Comparative analysis of serum ceruloplasmin levels in wilson disease by conventional enzymatic assay and immunologic method.

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.

Comparative analysis of venous blood lactate levels by automatic lactate strip kit (accusport) and by standard marbach’s enzymatic method.

Lactic acidosis is an emerging life-threatening condition that needs to be diagnosed and treated as early as possible. The complete analysis of blood lactate levels by standard method takes at least a few hours and is not available at all times. The automatic lactate strip kit (Accusport) will be more practical for diagnosis and treatment of lactic acidosis patients. This study showed the results of blood lactate determined by standard enzymatic method of Marbach compared to the lactate strip. The results showed a strong correlation between the two methods (r2=0.966). The correlation increased in the case of high blood lactate levels (r2=0.978) and decreased in normal blood lactate levels (r2=0.943). Overall lactate values measured from the strip method were lower than those from the enzymatic method. From this study we can calculate a constant factor of 0.981 which when multiplied with the value of blood lactate analysed by lactate strip then added with 0.532, the result will be equal to that from Marbach’s enzymatic method.

Serum ceruloplasmin in wilson’s disease.

Wilson’s disease is a rare inherited disease with an incidence of 1:50,000 to 1:1,000,0001. The mode of transmission of this disease is an autosomal recessive. The defects of the disease involve both an impairment in biliary copper excretion and a decreased incorporation of free copper into ceruloplasmin due to a low level or abnormal function of this alpha 2-globulin. The toxic accumulation of copper damages many tissues especially basal ganglia of brain and liver. The diagnosis of this disease is made from the family history, signs and symptoms especially from the damaged organs, the detection of Kayser-Fleischer ring, a copper deposit in cornea and the decreased level of serum ceruloplasmin below 20 mg/ml which is normally found in more than 95% of cases. In this study, we analysed the levels of serum ceruloplasmin from 23 cases of Wilson’s disease admitted in Siriraj Hospital from 1989-1998. The average value, (X+1 SD), of 1.38+3.55 mg/ml was significantly lower when compared with the value of 20.82+3.63 mg/ml from 46 normal controls. The cut off level of ceruloplasmin for Wilson’s disease in Thai patients from this study was estimated to be 13 mg/ml which is lower than the level of 20 mg/ml in standard textbook. Twenty two out of 23 cases of Wilson’s disease (95.65%) had serum ceruloplasmin levels less than 13 mg/ml while 1 out of 23 cases (4.35%) had normal level. The data strongly supported the usefulness of serum cerloplasmin analysis in the diagnosis of Wilson’s disease.