Periductal lymphocytic infiltrates in salivary glands in myasthenia gravis patients lacking Sjögren's syndrome

In eight of eleven patients with clinical and serological evidence of myasthenia gravis (MG), immunohistological analysis of biopsies from labial salivary glands (LSG) showed focal periductal lymphocytic infiltrates, mainly composed of anti-Leu 3a+ T helper lymphocytes, a finding usually regarded as indicative for Sjögren's syndrome (SS). None of the patients could however, according to functional criteria, be considered as having SS. This study thus indicates that lymphocytic infiltrates in LSG can be seen in MG, which has been thought of as an organspecific autoimmune disease with symptoms and signs confined to striated muscles.