[A case of an old woman with Sjögren's syndrome associated with insulin-dependent diabetes mellitus].

Insulin-dependent diabetes mellitus (IDDM) is thought to result from the autoimmune destruction of the insulin-dependent beta cells of the pancreas. Sjögren's syndrome is also an autoimmune disease characterized by the destruction of the lacrimal and salivary glands that leads to keratoconjunctivitis sicca and xerostomia. But it is a very rare case that a patient with Sjögren's syndrome developed IDDM. We present a case of a 65-year old woman with Sjögren's syndrome who developed diabetic ketoacidosis due to IDDM. Recent studies have revealed that there was molecular mimicry between glutamic acid decarboxylase (GAD) and coxsackievirus. Furthermore, some reports have shown that sialadenitis was represented in IDDM model mice. This case shows the possibility that a causal relationship between IDDM and Sjögren's syndrome may exist.