Expression of acetylcholine and its receptor in human sympathetic ganglia in primary hyperhidrosis

The pathophysiologic characteristics of primary hyperhidrosis are not well understood and seem to be related to a sympathetic nervous system dysfunction. The resection of thoracic sympathetic chain ganglia is the most effective treatment for hyperhidrosis; however sympathetic ganglia function in normal individuals and in patients with hyperhidrosis is unknown.

A cross-sectional study, in which 2 groups of 20 subjects were analyzed: the hyperhidrosis group (HYP), comprised of patients with hyperhidrosis who were eligible for thoracic sympathectomy, and the control group (CON) comprised of brain-dead organ donors without a history of hyperhidrosis. For each subject, the following were performed: resection of the third left sympathetic ganglion, measurement of the ganglion's diameter, and immunohistochemical evaluation by quantification of strong and weak expression areas of primary antibodies against acetylcholine and alpha-7 neuronal nicotinic receptor subunit.

The presence of a strong alpha-7 subunit expression area was 4.85% in patients with primary hyperhidrosis and 2.34% in controls (p < 0.001), whereas the presence of a weak expression area was 11.48% in the HYP group and 4.59% in the CON group (p < 0.001). Strong acetylcholine expression was found in 4.95% of the total area in the HYP group and in 1.19% in the CON group (p < 0.001), whereas weak expression was found in 18.55% and 6.77% of the HYP and CON groups, respectively (p < 0.001). Furthermore, diameter of the ganglia was 0.71 cm in the HYP group and 0.53 cm in the CON group (p < 0.001).

There is a higher expression of acetylcholine and alpha-7 neuronal nicotinic receptor subunit in the sympathetic ganglia of patients with hyperhidrosis. Furthermore, the diameter of the thoracic sympathetic chain ganglia is larger in such patients.