Investigation of Genomic Instability in Patients with Sjogren's Syndrome by Using Sister Chromatid Exchange Analysis

Abstract

Purpose: To investigate genomic instability by using Sister Chromatid Exchange (SCE) in the peripheral blood lymphocytes in patients with Sjogren's syndrome (SS). Patients and Methods: The frequency of SCE (per metaphase) was investigated in patients with primary Sjogren's Syndrome (n=30), in untreated lymphoma patients (n=15) and healthy individuals (n=15) who constitute the control groups. Results: We found the mean frequencies of SCE in the patients with SS, untreated lymphoma and healthy controls as 7.77 +/- 1.50, 8.80 +/- 0.75, 6.65 +/- 1.50, respectively. We found statistically significant differences between patients with SS and lymphoma (p=0.007) and also between patients with lymphoma and healthy controls (p=0.0001). No significant difference was observed between patients with SS and healthy controls in regard of mean frequencies of SCE (per metaphase). Conclusion: It is well known that up to 5.0% of all SS patients may develop lymphoma. High frequency of SCE is regarded as a cytogenetic biomarker of early mutagenic effect suggesting increased risk of cancer. We observed that the mean frequencies of sister chromatid exchanges (per metaphase) of three patients with SS were higher than those of untreated lymphoma patients. This result can only be verified by prolonged follow-up of these patients. We suggest that results should be interpreted by evaluating other parameters which play important roles in malignant transformation.