Cancer Treatment

Autoimmune hemolytic anemia basics

Lay Summary: I discuss some very basic facts about AIHA.

Autoimmune hemolytic anemia (AIHA) due to the presence of warm agglutinins is almost always due to IgG antibodies that react with protein antigens on the red blood cell (RBC) surface at body temperature. For this reason, they are called "warm agglutinins" even though they seldom directly agglutinate the RBCs. IV Gammaglobulin blocks this process.

I some cases, AIHA can be characterised by a chronic course and an unsatisfactory control of haemolysis, thus requiring prolonged immunosuppressive therapy. Sometimes when medical measures fail, it may be necessary to surgically remove the spleen (splenectomy). The clinical course of the disease may show either resistance to steroids or dependence on high-dose steroids with subsequent development of severe side effects on growth, bone mineralisation, and the endocrine system. Splenectomy is effective in about 50 to 60 percent of the time in IgG antibody diseases but is not usually effective in IgM antibody haemolysis. Splenectomy is of benefit in these people because the spleen behaves like a sieve and if it is removed, even though the RBCs are coated by antibodies, they are no longer caught and destroyed in the spleen.

IVIG is an accepted treatment for autoimmune hemolytic anemia. Unlike steroids, it does not induce remissions but is a temporizing measure until a definitve treatment can be planned and delivered.  IVIG is not as effective in AIHA as it is in ITP. Other treatments can sometimes be used.

Ucar K. Clinical presentation and management of hemolytic anemias. Oncology [Huntingt] 2002;16(9 suppl 10):163-70.

Schwartz RS, Berkman EM, Silberstein LE. Autoimmune hemolytic anemias. In: Hoffman R, Benz EJ Jr, Shattil SJ, Furie B, Cohen HJ, Silberstein LE, et al., eds. Hematology: basic principles and practice. 3d ed. Philadelphia: Churchill Livingstone, 2000:624.

Aranesp intravenously

Lay Sumamry: Aranesp intravenously works as well as by injection under the skin.

Darebpoietin is FDA approved for sq administration unlike erytrhopoietin. However, there are situations in which IV adminsitration is more convenient for the patient, such as, for example, when there is on onging IV line for another reason. The two most common settings of this kind are the neonates and patients on dyalisis. The treatment of renal anaemia using erythropoiesis stimulating agents (ESAs) [darbepoetin alfa and recombinant human erythropoietin (rHuEPO) alfa or beta] is now a common clinical practice in patients with chronic kidney disease (CKD). There is evidence that both routes of administration result in similar blood levels and effectiveness. This evidence is sufficiently convincing for the pharamcologic standpoint to consider the IV route to be standard of care.

T L Warwood et al, Urinary excretion of darbepoetin after intravenous vs subcutaneous administration to preterm neonates Journal of Perinatology (2006) 26, 636–639.

Fernando Carrera, Lino Oliveira, Pedro Maia, Teresa Mendes and Candido Ferreira The efficacy of intravenous darbepoetin alfa administered once every 2 weeks in chronic kidney disease patients on haemodialysis Nephrology Dialysis Transplantation 2006 21(10):2846-2850

I. C. Macdougall, D. Padhi, and G. Jang
Pharmacology of darbepoetin alfa
Nephrol. Dial. Transplant., June 1, 2007; 22(suppl_4): iv2 - iv9.