I. Lautenschlager

Cytomegalovirus infection enhances smooth muscle cell proliferation and intimal thickening of rat aortic allografts.

Inbred DA (AG-B4, RT1a) and WF (AG-B2, RT1v) rats were used as donors and recipients of aortic allografts. The recipient rats were inoculated i.p. either on day 1 (early infection) or on day 60 (late infection) with 10(5) plaque-forming units of rat cytomegalovirus (RCMV). The control rats were left noninfected. The presence of viral infection was demonstrated by plaque assays from biopsies of the salivary glands, liver, and spleen at sacrifice. The rats received 300 microCi[3H]thymidine by i.v. injection 3 h before sacrifice, and the grafts were removed at various time points for histology, immunohistochemistry, and autoradiography. RCMV infection significantly enhanced the generation of allograft arteriosclerosis. Infection at the time of transplantation had two important effects. First, the infection was associated with an early, prominent inflammatory episode and proliferation of inflammatory cells in the allograft adventitia. Second, the viral infection doubled the proliferation rate of smooth muscle cells and the arteriosclerotic alterations in the intima. In late infection the impact of RCMV infection on the allograft histology was nearly nonexistent. RCMV infection showed no effect in syngeneic grafts. These results suggest that early infection is more important to the generation of accelerated allograft arteriosclerosis than late infection, and that an acute alloimmune response must be associated with virus infection, to induce accelerated allograft arteriosclerosis. RCMV-infected aortic allografts, as described here, provide the first experimental model to investigate the interaction between the virus and the vascular wall of the transplant.

Human Herpesvirus-6 Infection After Liver Transplantation

A diagnosis of posttransplantation human herpesvirus-6 (HHV-6) infection was established for eight adult recipients among a liver transplantation patient population of 121. The diagnosis was based on serology and demonstration of HHV-6 specific antigens in liver biopsy specimens with use of monoclonal antibodies and immunoperoxidase staining. A significant graft dysfunction was recorded in association with serodiagnosis. HHV-6 early antigens, as well as HHV-6 variant B antigens, were detected retrospectively in all six available liver biopsy specimens. Histologic examination of biopsy specimens demonstrated acute rejection in 5 of the 8 patients, and 3 patients had portal lymphocyte infiltration. In five cases cytomegalovirus (CMV) infection was associated with HHV-6 infection; in four cases CMV antigens were also detected in the biopsy specimens. Two patients who had pure HHV-6 infection without CMV infection or rejection had significantly impaired graft function, with a positive antigen-detection test. Thus, HHV-6 may infect the liver allograft and cause graft dysfunction and may possibly be associated with rejection and/or CMV infection.

Cytomegalovirus Infection of the Heart Is Common in Patients with Fatal Myocarditis

BACKGROUNDnAlthough enteroviruses and adenoviruses are considered to be the leading causes of the usually mild clinical myocarditis, little is known about the etiology of severe or fatal myocarditis.nnnMETHODSnWe collected all available clinical records and myocardial autopsy samples for patients who had myocarditis recorded as the underlying cause of death in Finland during the period of 1970-1998. Findings for all available patients (20 men and 20 women; median age, 49 years) with myocarditis that fulfilled the Dallas criteria and who had sufficient data were included in the study. Twelve subjects who had died accidentally served as control subjects. Polymerase chain reaction (PCR) and in situ hybridization assays were used for detection of viral genomes (adenovirus, cytomegalovirus, enterovirus, human herpesvirus 6, influenza A and B viruses, parvovirus B19, and rhinovirus) in heart samples.nnnRESULTSnViral nucleic acids were found in the hearts of 17 patients (43%), including cytomegalovirus (15 patients), parvovirus B19 (4 patients), enterovirus (1 patient), and human herpesvirus 6 (1 patient). In 4 patients, cytomegalovirus DNA was found in addition to parvovirus B19 or enterovirus genomes. No adenoviruses, rhinoviruses, or influenza viruses were detected in this study of fatal myocarditis. In 67% of the patients for whom PCR was positive for cytomegalovirus, in situ hybridization revealed viral DNA in cardiomyocytes. Only 1 of these patients was immunocompromised. In the control group, only human herpesvirus 6 (1 subject) and parvovirus B19 (1 subject) DNA were detected.nnnCONCLUSIONSnIn this population-based study, cytomegalovirus was found to be the most common specific finding in immunocompetent patients with fatal myocarditis. This may have important clinical implications for the treatment of severe acute myocarditis.

