Intragraft cytomegalovirus protein expression is associated with reduced renal allograft survival

A Randomized Trial of Valganciclovir Prophylaxis Versus Preemptive Therapy in Kidney Transplant Recipients

SIGNIFICANCE STATEMENT

Although cytomegalovirus (CMV) infection is an important factor in the pathogenesis of kidney allograft rejection, previous studies have not determined the optimal CMV prevention strategy to avoid indirect effects of the virus. In this randomized trial involving 140 kidney transplant recipients, incidence of acute rejection at 12 months was not lower with valganciclovir prophylaxis (for at least 3 months) compared with preemptive therapy initiated after detection of CMV DNA in whole blood. However, prophylaxis was associated with a lower risk of subclinical rejection at 3 months. Although both regimens were effective in preventing CMV disease, the incidence of CMV DNAemia (including episodes with higher viral loads) was significantly higher with preemptive therapy. Further research with long-term follow-up is warranted to better compare the two approaches.

BACKGROUND

The optimal regimen for preventing cytomegalovirus (CMV) infection in kidney transplant recipients, primarily in reducing indirect CMV effects, has not been defined.

METHODS

This open-label, single-center, randomized clinical trial of valganciclovir prophylaxis versus preemptive therapy included kidney transplant recipients recruited between June 2013 and May 2018. After excluding CMV-seronegative recipients with transplants from seronegative donors, we randomized 140 participants 1:1 to receive valganciclovir prophylaxis (900 mg, daily for 3 or 6 months for CMV-seronegative recipients who received a kidney from a CMV-seropositive donor) or preemptive therapy (valganciclovir, 900 mg, twice daily) that was initiated after detection of CMV DNA in whole blood (≥1000 IU/ml) and stopped after two consecutive negative tests (preemptive therapy patients received weekly CMV PCR tests for 4 months). The primary outcome was the incidence of biopsy-confirmed acute rejection at 12 months. Key secondary outcomes included subclinical rejection, CMV disease and DNAemia, and neutropenia.

RESULTS

The incidence of acute rejection was lower with valganciclovir prophylaxis than with preemptive therapy (13%, 9/70 versus 23%, 16/70), but the difference was not statistically significant. Subclinical rejection at 3 months was lower in the prophylaxis group (13% versus 29%, P = 0.027). Both regimens prevented CMV disease (in 4% of patients in both groups). Compared with prophylaxis, preemptive therapy resulted in significantly higher rates of CMV DNAemia (44% versus 75%, P < 0.001) and a higher proportion of patients experiencing episodes with higher viral load (≥2000 IU/ml), but significantly lower valganciclovir exposure and neutropenia.

CONCLUSION

Among kidney transplant recipients, the use of valganciclovir prophylaxis did not result in a significantly lower incidence of acute rejection compared with the use of preemptive therapy.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Optimizing Valganciclovir Efficacy in Renal Transplantation (OVERT Study), ACTRN12613000554763 .

Mass cytometry reveals single-cell kinetics of cytotoxic lymphocyte evolution in CMV-infected renal transplant patients

Cytomegalovirus (CMV) infection is associated with graft rejection in renal transplantation. Memory-like natural killer (NK) cells expressing NKG2C and lacking FcεRIγ are established during CMV infection. Additionally, CD8+ T cells expressing NKG2C have been observed in some CMV-seropositive patients. However, in vivo kinetics detailing the development and differentiation of these lymphocyte subsets during CMV infection remain limited. Here, we interrogated the in vivo kinetics of lymphocytes in CMV-infected renal transplant patients using longitudinal samples compared with those of nonviremic (NV) patients. Recipient CMV-seropositive (R+) patients had preexisting memory-like NK cells (NKG2C+CD57+FcεRIγ-) at baseline, which decreased in the periphery immediately after transplantation in both viremic and NV patients. We identified a subset of prememory-like NK cells (NKG2C+CD57+FcεRIγlow-dim) that increased during viremia in R+ viremic patients. These cells showed a higher cytotoxic profile than preexisting memory-like NK cells with transient up-regulation of FcεRIγ and Ki67 expression at the acute phase, with the subsequent accumulation of new memory-like NK cells at later phases of viremia. Furthermore, cytotoxic NKG2C+CD8+ T cells and γδ T cells significantly increased in viremic patients but not in NV patients. These three different cytotoxic cells combinatorially responded to viremia, showing a relatively early response in R+ viremic patients compared with recipient CMV-seronegative viremic patients. All viremic patients, except one, overcame viremia and did not experience graft rejection. These data provide insights into the in vivo dynamics and interplay of cytotoxic lymphocytes responding to CMV viremia, which are potentially linked with control of CMV viremia to prevent graft rejection.

