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Genetic and nutritional predictors of hyperhomocysteinemia in inflammatory bowel disease
490
Letters to the Editor
The hospital course was complicated by continued fevers and development of FHF within 72 h. Peak liver enzyme levels were LDH, 3529 U/L; ALP, 1095 U/L; AST, 2255 U/L; and ALT, 1974 U/L. Total bilirubin increased to 33.4 mg/dl; unconjugated bilirubin was 0.0 mg/dl; PT, 21 s; and activated PTT, 51 s. Etiologies of FHF, including pregnancy; Ebstein-Barr virus; varicella; Wilson’s disease; and hepatitis A, B, C, D, or E virus, were excluded. The following tests were normal or negative: fibrinogen, D dimer, fibrin degradation products, haptoglobin, HIV, serum iron, ␣-fetoprotein, cytomegalovirus DNA, antibodies to liverkidney microsomal type 1, antineutrophil, mitochondria, and smooth muscle. An abdominal CT scan was significant only for periportal edema. ERCP showed intermittent drainage of bile, with a normal esophagus, stomach, duodenum, and ampulla. The pancreatic duct was normal. A normal common bile duct without a filling defect was seen on magnetic resonance cholangiopancreatography. The patient was transferred to an outside hospital for evaluation for liver transplantation. Transjugular core liver biopsy demonstrated liver parenchyma with moderate cholestasis and microvesicular steatosis and increased eosinophilic infiltrate involving the portal tracts and hepatic lobules with ballooning degeneration of hepatocytes with occasional hepatocyte dropout. No bile duct injury was identified. There was no evidence of viral inclusion or cytomegalovirus infection. The histological findings were indicative of drug-induced liver damage. The patient developed progressive encephalopathy, coagulopathy, hemodynamic instability, metabolic acidosis, and respiratory failure. The patient was terminally extubated on day 13 per the wishes of the family. In general, clarithromycin is well tolerated (2). Dosage adjustments are needed in patients with severe renal impairment, and a 50% reduction is needed in those on dialysis. The manufacturer reports mild elevations in liver function tests in less than 1% of patients. Clarithromycin is reported to be associated with cholestatic hepatitis in a patient who received clarithromycin therapy for Mycobacterium chelonae lung infection (3). Idiosyncratic drug-induced FHF is reported after clarithromycin use with exclusion of known causes of FHF (1). In our case, biopsy was consistent with drug-induced toxicity, and other causes of FHF were not present. In addition, the patient did not have preceding liver dysfunction. An immunological idiosyncratic drug reaction in this case is supported by fever, eosinophilia, and eosinophilic infiltration on biopsy. A sensitization period to clarithromycin of 1 wk is consistent with an immune-mediated idiosyncratic drug reaction (4). Nonzonal panacinar necrosis is characteristic of an idiosyncratic phenomenon. Although acetaminophen levels were not obtained in this case, the pattern of peak liver enzyme elevation, eosinophilia, panacinar nonzonal necrosis, and eosinophilic infiltrate on biopsy do not support the hypothesis of acetaminophen-associated FHF. We believe that, in this case, the
AJG – Vol. 97, No. 2, 2002
immunologically mediated idiosyncratic drug reaction leading to FHF was associated with clarithromycin exposure. Kenneth Christopher, M.D. Patrick A. Hyatt, M.D. Clare Horkan, M.B. Paul C. Yodice, M.D., F.A.C.P., F.C.C.P. Division of Critical Care and Department of Medicine The Miriam Hospital Brown University School of Medicine Providence, Rhode Island Department of Neurology Beth Israel Deaconess Medical Center Harvard Medical School Boston, Massachusetts
REFERENCES 1. Shaheen N, Grimm IS. Fulminant hepatic failure associated with clarithromycin. Am J Gastroenterol 1996;91:394 –5. 2. Guay DR, Patterson DR, Seipman N, Craft JC. Overview of the tolerability profile of clarithromycin in preclinical and clinical trials. Drug Saf 1993;8:350 – 64. 3. Yew WW, Chau CH, Lee J, Leung CW. Cholestatic hepatitis in a patient who received clarithromycin therapy for Mycobacterium chelonae lung infection. Clin Infect Dis 1994;18:1025– 6. 4. Zimmerman HJ. Drug-induced liver disease. Clin Liver Dis 2000;4:73–96. Reprint requests and correspondence: Kenneth Christopher, M.D., Division of Critical Care Medicine, The Miriam Hospital, 164 Summit Avenue, Providence, RI 02906. Received Aug. 15, 2001; accepted Aug. 22, 2001.
