ANTI-D IMMUNOGLOBULIN IN RH(D) NEGATIVE VOLUNTEERS - CLEARANCE OF RH(D) POSITIVE RED-CELLS AND KINETICS OF SERUM ANTI-D LEVELS

Properties of a new anti-D immunoglobulin were assessed in Rh(D) negat ive healthy male adults. Six volunteers received intravenous, and five volunteers intramuscular injections of 200 mu g anti-D, 48 hours afte r pre-treatment with 5 mL of Rh(D) positive erythrocytes. Immediately after intravenous administration of anti-D, a rapid decrease of the Rh (D) positive erythrocytes was noted. After intramuscular injection of anti-D, there was a lag phase of 6 hours until the erythrocytes decrea sed, and the elimination rate was slower. Twenty-four hours after inje ction of anti-D, the Rh(D) positive erythrocytes were at the detection limit or no longer detectable in all volunteers. After intravenous ad ministration, anti-D serum levels decreased from 45 ng/mL at two hours to 29 ng/mL at 24 hours, whereas after intramuscular administration, anti-D became detectable at 4 hours and increased to 11 ng/mL at 24 ho urs. During subsequent months, anti-D serum levels decreased at simila r rates in both groups. After six months, anti-D was not detectable in any of the volunteers. Thus, the new anti-D immunoglobulin induced el imination of the Rh(D) positive erythrocytes and suggested that Rh(D) immunization of the volunteers was prevented. (C) Elsevier 1998, Paris .