Rat and human cytomegalovirus ORF116 encodes a virion envelope glycoprotein required for infectivity

Herpesviruses encode multiple glycoproteins required for different stages of viral attachment, fusion, and envelopment. The protein encoded by the human cytomegalovirus (HCMV) open reading frame UL116 forms a stable complex with glycoprotein H that is incorporated into virions. However, the function of this complex remains unknown. Herein, we characterize R116, the rat CMV (RCMV) putative homolog of UL116. Two R116 transcripts were identified in fibroblasts with three proteins expressed with molecular weights of 42, 58, and 82 kDa. R116 is N-glycosylated, expressed with late viral gene kinetics, and is incorporated into the virion envelope. RCMV lacking R116 failed to result in productive infection of fibroblasts and siRNA knockdown of R116 substantially reduced RCMV infectivity. Complementation in trans of an R116-deficient virus restored ability of the virus to infect fibroblasts. Finally, UL116 knockdown also decreased HCMV infectivity indicating that R116 and UL116 both contribute to viral infectivity.

Cytomegalovirus DNA in non-glioblastoma multiforme brain tumors of infants

PURPOSE

CMV antigens have been detected in some brain tumors specially glioblastoma multiforme (GBM). As brain tumors in the first years of life are among the most aggressive neoplasms with poor prognosis, novel therapeutic options like targeted therapy against virus antigens are demanded. Infantile central nervous system tumors, other than GBM, have not been so far studied for CMV. To our best knowledge, this is the first study in which the presence of CMV-DNA, as a potential viral target for therapy, in non-GBM infantile brain tumors has been investigated.

METHODS

The paraffin blocks of non-GBM brain neoplasms of 36 infants (age < 24 months) who were operated on between 2006 and 2016 were examined for CMV-DNA, using real-time polymerase chain reaction (PCR). Paraffin blocks of CMV infected lung tissue were used as positive control. Extraction and amplification of β2 microglobulin gene from each tumor tissue were carried as positive internal control. We also assayed 25 paraffin blocks of meningomyelocele for CMV DNA as negative tissue controls.

RESULTS

Histopathological diagnoses consisted of 13 glial/neuroglial tumors (36.1%), 8 ependymomas (22.2%), 7 medulloblastomas (19.4%), 3 choroid plexus tumors (8.3%), 2 atypical teratoid rhabdoid tumors (5.6%), 2 embryonal CNS tumors (5.6%), and 1 germ cell tumor (2.8%). We could not detect CMV DNA in all samples examined.

CONCLUSION

Although CMV may be associated with GBM, no role could be proposed for this virus in development of non-GBM infantile brain tumors. Further investigations on larger series of brain tumors should be conducted to confirm or rule out our conclusion.

Less renal allograft fibrosis with valganciclovir prophylaxis for cytomegalovirus compared to high-dose valacyclovir: a parallel group, open-label, randomized controlled trial

BACKGROUND

Cytomegalovirus (CMV) prophylaxis may prevent CMV indirect effects in renal transplant recipients. This study aimed to compare the efficacy of valganciclovir and valacyclovir prophylaxis for CMV after renal transplantation with the focus on chronic histologic damage within the graft.

METHODS

From November 2007 through April 2012, adult renal transplant recipients were randomized, in an open-label, single-center study, at a 1:1 ratio to 3-month prophylaxis with valganciclovir (n = 60) or valacyclovir (n = 59). The primary endpoint was moderate-to-severe interstitial fibrosis and tubular atrophy assessed by protocol biopsy at 3 years evaluated by a single pathologist blinded to the study group. The analysis was conducted in an intention-to-treat population.