Genetic and Nutritional Predictors of Hyperhomocysteinemia in Inflammatory Bowel Disease TO THE EDITOR: We read with interest the article by Romagnuolo et al. (1) regarding the prevalence and the predictors of hyperhomocysteinemia in patients with inflammatory bowel disease (IBD). The authors concluded that hyperhomocysteinemia is significantly more common in IBD patients than in healthy controls (15.4% vs 2.2%, p ⬍ 0.05), as previously reported (2– 4), and that advanced age, male sex, vitamin B12 deficiency or lower vitamin B12 serum levels, and multivitamin therapy were independently associated with hyperhomocysteinemia (1). Several studies showed that vitamin deficiencies (both folic acid and vitamin B12) are the major determinants of hyperhomocysteinemia in IBD patients (2– 4). However, increased plasma homocysteine levels are typically caused not only by nutritional deficiencies in vitamin cofactors such as folic acid, vitamin B12, and vitamin B6, but also by genetic defects in the enzymes involved in homocysteine metabolism. The most common enzyme defect associated with moderately
AJG – February, 2002
Letters to the Editor
raised homocysteine is a point mutation (C to T substitution at nucleotide 677) in the coding region of the gene for methylenetetrahydrofolate reductase (MTHFR), which is involved in the remethylation pathway of homocysteine. Recently, we performed a study in a population of 64 IBD patients in whom vitamin B12 and folic acid levels were determined together with the prevalence of the MTHFR genotypes. Among the 11 IBD patients carrying the TT MTHFR genotype, six had hyperhomocysteinemia, of whom five had concurrent folate and/or vitamin B12 deficiency. The relative risk of developing hyperhomocysteinemia was 5.3-fold (95% CI ⫽ 2.9 –9.6) in IBD patients with the TT MTHFR genotype associated with folate and/or vitamin B12 deficiency, in comparison to individuals with CC or CT MTHFR genotypes and adequate levels of folate and/or vitamin B12. Furthermore, in patients’ homozygotic for the C677T MTHFR gene mutation there is an increased folate requirement to mantain plasma homocysteine within normal levels (5). Thus, the IBD patients with this genetic background are at increased risk to develop hyperhomocysteinemia and may need vitamin B12 and folate supplementation. In conclusion, we suggest that determination of both the MTHFR genotype and vitamin status may predict the risk of developing hyperhomocysteinemia in IBD patients. Alfredo Papa, M.D. Silvio Danese, M.D. Giovanni Gasbarrini, M.D. Antonio Gasbarrini, M.D. Department of Internal Medicine Catholic University of Rome Rome, Italy
REFERENCES 1. Romagnuolo J, Fedorak RN, Dias VC, et al. Hyperhomocysteinemia and inflammatory bowel disease: Prevalence and predictors in a cross-sectional study. Am J Gastroenterol 2001;96: 2143–9. 2. Oldenburg B, Fijnheer R, van der Griend R, et al. Homocysteine in inflammatory bowel disease: A risk factor for thromboembolic complications? Am J Gastroenterol 2000;95:2825– 30. 3. Chowers Y, Sela B, Holland R, et al. Increased levels of homocysteine in patients with Crohn’s disease are related to folate levels. Am J Gastroenterol 2000;95:3498 –502. 4. Cattaneo M, Vecchi M, Zighetti ML, et al. High prevalence of hyperhomocysteinemia in patients with inflammatory bowel disease: A pathogenetic link with thromboembolic complications? Thromb Haemost 1998;80:542–5. 5. Jacques PF, Boston AG, Williams RR, et al. Relation between folate status, a common mutation in methylenetetrahydrofolate reductase, and plasma homocysteine concentrations. Circulation 1996;58:468 –76. Reprint requests and correspondence: Alfredo Papa, M.D., Istituto di Medicina Interna e Geriatria, Universita` Cattolica del Sacro Cuore—Policlinico “A. Gemelli,” Largo A. Gemelli, 8 00168 Roma, Italia. Received Aug. 15, 2001; accepted Aug. 22, 2001.
