Growth failure in gastrointestinal diseases

Circulating ghrelin levels in celiac patients

OBJECTIVE

Ghrelin, the gut-brain peptide, recently identified as the natural endogenous ligand for growth hormone secretagogue receptors, exerts various endocrine and nonendocrine effects, including the control of energy homeostasis and food intake, but its possible relevance in malabsorption syndromes is unknown. Therefore, the aim of this study was to evaluate circulating ghrelin levels in adults with untreated and treated celiac disease (CD) and, for comparison, in healthy subjects.

METHODS

Fasting serum ghrelin levels were measured in 30 consecutive patients with newly diagnosed CD, 13 celiac patients successfully treated with a gluten-free diet (GFD), and 30 healthy controls.

RESULTS

Ghrelin levels were abnormally high in patients with active CD compared with controls (297 +/- 17.6 vs 218 +/- 15.2 pmol/L, p<0.01) and correlated positively with intestinal mucosal lesion severity (rs=0.444, p<0.02). In the successfully GFD-treated patients, ghrelin values were normal compared with controls (233 +/- 22.0 vs 218 +/- 15.2 pmol/L, ns) and, moreover, correlated negatively with body mass index (r=-0.632, p=0.02), unlike in the untreated patient group (r=-0.263, ns).

CONCLUSION

High ghrelin levels characterized our series of adult patients with newly diagnosed CD and correlated significantly with the degree of severity of intestinal mucosal lesions. This is the first evidence of a relationship between ghrelin and inflammatory processes, but the mechanisms involved are still unclear. Furthermore, our findings suggest that an interplay of hormonal, metabolic, and nutritional factors could influence ghrelin secretion under pathophysiological circumstances.

Retarded growth and deficits in the enteric and parasympathetic nervous system in mice lacking GFR alpha2, a functional neurturin receptor

Glial cell line-derived neurotrophic factor (GDNF) and a related protein, neurturin (NTN), require a GPI-linked coreceptor, either GFR alpha1 or GFR alpha2, for signaling via the transmembrane Ret tyrosine kinase. We show that mice lacking functional GFR alpha2 coreceptor (Gfra2-/-) are viable and fertile but have dry eyes and grow poorly after weaning, presumably due to malnutrition. While the sympathetic innervation appeared normal, the parasympathetic cholinergic innervation was almost absent in the lacrimal and salivary glands and severely reduced in the small bowel. Neurite outgrowth and trophic effects of NTN at low concentrations were lacking in Gfra2-/- trigeminal neurons in vitro, whereas responses to GDNF were similar between the genotypes. Thus, GFR alpha2 is a physiological NTN receptor, essential for the development of specific postganglionic parasympathetic neurons.

Intestinal, pancreatic and hepatic involvement in carbohydrate-deficient glycoprotein syndrome type I

BACKGROUND

Children with carbohydrate-deficient glycoprotein syndrome type I during infancy have gastrointestinal symptoms and growth impairment, the cause of which is largely unknown.

METHODS

Seven children were investigated with small intestinal biopsy, liver biopsy, duodenal intubation with determination of lipolytic and proteolytic activity, and test meal. Weight, length-height, and head circumference were recorded regularly.

RESULTS

Growth was affected from early infancy, with an initial low rate of weight gain followed by impaired linear growth. Vomiting and diarrhea were dominant symptoms. Four of seven children had abnormal findings in light microscopic examination of small intestinal biopsy specimens, with short villi and increased inflammatory cells in the stroma, that did not respond to elimination of such food proteins as cow's milk or gluten. Electron microscopic study showed dilatation of smooth endoplasmic reticulum and abnormal inclusions containing lipids. The liver was abnormal in all. Besides steatosis and fibrosis or cirrhosis, there was a remarkable increase of inflammatory cells in portal zones. Activity of lipolytic enzymes in duodenal juice was low, except in one child, who no longer had growth problems or symptoms. Two of six had abnormal proteinolytic activity in duodenal juice. Digestion of triglycerides and absorption were within normal limits, as was the absorption of glucose and xylose.

CONCLUSIONS

Inflammation of small intestine and liver may be the cause of gastrointestinal symptoms. In all likelihood, the growth failure was because of low caloric intake and increased losses related to vomiting. Growth and gastrointestinal symptoms improved spontaneously as time elapsed.