RESULTS

Among the 101 patients who had a protocol biopsy specimen available, the risk of moderate-to-severe interstitial fibrosis and tubular atrophy was significantly lower in those treated with valganciclovir (22% versus 34%; adjusted odds ratio, 0.31; 95% confidence interval, 0.11-0.90; P = 0.032 by multivariate logistic regression). The incidence of CMV disease (9% versus 2%; P = 0.115) and CMV DNAemia (36% versus 42%; P = 0.361) were not different at 3 years.

CONCLUSIONS

Valganciclovir prophylaxis, as compared with valacyclovir, was associated with a reduced risk of moderate-to-severe interstitial fibrosis and tubular atrophy in patients after renal transplantation.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ( ACTRN12610000016033 ). Registered on September 26, 2007.

Absence of interaction between porcine endogenous retrovirus and porcine cytomegalovirus in pig-to-baboon renal xenotransplantation in vivo

BACKGROUND

Studies of xenotransplantation from swine have identified porcine viruses as potential barriers to clinical trials. The biology of these viruses has not been extensively investigated in the in vivo xeno-environment. Enhancement of viral gene expression by viral and cellular factors acting in trans has been demonstrated for certain viruses, including bidirectional interactions between human herpesviruses and endogenous (HERV) and exogenous (HIV) retroviruses. Both porcine cytomegalovirus (PCMV) and porcine endogenous retrovirus (PERV) infections have been identified in xenografts from swine. PERV receptors exist on human cells with productive infection in vitro in permissive human target cell lines. PCMV is largely species-specific with infection restricted to the xenograft in pig-to-baboon transplants. It is unknown whether coinfection by PCMV affects the replication of PERV within xenograft tissues which might have implications for the risk of retroviral infection in the human host.

METHODS

A series of 11 functioning, life-supporting pig-to-baboon kidney xenografts from PERV-positive miniature swine were studied with and without PCMV co-infection. Frozen biopsy samples were analyzed using quantitative, real-time PCR with internal controls.

RESULTS

PERV replication was not altered in the presence of PCMV coinfection (P = .70). The absence of variation with coinfection was confirmed when PERV quantitation was expressed relative to simultaneous cellular GAPDH levels with or without PCMV coinfection (P = .59).

CONCLUSIONS

PCMV coinfection does not alter the replication of PERV in life-supporting renal xenotransplantation in vivo in baboons.

CMV-infected kidney grafts drive the expansion of blood-borne CMV-specific T cells restricted by shared class I HLA molecules via presentation on donor cells

We aimed to determine the role of cytomegalovirus (CMV)-infected donor cells in the development of a CMV-specific immune response in kidney transplant recipients. We assessed the CMV pp65-specific immune response by using interferon-ɣ ELISPOT and dextramers in peripheral blood mononuclear cells from 115 recipients (D+R- 31, D+R + 44, D-R + 40) late after transplantation (mean 59 ± 42 months). Receiving a kidney from a D+ donor resulted in a higher number of IFN-ɣ-producing anti-CMV T cells (P = .004). This effect disappeared with the absence of shared HLA class I specificities between donors and recipients (P = .430). To confirm the role of donor cells in stimulating the expansion of newly developed CMV-specific CD8⁺ T cells after transplantation, we compared the number of HLA-A2-restricted CMV-specific CD8⁺ T cells in primo-infected recipients who received an HLA-A2 or non-HLA-A2 graft. The median of anti-CMV pp65 T cells restricted by HLA-A2 was very low for patients who received a non-HLA-A2 graft vs an HLA-A2 graft (300 [0-14638] vs. 17972 [222-85594] anti-CMV pp65 CD8⁺ T cells/million CD8⁺ T cells, P = .001). This adds new evidence that CMV-infected kidney donor cells present CMV peptides and drive an inflation of memory CMV-specific CD8⁺ T cells, likely because of frequent CMV replications within the graft.

