Sequential anti-core glycolipid immunoglobulin antibody activities in patients with and without septic shock and their relation to outcome

OBJECTIVE: This study follows the sequential changes in anti-lipopolysaccharide antibodies in infected patients with and without septic shock. SUMMARY BACKGROUND DATA: A relation between high endogenous levels of anti-LPS antibodies and protection against bacteremia and septic shock in at-risk patient groups has been observed. However, information on the daily follow-up and kinetics of apparition or disappearance of anti-LPS antibody activities and their relations with the protective properties of the different immunoglobulin classes has not been clearly investigated. METHODS: Two hundred and five septic surgical patients were studied during their stay in the intensive care unit during a period of 3 years. Among these patients, septic shock developed in 54 and 47 died. A sensitive ELISA was used to study circulating IgM and IgG antibodies to the core glycolipid (CGL) region of Salmonella minnesota R595. The activities were measured each day when sepsis occurred and every hour during septic shock. RESULTS: Anti-CGL IgM activity was found in 32% of the septic patients. This response, however, most often appeared to be transient. A strong correlation was observed between the occurrence of septic shock and the absence of anti-CGL IgM activity on admission to the ICU (p < 0.02). Anti-CGL IgG activity was detected in 82% of the patients and better correlated with outcome for patients with high or rising activities during their hospitalization (p < 0.0005). In patients with septic shock or irreversible organ failure, a fall in the anti-CGL IgG activity was observed before death, suggesting that the IgG antibodies were consumed during this acute event. Therefore, the anti-CGL IgG activity measured by ELISA could be used as a marker of the evolution of the illness. CONCLUSIONS: Our observations demonstrate the interest to follow-up the evolution of the anti-CGL antibodies during sepsis. The fall of these antibodies during septic shock and in patients who died was an additional argument to perform, as an additive form, passive antibody therapy to decrease lethality in this group of patients.