Proinflammatory cytokines IL-6, IL-1β, TNF-α in infective endocarditis

Aim. To study the features of macrophages in the tissues of resected valves in operated patients with infective endocarditis (IE), their significance and interaction with inflammatory markers to improve the effectiveness of IE diagnosis. Materials and methods. Prospectively the research included 25 adult patients with active IE (Duke criteria 2015) and 24 patients with heart defects without IE, hospitalized in a cardiosurgical hospital in Moscow (2021–2022). A standard laboratory and instrumental examination was carried out for the diagnosis of IE, including etiological diagnosis with microbiological and molecular biological methods, and echocardiographic examination of heart. Additionally, the neutrophil-to-lymphocyte ratio (NLR) was calculated. The study of macrophages was carried out in the tissues of resected valves with the determination of the expression of pro- and anti-inflammatory cytokine genes, macrophage markers (CD 68+) using real-time PCR. Results. Increased expression of proinflammatory cytokines IL-1β, TNF-α and IL-6 was revealed in the group of operated patients with IE with significant differences in IL-1β (CI [IQR] 0.00367 [0.00047–0.01553] vs 0.00018 [0.00012–0.00262]; p0.05) and IL-6 (CI [IQR] 0.00367 [0.00047–0.01553] vs 0.00018 [0.00012–0.00262]; p0.05) and IL-6 (CI [IQR] 0.00338 [0.00066–0.01674] vs 0.00054 [0.00044–0.00378]; p0.05). The expression of anti-inflammatory cytokines in valve tissues prevailed in the control group without significant differences from patients with IE. The macrophage marker CD 68+ was revealed in all examined patients with a significant quantitative predominance in the group of patients with IE. There were no differences in the expression of pro- and anti-inflammatory cytokines depending on the presence of embolic events, intracardiac complications, etiological affiliation to S. aureus, as well as hospital mortality and combined endpoint (death from all causes or recurrence of IE 6 months after surgery) in patients with IE with or without events. Cytokines IL-1β and IL-6 positively correlated with each other, with leukocytes and NLR. ROC analysis determined that IL-1β and NLR had the most favorable features for the diagnosis of IE [IL-1β AUC 0.816 (p=0.02), NLR AUC 0.807 (p=0.03)]. IL-6 did not show a diagnostic value in IE. The threshold value for IL-1β was 0.00029 (sensitivity 86.4%, specificity 60.0%, prognostic value of negative result 75.0% and positive 76.0%, AUC 0.761; p=0.008). Conclusion. The valve macrophages of patients with IE express elevated levels of proinflammatory cytokines IL-1β and IL-6, regardless of etiological affiliation or complicated course of IE. IL-1β has a high diagnostic value for determining the inflammatory activity in IE

Clinical and diagnostic value of including PCR blood test in the traditional algorithm for identifying causative agents of infective endocarditis: a cohort study of 124 patients

Background. If infective endocarditis (IE) is suspected, the determination of the etiology is of fundamental importance for the verification of the disease and the appointment of effective therapy. Microbiological diagnostic features are important, but they often need to be supplemented by culture-independent studies of pathological agents. Aim. To investigate of the diagnostic advantage and value of quantitative analysis of molecular biological methods (polymerase chain reaction PCR, sequencing) in addition to microbiological examination of whole venous blood in IE. Materials and methods. We examined 124 patients with suspected or significant IE (DUKE 2015) hospitalized in the Vinogradov City Clinical Hospital (20152021). All patients underwent parallel microbiological (cultural) and molecular biological (PCR or PCR followed by sequencing) examination of venous whole blood samples. Results. The introduction of an early parallel PCR study into the algorithm for the etiological diagnosis of IE made it possible to obtain an additional advantage in 43/124 (34.7%) patients, which made it possible to exclude unreliable results in the determination of CoNS skin commensals and pathogens atypical for IE or contamination and identify the true pathogens, and also for the first time to isolate the etiopathogenetic pathogen with a negative microbiological study. It was shown that in IE associated with CoNS, the association with the disease was confirmed by PCR in 21.4% (3/14) and refuted in 71.4% (10/14). The coincidence of the results of microbiological and PCR studies of blood samples was obtained only in 35/95 (36.8%). Positive results of PCR analysis of blood of biological material with negative results of culture were obtained in 22/51 (43.1%), of which 2/22 (9.0%) were able to confirm the presence of Bartonella spp DNA. The presented complex algorithm made it possible to significantly increase the possibility of intravital identification of the pathogen in the blood from 58.9 to 76.6%. IE with unknown etiology was present in 29/124 (23.4%) patients. A parallel PCR study allowed timely correction of antibiotic therapy in 43/124 (34.7%) patients. Conclusion. Expansion of indications for the use of PCR studies, primarily whole venous blood samples, is justified, not only in IE with negative results of microbiological examination, but also as a control method for the reliability of the results of traditional (cultural) diagnostic methods