Discrepancies betweenin vivo andin vitro responses toCandida antigen in patients with progressive systemic sclerosis (PSS; scleroderma)

Persistence of scleroderma-like phenotype in normal fibroblasts after prolonged exposure to soluble mediators from mononuclear cells

Supernatants of mononuclear cells (MNC-SN) were shown to increase synthesis of glycosaminoglycan (GAG) by cultured normal dermal fibroblasts. Fibroblasts from the skin of patients with progressive systemic sclerosis (PSS, scleroderma) were hyporesponsive. We exposed fibroblasts outgrowing from explants of normal adult skin to MNC-SN for up to 30 generations in culture. MNC-SN were obtained by incubating normal MNC with concanavalin A. Four experimental, 4 normal control, and 3 PSS control lines were passaged by trypsinizing and splitting the cultures 1:2 every 7 days. At the third and fifth passages, portions of the experimental fibroblasts were removed from MNC-SN, then passaged in medium alone. Cell counts, assays for GAG, and electron microscopy were performed and increases in GAG after brief reexposure to MNC-SN were determined at the third, fifth, and eighth passages. In normal dermal fibroblasts, baseline GAG production, measured by 3H-glucosamine uptake, was low and increased as much as 15 times after reexposure to MNC-SN. In contrast, production was high in both experimental and PSS lines, and increases after reexposure to MNC-SN were consistently small. This PSS-like behavior persisted in experimental fibroblasts removed from MNC-SN at the third and fifth passages. Growth of experimental and scleroderma fibroblasts was slower than that of control fibroblasts. Ultrastructurally, both scleroderma and experimental dermal fibroblasts differed from normal fibroblasts by their oval cellular shape, indentations in nuclear membrane, numerous organelles and bundles of microfilaments, prominent Golgi, and intranuclear inclusions. These experiments indicate that normal adult dermal fibroblasts subjected to MNC-SN in vitro acquire a scleroderma-like phenotype that persists for many generations.

Modulatory effect of sera from scleroderma patients on lymphocyte-induced angiogenesis

Sera from 22 patients with progressive systemic sclerosis were tested for the ability to modify the angiogenic capability of normal human mononuclear cells. The sera from patients with acrosclerosis, including the abortive form (CREST syndrome: calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias), markedly enhanced this capability compared with sera from both healthy donors and patients with severe acrosclerosis and diffuse scleroderma. The enhancing effect of sera from patients with acrosclerosis decreased and/or disappeared in cases where the patient's acrosclerosis was chronic and severe. Thus, this test may be of diagnostic value in distinguishing various subgroups of systemic sclerosis.

Suppressor cell function and T lymphocyte subpopulations in peripheral blood of patients with progressive systemic sclerosis

Three different in vitro assays--immunofluorescence with monoclonal anti-T cell reagents, enumeration of T gamma cells, and nonspecific suppressor cell function--were used for the analysis of suppressor lymphocytes in the circulation of 28 patients with progressive systemic sclerosis (PSS, scleroderma) and 20 normal individuals. Both OKT8+ and T gamma lymphocytes were significantly reduced (P less than 0.001 and P less than 0.02, respectively) in patients with PSS compared with controls. The OKT4/OKT8 ratio was increased (P less than 0.02). However, the mean suppressor cell index (SCI) of 1.9 (range 0.4-6.6) for patients with PSS was not significantly different (P greater than 0.05) from the SCI of 2.9 (range 1.2-14) for controls. Eleven of the patients had depressed suppressor cell function as indicated by the index value of less than 1.2. In only 5 of these patients, simultaneously measured T gamma and OKT8+ cells were reduced and OKT4+ lymphocytes were concomitantly increased. There were no significant correlations between the numbers of T gamma or OKT8+ cells and the SCI in patients and controls. Neither depressed suppressor cell function nor the OKT4+/OKT8+ ratio greater than 4.2 (greater than 2 SD of normal) in the patients could be related to other immunologic findings, to disease duration and severity, or to involvement of internal organs. These results suggest that depressed suppressor cell activity and immunoregulatory T cell imbalance in PSS may not be directly related to the pathogenesis of the disease.