High prevalence of cytomegalovirus infection in surgical intestinal specimens from infants with necrotizing enterocolitis and spontaneous intestinal perforation: A retrospective observational study

BACKGROUND

Necrotizing enterocolitis (NEC) is a severe, often fatal gastrointestinal emergency that predominantly affects preterm infants, and there is evidence that neonatal cytomegalovirus (CMV) infection may in some cases contribute to its pathogenesis.

OBJECTIVES

This study aimed to evaluate the prevalence of CMV in infants with NEC.

STUDY DESIGN

Seventy intestinal specimens from 61 infants with NEC, spontaneous intestinal perforation (SIP), or related surgical complications were collected at Karolinska University Hospital and Uppsala University Hospital, Sweden. Ten specimens from autopsied infants without bowel disease served as controls. Samples were analyzed for CMV immediate-early antigen (IEA), CMV late antigen (LA), 5-lipoxigenase (5LO) and CMV-DNA by immunohistochemistry (IHC) and in situ hybridization (ISH), respectively. In 10 index samples, CMV DNA was analyzed with Taqman PCR after laser capture microdissection (LCM) of cells positive for CMV IEA by IHC.

RESULTS

CMV IEA was detected by IHC in 57 (81%) and CMV LA in 45 (64%) of 70 intestinal specimens from index cases; 2 (20%) of 10 control specimens were positive for both antigens. 5LO was detected in intestinal tissue section obtained from all examined index and controls. CMV DNA was detected in 4 of 10 samples (40%) after LCM. By ISH, all 13 IHC-IEA-positive samples were positive for CMV DNA; however, 3 of 5 IHC-IEA-negative samples (60%) were also positive.

CONCLUSIONS

CMV-specific antigens and CMV DNA were highly prevalent in intestinal specimens from infants with NEC, SIP, and related surgical complications. Our findings provide further evidence that neonatal CMV infection contributes to the pathogenesis of these diseases and may affect patient outcome.

Relationship Among Viremia/Viral Infection, Alloimmunity, and Nutritional Parameters in the First Year After Pediatric Kidney Transplantation

The Immune Development in Pediatric Transplantation (IMPACT) study was conducted to evaluate relationships among alloimmunity, protective immunity, immune development, physical parameters, and clinical outcome in children undergoing kidney transplantation. We prospectively evaluated biopsy-proven acute rejection (BPAR), de novo donor-specific antibody (dnDSA) formation, viremia, viral infection, T cell immunophenotyping, and body mass index (BMI)/weight Z scores in the first year posttransplantation in 106 pediatric kidney transplant recipients. Outcomes were excellent with no deaths and 98% graft survival. Rejection and dnDSAs occurred in 24% and 22%, respectively. Pretransplant cytomegalovirus (CMV) and Epstein-Barr virus (EBV) serologies and subsequent viremia were unrelated to BPAR or dnDSA. Viremia occurred in 73% of children (EBV, 34%; CMV, 23%; BMK viremia, 23%; and JC virus, 21%). Memory lymphocyte phenotype at baseline was not predictive of alloimmune complications. Patients who developed viral infection had lower weight (-2.1) (p = 0.028) and BMI (-1.2) (p = 0.048) Z scores at transplantation. The weight difference persisted to 12 months compared with patients without infection (p = 0.038). These data indicate that there is a high prevalence of viral disease after pediatric kidney transplantation, and underweight status at transplantation appears to be a risk factor for subsequent viral infection. The occurrence of viremia/viral infection is not associated with alloimmune events.

Transplant Infectious Diseases: A Review of the Scientific Registry of Transplant Recipients Published Data

The Scientific Registry of Transplant Recipients (SRTR) serves to collect data on organ transplants performed in the United States. Although the infectious diseases data are limited and include mostly pretransplant serologies and other nonspecific infection-related outcomes, this multicenter data collection allows for insightful national data and the ability to monitor trends over time. We reviewed the published concise reports for each organ type in SRTR reports containing data from 2005 to 2014, and summarized our findings with respect to cytomegalovirus (CMV), Epstein-Barr virus, posttransplant lymphoproliferative disorder (PTLD), hepatitis B virus (HBV), hepatitis C virus (HCV), HIV, general infection, and prophylaxis. Our review highlights a few developments. While rates of donor-recipient CMV serology combinations remain fairly constant over time, there are generally more seronegative donors and recipients among living donor transplants. There has been a reduction in PTLD for pediatric transplant recipients. There has also been a slight reduction in anti-HBV core antibody-positive donor organs and stable reporting of HCV-positive donor organs and HIV-positive recipients.

