Comparative studies of the acid mucopolysaccharide composition of rheumatic and normal heart valves in man.

The nature and relative proportions of acid mucopolysacharides (AMPS) in mitral valves of normal individuals and individuals with rheumatic valvular disease were compared.The total AMPS content of valves from rheumatic patients under 21 years of age is significantly higher than that from older rheumatic patients and higher than that from age-matched normal controls.The major AMPS components of both normal and rheumatic valvular tissue are hyaluronic acid, chondroitin sulfate A/C, and chondroitin sulfate B. Valves from normal individuals in all age groups studied contain approximately 65% hyaluronic acid, 25% chondroitin sulfate A/C, and 10% chondroitin sulfate B. Valves from rheumatic patients under 40 years of age contain the same proportions of these components as do normal valves.However, valves from rheumatic patients above 40 years of age show a marked alteration in AMPS composition; they contain 35% hyaluronic acid, 47% chondroitin sulfate A/C, and 18% chondroitin sulfate B. The differences in total AMPS content between valves from young rheumatic and nonrheumatic individuals may reflect changes that are secondary to the acute inflammatory process or an abnormality in AMPS synthesis following acute injury that is peculiar to the rheumatic host.The alterations in AMPS content and composition in valves of older rheumatic patients probably reflect changes in AMPS turnover associated with fibrosis that occurs in chronic disease of valvular tissue.ACID mucopolysaccharides are primary components of the ground substance of valvular tissue.'Torii and his coworkers 2 described the nature of the acid mucopolysaccharide composition of human valvular tissue and the changes that occur in these components during the aging process.These investigators reported that differences in acid mucopolysaccharide content are encountered in valvular tissue from young individuals and that aging is associated with a decrease in acid mucopolysaccharide content of aortic, mitral, and tricuspid valves.Morphological studies by Sell and Scully :f revealed that aging of human valves is associated with fibrosis and degeneration of collagen fibers, a decrease in acid mucopolysaccharides, lipid accumulation, and progressive calcification.These changes are seen in both mitral and aortic valvular tissues but are more prominent in aortic valves.No data are available on the composition and changes in acid mucopolysaccharide content of valvular tissue in rheumatic valvular heart disease.The present study was undertaken to determine whether differences are present in the acid mucopolysaccharide composition of rheumatic valvular tissue, as compared to normal tissue, and to determine the changes in valvular tissue acid mucopolysaccharide composition that are associated with acute and chronic valvular disease in rheumatic patients.Because the mitral valve is more frequently and specifically af-From the Departments of Pediatrics and Surgery, University of Florida, Gainesville, Florida.