11/43. Homozygous mutation Arg768Trp in the ABC-transporter encoding gene MRP2/cMOAT/ABCC2 causes Dubin-Johnson syndrome in a Caucasian patient. Dubin-Johnson syndrome (DJS) is an autosomal recessive disorder characterized by conjugated hyperbilirubinemia and caused by mutations of the ATP-binding cassette (ABC) transporter encoding gene MRP2/cMOAT/ABCC2. Previous studies reported on mutations in DJS patients and polymorphisms in healthy human individuals. The genomic dna sequence of a female Caucasian DJS patient was analyzed by dna sequencing and revealed the identification of a homozygous missense mutation C2302T. This DJS-causing alteration results in an amino acid exchange Arg768Trp. ( info) |
12/43. Rotor's syndrome: report of one case. Rotor's syndrome is a rare hereditary non-hemolytic hyperbilirubinemia. This report concerns an 11-year-old boy who presented with fluctuant jaundice since birth. liver function tests showed conjugated hyperbilirubinemia with normal serum aminotransferase and globulin level. The diagnosis was confirmed by laboratory workup which included normal liver histology and oral cholecystography and typical sulfobromophthalein excretion curve. ( info) |
13/43. Lysosomal changes in liver tissue from patients with the Dubin-Johnson-Sprinz syndrome. 1. Clinical, morphological and biochemical data, including data obtained from the application of subcellular fractionation techniques to liver biopsy specimens, are presented for two patients with the Dubin-Johnson-Sprinz (DJS) syndrome. 2. Subcellular fractionation experiments demonstrate that the lysosomes, which have strikingly reduced equilibrium densities, accumulate melanin. Morphological studies confirm the presence of pigments within lysosomes. 3. Although there are increased activities of lysosomal acid hydrolases in the liver tissue from patients with the DJS syndrome, the integrity of these organelles is essentially normal and therefore the accumulation of pigment would not be expected to initiate liver damage. The DJS syndrome is thus a benign type of secondary lysosomal storage disease. ( info) |
14/43. Hepatocellular carcinoma in a case of Dubin-Johnson syndrome treated successfully with a central bilateral segmentectomy. A 72-year-old woman with hepatocellular carcinoma and HCV cirrhosis combined with Dubin-Johnson syndrome was successfully treated by a central bilateral segmentectomy. While the preoperative serum bilirubin level is one of the established criteria for determining the indications for a hepatic resection, it is not effective for HCV cirrhosis cases associated with Dubin-Johnson syndrome. Postoperative hyperbilirubinemia may be cured without special treatment such as bilirubin absorption or plasma exchange, but such patients must be carefully observed to ensure that liver failure does not occur. ( info) |
15/43. Dubin-Johnson-like black liver with normal bilirubin level. Black liver is a common finding in Dubin-Johnson syndrome (DJS), which is caused by the lack of multidrug resistance-associated protein 2 (MRP2). Impaired excretion of epinephrine metabolites is believed to be a cause of black liver in DJS. Recently, we experienced a patient with black liver whose serum bilirubin level was normal. Coarse brown granules were observed in the hepatocytes, and this finding closely resembled that observed in DJS. However, the granules were negative for Schmorl staining. The MRP2 gene did not show any mutation. Immunostaining study demonstrated MRP2 protein expression in the liver, and it was localized in the canalicular membranes of hepatocytes. This case illustrates for the first time that DJS is not the only cause of black liver. ( info) |
16/43. Improvement of serum bilirubin levels after venesection in a patient with Dubin-Johnson syndrome and HCV-positive chronic liver disease. Direct-type hyperbilirubinemia in Dubin-Johnson syndrome is due to the genetic dysfunction of multidrug resistance protein 2. However, serum bilirubin levels may fluctuate as a result of acquired conditions. Iron-reduction therapy by venesection, an alternative to interferon, was performed in a 55-year-old male patient with Dubin-Johnson syndrome complicated by hepatitis c virus-positive chronic liver disease and hepatic iron overload. His pretreatment serum total bilirubin was 10.2 mg/dl, with a dominant direct fraction. The treatment induced a significant reduction in serum total bilirubin, although it remained as high as 7.9 mg/dl. A negative correlation between serum total bilirubin and cumulative bled volume suggested that venesection could suppress bilirubin production from aged erythrocytes. The hepatic iron overload was distributed in hepatocyte lysosomes with Dubin-Johnson granules; thus, it seems that iron removal from the lysosomal granules may also help to reduce serum bilirubin. In conclusion, deep jaundice in a patient with Dubin-Johnson syndrome complicated by hepatitis c virus-positive chronic liver disease and iron overload was partially improved by iron-reduction therapy. ( info) |
