Medication Summary
The goals of therapy for pure red cell aplasia (PRCA) are to restore erythroid production, to maintain hemoglobin at an adequate level, and to treat underlying disorders. Therapy is also designed to prevent and treat complications of therapy.
Corticosteroids
Class Summary
Corticosteroids are the mainstay of therapy for pure red cell aplasia (PRCA). Approximately 45% of patients with PRCA respond to corticosteroids.
Prednisone (Sterapred)
Useful in acquired PRCA because they can modify the body's immune response. In congenital PRCA, corticosteroids are believed to allow abnormal stem cells to become more sensitive to growth factors. Have an anti-inflammatory effect, a profound effect on metabolism, and numerous potentially serious adverse effects.
Benefits and risks should be individualized when treating PRCA.
Prednisolone (Delta-Cortef, Econopred)
High-dose treatment is an option if no response to prednisone occurs.
Immunosuppressives
Class Summary
Immunosuppressive therapy can be effective, especially when PRCA is thought to be due to autoimmunity or idiopathic. Cyclophosphamide 6-mercaptopurine, azathioprine, cyclosporin A, and rituximab have been used. Typical doses for immunosuppressive agents are listed below. A hematologist should be consulted to individualize doses of immunosuppressive agents. Other options include antithymic globulin (ATG) and high-dose intravenous immunoglobulin G. Danazol may be effective in some cases of refractory PRCA but is contraindicated in children.
Cyclophosphamide (Cytoxan, Neosar)
Chemically related to nitrogen mustards. As an alkylating agent, mechanism of action of active metabolites may involve cross-linking of DNA, which may interfere with growth of normal and neoplastic cells.
6-Mercaptopurine (Purinethol)
Purine analog that inhibits DNA and RNA synthesis, causing cell proliferation to arrest.
Azathioprine (Imuran)
Antagonizes purine metabolism and inhibits synthesis of DNA, RNA, and proteins. May decrease proliferation of immune cells, which results in lower autoimmune activity.
Cyclosporine (Sandimmune, Neoral)
Cyclic polypeptide that suppresses some humoral immunity and, to a greater extent, cell-mediated immune reactions such as delayed hypersensitivity, allograft rejection, experimental allergic encephalomyelitis, and graft versus host disease for a variety of organs.
For children and adults, base dosing on ideal body weight.
Antithymocyte globulin (Thymoglobulin)
Purified concentrated gamma-globulin (primarily monomeric IgG) from hyperimmune horses immunized with human thymic lymphocytes. Mechanism of action is thought to be its effect on lymphocytes responsible in part for cell-mediated immunity and lymphocytes involved in cell immunity.
A hematologist or another physician with extensive experience must be involved in administration and monitoring because of the many complications and adverse effects of this therapy.
Intravenous immune globulin (Gamimune, Gammagard, Sandoglobulin, Gammar-P)
A hematologist or a physician experienced in administering this agent should be consulted because anaphylaxis, renal failure, transmission of infections, and aseptic meningitis are potential complications. Experience in selecting patients who can tolerate IVIG, dosage, monitoring for adverse effects, and managing complications of therapy is mandatory. Consider the expense of this therapy.
Mechanism is not fully established. Has been reported that IVIG neutralizes autoantibodies. Down-regulates proinflammatory cytokines, including INF-gamma; blocks Fc receptors on macrophages; suppresses inducer T and B cells and augments suppressor T cells; and blocks complement cascade.
Total dose is administered IV but is graduated with low doses initially to monitor for anaphylaxis and other complications. Therefore, doses mentioned in package insert should be followed. Lower dosages per day but extended over 4 d are indicated in patients with fluid overload.
Danazol (Danocrine)
Reduces autoimmune responses. Used to treat pure red cell aplasia.
