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.