Classification criteria of Sjögren's syndrome.

Sjögren's syndrome (SS) is a chronic, systemic autoimmune disease that affects typically the exocrine glands causing mucosal dryness. Dry eyes and mouth are considered by far the most common and early symptoms of the disease but systemic complications may also occur. In 1993, the preliminary European criteria were proposed and widely accepted, consisting of both subjective and objective criteria. Almost ten years later, these classification criteria were revised by introducing more stringent rules and precise diagnostic procedures leading to the currently used American-European Consensus Group (AECG) criteria. The AECG criteria have been largely employed to conduct epidemiologic and clinical studies of patients with SS and proved to be more specific compared to the preliminary European criteria. The recent American College of Rheumatology/Sjögren's International Collaborative Clinical Alliance (ACR/SICCA) criteria that are based exclusively on objective tests, the stringency of the AECG criteria and the potential therapeutic use of biologic agents in SS clearly set the need for new classification criteria. Whether the new diagnostic approach will further encompass subclinical and early forms of the disease remains to be addressed by the scientific community.