Cytomegalovirus infection of the liver in transplant recipients

Role of Polymerase Chain Reaction in the Diagnosis of Cytomegalovirus Infection in Liver Transplant Patients

Eighty-eight formalin-fixed, paraffin-embedded needle biopsies from 58 liver trans plant recipients were analyzed for the presence of cytomegalovirus (CMV) by light microscopy and the polymerase chain reaction (PCR). Twenty-seven biopsies were positive for CMV by both light microscopy and PCR, 41 were negative by both methods, 17 were positive by PCR only, and 3 were positive by light microscopy only. In the absence of cytomegalic cells, immunohistochemical staining was unable to detect CMV that could have been identified by PCR. Serum total bilirubin was higher in patients whose biopsies contained PCR (but not histologic) evidence of CMV infection. No evidence of association of the presence of CMV was found by either PCR or light microscopy with serum levels of aminotransferase or alkaline phosphatase, nor with histologic evidence of rejection or hepatitis. PCR was negative for CMV in 22 liver biopsies from immunocompetent individuals without evidence of hepatic dysfunction. Although PCR can detect the presence of CMV in the absence of cytomegalic cells, the clinical significance of PCR-proven, histologically undetectable CMV in the liver is undetermined. Int J Surg Pathol 2(3):221-226, 1995

Pathogenesis and vertical transmission of a transplacental rat cytomegalovirus

BACKGROUND

Cytomegalovirus (CMV) congenital infection is the major viral cause of well-documented birth defects in human. Because CMV is species-specific, the main obstacle to developing animal models for congenital infection is the difference in placental architecture, which preludes virus transmission across the placenta. The rat placenta, resembling histologically to that of human, could therefore facilitate the study of CMV congenital infection in human.

RESULTS

In this report, we present clear evidences of the transplacental property of a new rat CMV (RCMV), namely ALL-03, which had been isolated from placenta and uterus of the house rat. Our study signifies the detection of infectious virus, virus particles, viral protein and DNA as well as immune response to demonstrate a natural model of acute CMV infection including the immunocompetent and immunocompromised host associated with or without pregnancy. It is characterized by a full range of CMV related clinical signs; lesions and anatomical virus distribution to uterus, placenta, embryo, fetus, neonate, lung, kidney, spleen, liver and salivary gland of the infected rats in addition to the virus-specific seroconversion. The preference of the virus for different organs mimics the situation in immunocompromised man. Most interestingly, the placenta was observed to be involved in the maternofetal infection and hence confirmed the hypothesis that the RCMV strain ALL-03 is capable to cross the placenta and infect the offsprings congenitally.

CONCLUSION

The maternal viremia leading to uterine infection which subsequently infecting to the fetus through the placenta is the most likely phenomenon of CMV vertical transmission in our study.

Cholestasis after hematopoietic cell transplantation

Cholestasis and jaundice are common after hematopoietic cell transplantation and may have multiple causes. Specific disorders that may contribute to cholestasis in this setting include sepsis, hemolysis, cyclosporine administration, drug toxicity, parenteral nutrition, graft versus host disease, viral infection, and extrahepatic obstruction.

