Influence of biopsy specimen size, tissue fixation, and assay variation on copper, iron, and zinc concentrations in canine livers

Andrea N. Johnston Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.

Search for other papers by Andrea N. Johnston in
Current site
Google Scholar
PubMed
Close
 DVM
,
Sharon A. Center Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.

Search for other papers by Sharon A. Center in
Current site
Google Scholar
PubMed
Close
 DVM
,
Sean P. McDonough Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.

Search for other papers by Sean P. McDonough in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
, and
Karen L. Warner Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.

Search for other papers by Karen L. Warner in
Current site
Google Scholar
PubMed
Close

Abstract

Objective—To determine whether metal concentrations in canine liver specimens were influenced by specimen size, assay variability, tissue processing (formalin fixation and deparaffinization), or storage in paraffin blocks.

Sample Population—Liver specimens (fresh frozen and deparaffinized) from 2 dogs with chronic hepatitis (high copper but unremarkable iron concentration [liver 1] and unremarkable copper but high iron concentration [liver 2]) as well as fresh and deparaffinized-archived liver specimens from 20 dogs with various hepatopathies.

Procedures—Fresh frozen liver specimens (obtained via simulated needle-core and wedge biopsy), fresh hepatic tissue, and deparaffinized-archived specimens (0.5 to 14 years old) were analyzed for concentrations of copper, iron, and zinc by atomic absorption flame spectrometry. Clinical severity scores were assigned on the basis of tissue metal concentrations.

Results—Interassay variation of metal standards was < 4%. Measurements of liver tissues on 8 consecutive days yielded high coefficients of variation (3.6% to 50%) reflecting heterogenous histologic metal distribution; variation was highest in liver 1 and deparaffinized-archived tissues. Heterogenous metal distribution was confirmed by histologic evaluation. The largest range of metal concentrations was detected in wedge biopsy specimens. In tissues with high metal concentrations, copper and iron concentrations were significantly lower in needle-core versus wedge biopsy specimens. A higher zinc concentration in deparaffinized-archived specimens masked a low zinc concentration in fresh liver tissue of 10 of 20 (50%) dogs.

Conclusions and Clinical Relevance—Retrospective measurement of copper and iron concentrations but not zinc concentrations in deparaffinized-archived liver specimens provided relevant information. The value of needle-core biopsy specimens for measurement of metal concentrations is questionable.

Abstract

Objective—To determine whether metal concentrations in canine liver specimens were influenced by specimen size, assay variability, tissue processing (formalin fixation and deparaffinization), or storage in paraffin blocks.

Sample Population—Liver specimens (fresh frozen and deparaffinized) from 2 dogs with chronic hepatitis (high copper but unremarkable iron concentration [liver 1] and unremarkable copper but high iron concentration [liver 2]) as well as fresh and deparaffinized-archived liver specimens from 20 dogs with various hepatopathies.

Procedures—Fresh frozen liver specimens (obtained via simulated needle-core and wedge biopsy), fresh hepatic tissue, and deparaffinized-archived specimens (0.5 to 14 years old) were analyzed for concentrations of copper, iron, and zinc by atomic absorption flame spectrometry. Clinical severity scores were assigned on the basis of tissue metal concentrations.

Results—Interassay variation of metal standards was < 4%. Measurements of liver tissues on 8 consecutive days yielded high coefficients of variation (3.6% to 50%) reflecting heterogenous histologic metal distribution; variation was highest in liver 1 and deparaffinized-archived tissues. Heterogenous metal distribution was confirmed by histologic evaluation. The largest range of metal concentrations was detected in wedge biopsy specimens. In tissues with high metal concentrations, copper and iron concentrations were significantly lower in needle-core versus wedge biopsy specimens. A higher zinc concentration in deparaffinized-archived specimens masked a low zinc concentration in fresh liver tissue of 10 of 20 (50%) dogs.

Conclusions and Clinical Relevance—Retrospective measurement of copper and iron concentrations but not zinc concentrations in deparaffinized-archived liver specimens provided relevant information. The value of needle-core biopsy specimens for measurement of metal concentrations is questionable.

Contributor Notes

Supported by the Dean's Fund for Clinical Excellence, College of Veterinary Medicine, Cornell University.

Address correspondence to Dr. Center (sac6@cornell.edu).
  • 1.

    Pietrangelo A. Iron, oxidative stress and liver fibrogenesis. J Hepatol 1998;28:813.

  • 2.

    Letelier ME, Lepe AM, Faúndez M, et al.Possible mechanisms underlying copper-induced damage in biological membranes leading to cellular toxicity. Chem Biol Interact 2005;151:7182.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 3.

    Ramm GA, Ruddell RG. Hepatotoxicity of iron overload: mechanisms of iron-induced hepatic fibrogenesis. Semin Liver Dis 2005;25:433449.

