CD40LG and irritable bowel syndrome: IgM antibodies against GnRH receptors have been found in patients with dysmotility, IBS, and primary Sjögren’s syndrome (44, 45), and IgM antibodies against progonadoliberin-2, the precursor of GnRH2 (46), have been found in patients with diabetes mellitus, dysmotility, and IBS (45).