What is Anemia characterized by a carrier of pathologically unstable hemoglobins?
The term “unstable hemoglobin” defines the instability of hemoglobin molecules, while they precipitate in the erythrocyte, which ultimately leads to hemolytic anemia in heterozygous carriers of the pathological gene.
The disease was first described in 1952 by Cathie, who described a sick child with congenital hemolytic anemia. In this child, after removal of the spleen, Heinz bodies were found in all red blood cells. Only 18 years later, the cause of the formation of Heinz’s Taurus, an abnormal fraction of hemoglobin, was established in this patient. In 1964, it was proved that part of the hemoglobin in patients with Heinz bodies is easily precipitated with a little heating.
Pathogenesis during Anemias characterized by the carriage of pathologically unstable hemoglobins
The disease is inherited according to the dominant type. The instability of the hemoglobin molecule is found when the amino acid substitutions relate to the connection between globin and heme, the connection between a and globin and the beta chains of globin.
The instability of the hemoglobin molecule is also detected when, in the part of the globin molecule to which heme is attached, a non-polar amino acid (glycine, valine, alanine) is replaced by a polar amino acid (glutamine, aspartic).
As a result of impaired stability in some forms of hemoglobinopathy, multiple little bodies-inclusions appear in the erythrocytes, due to the precipitation of unstable hemoglobin. In other cases, single Heinz bodies are found in erythrocytes, which are either hemoglobin devoid of heme or precipitate of isolated globin chains.
Heinz calves are attached to the inner surface of the erythrocyte membrane. This changes the shape and flexibility of red blood cells. The spleen knocks out the Heinz calf from the erythrocyte, the erythrocytes lose part of the surface, and their lifespan is shortened. After removal of the spleen, Heinz bodies appear in the erythrocytes, which before the operation were often not determined, and the life span of the erythrocytes is extended.
Symptoms of Anemias characterized by the carriage of pathologically unstable hemoglobins
The clinical picture of the disease is very diverse, depending on the localization of amino acid substitution. Some patients have normal hemoglobin content, others have severe anemia with a decrease in hemoglobin content of up to 40–60 g / l. Severe or moderate hemolytic anemia is detected since childhood. The severity of jaundice and anemia depends on amino acid substitution and is different. A number of patients have normal skin color and sclera, others have a constant or periodic pronounced jaundice. The spleen in most patients is enlarged, however, in some forms of hemoglobinopathy remains normal. A number of patients have an enlarged liver; anemia is often complicated by gallstone disease. Changes in the skeleton may be the same as in microspherocytosis; in milder forms they are absent.
In the blood picture during the carriage of unstable hemoglobins, anemia of varying severity is detected, more often normochromic, and sometimes hypochromic due to precipitation of a portion of hemoglobin into the sediment, especially if heme is split off from globin. Red blood cell targets, anisocytosis are detected. The content of reticulocytes is always increased. There is irritation of the red sprout of the bone marrow.
The blood picture and the clinical manifestations of hemoglobinopathy depend only on amino acid substitution. The same hemoglobinopathy in carriers of abnormal hemoglobin, not consisting in consanguinity, gives the same clinical manifestations.
In hemoglobinopathies characterized by increased affinity for oxygen, erythrocytosis is possible as a result of the development of tissue hypoxia. In those situations when the affinity for oxygen is reduced, anemia is not characterized by increased destruction of red blood cells, but by increased oxygen content in the body tissues, while anemia is not hemolytic, it is associated with a decrease in erythropoietin.
Treatment of Anemias characterized by a carrier of pathologically unstable hemoglobins
Some patients with unstable hemoglobins do not need any treatment. Patients with significant manifestations of the disease show removal of the spleen. It is effective in most patients, but the effect of the operation is often incomplete. Useful riboflavin or its active drugs. Probably, the concentration of reduced hydrogen is important for the integrity of the erythrocyte. The glutathione reducing enzyme uses riboflavin FAD as a coenzyme. With unstable hemoglobins and the ineffectiveness of spleen removal, it is advisable to use riboflavin (10 mg 3 times a day) or FAD (flavinate 2 mg 3 times a day intramuscularly).