Role of copper in Indian childhood cirrhosis

Indian childhood cirrhosis: a retrospective study -redefining the older myths!

AIMS

This retrospective study emphasises the need of awareness for clinicopathological attributes of Indian childhood cirrhosis (ICC) in order to enable timely diagnosis and management.

METHODS

This study was done on liver archival tissue of our department from the period of January 2016 to December 2022. Of these, cases of copper overload on paediatric biopsies were retrieved. The histopathological features were scrutinised independently by three pathologists, correlating with their clinico-radiological investigations.

RESULTS

Five children in infancy to middle childhood presented with features of chronic liver disease in the form of jaundice and abdominal distention, were included in the study. Characteristic firm hepatomegaly with sharp margins and transaminitis was noted in all cases. Autoimmune, viral and metabolic workup were negative in all these patients except one which showed positive autoimmunity and another whose Coomb's test was positive. Normal ceruloplasmin levels and unremarkable slit lamp examination excluded the possibility of Wilson's disease. The histological features of marked ballooning degeneration with diffuse Mallory Denk, pericellular fibrosis, absence of steatosis and panlobular copper deposits clinched the diagnosis of ICC.

CONCLUSIONS

ICC once believed to be extinct has still not vanished and remains underdiagnosed in routine practice. It is a rapidly fatal disease with a debatable pattern of inheritance and controversial role of copper as etiological agent. The clinical presentation is often deceptive and lack of awareness leads to misdiagnosis. Histopathological attributes are pathognomonic and possibility of ICC should be kept in all cases of cryptogenic cirrhosis.

Indian Childhood Cirrhosis: Report of 2 Cases With Review of Literature and Implication of Metallothionein Immunohistochemical Expression

Indian childhood cirrhosis is a chronic liver disease in infants and children. Indian childhood cirrhosis is unique to the Indian subcontinent and occurs from 6 months to 5 years of age. We report 2 cases in a period of 5 years, including 1 male and 1 female. Both children were less than 3 years of age. Presenting complaints were jaundice and hepatosplenomegaly. The clinical diagnosis was metabolic liver disease. Histological findings included diffuse hepatocellular ballooning degeneration, prominent Mallory Denk bodies, diffuse pericellular fibrosis, and marked copper/copper-associated protein deposits, along with the absence of steatosis and glycogenated nuclei. Mettalothionein immunohistochemistry was performed in 1 case and showed strong positivity. The first child developed liver failure and died. The second child was started on oral penicillamine therapy and is alive on the most recent follow-up. Whole-exome studies of both patients showed no significant findings. None of the children had exposure to excess dietary copper. Sporadic cases of Indian childhood cirrhosis continue to occur. There should be greater awareness among pediatricians and pathologists of the disease to enable earlier diagnosis. Awareness of metallothionein expression in biopsies of patients with Indian childhood cirrhosis is important to prevent misdiagnosis of Wilson disease.

Estimation of copper in saliva and areca nut products and its correlation with histological grades of oral submucous fibrosis

BACKGROUND

The purpose of this study was to estimate the copper levels in saliva of patients with oral submucous fibrosis (OSF) and different areca nut products and its correlation with different histological grades of OSF.

METHODS

The study comprised 60 individuals, 30 OSF patients and 30 non-OSF individuals. Unstimulated whole saliva was collected, and copper analysis was performed using colorimetric method. The commercial areca nut products used by the patients were acquired and subjected to copper analysis through the atomic absorption spectrophotometer method. Oral biopsies were performed for OSF patients for histopathological correlation.

RESULTS

The mean salivary copper level was 27.023 μg/dl in OSF patients when compared with 8.393 μg/dl in non-OSF individuals (P < 0.005). The mean copper content in different areca nut products was 13.313 ppm (P < 0.005). Comparison of copper content in different areca nut products with salivary copper levels of OSF patients showed negative correlation (P < 0.853). Comparison of salivary copper levels between different histological grades of OSF yielded a statistically significant association between grades I and III (P < 0.005) and grades II and III OSF (P < 0.019). Comparison of copper content in areca nut products and different histological grades of OSF yielded weak negative statistical correlation (r = -0.116).

