Accuracy of the radioactive copper incorporation test in the diagnosis of Wilson disease.

BACKGROUND & AIMS: In Wilson disease (WD), copper accumulates in the liver and other tissues because of mutations in the ATP7B copper transporter gene. Early and effective anticopper treatment is crucial. However, routine diagnostic methods based on clinical findings, copper metabolism tests, liver biopsies and DNA analyses do not always provide a conclusive diagnosis. The aim was to evaluate radioactive copper incorporation as a diagnostic test. METHODS: We included cases with a diagnosis of WD supported by radiocopper testing and later, when available, confirmed by DNA analysis. Incorporation of 64 Cu was measured at 2, 24 and 48 hours following intravenous injection. Diagnostic accuracy (area under the receiver operating characteristic curve [AUC]), sensitivity, specificity and predictive value were assessed for 24 hours/2 hours and 48 hours/2 hours 64 Cu ratios and compared with serum measurements of ceruloplasmin, copper, non-ceruloplasmin-bound copper and urinary 24-hours copper excretion. RESULTS: Patients having two pathogenic ATP7B mutations (homozygotes/compound heterozygotes) (n = 74) had significantly lower 24 hours/2 hours and 48 hours/2 hours 64 Cu ratios than heterozygote controls (n = 21) (mean 0.14 and 0.12 vs 0.49 and 0.63, respectively; both P < .001). Of note, 24 hours/2 hours and 48 hours/2 hours 64 Cu ratios had excellent diagnostic accuracy, with AUCs approaching 1, and only 24-hours urinary copper excretion displayed similar positive features. Other copper metabolism tests studied had lower accuracy, specificity and sensitivity. CONCLUSIONS: The radioactive copper test had excellent diagnostic accuracy and may be useful in the evaluation of new therapies aimed at restoring ATP7B function.

Paraoxonase 1 activity and level of antibodies directed against oxidized low density lipoproteins in a group of an elderly population in Poland - PolSenior study.

UNLABELLED: The aim of this study was to assess two factors influencing the amount of oxidized LDL-paraoxonase 1 (PON1) activity and the level of anti-oxidized LDL antibodies (anti-ox LDL) in a large group of elderly individuals in Poland. The effects of cognitive status, hypertension and metabolic syndrome and of selected serum lipids and inflammation indicators on PON1 activity and anti-ox LDL level were also examined. The investigated population consisted of 3154 individuals aged 65 and more - participants of the population-based PolSenior project. PON1 arylesterase activity was determined spectrophotometrically, anti-ox-LDL antibodies using ELISA method. PON1 activity significantly decreased with advancing age, was lower in males than in females and decreased in persons with impaired cognition. Individuals with hypertension and high lipid levels showed higher PON1 activity. Lower PON1 activity was related to higher level of inflammation indicators - hsCRP and IL-6. The significant association of PON1 activity with age, HDL-C, LDL-C, sex and IL-6 was confirmed in multivariate analysis. Anti-ox LDL antibodies level was significantly higher in the two oldest subgroups of males. It was significantly lower in males than in females. It was decreased in persons with higher serum triglycerides. No relationship of anti-ox LDL level with cognition, hypertension, metabolic syndrome, inflammation indicators and serum lipid levels was observed. In some persons very high levels of anti-ox LDL were stated, most frequently in the oldest persons, particularly in men. CONCLUSION: Both investigated antioxidant factors - PON1 activity and anti-ox LDL level, could play an important role in aging.

Paraoxonase 1 (PON1) gene-108C>T and p.Q192R polymorphisms and arylesterase activity of the enzyme in patients with dementia.

