Posted on Mar 09, 2008 | Comments 0
The parvovirus B19 that is responsible for the development of viral infection “fifth disease,” also known as erythema infectiosum, can result in a wide range of severe conditions in people with chronic blood disorders, such as sickle cell disease.
Sickle cell disease is a rare blood disorder where hemoglobin S, a blood component that helps RBC to carry oxygen is affected and causes the red blood cells to change shape.
How does fifth disease affect patients with chronic blood disorders?
Patients with underlying sickle cell disease who become infected with the parvovirus are at high risk for aplastic crisis.
This is because the fifth disease virus infects erythroid cells, the cells of the erythrocytic (red blood cells) series of bone marrow and interferes with the production of red blood cells (RBC) as they mature and differentiated all along the erythroid lineage.
The cessation of red blood cells production lasts for about ten days. The condition is harmless and not a problem in patients that are otherwise healthy. However, people with chronic blood disorders (sickle cell disease, hereditary spherocytosis or thalassemia) can have serious worsening conditions such as transient aplastic crisis.
As people with blood disorders depend on fast production of erythrocytic cells so as to replace the destroyed sickle cells rapidly, the short-term shutdown of RBC production result in a sudden drop in the reticulocyte (immature red blood cells) count to undetectable levels and are followed by severe anemia for about two weeks.
How does fifth disease affect patients with impaired immune system?
The virus of fifth disease in patients with defective cell-mediated immunity (such as acquired immunodeficiency syndrome and organ transplantations) develops pure red cell aplasia, a medical condition where suppression of erythropoiesis with little or no abnormality of leukocyte production takes place.
As patients with immune deficiency disorder are not able to mount an adequate immune response (antibodies) against the virus that develops fifth disease, it leads to the development of a persistent infection in the bone marrow and severe chronic anemia.
Infection control for fifth disease in infected people who have blood or immune disorders
Antibiotics are ineffective in controlling the virus that develops fifth disease. Hospitalization is necessary for close observation in patients with blood or immune disorders.
Blood transfusion has been successfully used as an infection control method for blood disorders to increase the red blood cells counts in the bone marrow. Doctors use blood transfusion when the hemoglobin level is less than 8 grms/ deciliter.
A blood transfusion keeps the red blood cells count high enough in the bone marrow, which has been stopped by the virus that develops the fifth disease. It increases the red blood cells count.
Intravenous immunoglobulin (IVIG) has been used as an infection controlling method for chronic anemia and persistent infections in fifth disease patients who have immunodeficiency.
Intravenous immunoglobulin is a medication of IgG immunoglobulin (antibodies extracted from the plasma of blood donors) to minimize the risk of infection in people with immune system disorders. It is administered intravenously into the blood to maintain adequate levels of antibodies to fight against foreign substances.
Posted in: Blood Disorders