A 32-year-old woman presents to the clinic complaining of symptoms of a dry mouth and dry eyes. She otherwise feels well and reports no joint or systemic symptoms. On physical examination, the only findings are enlarged salivary glands. Studies for autoantibodies to Ro (SS-A) are positive. A salivary gland biopsy reveals lymphocytic infiltration. Which of the following is the most likely diagnosis?

The sicca syndrome is a recognized feature of Sjogren syndrome. It can be primary or secondary to other autoimmune disorders such as RA, SLE, scleroderma, or vasculitis. Primary Sjogren syndrome is most common in middle-aged women; sicca symptoms can also occur as a complication of HIV infection or in sarcoidosis. Sjogren syndrome is more likely to have positive serology, while the serology in sarcoid or HIV is negative. Both HIV and Sjogren can have lymphocytic infiltration, but in HIV it is predominantly by CD8+ lymphocytes, whereas in Sjogren syndrome, the infiltration is by CD4+ lymphocytes. In sarcoidosis, biopsy reveals granulomas.