The prevalence of enteroviral RNA and protein in mitral valves of chronic rheumatic heart disease.

INTRODUCTION: Acute Rheumatic Fever/ Rheumatic Heart Disease (ARF/RHD), a sequel of group A streptococcal (GAS) infection, even today constitutes a public health issue in developing countries including India. Differences in the prevalence of ARF/RHD in countries with a similar prevalence of GAS infections indicate the role of other cofactors in pathogenesis of RHD. METHODOLOGY: We investigated the prevalence of enterovirus (EV) in RHD by probing for both EV RNA and VP1 protein using Nonisotopic In Situ Hybridization (NISH) and Immunohistochemistry (IHC) respectively in 75 valvectomy specimens obtained from RHD cases. RESULTS: Twenty-eight (37%) of the valves showed tissue inflammation with lymphocytic infiltration in a majority of the cases. Twenty-six and 27 (38% and 40%) of the 68 valves showed the presence of EV by IHC and NISH respectively, indicating a very good association between the two tests; however, only about 46 to 48% of them exhibited tissue inflammation. In eight cases (12%) the EV genome was detectable in absence of VP1 protein perhaps indicating a latent viral infection. CONCLUSIONS: Due to a high degree of endemicity of EV in India, we are tempted to speculate that EV may be responsible for the severity and rapid progression of RHD. The virus could either be working synergistically with GAS or could be an opportunist infecting damaged valves.

Valvular Cytomegalovirus Endocarditis.

Endocarditis is a rare presentation for cytomegalovirus (CMV) infection. We present the case of a 49-year-old man who underwent mitral and tricuspid valve replacement for valvular CMV endocarditis. The patient's past medical history was significant for human immunodeficiency virus, intravenous drug abuse, and chronic hepatitis B. During his clinical course, he was found to have tricuspid and mitral valve vegetations. After progressive valvular destruction despite antibiotic therapy, he underwent successful mitral and tricuspid valve replacement. Pathologic analysis of the culture-negative valve specimens were found to contain inclusion bodies consistent with CMV, and quantitative serum polymerase chain reaction returned a highly elevated CMV DNA count.

Demonstration of Chlamydophila pneumoniae, Mycoplasma pneumoniae, Cytomegalovirus, and Epstein-Barr virus in atherosclerotic coronary arteries, nonrheumatic calcific aortic and rheumatic stenotic mitral valves by polymerase chain reaction.

OBJECTIVE: The aim of this study was to investigate whether bacterial and viral infectious agents can be demonstrated in atherosclerotic lesions of patients with coronary artery disease (CAD) as well as in stenotic aortic and mitral valves from patients undergoing heart valve replacement. METHODS: In this cross-sectional study, the presence of Chlamydophila pneumoniae, Mycoplasma pneumoniae, Cytomegalovirus (CMV), and Epstein-Barr virus (EBV) was investigated by polymerase chain reaction in atherosclerotic and non-atherosclerotic vascular samples taken from patients undergoing coronary artery bypass surgery due to CAD, and from patients undergoing aortic (AVR) and/or mitral valve replacement (MVR) secondary to valvular stenosis. For statistical analyses ANOVA, Chi-square test or Fisher's exact test were used. RESULTS: The presence of C. pneumoniae, M. pneumoniae, and CMV in atherosclerotic versus non-atherosclerotic samples was as follows: 30% vs. 16.7% (p=0.222), 6.7% vs. 3.3% (p=0.554), and 10% vs. 0% (p=0.076), respectively. In valve group, same pathogens were present in AVR and MVR patients as follows: 24.2% vs. 21.4% (p=0.773), 9.1% vs. 7.1% (p=0.758), and 21.2% vs. 11.9% (p=0.275). EBV DNA was not detected in any of vascular specimens, but in one (3%) patient with AVR (p=0.256). CONCLUSION: Our results suggest that C. pneumoniae, M. pneumoniae, and CMV are present with similar frequency both in atherosclerotic and non-atherosclerotic vessels. We conclude that although non-atherosclerotic, vascular samples of CAD patients are invaded by infectious agents as like as atherosclerotic vessels. We further conclude that C. pneumoniae, M. pneumoniae, and CMV are present in stenotic aortic and mitral valves and atherosclerotic tissues with similar frequency indicating that atherosclerosis and valvular stenosis might share a common etiology related to infection.

Heart valves from pigs and the porcine endogenous retrovirus: experimental and clinical data to assess the probability of porcine endogenous retrovirus infection in human subjects.

OBJECTIVE: Replacement of heart valves in human subjects has become a routine procedure in cardiac operations. We sought to investigate whether commercially available glutaraldehyde-fixed porcine heart valve prostheses cause porcine endogenous retrovirus infection in human subjects because recent studies revealed that human cells can be infected with porcine endogenous retrovirus. METHODS: Blood samples of 18 patients who underwent aortic or mitral valve replacement with porcine heart valves were collected 6 months to 3 years after operation and tested for porcine endogenous retrovirus by means of polymerase chain reaction and reverse transcriptase-polymerase chain reaction. In addition, we tried to trace porcine endogenous retrovirus in 3 commercially available, glutaraldehyde-fixed, porcine heart valves. RESULTS: Porcine endogenous retrovirus can be easily detected in native porcine heart valves and degrades completely within 1 week of fixation in glutaraldehyde. In all 3 commercially available porcine heart valves, no traces of porcine endogenous retrovirus were found. All blood samples showed negative test results for the porcine endogenous retrovirus genome. CONCLUSION: Our results indicate that glutaraldehyde fixation of porcine heart valves reliably prevents cross-species transmission of porcine endogenous retrovirus.