Histological diagnosis of cytomegalovirus hepatitis in liver allografts

AIMS--To determine the incidence of histologically documented cytomegalovirus (CMV) hepatitis following orthotopic liver transplantation (OLT) and to assess the effectiveness of immunohistochemistry and in situ hybridisation (ISH) in detecting CMV. To describe the histological pattern most frequently associated with CMV hepatitis in order to select the biopsy group in which these modern techniques are most effective. METHODS--A prospective histological study was carried out on 853 biopsy specimens, obtained from 191 liver allografts (160 patients). Specimens were stained with haematoxylin and eosin and immunohistochemically (avidin-biotin complex) using monoclonal antibodies directed against early and late CMV antigens. A retrospective selection was made of 23 specimens with viral inclusion bodies in cytomegalic cells (group A) to characterise the most frequently associated histological pattern, and of 34 other specimens without viral inclusion bodies (group B) but with the same microscopic features as group A. Re-cuts from both specimen groups were studied using immunohistochemistry and ISH with a CMV specific complementary DNA probe. RESULTS--CMV infection was confirmed in 35 specimens (29 by immunohistochemistry, 23 by presence of inclusion bodies in haematoxylin and eosin stained sections, 16 by ISH) from 27 patients (incidence 16.9%). CMV hepatitis was diagnosed within 46 +/- 19 (range 21-114) days posttransplant. Twenty on (91.3%) of the 23 biopsy specimens with inclusion bodies (group A) displayed heterogeneous inflammatory foci disseminated throughout the hepatic lobule. Nineteen specimens (82.6%) were positive by immunohistochemistry and 14 (60.9%) by ISH. In eight (23.5%) of the 34 group B specimens CMV infection was confirmed by immunohistochemistry (n = 6) or ISH (n = 2). Another 12 (35.3%) of the group B specimens negative on staining with haematoxylin and eosin, immunohistochemistry and ISH came from allografts in which previous or subsequent biopsy specimens were CMV positive. CONCLUSIONS--Demonstration of cytomegalic inclusion bodies in haematoxylin and eosin sections is sufficient for a diagnosis of CMV hepatitis. The routine use of immunohistochemistry in all allograft biopsy specimens in more sensitive than demonstration of inclusion bodies by staining with haematoxylin and eosin but may yield false negative results because of the focal distribution of positive cells. ISH was less sensitive than staining with haematoxylin and eosin and/or immunohistochemistry. A histological picture of "disseminated focal hepatitis" without viral inclusion bodies selects a group of allograft biopsy specimens in which immunohistochemistry and/or ISH may improve detection of CMV.

Primary care management of the liver transplant patient

The patient referred for liver transplantation typically has complications from a progressive, irreversible liver injury. Less traditional complications of end-stage liver disease, such as bone disease and some hepatobiliary malignancies, may also prompt referral. However, there are contraindications to liver transplantation, such as metastatic malignancy and persistent substance abuse. Each patient should be referred as early as possible. The evaluation process includes a complete physical examination and social and psychologic evaluations. If transplantation is agreed upon, the patient is listed by clinical status and enters a waiting period for a donor liver. Following transplantation, the patient is maintained on a regimen of immunosuppressive drugs to prevent allograft rejection. Each patient is also maintained on prophylactic medications, to decrease the risk of opportunistic infection. Many of the postoperative problems in liver transplantation are a result of immunosuppression, either as side effects of the medications used to prevent and control rejection or from the intensity of the resulting immunosuppression. These problems include headaches, systemic hypertension, acute and chronic allograft rejection, renal dysfunction, opportunistic infection with cytomegalovirus or Pneumocystis carinii, disease recurrence, and neoplasia. Routine, long-term care includes systematic clinical follow-up and repetitive blood tests. Communication among the transplant center, the patient, and the referring physician are essential to a successful outcome over the long term.

Controlled trial of prophylactic versus therapeutic use of ganciclovir after liver transplantation in adults

The potential of prophylactic ganciclovir for the control of cytomegalovirus (CMV) infection was evaluated in a prospective controlled trial of 65 patients after liver transplantation. A group of 33 patients received ganciclovir (10 mg/kg/day) during the third and fourth weeks after transplantation, while 32 patients were randomised to receive ganciclovir (10 mg/kg/day) only when clinical CMV disease was diagnosed. Eight patients (25%) in the latter group received ganciclovir and included the only death attributed to CMV infection in the study. Prophylactic ganciclovir was associated with a lower incidence of serologically diagnosed secondary infection and the development of the IgM anti-CMV antibody. However, the frequency of clinical infections was similar in the two groups (9/33 vs. 11/32). Liver function tests during the second month after transplantation were not significantly better in the patients receiving prophylactic ganciclovir. Leucopaenia was not seen in patients receiving prophylactic ganciclovir.

