IgM, IgG, and IgA rheumatoid factors in pigeon hypersensitivity pneumonitis
The association of rheumatoid factor (RF) and lung disease in several immunologically mediated conditions has suggested that it may be physiopathologically relevant. Since previous reports in hypersensitivity pneumonitis (HP) have dealt mainly with the immunoglobulin M (IgM) RF measurement, we studi...
Saved in:
Published in | Journal of clinical laboratory analysis Vol. 21; no. 5; pp. 315 - 321 |
---|---|
Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Hoboken
Wiley Subscription Services, Inc., A Wiley Company
2007
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The association of rheumatoid factor (RF) and lung disease in several immunologically mediated conditions has suggested that it may be physiopathologically relevant. Since previous reports in hypersensitivity pneumonitis (HP) have dealt mainly with the immunoglobulin M (IgM) RF measurement, we studied such antibody activity in other immunoglobulins, to determine the IgG and IgA RF levels in pigeon‐HP, and in asymptomatic breeders (AB) and rheumatoid arthritis (RA) as controls. RFs were measured in 35 HP patients, 41 AB, 31 RA controls, and 55 healthy donors by enzyme‐linked immunosorbent assay (ELISA) using human or rabbit immunoglobulin G (IgG), anti‐IgM, F(ab′)2 of IgG, and IgA F(ab′)2 conjugates. An affinity chromatography, fragment crystallizable (Fc) preparations of IgG, pepsin digestion, and Western blots were used to confirm RF specificity. We also evaluated anti‐avian antibodies (AA) and cross‐reacting antibodies. The HP group revealed positive IgM (51.4%), IgG (31.4%), and immunoglobulin A (IgA) (34.2%) RF tests, and these antibody values exceeded the AB reference levels (P<0.02). HP and RA showed a similar frequency and distribution of RFs. Possible immunoassay interferences were excluded. As in other immunologically mediated diseases, IgG and IgA RFs may play a pathogenic role in HP, amplifying the inflammatory reaction, immune‐complex formation, and complement activation. IgM‐RF producing cells that have been implicated in the presentation of self and foreign antigens, and T‐cell activation might induce the isotype switching of RFs. J. Clin. Lab. Anal. 21:315–321, 2007. © 2007 Wiley‐Liss, Inc. |
---|---|
Bibliography: | ArticleID:JCLA20188 istex:EAE6C0FC998F2827BCECE6E0BD2E7F70D60A6CA4 ark:/67375/WNG-NC06S0BJ-J ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0887-8013 1098-2825 |
DOI: | 10.1002/jcla.20188 |