Putative role of antireticulin antibody in antiacetylcholine-receptor-antibody-negative myasthenia gravis.

It has recently been demonstrated that pathogenic immunoglobulins circulate in the blood of patients with acetylcholine-receptor-antibody (A-AChR)-negative myasthenia gravis (MG). Evidence has been presented that in this form of MG the neuromuscular transmission is impaired by antibodies that bind to endplate determinants other than the AChR. We describe three patients with clinical manifestations of A-AChR-negative MG in whom antibody directed to reticulin (A-Ret) was detected. Antibody directed to reticulin is usually associated with celiac disease; however, none of the patients had symptoms or signs of celiac disease. To our knowledge, the association of A-Ret with A-AChR-negative MG has not been reported before. We postulate that A-Ret might help to differentiate between A-AChR-negative MG and congenital myasthenia. Further studies are needed to determine whether A-Ret plays a pathogenic role in A-AChR-negative MG or should instead be considered as an epiphenomenon.