Open AccessIdiotypic characteristics of immunoglobulins associated with human systemic lupus erythematosus: association of high serum levels of IdGN2 with nephritis but not with HLA class ii genes predisposing to nephritis
Author(s) -
Hahn Bevra H.,
Kalunian Kenneth C.,
Fronek Zdenka,
PanosianSahakian Niver,
Louie James S.,
Mcdevitt Hugh O.,
Ebling Fanny M.
Publication year - 1990
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.1780330709
Subject(s) - lupus nephritis , immunology , idiotype , nephritis , medicine , polyclonal antibodies , human leukocyte antigen , antibody , systemic lupus erythematosus , disease , antigen , monoclonal antibody
Serum levels of IdGN2 (an idiotype enriched in nephritogenic antibodies), IdX (an idiotype not enriched in nephritogenic antibodies), IgG, and anti‐DNA were measured in 23 Caucasian patients with lupus nephritis, in age‐ and sex‐matched lupus patients without nephritis, and in similarly matched healthy individuals. Serum levels of IdGN2 were significantly higher in the patients with lupus nephritis than in those without, and they were higher in all lupus patients compared with the healthy control subjects. However, the same observations were true for serum levels of IdX. There were significant positive correlations between the serum levels of IgG, IdGN2, IdX, and anti‐DNA. HLA typing at the DR and DQ loci was performed in 105 lupus patients of different races (Caucasian, black, and Asian/Polynesian/Filipino). Serum levels of IdGN2 in 83 of these individuals did not correlate with any of the HLA class II haplotypes currently known to predispose to lupus nephritis. We conclude that the high serum levels of IdGN2, which are characteristic of some patients with lupus nephritis, may often result from polyclonal B cell activation rather than from idiotype‐specific up‐regulation associated with one or more of the class II genes that predispose to nephritis in this disease.