Distinctive gene expression profiles associated with Hepatitis B virus x protein.

Hepatitis B virus (HBV) is a major risk factor for the development of hepatocellular carcinoma (HCC). HBV encodes the potentially oncogenic HBx protein, which mainly functions as a transcriptional co-activator involving in multiple gene deregulations. However, mechanisms underlying HBx-mediated oncogenicity remain unclear. To determine the role(s) of HBx in the early genesis of HCC, we utilized the NCI Oncochip microarray that contains 2208 human cDNA clones to examine the gene expression profiles in either freshly isolated normal primary adult human hepatocytes (Hhep) or an HCC cell line (SK-Hep-1) ecotopically expressing HBx via an adenoviral system. The gene expression profiles also were determined in liver samples from HBV-infected chronic active hepatitis patients when compared with normal liver samples. The microarray results were validated through Northern blot analysis of the expression of selected genes. Using reciprocally labeling hybridizations, scatterplot analysis of gene expression ratios in human primary hepatocytes expressing HBx demonstrates that microarrays are highly reproducible. The comparison of gene expression profiles between HBx-expressing primary hepatocytes and HBV-infected liver samples shows a consistent alteration of many cellular genes including a subset of oncogenes (such as c-myc and c-myb) and tumor suppressor genes (such as APC, p53, WAF1 and WT1). Furthermore, clustering algorithm analysis showed distinctive gene expression profiles in Hhep and SK-Hep-1 cells. Our findings are consistent with the hypothesis that the deregulation of cellular genes by oncogenic HBx may be an early event that favors hepatocyte proliferation during liver carcinogenesis.

Infection after liver transplantation.

Infections occurring in liver transplant recipients result in significant morbidity and mortality. Factors influencing the frequency of posttransplant infections include pretransplant nutritional status, latent viral infections, and the degree of immunosuppression used to modulate the immune response to the allograft. Infectious agents may be introduced into the patient via the allograft, through infusion of blood products, and through intravenous lines, catheters, and drains. Infections also develop as a result of reactivation of latent viruses or by overgrowth or invasion by endogenous organisms. The intensity of the immunosuppressive regimen directly affects the frequency of infection. Infection may be categorized as bacterial, viral, fungal, or protozoal. The most frequent organisms include bacterial--enterobacteriaceae; viral--cytomegalovirus; fungal--Candida species and Aspergillus species; and protozoal--Pneumocystis carinii. Diagnosing infection requires the use of many different methods in combination, including routine bacterial culture, viral culture, and fungal culture. Histologic and cytologic examination may lead to rapid identification of some organisms. Specialized collection procedures such as bronchoalveolar lavage provide rapid access to material for culture and cytologic examination. Serum serology in conjunction with histotopic or cytologic evaluation is useful in diagnosing some infections, such as Epstein-Barr virus. New technology such as polymerase chain reaction allows detection of all types of infection at or before the onset of clinical symptoms. Rapid and early diagnosis of infection in this patient population can reduce infection-related morbidity and mortality.

Epstein-Barr virus-associated syndromes in immunosuppressed liver transplant recipients. Clinical profile and recognition on routine allograft biopsy.

The clinical profile and histopathologic changes in needle biopsies of the liver were studied in 10 cases of acute Epstein-Barr virus infection occurring in liver transplant recipients. The systemic viral syndrome in four cases resembled that seen in infectious mononucleosis, whereas in six others it was characterized by atypical signs and symptoms in the form of jaw pain, arthralgias, joint space effusions, diarrhea, encephalitis, pneumonitis, mediastinal lymphodenopathy, and ascites. Laboratory investigation showed marked elevations in hepatocellular enzymes and circulating atypical lymphocytes in the peripheral blood. Pancytopenia was noted in eight cases. A range of histopathologic changes was noted in the allografts ranging from alterations typically observed in infectious mononucleosis to a distinctive constellation characterized by (a) mixed mononuclear portal and sinusoidal infiltrates containing atypical large noncleaved cells and immunoblasts; (b) associated lobular activity indicative of a hepatitic process, and (c) relatively mild duct damage not in proportion to the severity of the inflammatory infiltrates. The patients responded to reduced immunosuppression, but recurrent viral syndromes occurred in four instances and one patient died of systemic lymphoproliferative disease.

