Timing of illness onset influences leukocyte destruction in critically ill patients with suspected sepsis.

Background: The clinical significance of leukocyte destruction morphology in routine peripheral blood smears remains underexplored. This study aimed to systematically quantify leukocyte destruction and correlate these findings with clinical course, etiology, and outcome in patients with suspected sepsis.

Methods: This was a retrospective observational study involving 30 intensive care unit (ICU) patients with suspected sepsis. Peripheral blood smear findings were evaluated chronologically, with the day of blood culture collection designated as Day 0, followed by four distinct phases. Leukocyte destruction was defined as clear evidence of cytoplasmic or nuclear dissolution. Correlations were assessed with 28-day prognosis and symptom onset (acute [no preceding symptoms before admission] vs. non-acute [preceding symptoms present]).

Results: Leukocyte destruction showed no significant difference concerning 28-day mortality. However, it was significantly more frequent in acute onset cases within the first 48 h (7.0 % vs. 3.7 %, p < 0.05). Conversely, cases with toxic granulation were significantly more common in non-acute onset cases within the first 48 h (70 % vs. 14 %, p < 0.01).

Discussion: The patterns of leukocyte destruction and toxic granulation may provide insights into the underlying pathophysiology of critically ill patients and warrant further investigation.