Evaluating small vessel neutrophils as a marker for sepsis

A retrospective case-control study of 100 sepsis autopsy cases and 103 controls over a 9-year period was conducted to analyze patterns of neutrophils in small caliber vessels of the liver, heart, and lungs in relation to sepsis as the cause of death. Data extracted included demographics of the decedent, cause of death, presence of conditions that could interfere with an inflammatory response, history of hospitalization, and results of microbiology cultures. Histologic sections of the liver, heart, and lungs were assessed. Organs were scored for neutrophilic inflammation based upon a predetermined grading system. Scores of 0, 1, and 2 were assigned according to mild, moderate, and florid neutrophilic presence, respectively; a total score was also assigned based on the sum of the scores from all three organs. Comparing the histologic grading between cases and controls found a statistical difference with the neutrophil grading in the liver (p < 0.001), lung (p < 0.001), and heart (p < 0.001) and between the combined total scores (p < 0.001). Combined neutrophilic scores of 4 and greater showed high specificities (90% to 100%) for sepsis-related deaths. Examining the percentage of sepsis cases as the histologic neutrophilic score increased found a positive slope in all three organs. However, only the linear regression looking at the lung (p = 0.03) and the combined score (p = 0.001) were statistically significant. Despite the above results, sepsis cases with low scores and controls with moderate and florid neutrophilic infiltrates were also seen.