Rapid identification of cytomegalovirus in liver allograft biopsies by in situ hybridization.

Identifying the etiology of hepatic dysfunction in liver transplant patients is critical to their clinical management and in maintaining graft survival. While cytomegalovirus (CMV) is a well-known cause of posttransplant hepatitis, the morphologic diagnosis of CMV hepatitis in liver biopsies can be difficult. Because conventional tissue culture for CMV requires days to weeks, the final results often arrive too late to be clinically useful. In this study, 44 liver allograft biopsies from 21 patients with hepatic dysfunction were evaluated for CMV by routine light microscopy, conventional tissue culture, and in situ DNA hybridization (IH) using commercially available biotinylated CMV-specific DNA probes. Whereas 38.6% of the biopsy specimens were positive by IH, 15.9% were culture-positive biopsies and 13.6% were positive by routine light microscopy. Assuming tissue culture to be the standard, IH demonstrated a sensitivity of 100% and a specificity of 73%. In comparison, routine light microscopy showed a sensitivity of 71.4% and specificity of 97.3%. In addition, three biopsy specimens positive only by IH were from three patients who had other liver biopsies positive for CMV by either light microscopy or viral culture. In situ DNA hybridization allows rapid detection (5-6 h) of CMV in paraffin-embedded liver allograft biopsies; it also has a sensitivity that surpasses routine histologic examination and perhaps even tissue culture.

Pontine and extrapontine myelinolysis following liver transplantation. Relationship to serum sodium.

The relationship between central pontine myelinolysis (CPM) and extrapontine myelinolysis (EPM) and serum sodium changes in the setting of orthotopic liver transplantation (OLT) is examined. Postmortem examination of 14 patients with end-stage liver disease who underwent liver transplantation revealed CPM in four, of which three also had EPM. A retrospective review of clinical and laboratory data was performed on all patients. There were marked perioperative rises (21-32 mEq/L) in the serum sodium concentration in all four patients who developed myelinolysis. In contrast, the largest increase in sodium in patients without demyelination was 16 mEq/L. We conclude that perioperative rises in the serum sodium concentration increase the risk of myelinolysis. CPM and EPM should be considered if the patient develops mental status changes or focal neurological deficits several days after OLT.

Frozen section evaluation of donor livers before transplantation.

Frozen section examination was performed on 385 donor livers before transplantation. Exclusion criteria were applied to the donor livers examined to exclude potentially dysfunctional livers. The exclusion criteria included the following: severe macrovesicular steatosis, ischemic necrosis, prominent chronic portal inflammation, prominent periductular fibrosis, granulomatous inflammation, bridging fibrosis, and malignancy. Twenty-seven of the 385 donor livers examined were excluded before transplantation. The following histologic features were present in the excluded livers: severe steatosis (22), ischemic necrosis (2), portal inflammation (1), and periductular fibrosis (2). Steatosis was present in 51 of the 385 (13.25%) organs examined, including 22 of the donor organs excluded before transplantation. Twenty-nine livers with mild to moderate steatosis were implanted into size and blood type-matched recipients. Indicators of allograft function (prothrombin time and bilirubin) and damage (aspartate aminotransferase and alanine aminotransferase) were measured daily for the first 10 days after transplant. There was no statistically significant difference between the group of nonfat livers and donor livers containing mild steatosis. Statistically significant higher posttransplant serum alanine aminotransferase and prothrombin time levels were present in the patients with livers implanted with mild versus moderate steatosis. The 1-year survival rate for patients receiving fatty versus nonfatty donor livers was not statistically different (Kaplan-Meier, P = 0.592). No significant differences were found in the clinical and laboratory characteristics of donors whose organs were implanted compared with the clinical and laboratory characteristics of donors whose organs were excluded. The primary nonfunction rate after applying the exclusion criteria was 1.4%, which is a significant decrease compared with our primary nonfunction rate of 8.5% before using frozen section examination. Frozen section examination is useful in excluding donor organs which may become dysfunctional after transplantation.

