A role for autoantibodies in some cases of acquired non-paraneoplastic gut dysmotility

Antibody-mediated autoimmunity underlies a diverse range of disorders, particularly in the nervous system where domains of ion channels and receptors are potential targets. The aetiology of many adult-onset conditions of severe gut dysmotility is not known. We looked for antibodies to neuronal antigens in patients with severe (slow-transit-type) constipation (STC).

Eleven sera from adult-onset STC patients and 18 from childhood onset cases were tested by routine immunoprecipitation assays for antibodies against neuronal antigens including voltage-gated potassium channels (VGKCs), calcium channels (VGCCs), both muscle and neuronal acetylcholine receptor and glutamic acid decarboxylase (GAD). Results were compared with positive and negative control populations.

Two of the 11 sera from patients with adult-onset STC showed highly positive anti-VGKC antibodies. Both had onset of symptoms de novo in adulthood without evidence of autoimmune, neoplastic or neurological disease. One of these patients, and one other, had anti-GAD antibodies. None of the childhood-onset STC had evidence of anti-neuronal antibodies.

Anti-neuronal antibodies are found in some patients with a condition of severe acquired gut dysmotility of previously unknown aetiology. Future studies may demonstrate an autoimmune role for such antibodies.