Impact of Extracorporeal Detoxification on the Serum Levels of Microbial Aromatic Acid Metabolites in Sepsis

Abstract

A search for low molecular weight biomarkers to objectively evaluate the efficiency of extracorporeal detoxification methods is extremely relevant. For this purpose, the investigation is to verify whether metabolites, the production of which from aromatic amino acids in the human body can be of microbial ori gin, may be used. Objective: to evaluate the efficiency of extracorporeal detoxification methods on the serum level of phenyl carboxylic acids in patients with sepsis associated renal failure. Subjects and methods. Ten patients with acute or chronic (end stage) renal failure that had developed in the presence of severe sepsis, infective and toxic shock, long term extracorporeal circulation, postresuscitation disease, etc. were prospectively examined and treated. All the patients underwent extracorporeal detoxification; the choice of its technique was determined from their past medical history and intoxication patterns. The investigators eval uated organ dysfunctions using the Sequential Organ Failure Assessment (SOFA) scale, estimated body tempera ture, leukocyte count, and leukocyte index of intoxication, and assessed the results of a procalcitonin test. Hemodiafiltration was done as extrarenally indicated to ameliorate a systemic inflammatory response in septic shock, by applying an EMiC 2 superhigh permeability dialyzer. Low flux Diacap LO PS dialyzers were employed for hemodialysis. Blood samples were taken to estimate changes in the serum concentrations of phenylcarboxylic acid, benzoic acid, 3 phenylpropionic acid, phenyllactic acid, para hydroxyphenylacetic acid (p HPAA), and para hydroxyphenyllactic acid (p HPLA) directly before and immediately after extracorporeal detoxification. Results. The severity of organ dysfunctions by SOFA score was 10—22 (mean 16 scores); 10 day mortality rates were 40%. In all the patients, the baseline serum levels of some phenylcarboxylic acids were considerably above normal. After hemodiafiltration, the serum concentrations of p HPAA and p HPLA decreased (by an aver age of 1.7 and 1.85 fold, respectively). Conclusion. In sepsis associated renal failure, the clearance rate of microbial aromatic acid metabolites (p HPAA and p HPLA) is promising potential biomarker to evaluate the efficiency of extracorporeal detoxification methods.