Islet cell antibodies (ICA) have been proven to be important in the prediction and diagnosis of Type 1 diabetes mellitus. Indirect immunfluorescence (IF) technique has been used for ICA detection since 1974; but researchers have tried to establish a more practicable and convenient method. The peroxidase-labeled protein A (POPA) method has some advantages over conventional IF; for example it is cheaper and reevaluable for over 5 years. Also human pancreas obtained from donors of all blood groups and all ages can be used as a substrate in this method. In this study, we have tested 66 sera of insulin-dependent diabetes mellitus (IDDM) patients in the early clinical stage (< 6 months), 30 sera of slowly progressive Type 1 diabetic (SPIDDM) patients with both IF and POPA techniques. In the control groups, there were 8 sera of first degree non-diabetic relatives of IDDM patients and 10 non-diabetic healthy people. Although, there were no statistical differences between these two methods (p>0.05) if the IF method is accepted as gold standard; sensitivity and specificity of the POPA method were 80% and 60% respectively. Its positive predictive value was 76% and negative predictive value was found to be 72%.
Keywords: Indirect Immunofluorescence Method, Peroxidase-Labeled Protein a Method, Type 1 Diabetes Mellitus