title: An ELISA for IgA-IgG and IgM-RF measurement. II. RF in several disease and control groups and under gold therapy in RA.
abstract: The before introduced solid phase ELISA was employed for the RF determination in the sera of RA patients and controls. The threshold values for positive results (calculated as the 95% distribution percentile of healthy donors) were 8, 3, and 3 U/ml for IgA, IgG, and IgM-RF, respectively. The results confirm the validity of the assay with clear negative results in several negative control groups (healthy donors, patients of the oto-, rhino-, laryngeal ambulance, diabetes mellitus, degenerative arthropathies; n = 111, median IgA, IgG and IgM-RF values of less than or equal to 2, less than or equal to 2 and less than or equal to 1 U/ml, respectively; 25-75% distribution percentiles within the median value) and positive results in the positive control group (seropositive RA; n = 20, median IgA, IgG and IgM-RF values of 324, 479 and 170 U/ml, respectively). 16/24 patients with so-called seronegative RA (negative Latex Fixation Test or Waaler Rose Test) had positive results in the ELISA, two of them had rheumatoid nodules clinically. The IgG-RF activity in the ELISA appears to be a good parameter for the course control of RA under gold therapy. 10 RA patients with clinical improvement of disease (declining ESR, CRP, joint index) after six months of gold therapy (= 0.6 g total gold amount) had a decline of total RF activity of 70% in median, whereas 10 patients with no clear effect on disease activity had only a decline of 20% in median.
authors.affiliation: Department of Rheumatology and Clinical Immunology, Katholisches Krankenhaus Essen-Werden, FRG.
authors.forename: G
authors.initials: G
authors.lastname: Lemm
authors.forename: S
authors.initials: S
authors.lastname: Ruschen
authors.forename: H
authors.initials: H
authors.lastname: Warnatz
mesh_terms: D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000188:drug therapy; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006046:Gold / Q000627:therapeutic use; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis* / Q000276:immunology; D007074:Immunoglobulin G / Q000032:analysis* / Q000276:immunology; D007075:Immunoglobulin M / Q000032:analysis* / Q000276:immunology; D012217:Rheumatoid Factor / Q000032:analysis*
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D006046:Gold; D002097:C-Reactive Protein; D012217:Rheumatoid Factor