Chromosome studies in scleroderma with consideration of anticentromere antibody status and assessment of possible in vitro clastogenic activity.

The constitutional karyotype and frequency of sporadic chromosome abnormalities in peripheral blood leukocytes from 30 scleroderma patients and 15 normal controls were studied. Fifteen of the scleroderma patients were positive for the anticentromere antibody (ACA) and 15 were negative. The constitutional karyotype of all patients and controls were normal. No statistically significant difference in sporadic chromosome abnormalities was detected among the two groups of scleroderma patients compared with the control group. The possibility of clastogenic activity in serum from scleroderma patients was investigated by culturing lymphocytes from three normal individuals in medium enriched with serum from either a normal control, an ACA-negative scleroderma patient or an ACA-positive scleroderma patient. There was no statistically significant difference in the frequency of sporadic chromosomal abnormalities among the cells in these experiments. The results of this study suggest that, contrary to previously reported studies, the frequency of sporadic chromosome abnormalities is not increased significantly in scleroderma patients. In addition, although the anticentromere antibody is reactive with chromosomal material, patients with this antibody do not have increased chromosome breakage or aneuploidy, and the antibody does not induce chromosomal changes in vitro.