Analysis of islet cell antibodies on frozen sections of human pancreas.

The sensitivity and specificity of the assay for islet cell cytoplasmic antibodies in human serum were examined using cryostat sections from fresh frozen pancreas. The specificity of the assay was close to 100% while the sensitivity was 40%-98% depending on the pancreas used. Inter-observer variation was 12-27%. End-point titres of islet cell antibodies varied with the sensitivity of each pancreas. End-point titration of the antibodies in two different laboratories using the same pancreas was significantly correlated (Spearman test p less than 0.001). We conclude that a reliable determination of islet cell antibody titres in human serum requires careful characterization of the sensitivity and specificity of each pancreas used as a source of frozen sections, in the indirect immunofluorescence assay.