491
Diagnosis of Chronic Liver Disease: Reproducibility and Validation of Liver Biopsy TO THE EDITOR: The actual criteria for diagnosis of chronic active hepatitis (CAH) are levels of ALT higher than the normal range and histological features of liver biopsy. We suggest the use of a flow chart, after the discovery of the increase of ALT, to identify the the etiology (viruses, dysmetabolism, nonalcoholic steatohepatitis autoimmunity, etc) and the histology of the liver to stage the evolution of the disease. From that, liver biopsy may be considered the golden standard for the diagnosis of CAH. The reproducibility of the results from liver biopsy is a point of debate (1–3). Some authors support the idea that, whenever correctly performed, liver biopsy might reproduce the damage of a selected area of the liver that might under- or overestimate the damage of the entire organ. This might be a technical bias, reducing the accuracy of the diagnosis. The aim of this study was, then, to evaluate the reproducibility of results from a liver biopsy comparing two different liver specimens (right and left lobe) from the same liver. From January to July, 1999 we enrolled 52 consecutive patients aged from 30 to 60 yr to come under our observation for ALT increase and hepatitis C virus antibody positivity. Patients with clinical, instrumental, and/or laboratory signs of liver cirrhosis (LC) were excluded from the study. In our cohort none of the patients had signs of LC. Patients, after giving informed consent, underwent double percutaneous liver biopsies that were echo assisted on the right lobe using an 18-gauge ⫻ 90 mm Menghini modified needle (BIOMOL HS S.P.A., Pomezia, Italy) and echo guided on the left lobe with an 18-gauge ⫻ 150 mm needle. Liver specimens longer than 15 mm were considered useful for the diagnosis. Ten percent formalin– embebbed specimens were sent to the pathology unit, fixed with paraffin, and stained by ematossilyn-eosin and trichromic reaction. The diagnosis on the same specimen was done by two different liver pathologists with an interobserver agreement of 90%. Grading and staging were made according to the Ishack score. The Student’s t test was used for statistical analysis, with data considered significant at p ⬍ 0.05. Only two patients were not considered in the study because the lengths of their specimens were less than 15 mm. The medium lengths of the specimens were 2.8 ⫾ 1.1 cm, right lobe, and 2.5 ⫾ 0.9 cm, left lobe. No major or minor complications were observed. The comparative statistical analysis was done on total score, grading, and staging separately. Results (Table 1) did not show any difference between the two lobes. Percutaneous liver biopsy is considered the gold standard for the diagnosis of chronic liver disease. The histological examination allows evaluation of the inflammatory process, the progression of fibrosis, and the eventual evolution to LC. In the case of therapy with interferon, liver biopsy may also
Letters to the Editor
The hospital course was complicated by continued fevers and development of FHF within 72 h. Peak liver enzyme levels were LDH, 3529 U/L; ALP, 1095 U/L; AST, 2255 U/L; and ALT, 1974 U/L. Total bilirubin increased to 33.4 mg/dl; unconjugated bilirubin was 0.0 mg/dl; PT, 21 s; and activated PTT, 51 s. Etiologies of FHF, including pregnancy; Ebstein-Barr virus; varicella; Wilson’s disease; and hepatitis A, B, C, D, or E virus, were excluded. The following tests were normal or negative: fibrinogen, D dimer, fibrin degradation products, haptoglobin, HIV, serum iron, ␣-fetoprotein, cytomegalovirus DNA, antibodies to liverkidney microsomal type 1, antineutrophil, mitochondria, and smooth muscle. An abdominal CT scan was significant only for periportal edema. ERCP showed intermittent drainage of bile, with a normal esophagus, stomach, duodenum, and ampulla. The pancreatic duct was normal. A normal common bile duct without a filling defect was seen on magnetic resonance cholangiopancreatography. The patient was transferred to an outside hospital for evaluation for liver transplantation. Transjugular core liver biopsy demonstrated liver parenchyma with moderate cholestasis and microvesicular steatosis and increased eosinophilic infiltrate involving the portal tracts and hepatic lobules with ballooning degeneration of hepatocytes with occasional hepatocyte dropout. No bile duct injury was identified. There was no evidence of viral inclusion or cytomegalovirus infection. The histological findings were indicative of drug-induced liver damage. The patient developed progressive encephalopathy, coagulopathy, hemodynamic instability, metabolic acidosis, and respiratory failure. The patient was terminally extubated on