  • 4.

    McClain CJ, Marsano L, Burk RE, et al. Trace metals in liver disease. Semin Liver Dis 1991;11:321339.

  • 5.

    Stamoulis I, Kouraklis G, Theocharis S. Zinc and the liver: an active interaction. Dig Dis Sci 2007;52:15951612.

  • 6.

    Bravo AA, Sheth SG, Chopra S. Liver biopsy. N Engl J Med 2001;344:495500.

  • 7.

    Regev A, Berho M, Jeffers LJ, et al. Sampling error and intraobserver variation in liver biopsy in patients with chronic HCV infection. Am J Gastroenterol 2002;97:26142618.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Abdi W, Millan JC, Mezey E. Sampling variability on percutaneous liver biopsy. Arch Intern Med 1979;139:667669.

  • 9.

    Holund B, Poulsen H, Schlichting P. Reproducibility of liver biopsy diagnosis in relation to the size of the specimen. Scand J Gastroenterol 1980;15:329335.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 10.

    Schlichting P, Holund B, Poulsen H. Liver biopsy in chronic aggressive hepatitis. Diagnostic reproducibility in relation to size of specimen. Scand J Gastroenterol 1983;18:2732.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 11.

    Poniachik J, Bernstein DE, Reddy KR, et al. The role of laparoscopy in the diagnosis of cirrhosis. Gastrointest Endosc 1996;43:568571.

  • 12.

    Cholongitas E, Senzolo M, Standish R, et al. A systematic review of the quality of liver biopsy specimens. Am J Clin Pathol 2006;125:710721.

  • 13.

    Van Leeuwen DJ, Balabaud C, Crawford JM, et al. A clinical and histopathologic perspective on evolving noninvasive and invasive alternatives for liver biopsy. Clin Gastroenterol Hepatol 2008;6:491496.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 14.

    Cole TL, Center SA, Flood SN, et al. Diagnostic comparison of needle and wedge biopsy specimens of the liver in dogs and cats. J Am Vet Med Assoc 2002;220:14831490.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15.

    Faa G, Nurchi V, Demelia L, et al. Uneven hepatic copper distribution in Wilson's disease. J Hepatol 1995;22:303308.

  • 16.

    Ferenci P, Steindl-Munda P, Vogel W. Diagnostic value of quantitative hepatic copper determination in patients with Wilson's disease. Clin Gastroenterol Hepatol 2005;3:811818.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 17.

    Diaz G, Faa G, Fami AMG, et al. Copper distribution within and between newborn livers. J Trace Elem Electrolytes Health Dis 1990;4:6164.

    • Search Google Scholar
    • Export Citation
  • 18.

    Milman N, Laursen G, Podenphant J, et al. Trace elements in normal and cirrhotic human liver tissue. Iron, copper, zinc, selenium, manganese, titanium and lead measured by X-ray fluorescence spectroscopy. Liver 1986;6:111117.

    • Search Google Scholar
    • Export Citation
  • 19.

    Faa G, Diaz G, Farci AMG, et al. Variability of copper levels in biopsy tissue from a cirrhotic liver. J Trace Elem Electrolytes Health Dis 1990;4:4950.

    • Search Google Scholar
    • Export Citation
  • 20.

    Faa G, Liguori C, Columbano A, et al. Uneven copper distribution in the human newborn liver. Hepatology 1987;7:838842.

  • 21.

    Cassidy J, Eva JK. The variations in the concentrations of copper and iron within and between the lobes of pig's liver. Proc Nutr Soc 1958;17:30.

    • Search Google Scholar
    • Export Citation
  • 22.

    Howell JS. Histochemical demonstration of copper in copperfed rats and in hepatocellular degeneration. J Pathol Bacteriol 1959;77:473483.

  • 23.

    Bingley JB, Dufty JH. Distribution of copper in the tissues of the bovine neonate and dam. Res Vet Sci 1972;13:814.

  • 24.

    Haywood S. The non-random distribution of copper within the liver of rats. Br J Nutr 1981;45:295300.

  • 25.

    Su LC, Owen CA, Zollman PE, et al. A defect of biliary excretion of copper in copper-laden Bedlington terriers. Am J Physiol 1982;343:G231G236.

    • Search Google Scholar
    • Export Citation
  • 26.

    Thornburg LP, Rottinghaus G, McGowan M, et al. Hepatic copper concentrations in purebred and mixed-breed dogs. Vet Pathol 1990;27:8188.

  • 27.

    Thornburg LP. A perspective on copper and the liver disease in the dog. J Vet Diagn Invest 2000;12:101110.

  • 28.

