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We evaluated the occurrence of spontaneous chromosome damage in cultured peripheral lymphocytes of subjects with idiopathic and pre-scleroderma Raynaud's phenomenon, by means of molecular cytogenetic analysis. Using the micronucleus assay as a marker of chromosome alteration, we studied 30 patients with pre-scleroderma Raynaud's phenomenon, 30 patients with idiopathic Raynaud's phenomenon and 30 healthy subjects. All subjects were classified as ANA-, ACA+ or Scl 70+. To identify the mechanism of micronucleus formation, fluorescence in situ hybridisation analysis was also performed. Pre-scleroderma Raynaud's phenomenon subjects showed significantly higher micronucleus frequencies than idiopathic Raynaud's phenomenon subjects and controls (37.0 +/- 11.5 vs. 11.1 +/- 3.2 and 10.7 +/- 2.7 respectively p < 0.0001). Interestingly, subjects with idiopathic Raynaud's phenomenon displayed micronucleus frequency comparable to that of healthy controls. Furthermore, ACA+ subjects showed the highest micronucleus frequencies (41.0 +/- 7.6) as compared to subjects with Scl 70+ antibody (25.0 +/- 3.5). Our results show that circulating lymphocytes of only pre-scleroderma Raynaud's phenomenon subjects undergo chromosomal damage, as detected by the micronucleus assay, at a higher rate than expected. No prevalence of aneuploidogenic or clastogenic events in micronucleus formation is revealed by fluorescence in situ hybridisation analysis.

Objective: To evaluate the prevalence of spontaneous chromosome damage in cultured peripheral lymphocytes of patients with systemic sclerosis (SSc), idiopathic Raynaud's phenomenon (RP), and suspected secondary RP, by means of molecular cytogenetic analysis., Methods: We studied 43 patients with SSc, 13 with idiopathic RP, and 16 with suspected secondary RP and 25 healthy controls. As a marker of chromosome alteration we used the micronucleus (MN) assay. All subjects were also classified for antinuclear antibodies, anticentromere antibodies (ACA), or Scl70. To identify the mechanism of MN formation, we also performed MN fluorescence in situ hybridization (FISH) analysis using a pancentromeric DNA probe., Results: Patients with SSc and subjects with RP showed significantly higher MN frequencies than controls (25.9 +/- 1.7 and 19.1 +/- 2.15, respectively, vs 9.4 +/- 2.2; p < 0.001). Subjects with suspected secondary RP displayed MN frequency (23.5 +/- 2.7) comparable to that of SSc patients, while spontaneous MN level in idiopathic RP subjects (13.6 +/- 3.0) did not differ significantly from controls (9.4 +/- 2.2). ACA positive subjects showed the highest MN frequencies (32.8 +/- 1.7) compared to subjects with a different antibody pattern (18.3 +/- 1.6)., Conclusion: Our results show the presence of higher levels of micronuclei in circulating lymphocytes of patients with SSc and subjects with suspected secondary RP. They also suggest a possible role of ACA in determining cytogenetic anomalies. FISH analysis indicated that both aneuploidogenic and clastogenic events contributed to the formation of MN observed in SSc patients and subjects with suspected secondary RP.

Objective: To evaluate the prevalence of spontaneous chromosome damage in cultured peripheral lymphocytes of subjects with suspected presclerodermic Raynaud's phenomenon (RP), by means of molecular cytogenetic analysis., Methods: We studied 20 suspected presclerodermic RP, 20 idiopathic RP and 25 healthy subjects. As marker of chromosome alteration we used the micronucleus assay. All subjects were also classified as ANA-, ACA+ or Scl70+. To identify the mechanism of MN formation, a MN fluorescence in situ hybridisation (FISH) analysis using a pancentromeric DNA probe was also performed., Results: Suspected presclerodermic RP subjects, showed significantly higher MN frequencies than idiopathic RP and controls (39+/-15.2 vs 10+/-2.1 and 9.8+/-3.5 respectively p<0.0001). Interestingly, subjects with idiopathic RP displayed MN frequency comparable to that of controls. Furthermore, ACA+ subjects showed the highest MN frequencies (44+/-8.1) as compared to subjects with different antibody pattern (26+/-7.1)., Conclusions: Our results show the presence of higher levels of chromosomal damage in circulating lymphocytes of suspected presclerodermic RP. They also would suggest a key role of anti-centromere antibody in determining the observed cytogenetic anomalies. FISH analysis indicated that both aneuploidogenic and clastogenic events contribute to the formation of MN observed in suspected presclerodermic RP.