Hepatitis C viral infection in liver transplant recipients

In this study we examined multiple serial liver biopsy specimens from liver transplant recipients to determine the pathological features of hepatitis C virus-induced hepatitis. Hepatitis C virus infections acquired after transplantation and previous infections that recurred in patients after transplantation were confirmed by the results of the polymerase chain reaction. Of 43 patients infected with the hepatitis C virus, 18 had a mild form of chronic hepatitis. Four patients had hepatitis that progressed to focal bridging fibrosis or cirrhosis. There were no significant clinical or pathological differences between infections acquired after transplantation and recurrent infections (as determined by polymerase chain reaction) except that acquired infections more often developed into hepatitis. Findings indicative of hepatitis C infection included portal and parenchymal mononuclear infiltrates of varying degrees, acidophilic necrosis and swollen hepatocytes. Other common findings included lymphoid aggregates, bile duct damage and fatty change. Atypical pathological conditions included extensive hepatocyte swelling or acidophilic necrosis with minimal inflammation mimicking ischemia and ductal or ductular damage and proliferation with mixed portal infiltrates mimicking rejection or obstruction. We conclude that in transplant recipients infection by the hepatitis C virus usually produces a mild disease state, but the diagnosis of hepatitis can be difficult to make because indicators of hepatitis may mimic those of rejection, ischemia, obstruction or other hepatic infections. Serial biopsy specimens with persistent pathology and polymerase chain reaction may be necessary to define the presence of a hepatitis C virus lesion.

Clinicopathological study of liver involvement in cytomegalovirus infection in infant autopsy cases

To clarify the pathogenesis of hepatic cytomegalovirus (CMV) infection, we clinicopathologically investigated 18 infants and 10 adults with cytomegalic inclusion bodies (CIB) in the liver among a total of 75 autopsy cases with CIB in any organ of the body. CMV infection was confirmed by immunohistochemistry and in situ hybridization. When CIB were present in the liver, CMV infection also tended to be systemic. All the adults were immunocompromised patients, but diseases inducing immunodeficiency were present in only two of the infants. The severe and systemic CMV infections we found in infants might have been associated with congenital CMV infection. Histologically, hepatocyte necrosis, cholestasis, extramedullary hematopoiesis and fatty degeneration were more frequent and prominent in infants than in adults. However, inflammatory cell infiltration was only slight. In addition, the frequent association with premature birth and hypoplasia of the thymus suggested that insufficient development of immunity may result in hepatic CMV involvement in infants. CIB were most frequently observed in hepatocytes in both infants and adults, but in infants they were also frequently seen in the bile duct epithelium. These histopathological findings and the high incidence of jaundice in infant patients suggest that the bile duct is also an important site of CMV proliferation in infants, and that CMV infection may be one cause of infantile jaundice.

A quantitative analysis of T lymphocyte populations in human liver allografts undergoing rejection: the use of monoclonal antibodies and double immunolabeling

The aim of this study was to quantitate T-cell populations infiltrating portal tracts, bile ducts and hepatic lobules in 82 biopsy specimens from 25 patients after orthotopic liver transplantation. Biopsy specimens taken immediately after revascularization of the graft were used as controls. Patients studied include 18 with initial rejection episodes, 11 with unresolved rejection, five with vanishing bile duct syndrome and eight patients with other forms of liver injury. Quantitation was done in a blinded fashion for the first 20 biopsy specimens. A double immunolabeling technique was used to simultaneously immunolabel bile duct structures (with anti-major histocompatibility complex class II or antikeratins) and lymphoid populations (with anti-CD2, anti-CD4 or anti-CD8). This facilitated the accurate quantitation of intraepithelial lymphocytes within bile ducts. This technique also enabled simultaneous detection of CD4 and CD8 antigens on lymphocytes in portal tracts. The predominant lymphocyte subtype within biliary epithelium during acute and chronic rejection was of the CD2+/CD8+ phenotype. CD8+/CD4+ ratio in bile ducts was approximately 5:1 in acute, unresolved and chronic rejection. In vanishing bile duct syndrome, double immunolabeling enabled the detection of destroyed interlobular bile duct remnants that were not apparent on routine hematoxylin and eosin staining. Attached to some of these structures were CD8+ lymphocytes. Lobular CD8+ cells were not prominent in acute rejection but increased significantly in biopsy specimens from patients with unresolved and chronic rejection. In chronic rejection, a selective increase was seen in these CD8+ cells in centrizonal regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Early diagnosis of cytomegalovirus hepatitis in liver transplant recipients: role of immunostaining, DNA hybridization and culture of hepatic tissue

