Prevalence of autoantibodies against some selected growth and appetite-regulating neuropeptides in serum of short children exposed to Candida albicans colonization and/or Helicobacter pylori infection: the molecular mimicry phenomenon.

OBJECTIVES: Many of peptides synthesized in gastrointestinal tract (GI) and adipose tissues, regulate growth and food intake. The GI microflora is an antigenic source. Based on the molecular mimicry hypothesis, intestinal microbe-derived antigens may trigger the production of autoantibodies cross-reacting with some neuropeptides. DESIGN: The aim of the study was to assess whether in idiopathic short stature (ISS) children with Candida albicans (C.albicans) colonisation and/or Helicobacter pylori (H.pylori) infection the autoantibodies (in positive levels) against selected neuropeptides [anti-NP Abs(+)]: ghrelin, leptin, orexin A, αMSH are more prevalent than in Controls. SETTING: The study group comprised 64 children with ISS and 36 children with normal height (Controls). In each child, IgG antibodies against H.pylori, ghrelin, leptin, orexin A and αMSH were assessed in serum, while presence of C.albicans - in stool samples. RESULTS: The higher prevalence of anti-NP Abs(+) in ISS children with C.albicans and/or H.pylori than in normal height children with the colonization in question (34.4% vs 21.1%, p<0.01) was found. The prevalence of anti-NP Abs(+) in groups of children without C.albicans and H.pylori were low, anti-NP Abs(+) were detected in 9.4% of ISS children only, while in Controls they were not found. CONCLUSIONS: In short children with C.albicans and/or H.pylori the incidence of autoantibodies against selected neuropeptides is high. It probably is connected with molecular mimicry between antigens of these microbiota and the mentioned peptides. It is tempting to speculate that presence of cross-reacting autoantibodies against regulatory neuropeptides may results in worse growth velocity. However, further studies are necessary to elucidate this issue.