A pilot study of soluble adhesion molecules as surrogate markers for acute liver allograft rejection.

BACKGROUND: Tissue endothelial adhesion molecule expression is increased during acute liver allograft rejection. Soluble forms exist, but their correlation to rejection and their clinical value have not been determined. METHODS: We studied endothelial adhesion molecule tissue expression and soluble levels in blood and bile and correlated these to the clinical course of 11 adult patients followed for 30 consecutive days after liver transplantation. RESULTS: Three biopsies showing acute rejection demonstrated increased intercellular adhesion molecule (ICAM)-1 but not endothelial leukocyte adhesion molecule-1 expression on hepatic endothelial cells during rejection. Vascular cell adhesion molecule (VCAM)-1 staining was focally increased in two of three specimens. Levels of soluble ICAM-1 or soluble VCAM-1 by ELISA did not distinguish acute rejection from nonrejection conditions. CONCLUSION: We confirmed that endothelial ICAM-1 expression is more intense in rejecting allografts and is more sensitive than changes in VCAM-1 or endothelial leukocyte adhesion molecule-1. However, soluble adhesion molecule determination was not useful in the accurate detection of acute rejection.

Successful prophylaxis of cytomegalovirus disease after primary CMV exposure in liver transplant recipients.

UNLABELLED: During a 38-month period, we studied 320 liver transplants in 283 recipients (202 adults, 81 children). CMV disease was documented in 85 patients (30.0%) The major risk factor for CMV disease was primary CMV exposure (transplanting a seropositive allograft into a seronegative recipient). A total of 42 patients (14.8%) had primary CMV exposure. Twenty-one patients were historical controls, while the next 21 received prophylaxis for CMV infection in a nonrandomized trial of consecutive study groups. The regimen of prophylaxis consisted of intravenous immune globulin (IgG; 0.5 g/kg) at weekly intervals for 6 weeks and acyclovir for 3 months. CMV prophylaxis resulted in a dramatic reduction in the incidence of CMV disease (71.4% vs. 23.8%, (P less than 0.01). All cases of CMV were treated with intravenous ganciclovir (5 mg/kg b.i.d. for 14 days), with 5 patients in the control group developing recurrent CMV disease (33.3% relapse). In the 16 patients receiving prophylaxis who did not develop CMV disease, all developed positive CMV-IgG titers with the passive administration of IgG. However, none developed any evidence of CMV infection or viral shedding as assessed by IgM titers and surveillance viral cultures. Four deaths occurred (all control patients), but none were related to CMV disease. Overall patient and graft survivals after primary CMV exposure were 90.5% and 82.2%, respectively, after a mean follow-up of 14 months. CONCLUSION: Primary CMV exposure is a major risk factor for CMV disease in liver transplant recipients. Intravenous IgG plus acyclovir is safe and effective in preventing CMV infection and disease in this setting. Because of the scarcity of donor organs, we do not advocate protective matching to avoid primary CMV exposure but rather recommend prophylaxis to prevent CMV disease in this high-risk group.

The impact of extended preservation on clinical liver transplantation.