Cytomegalovirus infection of the liver transplant: virological, histological, immunological, and clinical observations

Abstract: The most common organ‐specific manifestation of cytomegalovirus (CMV) infection after liver transplantation is hepatitis. Here we retrospectively describe the detailed virological, histological, immunological, and clinical findings associated with CMV infection in 229 consecutive adult liver transplantation patients. CMV infection was diagnosed by pp65 antigenemia. From 439 liver biopsies, CMV antigens were demonstrated by immunohistochemistry and CMV DNA by hybridization. The Banff criteria were used for histology. The expression of various adhesion molecules (intercellular adhesion molecule‐1 [ICAM‐1], vascular cell adhesion molecule‐1 [VCAM‐1], endothelial leukocyte adhesion molecule‐1 [ELAM‐1]), their ligands (leukocyte function antigen‐1 [LFA‐1], very late antigen‐4 [VLA‐4], Sialyl‐LewisX‐molecule [SLeX]), and lymphoid activation markers (major histocompatibility complex [MHC] Class II, interleukin‐2‐receptor [IL‐2R]) was demonstrated by immunohistochemistry.

Human herpesvirus‐6 and ‐7 in pediatric stem cell transplantation

Human herpesvirus‐6 (HHV‐6) and ‐7 (HHV‐7) may reactivate with immunosuppression and cause symptoms varying from subclinical to severe organ manifestations. The presence of HHV‐6 and ‐7 and their possible association with clinical problems among pediatric recipients of stem cell grafts was studied in a single institution setting between November 1999 and December 2001.

BK polyomavirus-associated hemorrhagic cystitis among pediatric allogeneic bone marrow transplant recipients: Treatment response and evidence for nosocomial transmission

BACKGROUNDnBK polyomavirus-associated hemorrhagic cystitis (BK-PyVHC) is a significant complication of allogenic hematopoietic stem cell transplantation (HSCT), but risk factors and treatment are currently unresolved. BK-PyVHC typically presents with clinical cystitis, macrohematuria, and increasing urine and blood BKV loads.nnnOBJECTIVESnCharacterization of children undergoing allogeneic HSCT with BK-PyVHC and their clinical and antibody response to cidofovir treatment.nnnSTUDY DESIGNnBy prospective screening of urine and plasma in 50 pediatric allogenic HSCT performed between 2008 and 2010, we identified 6 (12%) children with BK-PyVHC. Cidofovir was administered intravenously to 5 patients and intravesically to 4 patients (3 double treatments).nnnRESULTSnDecreasing BKV viremia of>2log(10)copies/mL and clinical resolution was seen in 4 patients over 5-12 weeks. Responses occurred only in patients mounting BKV-specific IgM and IgG responses. Epidemic curve plots, BKV genotyping and contact tracing provided evidence of transmission between 2 BKV-seronegative patients, but ruled out transmission among the remaining four patientsnnnCONCLUSIONSnThe data suggest that BK-PyVHC may be the result of nosocomial transmission in children with low/undetectable BKV antibodies and raises urgent questions about appropriate infection control measures and the role of cidofovir.

Human herpesvirus-6 infection is associated with adhesion molecule induction and lymphocyte infiltration in liver allografts

BACKGROUND/AIMSnHuman herpesvirus-6 (HHV-6) infection has been recently described in liver transplants. HHV-6 may infect the transplant and cause graft dysfunction. Some association between HHV-6 and rejection has also been recorded. We have now investigated the possible involvement of HHV-6 in the intragraft immunological processes, adhesion molecules induction and lymphocyte activation.nnnMETHODSnHHV-6 was detected in liver biopsies of 19 patients transplanted in the period from 1996 to 2000. Patients with other infections or rejection were excluded from the study. Finally, 19 biopsies of eight allografts with pure HHV-6 infection were available. Adhesion molecules (ICAM-1, VCAM-1, ELAM-1) and their ligands (LFA-1, VLA-4, sLeX) and lymphoid activation markers (MHC class II, IL-2R) were demonstrated in liver biopsies by immunohistochemistry. Five biopsies from patients with normal graft function and without rejection or infection were used as controls for immune staining, and ten biopsies with acute rejection but without infection were used as positive controls.nnnRESULTSnBiopsy histology demonstrated mild to moderate lymphocyte infiltration associated with HHV-6 infection. HHV-6 significantly (P < or = 0.05) increased the vascular expression of ICAM-1 and VCAM-1, and the number of graft infiltrating lymphocytes positive for LFA-1, VLA-4 and class II antigens. A total of 3/8 grafts developed chronic rejection.nnnCONCLUSIONSnHHV-6 infection increased adhesion molecule expression and lymphocyte infiltration in liver allografts.