Paraoxonase 1 (PON1) activity was determined using phenylacetate as substrate (arylesterase activity) in 304 individuals with dementia--136 recognised as probable Alzheimer's disease (AD), 64 as dementia of vascular origin (VaD) and 104 as mixed dementia (MD) and in 129 persons without symptoms of dementia and in a good general health. -108C>T polymorphism in the PON1 gene promoter and p.Q192R polymorphism in the coding region were identified. PON1 activity was significantly lower in demented patients as compared with controls particularly in dementia of a neurodegenerative character (AD and MD). The prevalence of PON1-108T allele carriers was significantly higher in the AD group than in controls. The frequencies of the p.Q192R genotypes did not differ significantly between the investigated groups. An association of the rare T-R haplotype with dementia, particularly with dementia of the neurodegenerative type, was found. Multivariate regression analysis showed a significant association of PON1 activity with PON1 -108C>T and p.Q192R polymorphisms. The influence not only of promoter -108C>T, but also of p.Q192R polymorphism on PON1 arylesterase activity was observed. One has to admit that this kind of polymorphism does not preclude interference with the enzyme activity. It could be concluded that the PON1 gene promoter polymorphism plays an additional role in Alzheimer's disease development. It seems however that PON1 activity has a dominating influence on the dementia risk.

Positive correlation of paraoxonase 1 (PON1) activity with serum insulin level and HOMA-IR in dementia. A possible advantageous role of PON1 in dementia development.

Paraoxonase 1 (PON1) activity and metabolic syndrome traits were evaluated in 169 demented patients (81 recognized as AD, 32 as VaD, 56 as MD) and in 64 control individuals. Paraoxonase activity was determined spectrophotometrically using phenyloacetate as substrate. Metabolic syndrome was recognized according to AHA/NHLBI criteria. In the whole group with dementia significant positive correlation between PON1 activity/HDL cholesterol ratio (i.e. HDL corrected PON1 activity) and insulin level as well as HOMA IR index, was observed. The multivariate analysis showed that the PON1/HDL-C ratio was also significantly positively associated with the presence of metabolic syndrome (with insulin resistance as a major underlying trait) both in dementia and in control group. High insulin level and HOMA-IR are considered to be the traits of insulin resistance. It has however to be taken into account that they both could also depend on insulin production and release which, as was recently stated in cell experiments, are enhanced by PON1. The observed positive correlation suggests an advantageous role of the enzyme in metabolic syndrome influence on dementia development.

Antibodies against oxidized LDL and apolipoprotein E polymorphism in demented patients.

In serum of 114 patients with dementia and of 102 controls the level of IG class immunoglobulins directed against oxidized LDL and lipids were determined. In isolated DNA apolipoprotein E gene (APOE) polymorphism was identified. In some individuals very high levels of the antibodies were observed. exceeding the 90 percentile in the investigated group. The prevalence of very high anti-ox LDL antibodies level was significantly more frequent in the carriers of epsilon2 allele and less frequent in the carriers of epsilon4 allele.

Paraoxonase activity and dementia.

Paraoxonase activity, homocysteine level and lipids were determined in 120 patients with dementia (51 with Alzheimer disease, 28 with dementia of vascular origin, 41 with mixed dementia), 45 with mild cognitive impairment and in 61 age and sex matched controls without dementia. Paraoxonase activity was decreased in Alzheimer disease and in mixed dementia as compared with control group. In the same forms of dementia homocysteine levels were increased. In Alzheimer disease paraoxonase activity was negatively correlated with homocysteine levels. Minimental State Examination results showed positive correlation with paraoxonase activity. The results suggest an important role of oxidative stress in the development of the forms of dementia with prevailing neurodegeneration.

Late onset Wilson's disease: therapeutic implications.

The clinical symptoms of Wilson's disease (WD) usually develop between 3 and 40 years of age and include signs of liver and/or neurologic and psychiatric disease. We report on an 84-year-old woman with WD. Despite the absence of treatment, the only symptom she presented with, until the age of 74 years, was Kayser-Fleisher rings. At the age of 74, she developed slightly abnormal liver function. This case raises the following issues: (a) Should WD be considered in all patients of all ages who manifest signs related to the disease? (b) Are ATP7B mutations fully penetrant? (c) Should all patients diagnosed presymptomatically receive anticopper therapy?

Polymorphisms of apolipoprotein E and angiotensin-converting enzyme genes and carotid atherosclerosis in heavy drinkers.

