Uptake and elimination of hepatitis B immunoglobulins after intramuscular application in man

Hepatitis B immunoglobulins of 4 different manufacturers were administered intramuscularly into 37 healthy adults. Each person received an amount of 0.1 ml per kg bodyweight. Blood samples were taken on days 3, 7, 14, 21, 28, 63, 98 and 126 after passive immunization. The anti-HBs serum levels were determined using the International Reference Preparation of anti-HBs as standard reagent. The highest serum levels were seen on day 3 (38.9% of the test persons), day 7 (41.7%), day 14 (11.1%), and day 21 (8.3%) after application of the immunoglobulins with mean values between 138 and 355 mU anti-HBs/ml. The half-life of the preparations in man showed mean values between 17.5 and 25 days. The shortest half-life was 5.9 and the longest 35 days. Four months after passive immunization the anti-HBs levels had decreased to a percentage of 1.2 to 2.5 of the maximum serum concentration (1.7 to 8.9 mU anti-HBs/ml). The passive immunization via the intramuscular route does not accomplish an instantaneously available, maximum anti-HBs titer. There seems to be a great range of variation in uptake and elimination of the immunoglobulins in man. Still, since preparations for intravenous application are not at hand, hepatitis B immunoglobulins for intramuscular use must play a major role in post-exposure prophylaxis of hepatitis B virus infection.