Detection of circulating superantigens in an intensive care unit population

Objective: Plasma concentrations of superantigens were measured in an intensive care unit (ICU) population and the relationship of superantigen positive rates with the presence of sepsis was investigated. Methods: Plasma samples were collected at least twice a week from 78 patients whose primary diagnoses were abdominal disorders (n = 27), respiratory disorders (n = 11), trauma (n = 10), burns (n = 10), cardiovascular disorders (n = 4), neurological disorders (n = 2), and others (n = 14). Five different species of superantigens, i.e., staphylococcal enterotoxins A, B, and C (SEA, SEB, and SEC), toxic shock syndrome toxin-1 (TSST-1), and streptococcal pyrogenic exotoxin A (SPEA), were measured using an enzyme-linked immunosorbent assay. Results: Significant levels of plasma superantigens were detected in 16 patients. SEA was found in seven patients, SEB in four patients, SEC in two patients, TSST-1 in six patients, and SPEA in five patients. Superantigen detection rates were 6% (1/17) in patients without systemic inflammatory response syndrome (SIRS), 0% (0/21) in SIRS patients without infection, 31% (5/16) in septic patients without shock, and 42% (10/24) in septic shock patients. Conclusions: The presence of superantigens was confirmed in part of the ICU population. The role of superantigens in the pathogenesis of sepsis remains to be determined. (C) 2004 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.