Human Cytomegalovirus-Encoded Receptor US28 Is Expressed in Renal Allografts and Facilitates Viral Spreading In Vitro

BACKGROUND

Renal transplantation is the preferred treatment for patients with end-stage renal disease. Human cytomegalovirus (HCMV) activation is associated with decreased renal graft function and survival. Human cytomegalovirus encodes several immune modulatory proteins, including the G protein-coupled receptor US28, which scavenges human chemokines and modulates intracellular signaling.

METHODS

Our aim was to identify the expression and localization of US28 in renal allograft biopsies by immunohistochemistry and determine its role in viral spreading in vitro.

RESULTS

Immunohistochemistry revealed US28 in 31 of 34 renal transplant biopsies from HCMV-seropositive donors. Expression was independent of HCMV viremia or IgG serostatus. US28 was predominantly expressed in the cytoplasm of vascular smooth muscle cells (VSMCs) and tubular epithelial cells, with a median positivity of 20% and 40%, respectively. Also, US28-positive cells were present within arterial neointima. In contrast to US28, HCMV-encoded immediate early antigen was detected in less than 5% of VSMCs, tubular epithelial cells, interstitial endothelium, interstitial inflammatory infiltrates, and glomerular cells.Primary VSMCs were infected with green fluorescent protein-tagged wild type or US28-deficient HCMV. The viral spreading of US28-deficient HCMV, via culture medium or cell-to-cell transmission, was significantly impeded as shown by green fluorescent protein (ie, infected) cell quantification and quantitative real-time polymerase chain reaction. Additionally, the number and size of foci was smaller.

CONCLUSIONS

In summary, HCMV-encoded US28 was detected in renal allografts from HCMV-positive donors independent of viremia and serostatus. Also, US28 facilitates HCMV spreading in VSMCs in vitro. Because the vasculature is affected in chronic renal transplant dysfunction, US28 may provide a potential target for therapeutic intervention.

Immunomodulation by hyperimmunoglobulins after solid organ transplantation: Beyond prevention of viral infection

Hyperimmunoglobulins are pharmaceutical formulations of human IgG which contain high titers of antibodies against specific viruses. They have been successfully used in solid organ transplantation (SOT) to prevent Cytomegalovirus (CMV) and Hepatitis B Virus (HBV) infection. The introduction of effective and cheaper antiviral drugs has resulted in decreasing usage of hyperimmunoglobulins in SOT. However, it may still be attractive to combine antiviral drug therapy with hyperimmunoglobulins after SOT, as there is some evidence that hyperimmunoglobulins, similar to high doses of intravenous immunoglobulins (IVIgs), might exert anti-inflammatory activity and thereby prevent immunological graft damage and improve graft and patient survival. In this review we discuss the existing clinical evidence for beneficial anti-inflammatory effects of hyperimmunoglobulins after cardiac, lung, kidney, and liver transplantation. Only a limited number of studies have addressed this issue, and these studies often included small patient cohorts and showed considerable variations in the type, intensity and duration of treatment regimens. Due to these limitations, it is difficult to draw firm conclusions. Retrospective studies consistently demonstrated that addition of CMV hyperimmunoglobulin (CMV-Ig) to antiviral drug prophylaxis after lung transplantation is associated with reduced rates of CMV disease and bronchiolitis obliterans syndrome (BOS), and improved patient survival. The doses of CMV-Ig administered after SOT are much lower than the minimal effective dose of IVIg used for anti-inflammatory therapy in auto-immune diseases. Therefore, it is questionable whether the reduced incidence of BOS is the result of 'direct' anti-inflammatory effects of CMV-Ig or is caused by a reduction of CMV infection, which is a risk factor for BOS. No or very limited evidence for better prevention of immunological graft damage by anti-CMV combination therapy is available for heart, kidney and liver transplant patients. In liver transplantation published evidence suggests that the high-doses of Hepatitis B virus hyperimmunoglobulin (HBIg) administered to prevent HBV-infection may reduce the risk of acute rejection, while combination therapy of HBIg and antiviral drugs in HBV-infected patients is consistently associated with better graft and patient survival compared to antiviral monotherapy. Well-designed prospective randomized studies with larger patient cohorts are needed to substantiate the current limited evidence for anti-inflammatory benefits of hyperimmunoglobulins besides prevention of CMV and HBV infection after SOT.