day 13 per the wishes of the family. In general, clarithromycin is well tolerated (2). Dosage adjustments are needed in patients with severe renal impairment, and a 50% reduction is needed in those on dialysis. The manufacturer reports mild elevations in liver function tests in less than 1% of patients. Clarithromycin is reported to be associated with cholestatic hepatitis in a patient who received clarithromycin therapy for Mycobacterium chelonae lung infection (3). Idiosyncratic drug-induced FHF is reported after clarithromycin use with exclusion of known causes of FHF (1). In our case, biopsy was consistent with drug-induced toxicity, and other causes of FHF were not present. In addition, the patient did not have preceding liver dysfunction. An immunological idiosyncratic drug reaction in this case is supported by fever, eosinophilia, and eosinophilic infiltration on biopsy. A sensitization period to clarithromycin of 1 wk is consistent with an immune-mediated idiosyncratic drug reaction (4). Nonzonal panacinar necrosis is characteristic of an idiosyncratic phenomenon. Although acetaminophen levels were not obtained in this case, the pattern of peak liver enzyme elevation, eosinophilia, panacinar nonzonal necrosis, and eosinophilic infiltrate on biopsy do not support the hypothesis of acetaminophen-associated FHF. We believe that, in this case, the
AJG – Vol. 97, No. 2, 2002
immunologically mediated idiosyncratic drug reaction leading to FHF was associated with clarithromycin exposure. Kenneth Christopher, M.D. Patrick A. Hyatt, M.D. Clare Horkan, M.B. Paul C. Yodice, M.D., F.A.C.P., F.C.C.P. Division of Critical Care and Department of Medicine The Miriam Hospital Brown University School of Medicine Providence, Rhode Island Department of Neurology Beth Israel Deaconess Medical Center Harvard Medical School Boston, Massachusetts
REFERENCES 1. Shaheen N, Grimm IS. Fulminant hepatic failure associated with clarithromycin. Am J Gastroenterol 1996;91:394 –5. 2. Guay DR, Patterson DR, Seipman N, Craft JC. Overview of the tolerability profile of clarithromycin in preclinical and clinical trials. Drug Saf 1993;8:350 – 64. 3. Yew WW, Chau CH, Lee J, Leung CW. Cholestatic hepatitis in a patient who received clarithromycin therapy for Mycobacterium chelonae lung infection. Clin Infect Dis 1994;18:1025– 6. 4. Zimmerman HJ. Drug-induced liver disease. Clin Liver Dis 2000;4:73–96. Reprint requests and correspondence: Kenneth Christopher, M.D., Division of Critical Care Medicine, The Miriam Hospital, 164 Summit Avenue, Providence, RI 02906. Received Aug. 15, 2001; accepted Aug. 22, 2001.
Genetic and Nutritional Predictors of Hyperhomocysteinemia in Inflammatory Bowel Disease TO THE EDITOR: We read with interest the article by Romagnuolo et al. (1) regarding the prevalence and the predictors of hyperhomocysteinemia in patients with inflammatory bowel disease (IBD). The authors concluded that hyperhomocysteinemia is significantly more common in IBD patients than in healthy controls (15.4% vs 2.2%, p ⬍ 0.05), as previously reported (2– 4), and that advanced age, male sex, vitamin B12 deficiency or lower vitamin B12 serum levels, and multivitamin therapy were independently associated with hyperhomocysteinemia (1). Several studies showed that vitamin deficiencies (both folic acid and vitamin B12) are the major determinants of hyperhomocysteinemia in IBD patients (2– 4). However, increased plasma homocysteine levels are typically caused not only by nutritional deficiencies in vitamin cofactors such as folic acid, vitamin B12, and vitamin B6, but also by genetic defects in the enzymes involved in homocysteine metabolism. The most common enzyme defect associated with moderately
AJG – February, 2002
Letters to the Editor
raised homocysteine is a point mutation (C to T substitution at nucleotide 677) in the coding region of the gene for methylenetetrahydrofolate reductase (MTHFR), which is involved in the remethylation pathway of homocysteine. Recently, we performed a study in a population of 64 IBD patients in whom vitamin B12 and folic acid levels were determined together with the prevalence of the MTHFR genotypes. Among the 11 IBD patients carrying the TT MTHFR genotype, six had hyperhomocysteinemia, of whom five had concurrent folate and/or vitamin B12 deficiency. The relative risk of developing hyperhomocysteinemia was 5.3-fold (95% CI ⫽ 2.9 –9.6) in IBD patients with the TT MTHFR genotype associated with folate and/or vitamin B12 deficiency, in comparison to individuals with CC or CT MTHFR genotypes and adequate levels of folate and/or vitamin B12. Furthermore, in patients’ homozygotic for the C677T MTHFR gene mutation there is an increased folate requirement to mantain plasma homocysteine within normal levels (5). Thus, the IBD patients with this genetic background are at increased risk to develop hyperhomocysteinemia and may need vitamin B12 and folate supplementation. In conclusion, we suggest that determination of both the MTHFR genotype and vitamin status may predict the risk of developing hyperhomocysteinemia in IBD patients. Alfredo Papa, M.D. Silvio Danese, M.D. Giovanni Gasbarrini, M.D. Antonio Gasbarrini, M.D. Department of Internal Medicine Catholic University of Rome Rome, Italy
