Intractable diarrhoea in infancy in the 1990s: a survey in Italy

Intractable diarrhea in infancy and molecular analysis: We are beyond the tip of the iceberg

BACKGROUND

Intractable diarrhea (ID) could be defined as a syndrome of severe chronic diarrhea associated with malnutrition not easily resolved by conventional management.

AIMS

To provide an overview on etiology and management of ID patients in Italy in the last 12 years.

METHODS

The members of Italian Society for Pediatric Gastroenterology, Hepatology and Nutrition (SIGENP) enrolled all ID patients seen between January 1, 2011 and December 31, 2022.

RESULTS

69 children were enrolled (49 M, 20 F; median age at ID onset 9.5 days) from 7 tertiary care pediatric centers. Overall 62 patients had genetic diseases; 3 had infantile Inflammatory Bowel Disease and 1 autoimmune enteropathy in absence of genetic mutations; 2 undefined ID. Defects of intestinal immune-related homeostasis caused ID in 29 patients (42 %).

CONCLUSION

ID is a rare but challenging problem, although the potential for diagnosis has improved over time. In particular, molecular analysis allowed to identity genetic defects in 90 % of patients and to detect new genetic mutations responsible for ID. Due to both the challenging diagnosis and the treatment for many of these diseases, the close relationship between immune system and digestive tract should require a close collaboration between pediatric immunologists and gastroenterologists, to optimize epidemiologic surveillance and management of ID.

Microvillous atrophy: atypical presentations

OBJECTIVES

Microvillous inclusion disease (MVID) is a cause of intractable diarrhea in infancy. In its classic form, the disease is characterized by a severe persistent watery diarrhea starting within the first days of life. Parenteral nutrition and small bowel transplantation are the only known treatments for the affected children. Histologically, periodic acid-Schiff (PAS) staining shows accumulation of periodic acid-Schiff-positive staining material along the apical pole of enterocytes, whereas transmission electron microscopy exhibits microvillus inclusion bodies within the cytoplasm of enterocytes with rarefied and shortened microvilli and secretory granules. The objective of this work was to explore clinical, morphological, and genetic findings in cases of MVID with unusual presentations.

METHODS

Clinical, histological, and genetic findings are reported for 8 cases of MVID with atypical presentation.

RESULTS

The diarrhea started after several months in 3 cases. It was usually less abundant and 3 patients were weaned off parenteral nutrition. None required intestinal transplantation. Three patients experienced malformations, dysmorphy, sensory disabilities, and severe mental retardation. One had a hydrocephaly. Three patients had a cholestasis with low γ-glutamyl transferase levels. Light microscopy showed histological abnormalities consistent with MVID in all of the cases, but the lesions were sometimes focal or delayed. Transmission electron microscopy retrieved some criteria of MVID in 4 patients. Finally, 6 patients were homozygotes or compound heterozygotes for MYO5B mutations.

CONCLUSIONS

This study extends the spectrum of MVID to less severe clinical presentations.

Intractable diarrhea with "phenotypic anomalies" and tricho-hepato-enteric syndrome: two names for the same disorder

Tricho-hepato-enteric syndrome and syndromic diarrhea are quite rare conditions with only 15 patients described to date. Both include severe diarrhea requiring total parenteral nutrition, facial dysmorphism, immunity defect, and hair abnormalities (mostly trichorrhexis nodosa). A definite clear clinical description of the two syndromes is lacking; the outcome is also poorly known. Here, we report on two additional patients. Analysis of our observations together with a review of previously published cases suggests that patients with tricho-hepato-enteric syndrome and/or syndromic diarrhea actually have the same heterogeneous disease that has been incorrectly and confusingly separated into different entities. The acknowledgment that these two syndromes represent the same disease is a crucial step toward a better description of this syndrome and its outcome toward studies of the underlying genetic cause.

Natural history of intestinal failure, investigated through a national network-based approach

OBJECTIVES

Intestinal failure (IF) is a condition whose treatment requires advanced knowledge and techniques and a multidisciplinary approach. Intestinal failure is the endpoint of many intestinal diseases and may result in full recovery, in life-long parenteral nutrition, or in the death of the child. The aim of this study was to evaluate the natural history of IF in children using a national network of resources.

METHODS

Italian centers of pediatric gastroenterology merged in a national network, developing a collaborative management approach for children with IF. A consensus definition of IF was achieved. A database was set up to investigate the cause, epidemiologic factors, and natural history of IF.

RESULTS

One hundred nine children were enrolled in 5 years. The cause of IF was: short bowel syndrome (n = 48), disorders of motility (n = 16), structural enterocyte defects (n = 14), multiple food intolerance (n = 10), autoimmune enteropathy (n = 7), and others or unknown (n = 14). The eventual outcome was closely related to the primary cause, ranging from full and permanent intestinal sufficiency in children with multiple food intolerance to high death rate or total dependance upon parenteral nutrition in those with structural enterocyte defects. Intermediate outcomes were observed for the other causes. Four children received intestinal transplantation.

CONCLUSIONS

The network approach for IF provides an effective model to optimize resources and to investigate prospectively the natural history of IF. Based on the work on this series, a European network for IF could be an effective model for fulfilling the diagnostic and management needs, including intestinal transplantation.

A 75-kD autoantigen recognized by sera from patients with X-linked autoimmune enteropathy associated with nephropathy

Autoimmune enteropathy (AIE) is a rare disorder characterized by intractable diarrhoea and antienterocyte autoantibody. In this study, we detected a 75-kD autoantigen which distributed through the whole intestine and the kidney, as assessed by Western blot analysis using sera from two unrelated cases of AIE associated with nephropathy. Our results suggest that the detection of the autoantibody against the 75-kD antigen has a diagnostic value in AIE and that the autoimmune reaction against the 75-kD antigen may be implicated in the development of intestinal and renal tissue damage in this rare disorder.