Sjögren syndrome and fibromyalgia after radioiodine therapy in cancer thyroid patients

Abstract

IntroductionSalivary and lacrimal gland dysfunction is relatively frequent after radioiodine therapy. An association of Sjögren’s syndrome (SS) and other autoimmune rheumatic diseases as fibromyalgia syndrome (FMS) has been reported. Thyroid autoimmunity in FMS patients is higher than normal subjects. Aim of the workTo detect the occurrence of Sjögren syndrome (SS) and any rheumatologic association in cancer thyroid patients after radioactive iodine therapy (I-131) and evaluate the salivary and lacrimal glands function. Patients and MethodsThirty-one patients with post-surgical differentiated thyroid carcinomas with a mean age 40.13±9.82years, were referred for I-131 therapy (mean dose 212.9±101.63mCi) and continued the follow-up study. All patients had no symptoms or signs of SS. Thorough rheumatological examination was performed for any musculoskeletal manifestation or associated fibromyalgia syndrome (FMS). Before and 8–12months after I-131 therapy, salivary glands function was estimated by sequential scintigraphy, while lacrimal gland function was assessed by Schirmer’s test. Antinuclear antibody (ANA), anti-Ro (SS-A), anti-La (SS-B) and rheumatoid factor (RF) were performed. ResultsAll patients had a normal salivary glands scintigraphy and Schirmer’s test before I-131 therapy. On follow up, primary SS occurred in 8 patients (25.81%) while a significant decrease in salivary function occurred in 18 (58.1%) patients and significantly correlated with the I-131 dose. Schirmer’s test was significantly abnormal in those with SS. Serum Anti Ro and Anti La levels became significantly higher in SS patients (18.25±11.61 and 25±13.06U/ml) compared to the others (6.57±1.8 and 7.35±1.8U/ml), respectively, (p 0.025 and 0.006). Fibromyalgia syndrome was present in 12 patients (38.71%) and 6 of them developed SS. ConclusionAssessment and follow up of salivary and lacrimal glands function is essential in patients receiving radioiodine therapy. Abnormal level of anti-Ro and Anti-La increase the risk for SS that should be closely monitored and fibromyalgia is a common association.