Hereditary spherocytosis medical therapy
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
- As with most inherited hemolytic anemias, treatment is directed at preventing or minimizing complications of chronic hemolysis and anemia. There are no specific treatments directed at the underlying red blood cell (RBC) membrane defect.
- If a neonate is suspected of having HS (eg, based on positive family history and neonatal jaundice), treatment can be initiated for HS without awaiting diagnostic confirmation. This may include therapy for hyperbilirubinemia and, in severe cases, transfusion or even exchange transfusion [83
- The goals of pharmacotherapy for hereditary spherocytosis are to reduce morbidity and prevent complications. Folic acid supplementation is indicated to prevent megaloblastic crisis.
Medical Therapy
General supportive measures may include the following, depending on disease severity:
●Folic acid – Folic acid supplementation is appropriate for those with moderate to severe hemolysis and/or during pregnancy. This is based on an increased requirement for folate in RBC production; there are no clinical trials investigating the role of folic acid treatment, and observational studies that documented megaloblastic anemia in a small number of patients with HS were performed before the institution of routine folic acid supplementation of grains and cereals.[1] The typical dose for those with moderate to severe hemolysis is 1 to 2 mg/day, while those who have HS of any severity and are pregnant should receive doses as high as 4 to 5 mg/day, as discussed separately.
For individuals with mild hemolysis who have normal intake of fresh fruits and vegetables (or folic-acid-supplemented grains), daily folic acidis not required, but for those who place a high value on avoiding folate deficiency, which could cause worsening anemia, taking daily folic acid (typical dose, 1 to 2 mg daily) is safe and inexpensive, and there are essentially no side effects or contraindications.
●Transfusions – Blood transfusion is often required in severely affected infants and may be needed during certain times in other settings (eg, aplastic crisis, pregnancy). However, transfusions usually are not required on a chronic basis or for a long enough time to cause iron overload.
Typical hemoglobin thresholds for transfusion depend on the age of the patient, symptoms, and comorbidities.
•Some infants may require transfusions for anemia and/or hyperbilirubinemia. Older children may be able to tolerate a hemoglobin level of 5 to 6 g/dL without transfusions.
•Adults may require transfusions for anemia, with thresholds determined by their clinical status,
•Individuals with an aplastic crisis due to parvovirus infection or other bone marrow insult may require transfusions if they have a decreasing hemoglobin level without a robust reticulocytosis. The usual course of parvovirus-associated anemia is spontaneous resolution within a few days or weeks. Infected individuals are monitored with twice-weekly complete blood counts (CBCs) and reticulocyte counts to determine the expected hemoglobin nadir and the need for transfusion.
Consideration of transfusional iron overload typically occurs after transfusion of more than 15 to 20 units of RBCs (more than 10 units in smaller children). Adults with mild hemolysis may have a slight increase in iron absorption, and if this occurs in the setting of hereditary hemochromatosis, which is common, iron overload may occur.
●Erythropoietin – Erythropoietin (EPO) may be helpful in reducing the need for transfusion in some infants.[2] Typically, this can be discontinued around the age of nine months. In one study, the use of recombinant human EPO (1000 international units/kg per week) with iron supplementation obviated the need for transfusion in 13 of 16 infants with severe HS.[3] As the infants grew and began to mount an adequate erythropoietic response, the EPO dose could be tapered and discontinued before the age of nine months.
●Splenectomy and/or cholecystectomy – For those with relatively severe hemolysis, splenectomy is effective at improving anemia. Ideally, this is delayed until the individual is older than six years. Simultaneous cholecystectomy can be performed if gallstones are also present. Likewise, individuals with symptomatic gallstone disease who require cholecystectomy should be evaluated for the possible role of simultaneous splenectomy, but this should only be pursued if clinically indicated (eg, symptomatic hemolytic anemia and/or severe complications of hemolysis).
There are no special restrictions (eg, no activity limitations) on children with splenomegaly due to HS.[4]
●Other therapies – Allogeneic hematopoietic cell transplantation (HCT) is not used in HS due to an unfavorable risk-benefit ratio, but a case was reported in which an individual with both HS and chronic myelogenous leukemia (CML) underwent allogeneic HCT, which cured both disorders.[5]
References
- ↑ Bolton-Maggs PH, Stevens RF, Dodd NJ, Lamont G, Tittensor P, King MJ; et al. (2004). "Guidelines for the diagnosis and management of hereditary spherocytosis". Br J Haematol. 126 (4): 455–74. doi:10.1111/j.1365-2141.2004.05052.x. PMID 15287938.
- ↑ Bolton-Maggs PH, Langer JC, Iolascon A, Tittensor P, King MJ, General Haematology Task Force of the British Committee for Standards in Haematology (2012). "Guidelines for the diagnosis and management of hereditary spherocytosis--2011 update". Br J Haematol. 156 (1): 37–49. doi:10.1111/j.1365-2141.2011.08921.x. PMID 22055020.
- ↑ Tchernia G, Delhommeau F, Perrotta S, Cynober T, Bader-Meunier B, Nobili B; et al. (2000). "Recombinant erythropoietin therapy as an alternative to blood transfusions in infants with hereditary spherocytosis". Hematol J. 1 (3): 146–52. doi:10.1038/sj/thj/6200022. PMID 11920183.
- ↑ Tchernia G, Delhommeau F, Perrotta S, Cynober T, Bader-Meunier B, Nobili B; et al. (2000). "Recombinant erythropoietin therapy as an alternative to blood transfusions in infants with hereditary spherocytosis". Hematol J. 1 (3): 146–52. doi:10.1038/sj/thj/6200022. PMID 11920183.
- ↑ Zhang XH, Fu HX, Xu LP, Liu DH, Chen H, Han W; et al. (2012). "Allo-hematopoietic stem cell transplantation is a potential treatment for a patient with a combined disorder of hereditary spherocytosis". Chin Med J (Engl). 125 (5): 947–50. PMID 22490603.