Polymorphism in programmed cell death 1 gene is strongly associated with lung and kidney allograft survival in recipients from CMV-positive donors

BACKGROUND

Cytomegalovirus (CMV) has a role in chronic rejection and graft loss in kidney transplant (KTx) and lung transplant (LTx) recipients. In addition, donor CMV seropositivity is an independent risk factor for renal graft loss. The anti-CMV response might modulate this risk. Expression of programmed cell death 1 (PD-1), a receptor involved in viral-specific T-cell exhaustion, is influenced by a single nucleotide polymorphism called PD-1.3 (wild-type allele G, variant allele A).

METHODS

We performed a retrospective study to assess the impact of PD-1.3 on graft outcome in donor CMV seropositive (D+) and donor CMV seronegative (D-) KTx and LTx. We also performed a case-control study to evaluate the anti-CMVpp65 response according to genotype.

RESULTS

PD-1.3 was determined in 1,119 KTx and 181 LTx. In 481 D+ KTx, A allele carriers (24%) experienced significantly less graft failure compared with GG carriers (p = 0.001). Multivariate analysis showed that this association was independent of donor and recipient age, acute rejection episodes, and number of human leukocyte antigen mismatches (hazard ratio, 0.381; 95% confidence interval, 0.209-0.696; p = 0.002). Analysis in 85 D+ LTx showed similar results: A allele carriers had better survival (hazard ratio, 0.302; 95% confidence interval, 0.128-0.716; p = 0.006) and greater 6-month forced expiratory volume (71% ± 17% vs 54% ± 16%, p = 0.001). In D- recipients, PD-1.3 did not affect KTx or LTx outcome. Finally, AA recipients had a stronger anti-CMVpp65 T-cell response than matched GG recipients (p = 0.003).

CONCLUSIONS

The A variant allele in PD-1.3 single nucleotide polymorphism improved graft survival in kidney and lung transplant recipients receiving grafts from CMV-positive donors.

The Microbiome, Systemic Immune Function, and Allotransplantation

Diverse effects of the microbiome on solid organ transplantation are beginning to be recognized. In allograft recipients, microbial networks are disrupted by immunosuppression, nosocomial and community-based infectious exposures, antimicrobial therapies, surgery, and immune processes. Shifting microbial patterns, including acute infectious exposures, have dynamic and reciprocal interactions with local and systemic immune systems. Both individual microbial species and microbial networks have central roles in the induction and control of innate and adaptive immune responses, in graft rejection, and in ischemia-reperfusion injury. Understanding the diverse interactions between the microbiome and the immune system of allograft recipients may facilitate clinical management in the future.

The Cell Biology of Cytomegalovirus: Implications for Transplantation

Interpretation of clinical data regarding the impact of cytomegalovirus (CMV) infection on allograft function is complicated by the diversity of viral strains and substantial variability of cellular receptors and viral gene expression in different tissues. Variation also exists in nonspecific (monocytes and dendritic cells) and specific (NK cells, antibodies) responses that augment T cell antiviral activities. Innate immune signaling pathways and expanded pools of memory NK cells and γδ T cells also serve to amplify host responses to infection. The clinical impact of specific memory T cell anti-CMV responses that cross-react with graft antigens and alloantigens is uncertain but appears to contribute to graft injury and to the abrogation of allograft tolerance. These responses are modified by diverse immunosuppressive regimens and by underlying host immune deficits. The impact of CMV infection on the transplant recipient reflects cellular changes and corresponding host responses, the convergence of which has been termed the "indirect effects" of CMV infection. Future studies will clarify interactions between CMV infection and allograft injury and will guide interventions that may enhance clinical outcomes in transplantation.

