Cellular immunity in progressive systemic sclerosis (scleroderma).

Progressive systemic sclerosis (PSS) or scleroderma is a multisystem disease which is usually grouped with other systemic rheumatic or connective tissue disorders. As a class these conditions are believed to result, at least in part, from aberrant immunity (Rodnan, 1971). Previous studies have demonstrated that a significant percentage of affected patients develop a spectrum of autoantibodies, including antinuclear antibodies and rheumatoid factor (Rothfield and Rodnan, 1968; Beck, Anderson, Gray, and Rowell, 1963; Selignann, Cannat, and Hamard, 1965). However, to date, there has been no systematic investigation of cell-mediated immunity in this *disorder. The present investigation constitutes an evaluation of two parameters of this immune defence mechanism: the ability to manifest a cutaneous delayed hypersensitivity reaction and the in vitro lymphoproliferative response to the non-specific mitogen phytohaemagglutinin (PHA).