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The term "intestinal lymphangiectasia" is denoted byan isolated lesion of the lymphatic vessels of the small intestine, accompanied by a difficulty in the outflow of lymph from this organ. Other authors call this disease "idiopathic hypoproteinemia" (Waldmann, 1961), "hypercatabolic enteropathy" (Bockus, 1976).
It is customary to distinguish the innate form of this disease,the origin of which, apparently, does not differ from the origin of the congenital form of the lymphatic edema of the lower extremities, and acquired, which develops as one of the complications of prolonged inflammation of the lymphatic vessels of the small intestine or its mesentery. As a cause of chronic inflammation, the filariasis and the sensitization of the vessels to their own lymphocytes result (Kawai, 1973). The outflow of lymph from the small intestine can be blocked by tumors of regional lymph nodes or tumor metastases in the lymph nodes of the mesentery.
The small intestine is viewed several timesenlarged, the wall of the affected loops is thickened, edematous, the external surface of it is dull, the lymphatic vessels of the serous membrane are sharply enlarged. After injection into their lumen of the dye on the surface of the small intestine appears a dense network of overflowing lymph vessels. The diameter of some of them reaches 4-5 mm.
In a biopsy specimen of the small intestine,expansion of lymphatic vessels of the mucosa and submucosa. In the lumen they are often found lipofagi, in the protoplasm of which contain vacuoles. Each villus of the mucosa contains not one, but usually several sharply enlarged lymphatic capillaries, as a result of which the villi are thickened, the apical parts of them sometimes noticeably thicken and flatten. The cellular composition of the mucosa is mainly represented by lymphocytes and plasma cells. Neutrophils and eosinophils are contained in a very moderate amount.
Disease in most cases begins inchildhood. For no apparent reason, swelling of the subcutaneous tissue appears. They can disappear for a short time. Once again, they become generalized. Soon, ascites, and sometimes hydrothorax, joins the anasarka. There is weakness, fatigue, apathy. Diarrhea develops periodically, but it is never a leading or early sign of a disease. Initially, the patient is usually sent for examination to the cardiology or nephrologic department, where pronounced hypoproteinemia is detected due to a low content of mainly albumins. The content of cholesterol in the blood is normal or low. Lymphopenia and mild anemia are often found.
Despite significant swelling, the patient remainsfree from shortness of breath. When performing work that requires physical effort, he quickly gets tired, but does not choke. The size of the heart remains normal, there are no signs of blood stagnation in the small circle of blood circulation. Dimensions of the liver often can not be determined due to ascites, but venous pressure is normal, and the subcutaneous veins of the neck are not dilated. Visible mucous membranes are pale, not cyanotic. Hypoalbuminemia in heart failure develops only after many years of illness and after several decompensations, whereas in intestinal lymphectasia it is detected at the first blood test, usually within the first month after the onset of edema. The diagnosis of heart failure syndrome can be excluded usually at the first clinical examination of the patient.
A characteristic type of generalizedhypoproteinemic edema accompanied by dropsy, indicates the need to discuss their possible relationship with the nephrotic syndrome and primarily with edema in kidney amyloidosis and with nephritis with minimal changes. If a patient with intestinal lymphangiectasia has not suffered any disease of the urinary tract, then the urine can not detect any traces of protein, no red blood cells, no leukocytes.
Expressed hypoproteinemia and its associatededema and edema of cavities in nephrotic syndrome are caused by proteinuria. Since the results of repeated urine tests are normal, the cause of hypoproteinemia should be linked to the loss of blood plasma proteins in the lumen of the gastrointestinal tract. Quantification of these losses is easiest to produce by intravenous administration of one of the blood plasma proteins labeled with some radioactive substance, for example, iodine, chromium, copper, niobium. In our experience, the most suitable preparation for this purpose is the radioactive albumin of human serum.
After intravenous administration to a healthy person25 μCi of radioactive albumin, labeled with iodine, the radioactivity of its feces does not exceed 3% of the administered dose. The radioactivity of feces of patients with intestinal lymphangiectasia always exceeds this value. The results of the determination of the half-life of radioactive albumin also have great differential diagnostic significance: in a healthy person, it varies from 14 to 24 days. The decomposition of albumin in the patient's intestinal lymphangiectasia is markedly accelerated.
Absorption of nutrients in intestinallymphangiectasia is not significantly impaired. This is evidenced by normal results of samples with loads of xylose and vitamin B12. Digestion of fats and absorption of fatty acids in most patients with intestinal lymphectasia is not impaired. The content of fat in the stool and the coefficient of its cleavage also remain normal. Thus, intestinal lymphangiectasia is characterized by accelerated decay of blood plasma proteins and increased losses in the lumen of the gastrointestinal tract with normally preserved functions of digestion and absorption of carbohydrates, fats and vitamins.
Results of X-ray studyThe small intestine does not have a large differential diagnostic value. Usually there is a discordantly pronounced dilatation of the jejunum with a thickening of its folds. The characteristic picture of the biopsy specimen of the small intestine described above is of decisive differential diagnostic value. Biopsy of the small intestine is one of the procedures that are safe for the patient, therefore, in diagnostic and unclear cases, it should be performed earlier than kidney biopsy.
Hypoproteinemia due to a decreased content inblood, mainly albumins in combination with edema and dropsy, is often observed in liver diseases, but these diseases easily differ from intestinal lymphangiectasia by the results of conventional clinical and laboratory methods of investigation. Functions of the liver with intestinal lymphangiectasia are not violated, whereas in liver cirrhosis they often turn out to be altered. Signs of portal hypertension are found only in liver diseases. Hypoalbuminemia in liver diseases is caused by a slowdown in the synthesis of albumin, and in intestinal lymphangiectasia, its synthesis is markedly accelerated.
Hypoproteinemia with hypoalbuminemia and edemabelongs to the number of characteristic signs of alimentary dystrophy. Its characteristic laboratory feature is the slowdown in the synthesis of blood plasma proteins. The rate of albumin synthesis in intestinal lymphangiectasia is always increased, which is reflected even in one of the names of the disease - "hypercatabolic hypoalbumin-tia". Patients with intestinal lymphangiectasia differ from patients with alimentary dystrophy also in anemia and appearance.
A stooly stooly stool was observed in 2of our patients with intestinal lymphangiectasia, but steatorrhea was very moderate in them and could not be the cause of hypoproteinemia and edema. Such cases of intestinal lymphangiectasia have to be differentiated from the sprue syndrome, which can also lead to the development of hypoproteinemia and edema.