A novel heterophilic antibody interaction involves IgG4.
Scand J Immunol
; 71(2): 109-14, 2010 Feb.
Article
in En
| MEDLINE
| ID: mdl-20384862
ABSTRACT
IgG4 has been implicated in a diverse set of complex pathologies - e.g. autoimmune pancreatitis (AIP), idiopathic membranous nephropathy - and carries unique features including lack of activation of the classical complement pathway and a dynamic Fab-arm exchange. We recently showed that the rheumatoid factor (RF)-like activity of IgG4 is achieved through a hitherto unknown, Fc-Fc (and not Fab-Fc as is the case in classical RF; CRF) interaction; hence the name, novel RF (NRF). Here, we further explore the resemblance/difference between CRF and NRF. As heterophilic interactions of human IgM RF (CRF) are well known, we checked whether this is the case for IgG4. Human IgG4 showed variable reactivity to animal IgGs reacting intensely with rabbit and mouse IgGs, but weakly with others. The binding to rabbit IgG was not through the Fab (as in CRF) but via the Fc piece, as was recently shown for human IgG (NRF). This binding correlates with the IgG4 concentration per se and could therefore be of diagnostic usage and incidentally explain some observed interferences in biological assays. In conclusion, here is defined a novel heterophilic antibody interaction and is established the universality of the unique Fc-Fc binding, both involving IgG4.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Antibodies, Heterophile
/
Immunoglobulin G
/
Immunoglobulin Fc Fragments
Limits:
Adult
/
Aged
/
Animals
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Scand J Immunol
Year:
2010
Document type:
Article
Affiliation country:
Japan
Publication country:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
/
SCOTLAND
/
UK
/
UNITED KINGDOM