In vitro removal of anti-HLA IgG antibodies from highly sensitized transplant recipients by immunoadsorption with protein A and protein G sepharose columns: a comparison.
In the present study we compared the capabilities of sepharose-bound protein A versus protein G columns to remove in vitro lymphocytotoxic anti-HLA antibodies from sera of four highly sensitized renal transplant recipients (PRA > or = 70%). In none of the patients were protein A sepharose columns capable of completely removing anti-HLA antibodies, as demonstrated by the presence of residual alloreactive lymphocytotoxic activity in IgG3 antibodies containing fractions eluted at pH 7. In contrast, no residual anti-HLA lymphocytotoxic antibody activity was found in fractions eluted at pH 7 from protein G columns. These data demonstrate that: (1) IgG 3 antibodies can be partly responsible for lymphocytotoxic anti-HLA reactivity in some sensitized renal transplant recipients and (2) at least in this patient category, in vitro immunoadsorption with protein G is more efficient than protein A sepharose columns in completely removing anti-HLA IgG antibodies from sera.
Barocci
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S
Department of Immunology, San Martino Hospital, Genoa, Italy.
Nocera
A
A
D000293:Adolescent; D000328:Adult; D002846:Chromatography, Affinity; D003602:Cytotoxicity, Immunologic; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007074:Immunoglobulin G / Q000145:classification / Q000302:isolation & purification*; D007163:Immunosorbent Techniques; D016030:Kidney Transplantation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000276:immunology; D013205:Staphylococcal Protein A / Q000276:immunology
C029152:G-substrate; D006680:HLA Antigens; D007074:Immunoglobulin G; D009419:Nerve Tissue Proteins; D013205:Staphylococcal Protein A