Comparison of plasma polymerase chain reaction and pp65-antigenemia assay in the quantification of cytomegalovirus in liver and kidney transplant patients

BACKGROUNDnCytomegalovirus (CMV) is a significant problem in transplantation. The antiviral treatment is based on the clinical symptoms and the rapid laboratory diagnosis. Although polymerase chain reaction (PCR) methods have already been widely used, the clinical correlation of the findings is not clear.nnnOBJECTIVEnThe objective of this study was to investigate the usefulness of a quantitative plasma PCR test and compare it with the pp65-antigenemia test in the detection of clinically significant CMV infections in liver and kidney transplant patients.nnnSTUDY DESIGNnThe clinical material consisted of 253 consecutive blood samples was tested using a quantitative polymerase chain reaction test, Cobas Amplicor CMV Monitor (Roche) and pp65 antigenemia assay. Plasma was used for PCR and leucocytes were used for the antigenemia test.nnnRESULTSnCMV was detected in 89 out of 253 blood samples by one or both methods. PCR detected 78 (range 274-165000 copies/ml) and pp65 antigenemia test 79 (range 1-1500 positive cells/50000) of the positive findings. The sensitivity and specificity of PCR test was 86 and 94%, respectively. The PCR detected all clinically significant CMV infections (>10 positive cells in pp65 test) and infections which required antiviral treatment. In addition, the correlation between the two tests was almost linear.nnnCONCLUSIONSnThe quantitative PCR appears to be a suitable alternative to diagnose and monitor CMV infections in transplant patients.

Cytomegalovirus enhance expression of growth factors during the development of chronic allograft nephropathy in rats

Cytomegalovirus (CMV) accelerates chronic rejection (CRX) in a model of rat kidney allograft. In this model, the expressions of transforming growth factor beta 1 (TGF‐β), platelet‐derived growth factor (PDGF)‐AA, PDGF‐BB and connective tissue growth factor (CTGF) were investigated with and without CMV. Transplantations were performed under immunosuppression. One group of animals was infected with CMV and the other was left uninfected. The grafts were harvested on days 3–60 after transplantation. Growth factor proteins were demonstrated by immunohistochemistry, and mRNAs by in situ hybridization. A significantly more intense and earlier endothelial TGF‐β (2.4u2003±u20030.8 vs. 1.0u2003±u20030.0; Pu2003<u20030.05) and PDGF‐AA (1.8u2003±u20030.4 vs. 1.0u2003±u20030.0; Pu2003<u20030.05) expressions, confirmed by mRNA hybridization, occurred in the CMV group compared with the noninfected group. PDGF‐BB appeared in a few inflammatory cells only. In addition CTGF appeared earlier and has more intense in the CMV group (2.5u2003±u20030.6 vs. 1.2u2003±u20030.5) and the number of CTGF mRNA‐positive fibroblasts (57u2003±u20039 vs. 3u2003±u20034; Pu2003<u20030.05) was significantly higher. Thus, CMV enhanced expression of TGF‐β1, PDGF‐AA and CTGF during the development of CRX.

Current characteristics and outcome of cytomegalovirus infections after kidney transplantation

The clinical course of cytomegalovirus (CMV) infections in the current era is poorly described. We characterized the symptoms and outcome of all CMV infections in a large cohort of kidney transplant recipients. Among 1129 kidney transplant recipients transplanted between 2004 and 2011 in Charité Universitätsmedizin Berlin and Helsinki University Hospital, 297 patients with CMV infection were characterized.