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Ouantitation of granulocyte antibodies in sera and determination of their binding sites
Author(s) -
Bux J.,
Sohn M.,
And R. Hachmann,
MuellerEckhardt C.
Publication year - 1992
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1992.tb04588.x
Subject(s) - granulocyte , antibody , monoclonal antibody , microbiology and biotechnology , incubation , immunology , immunoassay , monoclonal , antigen , chemistry , immunoglobulin g , biology , biochemistry
Summary An enzyme immunoassay using eluates was developed for the quantitation of granulocyte antibodies in sera. Incubation of donor granulocytes with sera containing granulocyte alloantibodies (NA1, NA2, NB1, 5b. HLA) or autoantibodies resulted in a significantly higher amount of immunoglobulin G (IgG) per cell than did incubation with control sera. Ultracentrifugation of the sera prior to testing reduced unspecific binding of IgG to granulocytes. In eight of 10 assessed sera from patients with Felty's syndrome eluted IgG decreased from elevated to normal levels. Ultracentrifugation further allowed determination of the binding sites of granulocyte‐reactive alloantibodies. Using sera containing NA1‐and NA2‐specific alloantibodies 173000–188000 binding sites on homozygous and 84000–110000 on heterozygous cells were determined. A similar number was found using a Fc gamma receptor III (FcRIII)‐speciflc monoclonal antibody. Granulocytes from patients with paroxysmal nocturnal haemoglobinuria showed greatly reduced binding sites for NA‐specific alloantibodies. The binding sites for the human alloantibody NB1 ranged from 36000 to 318000 and for the 5b alloantibody from 44000 to 65000. Mean values of 139000 binding sites for HLA antigens and 27000 binding sites for the FcRII were determined using monoclonal antibodies.