Opsonic activity of sera and blister fluid from severely burned patients evaluated by a chemiluminescence method

Burn wound sepsis is the most common and severe complication in the patients with severe burn. To know the systemic and local defect in immunity of burned patients, we measured the luminol-enhanced chemiluminescence (CL) response of normal polymorphonuclear leukocytes (PMNs) upon exposure to zymosan particles, bacteria or Candida albicans that were opsonized with any of patient's serum, blister fluid of burn wound or pooled normal serum (blood type AB). Sera from patients exhibited lower opsonic activities than those of pooled normal serum in the early postburn days. The levels of serum immunoglobulins, complement components and plasma fibronectin were found to correlate well with opsonin-index (OI), which was determined based on the CL response data obtained during the course of infusion therapy with fresh frozen plasma. Furthermore, patient's blister fluid showed much lower opsonic activity against bacteria such as Pseudomonas aeruginosa than patient's own serum. These results indicate that blister fluid is also not effective to opsonize bacteria because of the marked depression of the levels of immunoglobulins and complement components. Destruction of the skin barrier by thermal injury and impairment of systemic or local humoral immunity may predispose these patients to burn wound sepsis.