Humoral immunity and composition of immune complexes in patients with rheumatoid arthritis, with special reference to IgE-containing immune complexes.
IgE-containing circulating immune complexes (IgE-CIC) were determined with a 2.5% PEG-precipitation assay in 98 patients with classical or definite rheumatoid arthritis (RA). Of the 45 IgE-CIC positive sera, only 4 had elevated total serum IgE. IgE-CIC positive patients had more active disease than patients without IgE-CIC, as determined by their more swollen joints and higher Ritchie indices (p less than 0.04 and 0.02, respectively). Apart from IgE, other immunoglobulin isotypes, rheumatoid factor (RF) of the IgG-, IgA- and IgM-classes, C3 and antinuclear antibodies could be demonstrated in the IgE-containing PEG-precipitates. IgE-RF could not be demonstrated in serum or in IgE-CIC. Anti-IgE of the IgM-class (IgMaIgE) were frequently found (28/45 patients) in the IgE-positive PEG-precipitates. All 14 patients positive for IgGaIgE in the IgE-CIC were also positive for IgMaIgE in the CIC. As in the serum, there was a good correlation in the CIC between the level of IgGaIgE and the level of IgMaIgE (r = 0.64). The correlation between the respective levels of IgGaIgE and IgMaIgE in serum and in CIC was high (r = 0.93 and 0.79, respectively). On the other hand, only 1 patient was positive for IgAaIgE in the IgE-CIC. We conclude that IgE and aIgE of the IgM- and IgG-classes are frequently present in the immune complex form in RA and that they are correlated with the clinical activity of arthritis.
De Clerck
L S
LS
Department of Immunology and Rheumatology, University of Antwerp, Belgium.
Struyf
N J
NJ
Bridts
C H
CH
Francx
L
L
Van Offel
J F
JF
Empsten
F A
FA
Westedt
M L
ML
Breedveld
F C
FC
Cats
A
A
Stevens
W J
WJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000888:Antibodies, Anti-Idiotypic / Q000032:analysis*; D000974:Antibodies, Antinuclear / Q000032:analysis; D000917:Antibody Formation; D000936:Antigen-Antibody Complex / Q000032:analysis*; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D003176:Complement C3 / Q000032:analysis; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007073:Immunoglobulin E / Q000032:analysis*; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D008297:Male; D008875:Middle Aged; D012217:Rheumatoid Factor / Q000032:analysis
D000888:Antibodies, Anti-Idiotypic; D000974:Antibodies, Antinuclear; D000936:Antigen-Antibody Complex; D003176:Complement C3; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007073:Immunoglobulin E; D012217:Rheumatoid Factor