| 摘要 |
<p>Novel immunoassay methods and diagnostic sets for diagnosing systemic lupus erythematosus and for determining the severity stage of the disease are disclosed. A test sample, e.g. serum diluted at a volume ratio of sample to dilution buffer of up to 1:1000, is combined with a VH4-34 binding anti-idiotypic antibody, e.g. 9G4 monoclonal antibody (mAb), and the proportion of VH4-34 binding anti-idiotypic antibody which binds to VH4-34 antibody in the sample is determined and compared to a standard. An immunoassay, e.g. ELISA, using immobilized reagent VH4-34 Ab and unbound 9G4 mAb; a competitive immunoassay using immobilized 9G4 mAb and labeled reagent VH4-34 Ab; and a sandwich immunoassay test using immobilized 9G4 mAb are disclosed. Serum samples can be adjusted with buffer to yield a total IgG level within a selected range, preferably within the range for normal serum, prior to analysis. The method can include determining that the sample is substantially free from rheumatoid factor antibody. Interference in the assay by rheumatoid factor antibody can be reduced by the use of a binding fragment of 9G4 mAb, such as (Fab')2.</p> |
