Diagnosis of infectious complications in patients with acute pancreatitis
Authors: Sishchikov Dmitry S. , Alent’ev Sergey A. 
Published: July 2022

BACKGROUND: Up to 30% of patients with acute pancreatitis suffer from the severe form of the disease, of which 30% of cases are lethal, significantly rising to 80% at the development of infectious complications.
AIM: To improve treatment results of patients with acute pancreatitis due to early diagnostics of infectious complications.
MATERIALS AND METHODS: Expression of CD64 antigen on neutrophil membrane (DC64 index of neutrophils) was studied using a flow cytometer Cytomics FC500 (Beckman Coulter, USA) using 3-color combination of direct monoclonal antibodies Beckman Coulter: СD14FITC/CD64PE/CD45PC5. Material was whole blood.
RESULTS: A direct correlation of moderate strength with the development of sepsis was found for both the procalcitonin value and C-reactive protein concentration at this period of illness. However, no relations of endogenous intoxication markers with the development of infectious complications were found (correlation coefficients less than 0.4). Thus, it should be noted that the difference in the indices of the studied parameters of the CD64 antigen expression in the groups began to increase exactly during the 23rd week of the disease.
CONCLUSION: Based on the literature data, we formulated a working hypothesis, which states that the degree of CD64 receptor expression on peripheral blood neutrophils is an early marker of infectious complications of acute pancreatitis. The value of average fluorescence intensity index of molecules CD64 equal to 10 conventional units was accepted as a threshold value with regard to the development of IE, and the value of 15 conventional unitsas a threshold value with regard to sepsis. The study was conducted in a prospective group of 28 patients. In accordance with the provision of the working hypothesis, the patients were divided into 3 groups depending on the level of average fluorescence intensity index of molecules CD64. Expression of the CD64 receptor on peripheral blood granulocytes as an early laboratory marker of infectious complications of the disease was studied for the first time. We determined sensitivity and specificity, optimal terms of the given research, detected regularities of CD64 expression changes in the course of acute pancreatitis, correlations with other clinical and laboratory indexes, including prospective markers of infection (procalcitonin, C-reactive protein), with the integral scales of severity estimation of patients with acute destructive pancreatitis. Determination of the level of the receptor CD64 expression on the peripheral blood neutrophils showed that this marker reflects the dynamics of the disease course and gives the possibility of the early diagnostics of the infectious complications of acute pancreatitis. The use of this method provides additional information about the development of the surgical infection. It is important that the changes of CD64 antigen expression in dynamics outrun other markers of systemic inflammatory response and sepsis. CD64 antigen expression data on peripheral blood neutrophils is an additional factor in determining differentiated surgical tactics in phase I of the diseases development with regard to acute fluid collections in patients with acute pancreatitis.