Cytomegalovirus driven immunosenescence-An immune phenotype with or without clinical impact?

The continuous emerging increase in life span has led to vulnerability to a number of different diseases in the elderly. Some of these risks may be attributed to specific changes in the immune system referred to as immunoscenescence. This term aims to describe decreased immune functions among elderly individuals, and is characterized to be harmful age-associated changes in the immune system that lead to its gradual immune dysfunction. An impaired function of the immune system may increase susceptibility to various diseases in the elderly population such as infections, cardiovascular diseases and cancer. Although it is unclear how this immune phenotype develops, emerging evidence suggest that it may reflect an exhaustion of the immune system, possibly caused by one or several chronic infections. The main candidate is human cytomegalovirus (CMV), which can induce immune dysfunctions observed in immunoscenescence. Although the immune system is currently considered to be exhausted in CMV positive elderly individuals, it is not known whether such dysfunction of the immune system is a main reason for increased susceptibility to other diseases, or if direct effects of the virus in disease pathogenesis reflect the increased vulnerability to them. These aspects will be discussed in this review.

Impact of Everolimus and Low-Dose Cyclosporin on Cytomegalovirus Replication and Disease in Pediatric Renal Transplantation

In order to investigate the hypothesis that the mammalian target of rapamycin inhibitor everolimus (EVR) shows anticytomegalovirus (CMV) activity in pediatric patients, we analyzed the impact of EVR-based immunosuppressive therapy on CMV replication and disease in a large cohort (n = 301) of pediatric kidney allograft recipients. The EVR cohort (n = 59), who also received low-dose cyclosporin, was compared with a control cohort (n = 242), who was administered standard-dose cyclosporin or tacrolimus and an antimetabolite, mostly mycophenolate mofetil (91.7%). Multivariate analysis revealed an 83% lower risk of CMV replication in the EVR cohort than in the control cohort (p = 0.005). In CMV high-risk (donor+/recipient-) patients (n = 88), the EVR-based regimen was associated with a significantly lower rate of CMV disease (0% vs. 14.3%, p = 0.046) than the standard regimen. In patients who had received chemoprophylaxis with (val-)ganciclovir (n = 63), the CMV-free survival rates at 1 year and 3 years posttransplant (100%) were significantly (p = 0.015) higher in the EVR cohort (n = 15) than in the control cohort (n = 48; 1 year, 75.0%; 3 years, 63.3%). Our data suggest that in pediatric patients at high risk of CMV, an EVR-based immunosuppressive regimen is associated with a lower risk of CMV disease than a standard-dose calcineurin inhibitor-based regimen.

[Morphological diagnosis of viral damage to a kidney transplant]

Due to the development of organ transplantation and its accompanying immunosuppression, recent years have been marked by the higher incidence of opportunistic viral infections that are of considerable importance among posttransplantation complications. A variety of viral infections, the possibility of their concomitant or subtle course, and the ability to cause life-threatening complications in recipients make relevant the description of existing diagnostic methods. The article summarizes the data available in the literature on the etiology, clinical symptoms, and morphological manifestations of viral infections, such as polyomaviruses, adenoviruses, herpesviruses, including HSV-1, HSV-2, cytomegalovirus (CMV), and Epstein-Barr virus. It describes the principles of differential diagnosis of kidney transplant damage caused by these viruses and that with acute cellular and humoral rejection, which plays an important role due to opposite approaches to treating these diseases.

Human Cytomegalovirus Up-Regulates Endothelin Receptor Type B: Implication for Vasculopathies?

Background. Both endothelin receptor type B ([ET_BR], a G protein-coupled receptor that mediates the vascular effects of the potent vasoconstrictor endothelin-1) and human cytomegalovirus ([HCMV], a ubiquitous herpesvirus) have been implicated in the pathogenesis of cardiovascular disease (CVD). The effects of HCMV infection on ET_BR expression are unknown. We hypothesized that HCMV may contribute to the pathogenesis of CVD via ET_BR modulation.

