New developments in Sjögren's syndrome.

Over the past months, noteworthy contributions to our understanding of the clinical manifestations of Sjögren's syndrome have been made. Scintigraphic and echographic techniques have been refined to document xerostomia. Various systemic complications, such as nervous system involvement, pulmonary lesions, gastric and pancreatic dysfunction, and Raynaud's phenomenon have been further described. Mast cells have been shown to participate in the salivary gland infiltration, together with T lymphocytes, of which the majority are of the memory helper/inducer phenotype. Antinuclear antibodies are directed to SS-A/Ro and SS-B/La particles. Two studies have been devoted to the cloning of the DNA encoding the 52-kD component of the former, and a series of SS-B/La DNA fragments have been generated to analyze the peptides of the latter. Virologic data have been provided, particularly the detection of anti-human immunodeficiency virus type 1 p24 protein in a number of Sjögren's syndrome patients, and the discovery of a human intracisternal A-type retroviral particle in lymphoblastoid cells exposed to homogenates of salivary tissue from patients with Sjögren's syndrome.