The introduction of UW solution into clinical transplantation has permitted extended cold storage preservation of the liver. Over a 46-month period, we have performed 308 orthotopic liver transplants (266 primary, 42 retransplants) in 266 recipients. Our experience is divided into cold-storage preservation in Eurocollins (163 transplants in 140 recipients) and UW (145 transplants in 131 recipients) solutions. Donor and recipient factors were comparable between the two groups. The use of UW solution has permitted an increase in the mean preservation time from 5.2 +/- 1.0 [EC] to 12.8 +/- 4.3 [UW] hr (P less than 0.001). The mean total operating time was reduced but intraoperative blood loss was unchanged with UW preservation. The number of transplants performed during the daytime hours has increased dramatically (21.5% [EC] vs. 71% [UW], P less than 0.001). The incidence of primary nonfunction, hepatic artery thrombosis, 1-month graft survival, and early retransplantation were similar in the 2 groups. Initial allograft function as determined by bile production, histology, and clinical assessment were likewise similar. Mean serum bilirubin, transaminase, and prothrombin levels were virtually identical by 5 days posttransplant. The enhanced margin of safety afforded by extended preservation has increased the capability for distant organ procurement and sharing, minimized organ wastage, and improved the efficiency of organ retrieval. With the relaxation of logistical constraints, our rate of liver import has nearly doubled (20.9% [EC] vs. 39.3% [UW], P less than 0.001). Extended preservation has permitted the development of reduced-size liver grafting (n = 12), resulting in a significant reduction in the number of deaths occurring while awaiting transplantation. Therefore, we advocate the use of UW solution with selective extension of preservation based not only on donor and recipient factors but also on manpower, resource, and logistical considerations.

Induction of hyperplastic liver nodules in Wistar and MRC-Wistar rats by phenobarbital and the liver carcinogens acetoxime, 1-nitroso-5,6-dihydrouracil and 3-nitroso-2-oxazolidinone.

We tested the ability of phenobarbital and two liver carcinogens, acetoxime and 1-nitroso-5,6-dihydrouracil (NDHU), to induce hyperplastic liver nodules (HLN) in MRC-Wistar and Wistar rats, using a system that included a single diethylnitrosamine (DEN) treatment, partial hepatectomy, and administration of the test compound in drinking water for 8 weeks. All three compounds induced significant HLN frequencies (number of HLN/cm2) in both rat strains. When the results for each strain were "normalized" for each compound and then combined, HLN frequency in MRC-Wistar rats was significantly lower (P less than 0.01) than that in Wistar rats. The weak liver carcinogen 3-nitroso-2-oxazolidinone (NOZ) did not induce a significant HLN frequency in MRC-Wistar rats. Acetoxime was highly volatile and was not mutagenic in the Ames test under a variety of conditions. The results for acetoxime are of interest because simple oximes are common constituents of oil paints. HLN induction by nitrosodihydrouracil is of interest because, unlike most liver carcinogens, this compound probably does not require metabolic activation and shows only a mild acute hepatoxicity.

Intrahepatic arteriopathy associated with primary nonfunction of liver allografts.

In this report we describe two cases of liver allograft primary non-function in which the donor organs were obtained from patients with a long-standing history of hypertension and placed in normotensive 2 recipients. Examination of these failed grafts showed marked luminal narrowing of the medium and large intrahepatic arteries along with extensive hepatocellular necrosis. No evidence of cellular allograft rejection was present. Preoperative frozen section evaluation of the donor liver failed to detect any pathological changes in the donor organs. Morphometric studies showed a statistically significant luminal narrowing of the medium arteries in these patients compared with controls with graft failure because of other causes (P < .0001). To our knowledge there are no previous reports describing this finding in the literature. We hypothesize that the arterial narrowing in these livers resulted in compromised blood flow to the organ after transplantation into a normotensive patient. Further studies are necessary to determine the frequency of these changes in the hypertensive population. Such studies may lead to the development of criteria that will identify potential donors who are likely to have such changes before organ procurement.

Laboratory automation systems. An introduction to concepts and terminology.