AIMS: To investigate the influence of apolipoprotein E (APOE) and angiotensin-converting enzyme (ACE) gene polymorphisms on carotid artery atherosclerosis in alcoholism. METHODS: Polymorphism of both genes was identified by DNA analysis in 130 male alcohol-dependent patients. Intima-media thickness (IMT) was measured ultrasonographically. RESULTS: Multivariate regression analysis showed that of all the known risk factors the greatest impact on carotid atherosclerosis in alcoholics was exerted by age, hypertension, LDL cholesterol and fasting plasma glucose levels. Subjects carrying the APO E epsilon4 allele were more liable to develop atherosclerotic changes in carotid arteries compared with subjects with the epsilon3/3 genotype, which showed statistical significance in patients under 50 years of age. No association was shown between ACE I/D polymorphism and carotid atherosclerosis. CONCLUSIONS: APO E polymorphism can increase the risk of carotid atherosclerosis development in an alcoholic subject. The association of the APO E epsilon4 allele with carotid atherosclerosis was significant in younger patients. Since the elevated carotid IMT is considered to be a good marker of increased risk of generalized atherosclerosis the consequences could involve both cardiac and cerebrovascular events.

Apolipoprotein E polymorphism and low density lipoprotein (LDL) oxidation in patients with dementia.

In patients with dementia, 29 diagnosed as probably suffering from Alzheimer's disease and 46 subjects with dementia of vascular origin, and in 41 non demented control subjects LDL oxidation in vitro was compared in carriers of various apolipoprotein E alleles. Restriction isotyping was performed by gene amplification and cleavage with Hhal, LDL oxidation was investigated by determination of conjugated dienes and vitamin E (alpha tocopherol) plasma level was measured by HPLC. In subjects with dementia oxidation of LDL was shown to be higher in carriers of epsilon4 allele as compared with non-carriers of this allele. It was especially observed in the propagation phase, which illustrates oxidation intensity after the exhaustion of the antioxidant reserve in LDL. Vitamin E level did not show differences between carriers of different alleles. It is concluded that the differences in oxidation susceptibility of LDL between demented subjects possessing particular apolipoprotein E forms can result partially from differing antioxidant properties of apolipoprotein E isoforms and, in a substantial degree, from the size and quality of LDL.

Plasma antioxidant activity and vascular dementia.

Little is known about the role of antioxidant activity in the pathogenesis of stroke-associated neuronal damage and impairment following a stroke. Increased free radical formation together with reduced antioxidant defense may increase neuronal injury. A low concentration of antioxidants such as alpha-tocopherol may influence the development of post-stroke dementia. The aim of this study was to evaluate the level of alpha-tocopherol and susceptibility of LDL to oxidation in a group of patients with dementia in comparison to controls. In a group of 68 patients with dementia, according to DSM-IV criteria, 42 with vascular dementia (VaD), 26 with Alzheimer type of dementia (AD) and 46 age-matched persons, with no signs of cognitive disorders (control group), we measured lipids, alpha-tocopherol and the kinetics of LDL oxidation. The levels of triglycerides (TG) and low-density lipoprotein (LDL) were significantly lower in patients with VaD in comparison to AD patients, but the atherogenic index was similar in both groups. alpha-Tocopherol was significantly lower in patients with VaD in comparison to patients with AD and controls: 9.9, 12.6 and 12.6 ng/ml, respectively, p<0.0001. Susceptibility of LDL to oxidation, measured by duration of lag phase did not reveal statistically significant differences between the groups. In patients with VaD, low levels of plasma alpha-tocopherol were observed, which indicate a reduced antioxidant defense in these subjects.

Uptake of acetaldehyde-modified (ethylated) low-density lipoproteins by mouse peritoneal macrophages.

The uptake of acetaldehyde-modified (ethylated) low-density lipoproteins (LDLs) by murine peritoneal macrophages is described and compared with the uptake of acetylated LDLs. The fluorescent marker DiI was used. No competition between ethylated and acetylated LDLs was observed. Ethylated LDL uptake was not inhibited by polyinosinic acid or fucoidin. Our conclusion is that uptake of ethylated and acetylated LDLs can be done by two different receptors.