The hemolytic anemias are characterized by excessive blood destruction which results in such symptoms as jaundice, formation of gallstones, and increased amounts of urobilinogen and urobilin in the stools and urine. Phagocytosis of red blood cells undergoing destruction with deposition of hemosiderin results in splenomegaly. The acute forms may result from bloodstream infections or various types of hemolytic poisons. The chronic forms are often congenital disorders and include familial hemolytic icterus, Mediterranean anemia and sickle cell anemia.
Acute Hemolytic Anemia. Acute hemolytic anemia may result from mismatched transfusions, hemolytic toxins, such as snake venoms, bacterial toxins, phenyl hydrazine or phenol, and from malaria or bartonellosis. The symptoms include chills and rigor, vomiting and diarrhea, pain in the back and legs, hemoglobinuria, albuminuria and anuria. The red blood cells show marked variation in size and staining reaction. There is striking evidence of regeneration, including reticulocytosis and circulating normoblasts. Treatment consists of removal of the cause.
Acquired and Congenital Hemolytic Icterus. In congenital hemolytic icterus repeated crises of blood destruction occur, with fever, abdominal pain and nausea. Once severe anemia and jaundice develop, they tend to persist. The spleen is enlarged, gallstones are found in 68 per cent of the cases, skeletal anomalies such as tower skull occur, and chronic leg ulcers are common. Reticulocytes, small dense red cells (sphcrocytes) and increased fragility of red cells to hypotonic salt solution are the chief blood findings. The acquired form is similar to the congenital, but the increased fragility of the red blood cells may be absent. Both forms show an increased icteric index, at times as high as 100, and a hyperplastic bone marrow on sternal puncture. Both are benefited by splenectomy.
Sickle Cell Anemia. This is a hereditary disease in Negroes. It is characterized by the appearance of sickle-shaped red corpuscles in blood which has been standing away from oxygen two to six hours after it has been withdrawn and protected from drying. The cells show increased resistance to hypotonic salt solution. The patients suffer from jaundice, rheumatic pains in the extremities, leg ulcers, and irregular thickenings of the cortex of the bones. There is no satisfactory treatment.
Mediterranean Anemia (Thalassanemia). This is a familial disease in individuals of Mediterranean stock. Those afflicted are often short in stature and have a large head. The bones about the hands and wrists may have increased density on roentgen examination. Examination of the blood shows variations in the size and staining reactions of the red blood cells. Nucleated forms are common. The hemoglobin is concentrated at the periphery of the red corpuscle or as a central dot forming so-called target corpuscles. Uniformly colored cells are rare. There is often a leukocytosis. The icteric index is moderately increased. The spleen is enlarged and infarcts are common. Later the organ shrinks and is fibrosed. The bone marrow is hyperplastic. Severe forms are present in children; milder forms in adults. Transfusion is of temporary value but there is no specific treatment.
Erythroblastosis Fetalis. This is a hemolytic anemia, occuring late in fetal life or in the newborn, in a child whose blood agglutinogens differ from its mother's. As a regenerative response to blood destruction, the hematopoietic centers in the bone mar row, liver and spleen become crowded with erythroblasts, hemosiderin and foci of hematopoiesis. Nucleated red blood cells appear in the peripheral blood. The infant in severe cases is edematous and jaundiced, and hence the terms fetal hydrops and familial icterus gravis. The basal ganglia of the brain may be deeply icteric, so called kernicterus.In rare instances the incompatibility of the fetal and maternal bloods is because of the ABO grouping. However, the cause of the disease nearly always is the immunization of the RH negative mother by previous transfusions with RH positive blood cells or by RH positive red cells of the fetus. The mother's RH antibodies pass into the fetal circulation and damage the child's erythrocytes. The offspring of an RH positive father and RH negative mother always will be RH positive if the male is homozygous (all dominant genes for RH). If the RH positive father is heterozygous (one or two of the genes recessive) 50 per cent or less of the offspring will be RH positive. Levine found that 87 per cent of the white population is RH positive. The mothers of infants developing erythroblastosis fetalis belong to the 13 per cent who are RH negative. The treatment consists of an adequate number of transfusions or exchange transfusions from a compatible RH negative donor.
