Investigation of the prevalence of Sjögren's syndrome in treatment naïve patients with chronic lymphocytic leukemia

AIM: Sjögren's syndrome (SS) is an autoimmune disease characterized by lymphocytic infiltration of exocrine glands. Chronic lymphocytic leukemia (CLL) is a hematologic malignancy resulting from malignant transformation of B cells. B cell dysregulation plays a central role in both diseases. This study aimed to evaluate the frequency of SS in CLL patients compared to a control group. MATERIALS AND METHODS: This retrospective study included 83 CLL patients under treatment-free follow-up with reported sicca symptoms, diagnosed between January 1, 2011, and December 31, 2024, at Sakarya University Training and Research Hospital. The control group consisted of 160 age-matched patients without diabetes mellitus or malignancy, who applied to the Internal Medicine Clinic between October 1, 2024, and January 31, 2025. Demographic data, comorbidities, drug use, laboratory results, and SS diagnostic criteria were evaluated retrospectively. RESULTS: The mean age was 66.7±11.1 years in the CLL group and 64.0±10.2 years in the control group. The CLL group included 45.8% women and 54.2% men; the control group included 53.8% women and 46.2% men. SS frequency was 1.2% (1/83) in the CLL group and 1.3% (2/160) in the control group (p=0.998). Dry eyes lasting more than three months were observed in 7.2% of the CLL group and 5.0% of the control group (p=0.564); dry mouth was observed in 4.8% and 10.0%, respectively (p=0.220). A significant association was found between dry mouth and hypothyroidism (p<0.001) and thyroid medication use (p<0.001). CONCLUSION: SS frequency was not increased in CLL patients compared to controls. Sicca symptoms occurred at similar rates in both groups. Dry mouth showed a strong association with hypothyroidism and thyroid medication use, suggesting an endocrine contribution to sicca symptoms. Keywords: Autoimmunity, b cell dysfunction, chronic lymphocytic leukemia, sicca symptoms, sjögren's syndrome