    Linder MC. Introduction and overview of copper as an element. In: Linder MC, ed. Biochemistry of copper. New York: Plenum Press, 1991;115.

    • Search Google Scholar
    • Export Citation
  • 29.

    Thornburg LP, Rottinghaus G, Dennis G, et al. The relationship between hepatic copper content and morphologic changes in the liver of West Highland White Terriers. Vet Pathol 1996;33:656661.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 30.

    She H, Xiong S, Lin M, et al. Iron activates NF-kB in Kupffer cells. Am J Physiol Gastrointest Liver Physiol 2002;283:G719G726.

  • 31.

    Center SA. Metabolic, antioxidant, nutraceutical, probiotic, and herbal therapies relating to the management of hepatobiliary disorders. Vet Clin North Am Small Anim Pract 2004;34:67172.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 32.

    Center SA, Warner KL, Erb HN. Liver glutathione concentrations in dogs and cats with naturally occurring liver disease. Am J Vet Res 2002;63:11871197.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 33.

    Sternlieb I. Copper and the liver. Gastroenterology 1980;78:16151628.

  • 34.

    Danks DM. Copper and liver disease. Eur J Pediatr 1991;150:142148.

  • 35.

    Association of Official Analytical Chemists (AOAC). In: Helrich K, ed. Official methods of analysis. 15th ed. Arlington, Va: AOAC, 1990.

    • Search Google Scholar
    • Export Citation
  • 36.

    Thornburg LP, Beissenherz M, Dolan M, et al. Histochemical demonstration of copper and copper-associated protein in the canine liver. Vet Pathol 1985;22:327332.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 37.

    Bischoff K, Lamm C, Erb HN, et al. The effects of formalin fixation and tissue embedding of bovine liver on copper, iron, and zinc analysis. J Vet Diagn Invest 2008;20:220224.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 38.

    Nooijen JL, van den Hamer CJA, Houtman JPW, et al.Possible errors in sampling percutaneous liver biopsies for determination of trace element status: application to patients with primary biliary cirrhosis. Clin Chim Acta 1981;113:335338.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 39.

    Ferenci P. Wilson's disease. Clin Gastroenterol Hepatol 2005;3:726733.

  • 40.

    Goldfischer S, Popper H, Sternlieb I. The significance of variations in the distribution of copper in liver disease. Am J Pathol 1980;99:715730.

    • Search Google Scholar
    • Export Citation
  • 41.

    Guido M, Colloredo G, Fassan M, et al. Clinical practice and ideal liver biopsy sampling standards: not just a matter of centimeters. J Hepatol 2006;44:818826.

    • Search Google Scholar
    • Export Citation
  • 42.

    Bedossa P, Dargere D, Paradise V. Sampling variability of liver fibrosis in chronic hepatitis. Hepatology 2003;38:14491457.

  • 43.

    Schultheiss PC, Bedwell CL, Hamar DW. Canine liver iron, copper, and zinc concentrations and association with histologic lesions. J Vet Diagn Invest 2002;14:396402.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 44.

    Pietrangelo A, Gualdi R, Casalgrandi G, et al. Molecular and cellular aspects of iron-induced hepatic cirrhosis in rodents. J Clin Invest 1995;95:18241831.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 45.

    Pietrangelo A. Hereditary hemochromatosis—a new look at an old disease. N Engl J Med 2004;350:23832397.

  • 46.

    Bonkovsky HL, Banner BF, Rothman AL. Iron and chronic viral hepatitis. Hepatology 1997;25:759768.

  • 47.

    Alla V, Bonkovsky H. Iron in nonhemochromatotic liver diseases. Semin Liver Dis 2005;25:461472.

  • 48.

    Jain S, Scheuer PJ, Archer B, et al. Histological demonstration of copper and copper-associated protein in chronic liver disease. J Clin Patho1 1978;31:784790.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 49.

    Theodossi A, Skene AM, Portmann B, et al. Observer variation in assessment of liver biopsies including analysis by Kappa statistics. Gastroenterology 1980;79:232241.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 50.

    Thornburg LP, Rottinghaus G, Gage H. Chronic liver disease associated with high hepatic copper concentration in a dog. J Am Vet Med Assoc 1986;188:11901191.

    • Search Google Scholar
    • Export Citation
  • 51.

    Webb CB, Twedt DC, Meyer DJ. Copper-associated liver disease in Dalmatians: a review of 10 dogs (1998–2001). J Vet Intern Med 2002;16:665668.

    • Search Google Scholar
    • Export Citation
  • 52.

    Hoffmann G, van den Ingh TS, Bode P, et al.Copper-associated chronic hepatitis in Labrador Retrievers. J Vet Intern Med 2006;20:856861.

    • Crossref
    • Search Google Scholar
    • Export Citation

Advertisement