Long time interval between multiple sclerosis onset and occurrence of primary Sjögren's syndrome in a woman treated with interferon-beta.

Primary Sjören's syndrome with central nervous system involvement can clinically mimic multiple sclerosis (MS). However, SS and MS may coexist. We report here a case of a 48-year-old woman affected by relapsing-remitting MS, good responder to interferon (IFN)-beta 1a, developing sicca complex after 29 years from MS onset. At the age of 48, after 5 years successful treatment with i.m. IFN-beta 1a, xerophtalmia and xerostomia with dysphagia occurred. Autoantibody screening for connective tissue diseases, including anti-ENA, was negative. Schirmer's test showed reduced lacrimal gland function and a minor salivary gland biopsy showed chronic inflammatory infiltration with fibrosis, acinar atrophy and ductal ectasia. According to clinical and pathological findings a diagnosis of SS was made. Other cases of connective tissue diseases after IFN-beta treatment have been described. However, this is, to our knowledge, the first report on the development of primary SS after long time interval from MS onset in a woman treated with IFN-beta. Although there are no evidences about a possible role of IFN-beta in triggering SS yet, a screening for clinical and laboratory signs of SS should be assessed in MS patients during IFN-beta treatment.