Chromogenic Limulus Amoebocyte Lysate Assay in Early Etiologic Diagnosis of Peritonitis in Patients on Continuous Ambulatory Peritoneal Dialysis

摘要

Although substantial progresses have been made in etiologic diagnosis of continuous ambulatory peritoneal dialysis (CAPD) peritonitis, the length of time until cultures are obtained remains unacceptable long; at least for the first 48 h, indiscriminate use of broad spectrum antibiotics is seen in clinical practice with various side effects and with high-rates of transfer on hemodialysis. Therefore, alternative methods for early etiological diagnosis are stringently needed. During a 4-years study, we conducted qualitative and quantitative chromogenic LAL (Limulus amoebocyte lysate) assay completed with beta-1,3-glucans blocking-sequence on 114 peritonitis episodes in 43 CAPD patients. The results were analyzed in parallel with the cultures of dialysate effluents. Sensitivity and specificity for Gram-negative peritonitis were evaluated in both tests; a receiver operating characteristic (ROC) plot was used to analyze the cutoff value for a maximum sensitivity and specificity of quantitative test in diagnosing Gram-negative infections. Screening LAL chromogenic test had a sensitivity of 92.7% and a specificity of 90.4% in establishing diagnosis of Gram-negative peritonitis. In quantitative LAL test (completed with blocking LAL-beta-1,3-glucans reaction), the ROC plot emphasized a sensitivity of 100% and a specificity of 95.89% at endotoxin levels of 0.423 EU/mL or greater. In conclusion, our study demonstrates a high sensitivity and specificity of chromogenic LAL assay for the detection of peritoneal Gram-negative peritonitis. Chromogenic LAL assay is a useful test in early diagnostic of peritonitis in CAPD patients and it should be recommended as a routine in clinical practice.