CONCLUSION

Despite high copper content in areca nut products, the observations yielded a negative correlation with different histological grades of OSF. This further raises a doubt about the copper content in areca nut as an etiological factor for this crippling disease.

Trace elements in human physiology and pathology. Copper

Copper is a trace element, important for the function of many cellular enzymes. Copper ions can adopt distinct redox states oxidized Cu(II) or reduced (I), allowing the metal to play a pivotal role in cell physiology as a catalytic cofactor in the redox chemistry of enzymes, mitochondrial respiration, iron absorption, free radical scavenging and elastin cross-linking. If present in excess, free copper ions can cause damage to cellular components and a delicate balance between the uptake and efflux of copper ions determines the amount of cellular copper. In biological systems, copper homeostasis has been characterized at the molecular level. It is coordinated by several proteins such as glutathione, metallothionein, Cu-transporting P-type ATPases, Menkes and Wilson proteins and by cytoplasmic transport proteins called copper chaperones to ensure that it is delivered to specific subcellular compartments and thereby to copper-requiring proteins.

Hohenheim consensus workshop: copper

Copper (Cu) is an essential trace element with many physiological functions. Homeostatic mechanisms exist to allow Cu to act as a cofactor in enzymatic processes and to prevent accumulation of Cu to toxic levels. The aim of this commentary is to better understand the role of dietary Cu supply in deficiency and under physiological and pathological conditions. The essentiality of Cu can be attributed to its role as a cofactor in a number of enzymes that are involved in the defence against oxidative stress. Cu, however, has a second face, that of a toxic compound as it is observed with accumulating evidence in hepatic, neurodegenerative and cardiovascular diseases. The destructive potential of Cu can be attributed to inherent physico-chemical properties. The main property is its ability to take part in Fenton-like reactions in which the highly reactive and extremely deleterious hydroxyl radical is formed. Diseases caused by dietary Cu overload could be based on a genetic predisposition. Thus, an assessment of risk-groups, such as infants with impaired mechanisms of Cu homeostasis regarding detoxification, is of special interest, as their Cu intake with resuspended formula milk may be very high. This implies the need for reliable diagnostic markers to determine the Cu status. These topics were introduced at the workshop by the participants followed by extensive group discussion. The consensus statements were agreed on by all members. One of the conclusions is that a re-assessment of published data is necessary and future research is required.

Effect of chronic exposure to excess dietary copper and dietary selenium supplementation on liver specimens from rats

OBJECTIVE

To determine the effects of chronic exposure to excess dietary copper (Cu) on liver specimens from rats and the effects of dietary selenium (Se) supplementation in experimental Cu toxicosis.

ANIMALS

60 weanling male Fischer 344 rats.

PROCEDURE

Rats were randomly assigned to 4 groups of 15 rats each and fed 1 of the following 4 diets: high Cu (500 microg/g)/adequate Se (0.2 microg/g); high Cu (500 microg/g)/supplemented Se (2 microg/g); adequate Cu (18 microg/g)/adequate Se (0.2 microg/g); or, adequate Cu (18 microg/g)/supplemented Se (2 microg/g). Five rats per group were euthanatized after 3, 6, and 12 months, and liver specimens were obtained for histologic examination, histochemistry, metal analysis by atomic absorption spectrophotometry, measurement of glutathione peroxidase activity, and assessment of lipid peroxidation, using quantification of malondialdehyde (MDA) by the thiobarbituric acid reaction.

RESULTS

Hepatic Cu concentration was significantly higher in rats fed high Cu diets (range, 9 to 18 microg/g of tissue [wet weight]), compared with rats receiving adequate Cu diets (4.0 to 5.7 microg/g of tissue). Rats fed high-Cu diets for 3, 6, and 12 months had mild multifocal hepatitis often surrounding necrotic foci. However, an increase in hepatic MDA content, indicative of lipid peroxidation, was not detected in these rats. Development of morphologic changes was not prevented by use of dietary Se supplementation.

CONCLUSION AND CLINICAL RELEVANCE

Long-term exposure to excess dietary Cu caused mild hepatic lesions in Fischer 344 rats. Dietary Se supplementation did not prevent hepatic damage in rats with Cu toxicosis.

