Functional in vitro studies of recombinant human immunoglobulin G and immunoglobulin A anti-D.
BACKGROUND
The use of anti-D purified from human serum to prevent hemolytic disease of the fetus and newborn due to D is well established. Owing to supply and safety reasons, however, an unlimited and non-plasma-derived source of antibodies for Rhesus prophylaxis is needed.


METHODS
Recombinant human immunoglobulin G (IgG)1, IgG2, IgG3, IgG4, IgA1, and IgA2 anti-D with the same variable region were expressed in Chinese hamster ovary cells. The effector functions of these antibodies were assessed by an antibody-dependent cell-mediated cytotoxicity (ADCC) assay and a chemiluminescence (CL) method for detection of respiratory burst.


RESULTS
In the ADCC assay, IgG1, IgG3, and IgA1 did the best and were as active as a currently used prophylactic polyclonal anti-D. IgG4 and IgA2 were moderately active, whereas IgG2 was not active. In the CL assay, IgG1 and IgG3 were active but much less so than a currently used prophylactic polyclonal anti-D. For some effector cell preparations, IgG4 was active in the CL assay, whereas IgG2, IgA1, and IgA2 were not. A mixture of IgG1 and IgG3 showed a synergistic effect in the CL assay and did as well as the prophylactic polyclonal anti-D in ADCC and CL. Mixtures of IgA1 and either IgG1 or IgG3 showed no synergistic effect.


CONCLUSIONS
A mixture of recombinant human IgG1 and IgG3 anti-D could be of value in future Rhesus prophylaxis.
Nielsen
Leif Kofoed
LK
H:S Blood Bank KI2034, Department of Clinical Immunology, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark. lkn@rh.dk
Green
Trine Hefsgaard
TH
Norderhaug
Lars
L
Sandlie
Inger
I
Dziegiel
Morten Hanefeld
MH
D000818:Animals; D000918:Antibody Specificity; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D015870:Gene Expression / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000235:genetics* / Q000276:immunology; D007074:Immunoglobulin G / Q000235:genetics* / Q000276:immunology; D066298:In Vitro Techniques; D011994:Recombinant Proteins / Q000235:genetics* / Q000276:immunology; D016897:Respiratory Burst; D012204:Rh-Hr Blood-Group System / Q000276:immunology*; D014162:Transfection
D007070:Immunoglobulin A; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen