Anti-D (also known as Rho(D) immune globulin intravenous or anti-D IGIV) is a blood product consisting of antibodies to the RH factor on red blood cells. It achieves a temporary rise in the platelet count in about 80 percent of people and occasionally has a longer term effect 1. First licensed in March, 1995, for the treatment of ITP, the anti-D products of Baxter (WinRho SDF) and CSL Behring (Rhophylac) are approved by the FDA. The product is used in both children and adults.
Following a treatment with anti-D, the patient's RH positive red blood cells link to the anti-D antibodies and the anti-body coated red blood cells are then removed in the spleen. Since red blood cells are eliminated, the process often causes a mild anemia. However, it is usually successful in keeping the antibody-coated platelets of the ITP patient in circulation.
For the product to be safe and effective, the patient must be RH positive, have a spleen, and not be anemic or deficient in IgA. The ITP Consensus Report recommends that doctors determine the patient’s blood group, do a direct antiglobulin test (DAT) to check for antibodies against red blood cells, and a reticulocyte count to test the rate of red cell production before administering anti-D6.
Anti-D is made from human plasma derived from a limited list of donors in a special program that stimulates the production of high levels of antibodies. The antibodies from the donors are combined in batches that undergo a viral inactivation and micro filtration process using solvent/detergent to remove or deactivate disease-causing agents that can be transmitted through blood infusions.2
Dosage
According to the package insert, the suggested dosing is 50 mcg/kg of bodyweight although some clinical studies report greater success at a 75 mcg/kg dose.3 Because the antibodies are concentrated, a treatment with anti-D requires less product and a shorter infusion time than IVIg. Premedication with paracetamol/acetaminophen, or corticosteroids is advised to reduce the risk of fever and chills.6
Side Effects
Side effects developed following 7% of infusions, and included headaches, chills, fever and body aches. A remote risk of anaphylaxis (shock response) exists for patients with hypersensitivity to blood products. 4,5
A very small number of people receiving anti-D experience intravascular hemolysis, the destruction of red blood cells in circulation. This type of red cell destruction can cause anemia, multi-system organ failure, difficulty breathing, and even death. In December, 2009, the FDA revised the WinRho SDF package insert to highlight these warnings and suggest additional tests and patient monitoring to be better able to identify and treat those patients at risk.4
Patients should immediately report symptoms of back pain, shaking chills, fever, discolored urine, decreased urine output, sudden weight gain, fluid retention/edema and/or shortness of breath to their physicians. 4,5
Anti-D can interfere with the efficacy of live virus vaccines, therefore the manufacturers do not recommend live virus immunizations within three months after an anti-D treatment. 4,5
Maltose in IVIG products, such as the liquid formulation of WinRho SDF, has been shown to give falsely high blood glucose levels in certain types of blood glucose testing systems. Only systems that are glucose-specific should be used to test or monitor blood glucose levels in patients receiving this product. 4,5
WinRho SDF was voluntarily withdrawn from the European market in August, 2009 because of safety concerns.7
1. http://www.ncbi.nlm.nih.gov/pubmed/11877261 (Blood. 2002 Mar 15;99(6):1922-7)
2. http://bloodjournal.hematologylibrary.org/cgi/content/full/95/8/2523 (Blood, Vol. 95 No. 8, April 15,2000: pp. 2523-2529)
3. http://www.ncbi.nlm.nih.gov/pubmed/11298610 (Br J Haematol. 2001 Mar;112(4):1076-8)
4. http://www.fda.gov/BiologicsBloodVaccines/BloodBloodProducts/ApprovedProducts/LicensedProductsBLAs/FractionatedPlasmaProducts/ucm089397.htm
5. http://www.fda.gov/downloads/BiologicsBloodVaccines/BloodBloodProducts/ApprovedProducts/LicensedProductsBLAs/FractionatedPlasmaProducts/ucm119473.pdf
6. http://bloodjournal.hematologylibrary.org/cgi/content/full/115/2/168
7. http://www.mhra.gov.uk/Safetyinformation/Safetywarningsalertsandrecalls/Safetywarningsandmessagesformedicines/Monthlylistsofinformationforhealthcareprofessionalsonthesafetyofmedicines/CON057078
