Kd. Kohnert et al., DISCORDANT RESULTS IN THE ASSAY OF CYTOPLASMIC ISLET-CELL AUTOANTIBODIES WITH ELISA AND IMMUNOHISTOCHEMICAL TECHNIQUES, European journal of clinical chemistry and clinical biochemistry, 33(7), 1995, pp. 447-449
We evaluated 6 batches of a solid phase enzyme-linked immunosorbent as
say (ELISA) Isletest(TM)-ICA kit commercially available for the determ
ination of autoantibodies to pancreatic islet cells, and compared the
results with those obtained by a standardized immunohistochemical meth
od. Following the immunohistochemical determination of autoantibodies
to pancreatic islet cells, sera from patients with insulin-dependent d
iabetes mellitus, both positive and negative for autoantibodies to pan
creatic islet cells, were randomly selected and analysed by ELISA. Ser
a from healthy control subjects, as well as standards recommended by t
he International Diabetes Workshop (IDW) ICA (Autoantibodies to Pancre
atic Islet Cells) Proficiency Program, were included. Of the sera test
ing positive for autoantibodies to pancreatic islet cells in the immun
ohistochemical assay, only 14 +/- 5% were found to give a positive rea
ction in the ELISA. Among the sera from healthy control subjects and p
ancreatic islet cell autoantibody-negative insulin-dependent diabetes
mellitus patients, 25 +/- 7% and 1 +/- 1%, respectively, yielded false
-positive readings for autoantibodies to pancreatic islet cells. These
results clearly show that the ELISA test presently available does not
reliably detect autoantibodies to pancreatic islet cells, even qualit
atively. Thus, it cannot be used for screening subjects at risk of dev
eloping diabetes.