Cell-free Fc-gamma receptor III in sera from patients with systemic lupus erythematosus: correlation with clinical and biological features.
Fifty patients (41 females and 9 males, ranging in age from 12 to 79 years) with systemic lupus erythematosus (SLE) and 20 normal controls were evaluated for the presence of plasma cell-free Fc gamma receptor III (Fc gamma RIII) using an ELISA based upon a sandwich of two monoclonal antibodies. The standard curve was obtained with serial dilutions of recombinant Fc gamma RIII. In the patients, the cell-free Fc gamma RIII levels ranged from to 1.76 micrograms/ml, while it did not exceed 0.21 microgram/ml in the controls. Assuming that the cutoff is 0.25 microgram/ml, 11 SLE patients and no controls had elevated cell-free Fc gamma RIII levels in the serum. Among the SLE patients, the level of cell-free Fc gamma RIII was significantly lower (p = 0.05) in 4 patients with sicca syndrome than in the remaining 46. Furthermore, cell-free Fc gamma RIII levels appeared to be lower in 11 patients with renal involvement than in those without. For the biological parameters, we observed that the 27 patients who presented lymphopenia also had a lower level of cell-free Fc gamma RIII when compared to the 23 patients without lymphopenia (0.09 +/- 0.19 versus 0.35 +/- 0.52 microgram/ml; p = 0.05). Circulating cell-free Fc gamma RIII may originate from shedding by presumably activated polymorphonuclear cells.
Hutin
P
P
Unit of Internal Medicine, Brest University Medical School Hospital, France.
Lamour
A
A
Pennec
Y L
YL
Soubrane
C
C
Dien
G
G
Khayat
D
D
Youinou
P
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D002474:Cell-Free System / Q000737:chemistry; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000473:pathology; D008231:Lymphopenia / Q000097:blood; D008297:Male; D008875:Middle Aged; D017452:Receptors, IgG / Q000032:analysis* / Q000276:immunology; D011994:Recombinant Proteins / Q000032:analysis / Q000276:immunology; D051437:Renal Insufficiency / Q000097:blood; D012859:Sjogren's Syndrome / Q000097:blood
D000911:Antibodies, Monoclonal; D017452:Receptors, IgG; D011994:Recombinant Proteins