The concept of laboratory automation has existed for years; such automation has been used primarily in nonclinical and industrial settings. The next step is to implement automation systems in the clinical laboratory. A laboratory automation system consists of robots, conveyor systems, machine vision, and computer hardware and software. Specimen movement and result reporting are based on the identification of specimens using bar coded specimens and bar coded specimen carriers. The implementation of a laboratory automation system is dependent on the presence of a laboratory information system. An interface between the laboratory information system and the laboratory automation system provides the information required to move the specimen through the laboratory. The reporting of results is dependent on the laboratory information system or manual input, depending on the type of work cell in which the results are produced. The greatest hurdle to overcome in developing and implementing a laboratory automation system is the integration of systems, including commercial laboratory instrumentation and user-defined work cells. The barriers to implementation primarily are proprietary in nature: instrument software and instrument hardware. When the instrument manufacturers realize the necessity for development of electronic and physical integration, the proliferation of laboratory automation systems will occur. Several opportunities exist for the reduction in laboratory expenses and the development of new positions, such as "robotechnologist," a staff member who would function in a manner similar to the current laboratory information systems manager. This article describes the author's concepts of laboratory automation.

Filtration of platelet-poor plasma specimens yields platelet-free plasma. Application for batch analysis of beta-thromboglobulin and platelet factor 4.

The authors investigated filtration of platelet-poor plasma through a 0.2-micron filter for the analysis of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) in frozen specimens. Platelets were detected by electron micrograph in the platelet-poor plasma preparation without filtration. No platelets or platelet fragments were seen after filtration. Freezing the unfiltered specimens resulted in a significant increase in the beta-TG and PF4 concentrations, presumably because of release of these proteins from the platelet alpha-granules during freezing and thawing. There was no change in the PF4 levels and only a slight decrease in beta-TG levels after freezing of the filtered specimens. The filtered samples could be frozen for later batch analysis, resulting in considerable cost savings to the laboratory.

Disseminated Trichosporon beigelii infection after orthotopic liver transplantation.

A 25-year-old male, who received an orthotopic liver transplant for fulminant hepatic failure resulting from hepatitis B, had disseminated Trichosporon beigelii infection develop. Of the 55 cases of disseminated T. beigelii that have been reported in the English-language medical literature, most have occurred in patients who were both neutropenic and had compromised cell-mediated immunity. Mortality has ranged from 60 to 78%. Outcome appears to depend significantly on leukocyte recovery. Histologically, Trichosporon can be confused with Candida; however, recognition of the arthroconidia and pleomorphic hyphae and pseudohyphae of Trichosporon should allow their differentiation.

The effects of dietary amino acids on hepatic L-asparagine synthetase.

Rats were fed Roger's synthetic amino acid diets, complete or without asparagine, aspartate, or glutamate, for 2 weeks. Hepatic and serum amino acid content and hepatic asparagine synthetase were assayed before and after the test diets were administered. Special attention was paid to the multiple forms of asparagine synthetase present. Rats fed the test diet without asparagine exhibited high molecular weight (110,000) alpha-form and intermediate molecular weight (57,000) beta-form of asparagine synthetase. Rats fed the complete test diet and the test diet without asparatate exhibited only the beta-form of the enzyme. Rats fed the test diet without glutamate exhibited no enzyme activity. These data are related to the hepatic amino acid levels and to the role of asparagine and asparagine synthetase in amino acid homeostasis.

A randomized prospective trial of acyclovir and immune globulin prophylaxis in liver transplant recipients receiving OKT3 therapy.

