Congenital disorders of the structure of the intestinal mucosa

Carrying out differential diagnostics with osmotic diarrhea requires exclusion of digestion and absorption disorders, congenital diseases with violation of enterocyte structure and immunoinflammatory diseases.

The so-called chronic non-curable diarrhea in newborns begins in the first days or weeks of life, does not have a provoking infectious factor, is characterized by a severe life-threatening course. Unlike digestion and absorption disorders, diarrhea does not stop when enteral nutrition is withdrawn. Such conditions can be associated with congenital disorders of the structure of enterocytes.

Congenital atrophy of microvilli (a syndrome of deactivation of microvilli) is characterized by the presence of cytoplasmic inclusions containing microvilli in the region of the apical pole of the enterocyte, there is no microvillin on the analogous surface of the mature enterocyte. These disorders can be detected by electron microscopy. Pathology is probably associated with a defect in endo- or exocytosis and a violation of the process of membrane restructuring. The newest studies have revealed violations of exocytosis of glycoprotein. When light microscopy of mucosal biopsy specimens, atrophy of villi is noted, a cluster of PAS-positive material at the apical pole of enterocytes.

ICD-10 code

P78.3. Noninfectious diarrhea in the newborn.

Symptoms

A typical clinical picture is characterized by the onset of watery diarrhea in the first days of a child's life, sometimes in the stool there is an admixture of mucus. Diarrhea is so intense that within a few hours it leads to dehydration, within a day the baby can lose up to 30% of the body weight. The stool volume is 150-300 ml / kg body weight per day, the sodium content in the feces is increased (100 mmol / l). Metabolic acidosis develops. Transfer to full parenteral nutrition allows a few to reduce the volume of the stool, but not less than 150 ml / kg per day. The combination with the developmental malformations of other organs is uncharacteristic. Some children experience skin itching due to increased concentrations of bile acids in the blood. In some cases, signs of dysfunction of the proximal tubules of the kidneys are noted.

An important differential diagnostic feature, in addition to maintaining diarrhea on complete parenteral nutrition, is considered to be the lack of polyhydramnios in the mother for this disease, in contrast to chloride and sodium diarrhea.

Treatment

The children are shown lifelong parenteral nutrition. Characteristic is the rapid development of cholestasis and impaired liver function. Often there is a secondary infection, a septic condition. Patients with atrophy of microvilli often require intestinal transplantation.

[1], [2], [3]