What should we pay attention to when using human immunoglobulin?

Intravenous human immunoglobulin is prepared from human plasma, in which the content of human immunoglobulin (gamma globulin) is not less than 95%. Infusion of human immunoglobulin can improve the patient's immunity. Intravenous human immunoglobulin has now entered the national medical insurance, and the reimbursement scope is limited to hypoimmunoglobulinemia, neonatal sepsis, immune thrombocytopenia (or thrombocytopenic purpura), Kawasaki disease, myasthenia gravis, and Guillain-Barré syndrome. The indications in the instructions include: primary immunoglobulin G deficiency, treatment of secondary immunoglobulin G deficiency diseases, such as severe infection, neonatal sepsis, infantile bronchiolitis, etc. Treatment of autoimmune diseases, such as primary thrombocytopenic purpura, Kawasaki disease, etc. Which groups are contraindicated? Contraindications include: 1. People who are allergic to immunoglobulin or have a history of other severe allergies. 2. People with selective IgA deficiency with anti-IgA antibodies.

Precautions for the use of human immunoglobulin include: Storage requirements are 2-8 degrees Celsius, dark storage and transportation. Freezing is strictly prohibited during transportation and storage. Some parents only remember that the medicine should be placed in the refrigerator, but did not remember to put it in the refrigerator, but mistakenly put it in the freezer, resulting in a waste of medicine. The medicine can only be infused intravenously and cannot be used for other routes of administration. It must not be used when the bottle is found to be cracked, the bottle cap is loose, or it has exceeded the expiration date. The medicine must not be used when it is turbid, foreign matter, flocculent or precipitated. These signs may indicate that the medicine has been contaminated. Once opened, it should be used up immediately at one time, and the unused portion should be discarded. It must not be kept for the next use or distributed to others.

In order to further ensure the safety of public drug use, the State Drug Administration decided in 2019 to add warnings to the instructions for intravenous human immunoglobulin (PH4) and to revise adverse reactions, precautions, etc. Clinicians and pharmacists are required to read the revised instructions carefully and conduct a full benefit/risk analysis based on the revised instructions when choosing medications. The warning reads: "Because the raw materials come from human blood, although the raw plasma has been screened for relevant pathogens and measures to remove and inactivate viruses have been added to the production process, there is still a theoretical potential risk of spreading certain known and unknown pathogens, and the pros and cons should be weighed during clinical use."

Next, let's talk about the issue of how children who use human immunoglobulin should be vaccinated, which is of great concern to parents. In order to avoid the interference of the specific antibodies in this product, some live attenuated vaccines, such as polio, measles, rubella, mumps and varicella virus vaccines, can only be received 3 months after the infusion of human immunoglobulin. Based on the same considerations, in non-emergency situations, patients who have received such vaccines can only receive human immunoglobulin infusions at least 3-4 weeks after vaccination; if human immunoglobulin is used 3-4 weeks after vaccination, it should be re-vaccinated 3 months after the last infusion of human immunoglobulin.

(Fu Zhengran, Beijing Children's Hospital Affiliated to Capital Medical University)