Immunohistochemical Evaluation of Collagen-I and Collagen-III Content in Heart Valve Tissue of Surgical Patients with Different Forms of Infective Endocarditis

Sergey A. Kovalev ¹, Dmitry V. Griaznov ¹, Alexander N. Kinshov ², Evgeniy V. Pershin ³

¹ Voronezh Regional Clinical Hospital No1, Voronezh Burdenko State Medical University, Voronezh, Russia; ² Voronezh Burdenko State Medical University, Voronezh, Russia; ³ Voronezh Regional Pathoanatomical Bureau, Voronezh, Russia;

Date, time and location: 2018.05.26 15:30, Congress Hall, 2F–B

Abstract

Objective. Imbalance in collagen type I (C1) and collagen type III (C3)incidence in heart valve tissue is described in bicuspid aortic valve (AV) and mitral valve (MV) prolapse. Also, the synthesis and destruction of these extracellular matrix (EM) proteins are in disproportion in conditions of inflammation. The aim of study was to evaluate the influence of infective endocarditis (IE) and the role of underlying heart disease on C-I and C-III expression.

Methods. 60 native heart valves from IE patients and 28 valves from patients with non-infective valve disease, all samples taken intraoperatively, were studied. Immunostaining was performed using Anti-Collagen types I and III antibodies. Protein expression was estimated via calculation of optical density.

Results. Inside the control group no differences in the level of C-I and C-III between MV and AV (p_C1=0.378,p_C3=0.486) were found. Tricuspid valve specimens both in control and in IE groups gave significantly lower rates of C-I and C-III expression (p<0.0001). Studying subgroups with calcified aortic stenosis (CAS) and IE-complicated CAS cases gave statistically less levels of both collagen types (p_C1=0.003; p_C3=0.019; p_C1IE<0.0001 and p_C3IE<0.0001).

The search of deviations results caused by IE were: comparing general IE and general control groups no differences in C-I expression were identified, and the level of C-III in IE group was significantly lower (p<0.0001). The studying of collagen expression in acute IE has revealed the decrease of both C-I and C-III (p<0.0001). In subacute IE the level of C-I was higher (p<0.0001) and the level of C-III was lower than in control group (p=0.001).

Conclusions. EM proteins distribution in IE is under the influence of valve lesion localization and the underlying heart disease. The main IE hallmark was the decrease of C-III. The results can provide useful information for understanding connective tissue dysfunctions in IE patients.