[A sensitive enzyme immunoassay for the measurement of small quantities of erythrocyte-associated IgG in patients with systemic lupus erythematosus who had negative direct antiglobulin test].
To measure the amount of erythrocyte-associated IgG (EAIgG) molecules from 70 patients with systemic lupus erythematosus (SLE) who had negative direct antiglobulin test (DAT), we employed a sensitive enzyme-linked immunosorbent assay (ELISA) technique. Ninety-five percent of healthy individuals were less than 65 molecules of EAIgG per red cell (RBC). About 51 percent of these patients with SLE were positive (over 65 molecules of EAIgG per RBC) by this technique that showed more sensitive than the DAT. EAIgG levels of these patients were inversely proportional to RBC count (r = -0.369, p < 0.005), and EAIgG positive patients were recognized by 88 percent in patients group who were less than 4 x 10(6)/microliter RBC counts. These results suggest that even a few EAIgG, as of a DAT shows negative, are related to the catabolism of erythrocytes in patients with SLE. EAIgG determination value in this method calculated and converted with CRM 470 that is the IFCC international reference preparation for plasma protein.
Hachimura
K
K
Department of Clinical Technology, Kitasato University School of Allied Health Sciences.
Uchiyama
Y
Y
Ohtani
H
H
D015415:Biomarkers / Q000097:blood; D003298:Coombs Test; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D004906:Erythrocyte Count; D004912:Erythrocytes / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis; D012680:Sensitivity and Specificity
D015415:Biomarkers; D007074:Immunoglobulin G