The high frequency of spontaneous micronuclei observed in lymphocytes of systemic sclerosis patients: preliminary results

Objective: aim of the study is to assess the presence of spontaneous chromosome damage in patients affected by limited (lSSc) or diffuse (dSSc) Systemic Slerosis, using the micronucleus (MN) assay. Methods: we evaluated MN frequency in cultured peripheral lymphocytes of 18 SSc and in a group of 20 healthy controls. Patients were also classified as ACA+, Scl70+, FAN+ according to the presence of the specific anti-nuclear antibodies. We also explored the hypothesis that the extent of cytogenetic alteration might be related to the severity of the pathological condition and/or to the immunological profile. Results: compared to controls, the patient group as a whole showed significantly higher MN frequencies (10.8±4.5 vs. 27.8±13.7, p<0.001). No correlation was found between spontaneous chromosome damage and severity of the disease, being MN frequency 33.1±17.0 and 19.8±2.7 in lSSc and dSSc, respectively. Interestingly, ACA+ subjects displayed the highest MN frequency (36.9±15.0), as compared to patients with different antibody pattern (Scl70+, FAN+; 19.7±8.2). Conclusions: our results confirm the presence of chromosomal damage in circulating lymphocytes of SSc patients and would suggest a key role of antibodies to the centromere in determining the observed cytogenetic anomalies.