The use of OKT3 therapy is a major risk factor for opportunistic infections in liver transplant recipients. In the last 2 years, we prospectively randomized 100 patients receiving OKT3 therapy into either a control group (n = 50) or a prophylaxis group (n = 50). Prophylaxis consisted of six doses of intravenous immune globulin over 4 weeks and oral acyclovir for 3 months after OKT3 therapy. The two groups were comparable with respect to demographic, immunologic, and clinical characteristics. The regimen of prophylaxis resulted in (1) a significant reduction in the incidence of herpetic and Epstein-Barr viral infections; (2) no change in the incidence of cytomegalovirus infections; (3) a significant decrease in the incidence of fungal infections; and (4) fewer deaths due to sepsis. The incidence of viral and fungal infections was higher after OKT3 induction than after rescue therapy. Our conclusion is that opportunistic infections are frequent after OKT3 therapy in hepatic allograft recipients. Treatment with intravenous immune globulin and oral acyclovir is safe and effective in preventing non-cytomegaloviral and fungal infections in this setting, thus conferring a survival advantage with fewer deaths due to sepsis.

Clinical patterns of cytomegalovirus disease after liver transplantation.

During a 43-month period, we performed 248 liver transplantations in 211 patients (127 adults and 84 children). Cytomegalovirus (CMV) disease was documented in 73 recipients (34.6%). Risk factors for CMV disease included donor CMV seropositivity, antilymphocyte therapy, and retransplantation. The mean time of occurrence of CMV disease was 38.3 days after transplantation, and the most frequent site of disease was the hepatic allograft. A total of 69 patients were treated with intravenous ganciclovir, with a prompt and lasting response documented in 51 (73.9%). The remaining 18 (26.1%) developed recurrent CMV disease, which was more common after primary CMV exposure. Cytomegalovirus disease was ultimately controlled by ganciclovir in 94.2% of cases. This disease occurs early after transplantation and can be related to well-defined risk factors. Although ganciclovir therapy is effective, preliminary experience with prophylaxis shows promise in reducing the incidence of CMV disease.

Clinical spectrum of fungal infections after orthotopic liver transplantation.

During a 50-month period, we identified 91 episodes of fungal infection in 72 liver transplant recipients (23.8%). Candida species accounted for 83.5% of cases. Clinical patterns of fungal infections included disseminated infection (19), peritonitis (17), pneumonitis (15), multiple sites of colonization (13), fungemia (11), and other sites (16). The diagnosis of fungal infection was usually made in the first 2 months (84.7% of cases), at a mean time of 16 days after transplantation. Risk factors for fungal infections included retransplantation, Risk score, intraoperative transfusion requirement, urgent status, Roux limb biliary reconstruction (in adults), steroid dose, bacterial infections and antibiotic therapy, and vascular complications. Fungal infections were successfully treated with amphotericin B in 63 cases (74.1%) but were associated with diminished patient survival (50% vs 83.5%). Fungal infection is a frequent source of early morbidity and can be related to well-defined risk factors, suggesting the need for effective prophylaxis.

Hepatic failure associated with imipramine therapy.

Imipramine, a widely used antidepressant, has rarely been associated with hepatic abnormalities. In the majority of reported cases, hepatic effects have been transient and readily reversible on discontinuation of the drug. We cared for an 11-year-old boy with hepatic failure and massive cell necrosis which followed treatment with imipramine for enuresis. This therapy led to fulminant hepatic failure and subsequent liver transplantation.

Syndrome of multiple bowel perforations in liver transplant recipients.

In an analysis of surgical complications following 500 consecutive orthotopic liver transplants, we identified 12 patients who developed the syndrome of multiple bowel perforations that was not due to iatrogenic injury. All cases occurred in small children (mean weight: 9.0 kg), who represented 7% of the pediatric population. Each patient had a minimum of three perforations. The typical intraoperative findings were pin-point perforations in areas of normal-appearing bowel. With only one possible exception (a patient with cytomegalovirus enteritis), no specific etiology could be determined. Management was based on multiple exploratory laparotomies and individualized operative procedures. All patients are currently alive (mean follow-up: 34.9 months). The pathogenesis of the syndrome of multiple bowel perforations remains unclear but is possibly multifactorial or related to high doses of steroids. Aggressive surgical management with semiopen treatment of peritonitis and frequent explorations has afforded excellent results.