Immunostaining techniques that use a monoclonal antibody against an early cytomegalovirus antigen or a polyclonal antibody, in situ DNA hybridization and inoculation of cell cultures for the detection of cytomegalovirus from liver biopsy specimens were studied in 20 liver transplant patients with cytomegalovirus hepatitis, as defined by histological criteria. A total of 108 liver biopsy specimens from 20 patients with a diagnosis of cytomegalovirus hepatitis (obtained per protocol at 7, 21, 90, and 180 days or whenever liver dysfunction occurred), which had previously been examined histologically and in cell culture, were again studied by recutting the liver tissue for histological examination, DNA hybridization and immunostaining with monoclonal or polyclonal antibodies to cytomegalovirus. In 5 of 20 patients, the diagnosis of cytomegalovirus hepatitis could have been made earlier (mean = 9.6 days) by immunostaining with a monoclonal antibody. Of 47 biopsy specimens with cytomegalovirus inclusion bodies, the sensitivity and specificity of the diagnostic procedures were immunostaining with monoclonal antibody (84% and 90%) and polyclonal antibody (72% and 97%), in situ DNA hybridization (72% and 100%) and cell culture detection (52% and 95%), respectively. Immunostaining with a monoclonal antibody against an early CMV antigen frequently detected cytomegalovirus infection in the liver allograft earlier than identification of typical histological inclusion bodies. DNA in situ hybridization was less sensitive than other techniques but highly specific; cytomegalovirus cell culture lacked sensitivity compared with the other procedures.

An animal model for therapeutic intervention studies of CMV infection in the immunocompromised host

An experimental rat model to study acute cytomegalovirus infections is described. Eight-week old male Brown Norway rats, immunosuppressed by total body irradiation, were infected with rat cytomegalovirus (RCMV). The effects of infection were determined by survival rates and the presence of virus or viral components in different organs was assayed by plaque test, immunoperoxidase staining, dot-blot DNA hybridization and in situ DNA hybridization. At days 10-post infection nearly 90% of the animals had died. Spleen, liver and bone marrow were heavily infected. Interstitial pneumonia was observed. Pathological findings strongly resembled the full scale of lesions in human CMV infections. Anti-RCMV hyperimmune serum was effective against mortality from RCMV infection and viral spread to lungs and liver was prevented. This model is appropriate for studies on the pathogenesis and antiviral therapy of CMV infections in the immunocompromised host.

A coded histologic study of hepatic graft-versus-host disease after human bone marrow transplantation

We tested the hypothesis that liver histology from patients with graft-versus-host disease could be distinguished from other common liver diseases. Liver biopsies from 33 allogeneic marrow transplant recipients with acute and chronic graft-versus-host disease and 37 nontransplant liver disease patients without graft-versus-host disease were recut, restained and coded for blind review. Analysis of individual histologic features showed significantly more cytologic aberration of bile duct epithelium and more cholestasis among biopsies with graft-versus-host disease when compared to biopsies without graft-versus-host disease (p less than or equal to 0.05). The duration of graft-versus-host preceding the biopsy influenced the histologic features. Biopsies before Day 35 showed frequent acidophilic bodies but infrequent bile duct changes. Biopsies from Days 35 to 90 posttransplant had more frequent bile duct exocytosis and disruption, and biopsies from patients with chronic graft-versus-host disease (beyond Day 90) showed more frequent portal fibrosis and bile duct dropout. Pattern assessment of coded biopsies showed that a histologic diagnosis of graft-versus-host disease had a positive predictive value of 86%, a sensitivity of 66% and a specificity of 91%. False-negative diagnoses occurred most frequently in biopsies obtained less than 4 weeks posttransplant, usually because bile duct abnormalities were not present. False-positive diagnoses of graft-versus-host disease occurred in nongraft-versus-host disease biopsies with periportal inflammation and proliferated bile ducts. However, biopsies of chronic graft-versus-host disease had more frequent dropout and disruption of bile duct epithelium than did biopsies of acute or chronic hepatitis.(ABSTRACT TRUNCATED AT 250 WORDS)