[Possible role of natural cytotoxicity in impairment of collagen catabolism in focal scleroderma].

Relationship between the state of natural cytotoxicity and collagen catabolism were studied in patients with focal sclerodermia. In the impairment activity of natural killer cells (NK cells) was markedly altered depending on such clinical parameters as duration, severity, activity and distribution of the disease as well as it was related to definite transformations in catabolism of collagen proteins. Low rate of collagen production and intensive collagenolytic processes correlated with the high level of hydrolytic activity of NK cells at the early steps of systemic morphea guttata accompanied by highly progressive course of the disease. Under conditions of subacute forms of focal morphea guttata activity of NK cells was distinctly decreased down to 50% of that of normal state and was accompanied by alterations in the spectrum of collagenolytic enzymes as well as by considerable variations in collagen production and in posttranslational modification of collagen fibrils. During the chronic step of sclerodermia activity of NK cells was normalized and correlated with the lowered rate of collagen production as well as with the subsequent alterations in collagen proteins catabolism. Alterations in the level of natural cytotoxicity appear to correlate with the state of collagen metabolism in focal sclerodermia.