17/43. Dual hereditary jaundice: simultaneous occurrence of mutations causing Gilbert's and Dubin-Johnson syndrome. BACKGROUND & AIMS: Dubin-Johnson syndrome is recessively inherited, conjugated hyperbilirubinemia induced by mutations in the ABCC2/MRP2 gene encoding the canalicular transporter for conjugated bilirubin. Gilbert's syndrome is recessively inherited, unconjugated hyperbilirubinemia caused by decreased conjugation rate of bilirubin associated mostly with homozygous A(TA) 7 TAA variant of the TATAA-box in the UGT1A1 gene promoter. Our aim was to establish the molecular diagnosis in a 3-year-old male with atypical, intermittent, predominantly unconjugated, hyperbilirubinemia. methods: 99m Tc-HIDA cholescintigraphy was used for imaging the biliary tree. Expression of ABCC2/MRP2 protein in hepatocytes was investigated immunohistochemically. UGT1A1 and ABCC2/MRP2 genes were sequenced from genomic dna, and the mutations were verified by fragment analysis, sequencing the cloned exons, and restriction fragment length polymorphism. RESULTS: Cholescintigraphy revealed delayed visualization of the gallbladder. A brown granular lipopigment differing from melanin-like pigment reported in Dubin-Johnson syndrome was present in hepatocytes, but, otherwise, liver histology was normal. ABCC2/MRP2 protein was not detected on the canalicular membrane of hepatocytes, and 2 novel mutations were found in the ABCC2/MRP2 gene: a heterozygous in-frame insertion-deletion mutation 1256insCT/delAAACAGTGAACCTGATG in exon 10 inherited from the father and a heterozygous deletion 4292delCA in exon 30 inherited from the mother. In addition, the patient was homozygous for -3279T>G and A(TA) 7 TAA mutations in the UGT1A1 gene promoter. CONCLUSIONS: Our patient represents a case of digenic mixed hyperbilirubinemia-a distinct type of constitutive jaundice resulting from coinherited defects in ABCC2/MRP2 and UGT1A1 genes. ( info) |
18/43. Ultrastructure of kupffer cells and hepatocytes in the Dubin-Johnson syndrome: a case report. Ultrastructure of kupffer cells and hepatocytes in liver bioptate was evaluated in a 17-year-old boy with Dubin-Johnson syndrome (DJS). The liver tissue obtained by needle biopsy was fixed in glutaraldehyde and paraformaldehyde and routinely processed for electron microscopic analysis. The ultrastructural examinations of liver bioptate revealed the accumulation of membrane-bound, electron-dense lysosomal granules within the cytoplasm of hepatocytes, characteristic of DJS. They were located mainly in the vicinity of the biliary pole, and preferentially in the centrilobular region that corresponded to the pigment deposits seen under light microscope. The presence of the granules was accompanied by dilated elements of the granular endoplasmic reticulum and paracrystalline mitochondrial inclusions as well as dilation of the bile canaliculi. The changes in hepatocytes co-existed with marked stimulation and enhanced phagocytic activity of kupffer cells. This was manifested in the accumulation of pigment deposits within their cytoplasm that corresponded to those observed in hepatocytes. Hyperactive pericentral kupffer cells which are involved in the response to pigmentary material originating from disintegrated hepatocytes may play an essential role in the development of DJS. ( info) |
19/43. Neonatal Dubin-Johnson syndrome: long-term follow-up and MRP2 mutations study. Neonatal Dubin-Johnson syndrome (DJS) is rarely diagnosed and mutational analysis of multidrug-resistance-associated protein 2 (MRP2) in such patients had not been reported. We aimed to investigate the possible correlations between genotype and phenotype of patients with DJS. Four cases of DJS, two diagnosed during the neonatal period and two diagnosed at adolescence, were followed for 5-20 y. Mutational analysis in the MRP2/ABCC2 gene was performed in all four cases. Biphasic pattern of jaundice attack was observed in one patient who was followed for 20 y, with jaundice subsiding before 1 y of age and recurring at adolescence. Six novel mutations in four patients were found, including deletions (2748del136, 3615del229, and Del3399-3400), and missense mutations (L441M and E1352Q) and nonsense mutation (Y1275X). The immunohistochemical staining in liver tissues from two patients with neonatal onset showed negative staining for MRP2. Reviewing previously reported cases, all patients diagnosed as DJS before 10 y of age have mutations involving one of the two ATP-binding cassettes (ABC) of the MRP2. This study suggests that long-term follow-up is indicated for neonatal DJS because of possible recurrence and/or second attacks of jaundice in later life, and that disruption of functionally important ABC domains in MRP2 may be related to the earlier onset of the disease. ( info) |
| We report the autopsy of a 79-year-old Japanese woman with Dubin-Johnson syndrome accompanied by pneumonia, an abetalipoproteinemia-like lipid profile and acanthocytosis. On admission, physical examination of the patient revealed malnutrition. blood tests revealed marked inflammatory changes and mild liver dysfunction. Chest X-ray indicated bilateral pneumonia. Total cholesterol, low-density lipoprotein (LDL) cholesterol and triglyceride levels were 89 mg/dL, 5 mg/dL and 6 mg/dL, respectively. Peripheral blood smears revealed numerous acanthocytes. Despite the administration of antibiotics and nutritional support, the patient died. autopsy revealed a black liver, atrophy of fat tissue on the mesentery, and pneumonia with bilateral pleural effusion. We believe that the abetalipoproteinemia-like lipid profiles in this case were caused by malnutrition and the inflammatory changes rather than the direct effects of Dubin-Johnson syndrome. We base this conclusion on the following three findings: 1) the patient's lipid profile before hospitalization was in the normal range, 2) her serum LDL cholesterol and triglyceride levels gradually increased after nutritional support began, and 3) blood tests revealed marked inflammatory changes (c-reactive protein 9.0 mg/dL; interleukin-6 16.4 pg/mL). This case provides important information that enhances our understanding of lipid metabolism under conditions of malnutrition and inflammation. ( info) |