Hereditary microspherocytosis
Hereditary microspherocytosis , known as the Minkowski-Schofar disease, is transmitted by an autosomal dominant type of inheritance. With this type of anemia, a change in shape and a shortening of the life span of red blood cells occurs. In this case, red blood cells acquire the form of microspherocytes. The disease is described more than 100 years ago. At the end of XIX century.the type of inheritance of the disease is established. The disease is widespread in various countries of Europe with a frequency of 1 case per 5000 population. Significantly, the disease occurs in Japan and Africa. In most cases, one of the parents can detect microspherocytosis. Sometimes a child has a serious illness, but the father or mother has a disease only after a blood smear. However, in parents of 20-25% of children with microspherocytosis, the most thorough analysis does not reveal any signs of the disease.
At the heart of the disorders with microspherocytosis is a defect in the structure of the erythrocyte membrane( red blood cells).It was established that in mice with hereditary microspherocytosis there is no specific protein of the erythrocyte membrane - spectrin. Changes in the structure of this protein lead to an increase in the permeability of the membrane of red blood cells and excessive intake of sodium ions into the erythrocytes. Sodium ions, in turn, are osmotically active, that is, they "pull" water behind them. This leads to excessive accumulation of it within the erythrocytes. Spherical shape of erythrocytes and features of the structure of the spectrin protein disrupt the ability of erythrocytes to deform in narrow sections of the blood stream, for example, in small spleen capillaries.
The ability of the spleen to destroy erythrocytes is associated with the uniqueness of the splenic circulation. When passing through the narrow spleen capillaries, pathologically altered red blood cells can not be deformed. This leads to slow progress and stagnation in the splenic ligaments. Eventually, each red blood cell passes through a narrow capillary, but may lose part of its surface. With microspherocytosis, the loss of part of the membrane and the cell surface leads to a gradual decrease in the erythrocyte. To destroy, it is necessary that the red blood cell again enter the narrow capillary of the spleen. Several such turns lead the erythrocyte to death.
As with many other forms of hereditary hemolytic anemia, the erythrocyte decay occurs with microspherocytosis. This causes the appearance of characteristic signs of the disease: jaundice, an increase in the size of the spleen, expressed in varying degrees anemia, a tendency to form gallstones, morphological changes in erythrocytes, reticulocytosis( an increase in the number of reticulocytes in the blood, which are still immature forms of erythrocytes,the formation of which occurs in the red bone marrow with the rapid and abundant death of red blood cells to restore their quantity in the blood - the mechanism of compensation for excess loss toasnyh blood cells).
The most severe forms of microspherocytosis occur during adolescence or in adults, and in children it is found when families are examined. If the disease from childhood has pronounced manifestations, then there may be various deformations of the skeleton, especially the skull. People with this disease can see a tower-like square skull, a reduced size of the eyes, a high sky, the position of the teeth changes. Some people have shortened little fingers. These signs are observed in other forms of hereditary hemolytic anemia.
Enlargement of the spleen( from slight to severe) is very typical for microspherocytosis. In most cases, uncomplicated microspherocytosis does not lead to an increase in the liver. The vast majority of people suffering from this disease, there are pain in the right upper quadrant, which is associated with the formation of stones in the gallbladder and biliary tract. This is one of the most frequent complications of microspherocytosis. The formation of stones is associated with a high content of bilirubin in bile. Stones are more often bilirubin, but there are also mixed, which contain cholesterol. A comparatively rare complication of microspherocytosis is trophic ulcers of the lower leg.
The severity of anemia with microspherocytosis varies, although in most cases it is small. The hemoglobin content is usually 90-100 g / l, during the exacerbation it decreases to 40-50 g / l, especially in young children. Hemolytic crises with microspherocytosis are most often provoked by an infectious disease. In blood smears when examining them under an electron microscope, the characteristic forms of erythrocytes - spherocytes - are determined. The content of reticulocytes( young forms of erythrocytes) with microspherocytosis can be different, depending on the severity of the disease, the time of examination, and usually does not exceed 10%.However, there are cases when the amount of reticulocytes rises to 50-60%( after the exacerbation of the disease).
The level of bilirubin in the blood with microspherocytosis depends on the severity of the disease and the period of the examination. Outside exacerbations the bilirubin content can be within the limits of the norm, during the exacerbation period it increases greatly.
Many people with microspherocytosis for a long time are diagnosed with chronic hepatitis or even cirrhosis of the liver, and anemia is considered a consequence of these diseases. In all cases, jaundice with an increase in the spleen requires a thorough examination of the patient, regardless of the level of hemoglobin.
Treatment. The main method of treatment of microspherocytosis is the removal of the spleen. With microspherocytosis, the life span of erythrocytes is sharply shortened. The destruction of these blood cells occurs mainly in the spleen. Indications for the removal of the spleen with microspherocytosis are a constant or arising in the form of exacerbations anemia, a significant increase in the level of bilirubin in the blood serum, even without anemia, the appearance of pain in the right hypochondrium, the developmental lag in children. After removal of the spleen, in almost all persons suffering from microspherocytosis, the general condition and hemoglobin level in the blood are normalized. The level of bilirubin and the content of young forms of red blood cells are significantly reduced.
The most serious, although rare complications of the postoperative period, not associated with the technique of surgery, are thromboses of pulmonary and intestinal blood vessels. An increase in platelet counts( white blood cells) in the postoperative period above 700-800 X 109 / L requires the use of drugs that can reduce the "gluing" of platelets, which leads to clogging of blood vessels( eg, quarantil).It is also advisable to use a drug such as heparin in the form of injections into the skin of the abdomen. This drug also prevents blood clotting and the formation of blood clots closing the lumen of blood vessels.
In case of detection of microspherocytosis in pregnant women with moderate anemia and a calm course of the disease, pregnancy can be saved and not resorted to by caesarean section. Later on such women, if necessary, are carried out the removal of the spleen.
Prognosis for life is always good with the timely removal of the spleen.