Background:
Since Harris et al. Developed radioimmunoassay using cardiolipin antigen for anti-cardiolipin antibody (ACA or aCL) in 1983, many methods were introduced for detection of aCL. Recently, enzyme immunoassay is widely used and commercial ELISA
kits are
available. In this study, we compared the results of currently available four ELISA kist and evaluated its clinical usefulness.
Methods:
The aCL screening and quantitation of IgG/IgM isotypes byfour ELISA kits were simultaneously performed I 90 patients requested for aCL. The four ELISA kits were INCSTAR/TheraTest EL-ACATM (INCSTAR Corp., MN, U.S.A.), Varelisa (Elias USA,
Inc.,
Osceola, USAQ), Quanta LiteTMACA Screen, Quanta LiteTM ACA IgG/IgM (INOVA Diagnostics, Inc., CA, USA) and Biopool ImulyseTM ACA (biopool, CA, USA). The results of aCL were reported as GPL/MPL. One GPL/MPL unit is the cardiolipin binding activity
of
1㎍/mL of affinity purified IgG/IgM aCL from a standard serum. We reviewed the clinical characteristics of the patients and compared with the results of aCL.
Results:
The mean age of patients was 48.7 years and male to female ratio was 1:2.2. The most common clinical diagnoses of positive aCL were cerebral infarction and systemic lupus erythematosus (SLE). Of the 40 aCL-positive patients, eight patients and
12
patients were positive in incstar and Elias respectively and 38 patients were positive in both INOVA and Biopool. In all four ELISA kits than in Incstar and Elias. But the subject number of patients was not so many that it is difficult to
differentiate
that his high positivity means its high sensitivity or false-positivity. Further study of prospective design will be helpful for clarifying the true reason and acurate comparison of the currently available commercial aCL ELISA kits.
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