REFERENCES 1. Romagnuolo J, Fedorak RN, Dias VC, et al. Hyperhomocysteinemia and inflammatory bowel disease: Prevalence and predictors in a cross-sectional study. Am J Gastroenterol 2001;96: 2143–9. 2. Oldenburg B, Fijnheer R, van der Griend R, et al. Homocysteine in inflammatory bowel disease: A risk factor for thromboembolic complications? Am J Gastroenterol 2000;95:2825– 30. 3. Chowers Y, Sela B, Holland R, et al. Increased levels of homocysteine in patients with Crohn’s disease are related to folate levels. Am J Gastroenterol 2000;95:3498 –502. 4. Cattaneo M, Vecchi M, Zighetti ML, et al. High prevalence of hyperhomocysteinemia in patients with inflammatory bowel disease: A pathogenetic link with thromboembolic complications? Thromb Haemost 1998;80:542–5. 5. Jacques PF, Boston AG, Williams RR, et al. Relation between folate status, a common mutation in methylenetetrahydrofolate reductase, and plasma homocysteine concentrations. Circulation 1996;58:468 –76. Reprint requests and correspondence: Alfredo Papa, M.D., Istituto di Medicina Interna e Geriatria, Universita` Cattolica del Sacro Cuore—Policlinico “A. Gemelli,” Largo A. Gemelli, 8 00168 Roma, Italia. Received Aug. 15, 2001; accepted Aug. 22, 2001.
491
Diagnosis of Chronic Liver Disease: Reproducibility and Validation of Liver Biopsy TO THE EDITOR: The actual criteria for diagnosis of chronic active hepatitis (CAH) are levels of ALT higher than the normal range and histological features of liver biopsy. We suggest the use of a flow chart, after the discovery of the increase of ALT, to identify the the etiology (viruses, dysmetabolism, nonalcoholic steatohepatitis autoimmunity, etc) and the histology of the liver to stage the evolution of the disease. From that, liver biopsy may be considered the golden standard for the diagnosis of CAH. The reproducibility of the results from liver biopsy is a point of debate (1–3). Some authors support the idea that, whenever correctly performed, liver biopsy might reproduce the damage of a selected area of the liver that might under- or overestimate the damage of the entire organ. This might be a technical bias, reducing the accuracy of the diagnosis. The aim of this study was, then, to evaluate the reproducibility of results from a liver biopsy comparing two different liver specimens (right and left lobe) from the same liver. From January to July, 1999 we enrolled 52 consecutive patients aged from 30 to 60 yr to come under our observation for ALT increase and hepatitis C virus antibody positivity. Patients with clinical, instrumental, and/or laboratory signs of liver cirrhosis (LC) were excluded from the study. In our cohort none of the patients had signs of LC. Patients, after giving informed consent, underwent double percutaneous liver biopsies that were echo assisted on the right lobe using an 18-gauge ⫻ 90 mm Menghini modified needle (BIOMOL HS S.P.A., Pomezia, Italy) and echo guided on the left lobe with an 18-gauge ⫻ 150 mm needle. Liver specimens longer than 15 mm were considered useful for the diagnosis. Ten percent formalin– embebbed specimens were sent to the pathology unit, fixed with paraffin, and stained by ematossilyn-eosin and trichromic reaction. The diagnosis on the same specimen was done by two different liver pathologists with an interobserver agreement of 90%. Grading and staging were made according to the Ishack score. The Student’s t test was used for statistical analysis, with data considered significant at p ⬍ 0.05. Only two patients were not considered in the study because the lengths of their specimens were less than 15 mm. The medium lengths of the specimens were 2.8 ⫾ 1.1 cm, right lobe, and 2.5 ⫾ 0.9 cm, left lobe. No major or minor complications were observed. The comparative statistical analysis was done on total score, grading, and staging separately. Results (Table 1) did not show any difference between the two lobes. Percutaneous liver biopsy is considered the gold standard for the diagnosis of chronic liver disease. The histological examination allows evaluation of the inflammatory process, the progression of fibrosis, and the eventual evolution to LC. In the case of therapy with interferon, liver biopsy may also