Pros and cons of immunochemical and enzymatic method in the diagnosis of Wilson's disease

BACKGROUND: Immunochemical method of measuring Ceruloplasmin (Cp) levels for the diagnosis of Wilson's disease has replaced enzymatic method for the main reason of being more sensitive and quantitative. SETTINGS AND DESIGN: In this study, we compared both the methods for various factors such as sensitivity, specificity and the time consumed in the diagnosis of Wilson's disease. MATERIALS AND METHODS: Serum samples from patients (n=33) with a provisional diagnosis of Wilson's disease were analyzed for Cp levels by enzymatic copper oxidase method and immunochemical method using polyclonal antibodies specific to Cp embedded in agar. STATISTICAL ANALYSIS: Pearson's regression analysis was performed to compare the two methods. RESULTS: The mean Cp obtained by immunochemical method is 5.87 mm ± 1.17 and by enzymatic method, it is 0.37 (Optical Density) ± 0.136. Pearson's Regression analysis of the measurements showed a good correlation with an 'r' value of 0.765 between the two methods. CONCLUSION: A good correlation indicated that these two tests are comparable and thus both these methods can be used together for a definitive and better diagnosis of Wilson's disease.