Investigation of antimuscarinic receptor autoantibodies in patients with acquired idiopathic generalized anhidrosis.

OBJECTIVE: The autoimmune mechanism is considered to play an important role in the development of acquired idiopathic generalized anhidrosis (AIGA), and muscarinic M3 receptors (M3Rs) on eccrine glands are possible autoimmune targets. We investigated the existence of autoantibodies against M3Rs in AIGA patients. METHODS: We immunostained M3R-expressing cultured cells with the serum of 12 AIGA patients (mean age: 35.0±11.7 years, mean disease duration: 26.6±25.8 months) and 10 healthy subjects (mean age: 32.4±10.4 years). RESULTS: The surface of the M3R-expressing cells was stained by the serum obtained from one of the 12 AIGA patients but not by the serum obtained from the remaining 11 patients or healthy subjects. CONCLUSION: The presence of M3R autoantibodies may therefore be related to the underlying mechanism of disease in a subset of AIGA patients.