Comparative Analysis of Serum Ceruloplasmin Levels in Wilson Disease by Conventional Enzymatic Assay and Immunologic Method

Abstract

Objective: Serum ceruloplasmin, which has markedly decreased in 95% of patients with Wilson disease, is one of the most useful markers in the diagnosis of this genetic disease. The disease is caused by an impairment of the excretion of hepatic copper, resulting in toxic accumulation of the metal in the brain, liver and other organs. Definite diagnosis leads to the need of continual, lifelong and effective treatment. Therefore, the accuracy of the measurement of this serum protein is clinically needed. Our study is aimed to compare the reliability of the two methods used in measuring serum ceruloplasmin: the conventional enzymatic assay and the recent immunologic method by using kit reagents.
Methods: Serum ceruloplasmin levels were performed by the conventional enzymatic assay as reported by Ravin in 1961, and compared to the immunologic method using kit reagents, Dade Behring Inc., Newark, USA. Seven patients with clinically proven Wilson disease and twenty-two controls were recruited for the study.
Results: The mean ± SD levels of serum ceruloplasmin from all patients and controls as measured by the enzymatic assay were 1.58 ± 2.28 mg/dl and 28.94 ± 9.60 mg/dl, respectively. The serum levels from those patients measured by the kit assay were less than 8 mg/dl while the mean ± SD of controls were 25.91 ± 7.71 mg/dl. All serum ceruloplasmin levels after measurement by both assays showed a strong correlation coefficient (r = 0.8713; p-value < 0.01), with a significant decrease in all patients with Wilson disease when compared to controls.
Conclusion: Our study supported the high correlation between the conventional enzymatic assay and the recent immunologic method in measuring serum ceruloplasmin. Although the analysis kit is expensive, it is more advantageous for routine laboratory service because of its simpler, automated test with a well-accepted quality control.