Family deficiency of lecithin-cholesterol-acyltransferase( lhat)

The syndrome is characterized by opacity of the cornea, anemia, proteinuria( the appearance of protein in the urine), a significant decrease in the level of cholesterol esters and lecithin in serum. For the first time, this pathology was detected in 1966 in a woman who received a check for chronic nephritis. By 1987, 18 families with a total number of 35 patients were described in different countries of the world. The disease is inherited by autosomal recessive type.

Proteinuria( the appearance of protein in the urine) is the earliest symptom of the disease. In addition to protein( mainly albumin), hyaline cylinders and erythrocytes are found in the urine. In biopsies of the kidney tissue, "foamy" cells are found. Moderate anemia and opacity of the cornea are usually detected already in adulthood( after 30 years).Accumulations of small point infiltrates, merging, form a kind of arc in the pupillary zone of the cornea. The defeat of the cornea, red blood cells and kidneys is associated with the accumulation in the tissues of non-esterified cholesterol. In the blood plasma, the total content of cholesterol is increased. Normally, the plasma cholesterol esters are about 60-70% of its total. Changes in the plasma lipoprotein spectrum( absence of high-density lipoproteins) are noted. The content of free cholesterol and lecithin in erythrocyte membranes is increased, as a result of which they can take out the outlines of the target. In the study of bone marrow tissue, "foamy" cells are found. However, in contrast to other accumulation diseases with a lecithin-cholesterol-acyltransferase deficiency, there is no increase in lymph nodes, liver and spleen sizes remain within normal limits. The enzyme lecithin-cholesterol-acetyltransferase is synthesized in the liver and enters the blood, where it carries the transfer of fatty acids from lecithin to free cholesterol. With the help of lecithin-cholesterol-acyltransferase, phospholipids and cholesterol are exchanged, which is essential for the vital functions of blood and tissue cells. The low activity of lecithin-cholesterol-acetyltransferase is established by incubating the blood plasma of patients at 37 ° C for several hours. In healthy individuals, the content of cholesterol and lecithin esters increases. In patients with this disease, the lipid profile does not change.

Deficiency of lecithin-cholesterol acyltransferase ultimately leads to the development of chronic renal failure and atherosclerotic changes in blood vessels. With a significant decrease in the level of albumins( proteins) of blood plasma, it is possible to form edematous syndrome. The methods of treatment have not been developed yet, however, periodic transfusions( transfusions) of the donor plasma allow us to correct lipid metabolism parameters.