Gonadotropin-releasing hormone (
GnRH) 1 and 2 and
luteinizing hormone (
LH) receptors have been described in the gastrointestinal tract. We have previously demonstrated
antibodies in serum against GnRH1 in patients with gastrointestinal dysfunction and
diabetes mellitus, and
antibodies against
GnRH receptor, LH, and
LH receptor in patients with
infertility. The aim of this study was to search for the expression of serum
antibodies against GnRH1 with an improved
enzyme-linked immune sorbent assay (ELISA), and
antibodies against progonadoliberin-2, GnRH2,
GnRH receptor, LH, and
LH receptor with newly developed ELISAs, in patients with gastrointestinal dysfunction or
diabetes mellitus. Healthy blood donors served as controls. Medical records were scrutinized. Our conclusion was that
IgM antibodies against GnRH1, progonadoliberin-2, and/or
GnRH receptors were more prevalent in patients with
functional gastrointestinal disorders, gastrointestinal dysmotility, and/or
diabetes mellitus, whereas
IgG antibodies against these
peptides, and LH- and
LH receptor antibodies, were expressed in the same magnitude as in controls.