

Absence of fever is associated with suppressed HLA-DR expression over time, a finding suggestive of monocyte dysfunction in sepsis, as well as worse clinical outcomes.