What is Rhogam (Rho(D) immune globulin) made of?

From the Guidelines

Rhogam (Rho(D) immune globulin) is made of concentrated anti-D antibodies derived from human plasma of donors who have high levels of anti-D antibodies, as stated in the most recent study 1. The product is purified and processed to create a sterile solution that can be administered as an injection.

• Rhogam contains IgG antibodies that target and bind to any Rh-positive fetal red blood cells that may have entered an Rh-negative mother's circulation, preventing her immune system from recognizing these cells as foreign and developing antibodies against them.
• This mechanism is crucial for preventing hemolytic disease of the newborn in subsequent pregnancies.
• The preparation also contains small amounts of stabilizers and preservatives to maintain its efficacy and shelf life.
• Rhogam is a biological product and undergoes rigorous testing for safety, including screening for infectious agents, before being approved for clinical use, as noted in 1 and 1. According to the latest research 1, Rhogam's composition and mechanism of action are well-established, and its use has significantly reduced the burden of RhD alloimmunization and its adverse perinatal outcomes. Key points to consider when administering Rhogam include:
• The recommended dose and timing of administration, which may vary depending on the clinical setting and patient needs.
• The importance of prioritizing postpartum patients and antenatal patients at later gestational ages for available doses when supply is limited.
• The need for local surveillance of anti-D alloimmunization rates to determine the impact of selective first-trimester RhIg administration.

From the FDA Drug Label

Rho(D) Immune Globulin (Human) — HyperRHO® S/D Full Dose treated with solvent/detergent is a colorless to pale yellow or pink sterile solution of immune globulin containing antibodies to Rho(D) for intramuscular administration; it is preservative-free, in a latex-free delivery system. HyperRHO S/D Full Dose is prepared by cold ethanol fractionation from human plasma The immune globulin is isolated from solubilized Cohn fraction II. The fraction II solution is adjusted to a final concentration of 0.3% tri-n-butyl phosphate (TNBP) and 0. 2% sodium cholate.

Rhogam (Rho(D) immune globulin) is made up of:

• Immune globulin containing antibodies to Rho(D)
• Prepared from human plasma using cold ethanol fractionation
• Contains 0.3% tri-n-butyl phosphate (TNBP) and 0.2% sodium cholate
• Formulated as a 15–18% protein solution at a pH of 6.4–7.2 in 0.21–0.32 M glycine 2

From the Research

Composition of Rhogam

Rhogam, also known as Rho(D) immune globulin, is a medication used to prevent Rh immunization in Rh-negative individuals. The exact composition of Rhogam is not explicitly stated in the provided studies, but it is mentioned that it is an Rh immune globulin prepared by ion exchange for intravenous use 3.

Mechanism of Action

The mechanism of RhIG-induced immunosuppression remains unknown, but a recent report has shown that women receiving RhIG produce elevated levels of transforming growth factor (TGF)β-1, a powerful immunosuppressant cytokine 4.

Administration and Dosage

The administration and dosage of Rhogam vary depending on the situation:

• 300 microg IM or IV should be given within 72 hours of delivery to a postpartum nonsensitized Rh-negative woman delivering an Rh-positive infant 5.
• 120 microg IM or IV may be given within 72 hours of delivery, with testing and additional anti-D Ig given for FMH over 6 mL of fetal red blood cells 5.
• Anti-D Ig 300 microg should be given routinely to all Rh-negative nonsensitized women at 28 weeks' gestation when fetal blood type is unknown or known to be Rh-positive 5.
• A minimum anti-D of 120 microg should be given before 12 weeks' gestation and 300 microg after 12 weeks' gestation in cases of miscarriage, abortion, or ectopic pregnancy 5, 6.

Key Points

• Rhogam is used to prevent Rh immunization in Rh-negative individuals.
• The exact composition of Rhogam is not explicitly stated, but it is an Rh immune globulin prepared by ion exchange for intravenous use.
• The mechanism of RhIG-induced immunosuppression remains unknown, but it may involve the production of TGFβ-1.
• The administration and dosage of Rhogam vary depending on the situation, including pregnancy, delivery, and potentially sensitizing events.
• Recent evidence suggests that women with molecularly defined Asian-type DEL (c.1227G>A) do not require RhIG before and after delivery 7.