HIV: several intestinal complications in patients infected

HIV appears directly responsible, through its Tat protein, several intestinal complications observed in patients infected, according to a study published in "Aids".

HIV + patients suffering from various intestinal complications including diarrhea, dehydration and poor absorption of glucose, which causes a gradual loss of weight. The origin of these disorders remains controversial, since some researchers attribute to opportunistic infections, while others see it as a direct action of HIV.

Roberto Berni Canani of the University Federico II of Naples, and his colleagues have sought to clarify the role of the viral protein Tat in these phenomena. This protein is secreted by infected cells, is already involved in diarrhea.

When researchers incubated cells from human intestinal line with the Tat protein, they observed a decrease in glucose uptake up to 70%.

This effect is due to the disruption of intestinal protein, called Sodium Glucose Transporter-1 (SGLT-1). Located on the inner wall of the digestive tract, SGLT-1 protein allows the assimilation of glucose and sodium from the diet.

"The lower activity of this transporter could not only lead to poor absorption of glucose, but also diarrhea, as SGLT-1 also has the characteristics of a water channel," say the authors.

Besides transport of glucose and sodium, protein and SGLT-1 is responsible for the daily transportation of five liters of water from the intestine to the indoor environment. A malfunction in the presence of Tat protein, and thus HIV and explain the diarrhea and dehydration observed in patients.

"The removal of extracellular Tat protein [secreted from infected cells], by active or passive immunization, reduce its pathogenic effects in the intestine," the authors suggest.