Passive immunization employs preformed antibodies provided to an individual that can prevent or treat infectious diseases. There are several situations in which passive immunization can be used:
- for persons with congenital or acquired immunodeficiency;
- prophylactic administration when there is a likelihood of exposure to a particular infection; or treatment of a disease state already acquired by the individual.
1. Raab CP. Passive immunization. Prim Care. 2011 Dec;38(4):681-91
Chronic hepatitis B virus (HBV), a liver infection, affects about 400 million people worldwide, and some 600,000 deaths each year are attributable to the disease. It is associated with cirrhosis and liver cancer, resulting in a lifetime risk of HBV-related death of 25-40%. Liver transplantation is often the only viable treatment option for patients with complications.
But liver transplantation can be frequently followed by HBV reinfection, resulting in rapidly progressing liver disease and significantly decreased overall survival. Reinfection can be effectively prevented by administration of anti-hepatitis B immunoglobulin (HBIg) alone or, more recently, in combination with antiviral nucleoside/nucleotide analogs. This preventive regimen reduces the risk of a recurrence of HBV infection and thereby the need for retransplantation.
Before its introduction, reinfection with HBV after transplantation occurred in more than 80% of recipients and the 5-year graft and patient survival rates were only 50%. Now, with the use of the HBIg/nucleoside/nucleotide analogue prophylaxis, transplant programs in North America and Europe can expect prevention of HBV recurrence in greater than 90% of their patients.
Hepatitis B is contagious, but it can be transmitted from mothers to infants at the time of birth. This transmission can be markedly reduced by the immediate postpartum administration of HBIg to the infant either alone or, as currently recommended, with commencement of hepatitis B vaccine.
1. Nair S, Perrillo RP. In: BoyerTD, ed: Hepatology (4th edn). Philadelphia: Saunders, 2003: 959.
2. Realdi G, Fattovich G, Hadziyannis S, et al. Survival and prognostic factors in 366 patients with compensated cirrhosis type B: a multicenter study. The Investigators of the European Concerted Action onViral Hepatitis (EUROHEP). J Hepatol 1994; 21: 656^666.
3. Arianeb Mehrabi, “The role of HBIg as hepatitis B reinfection prophylaxis following liver transplantation” Langenbeck's Archives of Surgery June 2012, Volume 397, Issue 5, pp 697-710.
4. American Academy of Pediatrics. Hepatitis B. In: Peter G, editor. 1997 Red Book. Report of the Committee on Infectious Diseases. 24th ed. Elk Grove Village, Ill: American Academy of Pediatrics; 1997. pp. 247–260.
HEMOLYTIC DISEASE OF THE NEWBORN
Also called erythroblastosis fetalis, hemolytic disease of the newborn (HDN) is a condition that can arise when a mother and her unborn child have different and incompatible blood types. If even a few of the fetus’s red blood cells cross over the placenta and get into the mother’s circulation during the pregnancy, they are recognized by her immune system as “foreign” and it will produce antibodies to attack them. If these antibodies cross back over into the fetus, they will begin to destroy fetal red blood cells.
Since it takes time for antibodies to develop, the first child might not be seriously affected, but the mother’s immune system will now be sensitized to these incompatible red blood cells and subsequent pregnancies involving similar incompatibility will be seriously threatened.
The most serious type of HDN is Rh incompatibility in which the mother has Type Rh Negative blood and the fetus, Rh Positive.
Although HDN can be extremely serious, it is rare and preventable.
Passive immunization with anti-D antigen Immune Globulin protects Rh(D)-negative women from sensitization against Rh(D)-positive red blood cells.
1. Liumbruno et al. The role of antenatal immunoprophylaxis in the prevention of maternal-foetal anti-Rh(D) alloimmunisation. Blood Transfus 2010; 8:8-16
2. Bowman JM. Controversies in Rh prophylaxis: who needs Rh immune globulin and when should it be given? Am J Obstet Gynecol 1985; 151: 289-94.
3. Clarke CA, Donohoe WTA, McConnell RB, et al. Further experimental studies on the prevention of Rh haemolytic disease. Br Med J 1963; 1: 979-84.
Tetanus is a serious disease affecting the nervous system and causing severe muscle contractions, especially around the jaw and neck (It is sometimes known as “lockjaw”). It is life-threatening without treatment.
Tetanus is contracted through a wound – especially a deep cut or puncture – that becomes contaminated by the tetanus bacterium, Clostridium tetani. These bacteria are ubiquitous in soil, dust and animal or human feces. Their spores germinate in the anaerobic environment of the wound and produce a potent neurotoxin, tetanospasmin, that impairs motor neurons controlling the muscles.
Fortunately, Tetanus can be effectively prevented by active immunization with Tetanus toxoid. For short-term, but immediate protection (passive immunization) or post-exposure treatment, Tetanus-specific immunoglobulin is effective.
1. Steven G. F. Wassilak, Katrina Kretsinger “Tetanus”. Bacterial Infections of Humans 2009, pp 813-832