Indian childhood-like cirrhosis in three Saudi Arabian siblings

Three Saudi siblings, two girls and one boy, presented at the ages of 7, 6 and 2.5 years, respectively, and were diagnosed as having features of Indian childhood cirrhosis (ICC). The two girls presented at a late stage of the disease and the boy was diagnosed during routine examination of the family. The initial presenting complaint was abdominal distention and pruritus. All three had a rapid and fatal course. There was no evidence of increased copper ingestion by the families, supporting the suggestion of a hereditary metabolic role in the aetiology of ICC. As far as we are aware, this is the first report of ICC in Saudi Arabian children.

Experimental induction of liver fibrosis in young guinea pigs by combined application of copper sulphate and aflatoxin B1

Aflatoxin B1 alone (0.05 mg resp. 0.037 mg/kg/d), copper alone (6.6 mg/kg/d or 200 mg/l drinking water) or a combination of both was administered orally for 6 months to young guinea pigs from the first/second day of life. In the copper group there were no pathomorphological changes. For the aflatoxin B1 group, liver damage was established. In the combined group, liver injury was more frequent and more severe compared to the aflatoxin B1 group and biliary copper excretion was diminished compared with the copper group. Histologically, only the livers of this group exhibited degeneration, atrophy and steatosis of liver cells, inflammatory processes and a more or less prominent fibrosis. For childhood cirrhosis (ICC and ICT) a combined etiology--a liver damaging agent plus elevated alimentary copper--is a plausible hypothesis.

hCTR1: a human gene for copper uptake identified by complementation in yeast

The molecular mechanisms responsible for the cellular uptake of copper in mammalian cells are unknown. We describe isolation of a human gene involved in this process by complementation of the yeast high-affinity copper uptake mutant, ctr1. Besides complementing ctr1 growth defect on nonfermentable media, the human gene also rescues iron transport and SOD1 defects in ctr1 yeast. Overexpression of the gene in yeast leads to vulnerability to the toxicity of copper overload. In addition, its expression in ctr1 yeast significantly increases the level of cellular copper, as demonstrated by atomic absorption. We propose this gene as a candidate for high-affinity copper uptake in humans and by analogy have named it hCTR1. The hCTR1 and yeast CTR1 predicted transmembrane proteins are 29% identical, but the human protein is substantially smaller in both the extracellular metal-binding and intracellular domains. An additional human gene similar to hCTR1, here named hCTR2, was identified in a database search. Both hCTR1 and hCTR2 are expressed in all human tissues examined, and both genes are located in 9q31/32. These studies, together with the previously recognized functional and sequence similarity between the Menkes/Wilson copper export proteins and CCC2 in yeast, demonstrate that similar copper homeostatic mechanisms are used in these evolutionarily divergent organisms.

Trace elements in drinking water coolers collected from primary schools, Riyadh, Saudi Arabia

A simple method for the spectrochemical analysis of water samples by inductively coupled plasma spectrometry is described. Samples from drinking water coolers in 32 schools in Riyadh were collected at a specific time during a typical school day and analyzed for aluminum (Al), beryllium (Be), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), silicon (Si), strontium (Sr), vanadium (V), and zinc (Zn) to ascertain the water quality. The analysis of drinking water showed high concentrations of metals and in some cases exceeded the guideline limits recommended by EEC and WHO.

Atypical copper cirrhosis in Indian children

In addition to ten children with Wilson's disease and one with Indian childhood cirrhosis, nine Indian children, aged from 4 to 15 years, with cryptogenic cirrhosis had significant deposits of stainable copper in their hepatocytes. These nine children had normal or elevated serum caeruloplasmin levels, absence of Kayser-Fleischer rings and a history of sibling death owing to liver disease in four cases. Histologically, fatty change was absent from all the biopsies but Mallory's hyaline, pericellular fibrosis and ballooning of hepatocytes were present in some. Since these children did not conform to the accepted clinical or histological definitions of either Indian childhood cirrhosis or Wilson's disease, they were designated as having atypical copper cirrhosis. The relationship of this group of cases to other types of copper cirrhosis is unknown.