Methods. Human CMV effects on ET_BR were studied in vitro in endothelial cells (ECs) and smooth muscle cells (SMCs) and ex vivo in human carotid plaque tissue specimens. Expression of ET_BR and viral immediate-early were quantified using quantitative polymerase chain reaction. Functional consequences after ET_BR blockade in ECs were examined by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide proliferation, wound healing, tube formation, and flow adhesion assays.

Results. Human CMV is capable of upregulating both ET_BR mRNA and protein expression in ECs and SMCs. The ET_BR was also abundantly expressed in ECs, foam cells, and SMCs, and, more importantly, in HCMV-positive cells in human carotid plaques. Endothelin receptor type B blockade led to decreased proliferation and reduced tumor necrosis factor α-mediated leukocyte recruitment in both uninfected and HCMV-infected ECs. Direct HCMV infection was antimigratory and antiangiogenic in ECs.

Conclusions. Human CMV may contribute to CVD via ET_BR induction.

The Impact of Infection on Chronic Allograft Dysfunction and Allograft Survival After Solid Organ Transplantation

Infectious diseases after solid organ transplantation (SOT) are a significant cause of morbidity and reduced allograft and patient survival; however, the influence of infection on the development of chronic allograft dysfunction has not been completely delineated. Some viral infections appear to affect allograft function by both inducing direct tissue damage and immunologically related injury, including acute rejection. In particular, this has been observed for cytomegalovirus (CMV) infection in all SOT recipients and for BK virus infection in kidney transplant recipients, for community-acquired respiratory viruses in lung transplant recipients, and for hepatitis C virus in liver transplant recipients. The impact of bacterial and fungal infections is less clear, but bacterial urinary tract infections and respiratory tract colonization by Pseudomonas aeruginosa and Aspergillus spp appear to be correlated with higher rates of chronic allograft dysfunction in kidney and lung transplant recipients, respectively. Evidence supports the beneficial effects of the use of antiviral prophylaxis for CMV in improving allograft function and survival in SOT recipients. Nevertheless, there is still a need for prospective interventional trials assessing the potential effects of preventive and therapeutic strategies against bacterial and fungal infection for reducing or delaying the development of chronic allograft dysfunction.

Cytomegalovirus in human brain tumors: Role in pathogenesis and potential treatment options

During the last years increasing evidence implies that human cytomegalovirus (CMV) can be attributed to human malignancies arising from numerous tissues. In this perspective, we will review and discuss the potential mechanisms through which CMV infection may contribute to brain tumors by affecting tumor cell initiation, progression and metastasis formation. Recent evidence also suggests that anti-CMV treatment results in impaired tumor growth of CMV positive xenografts in animal models and potentially increased survival in CMV positive glioblastoma patients. Based on these observations and the high tumor promoting capacity of this virus, the classical and novel antiviral therapies against CMV should be revisited as they may represent a great promise for halting tumor progression and lower cancer deaths.

Direct and Indirect Effects of Cytomegalovirus-Induced γδ T Cells after Kidney Transplantation

Despite effective anti-viral therapies, cytomegalovirus (CMV) is still associated with direct (CMV disease) and indirect effects (rejection and poor graft survival) in kidney transplant recipients. Recently, an unconventional T cell population (collectively designated as Vδ2^neg γδ T cells) has been characterized during the anti-CMV immune response in all solid-organ and bone-marrow transplant recipients, neonates, and healthy people. These CMV-induced Vδ2^neg γδ T cells undergo a dramatic and stable expansion after CMV infection, in a conventional “adaptive” manner. Similarly, as CMV-specific CD8+ αβ T cells, they exhibit an effector/memory TEMRA phenotype and cytotoxic effector functions. Activation of Vδ2^neg γδ T cells by CMV-infected cells involves the γδ T cell receptor (TCR) and still ill-defined co-stimulatory molecules such as LFA-1. A multiple of Vδ2^neg γδ TCR ligands are apparently recognized on CMV-infected cells, the first one identified being the major histocompatibility complex-related molecule endothelial protein C receptor. A singularity of CMV-induced Vδ2^neg γδ T cells is to acquire CD16 expression and to exert an antibody-dependent cell-mediated inhibition on CMV replication, which is controlled by a specific cytokine microenvironment. Beyond the well-demonstrated direct anti-CMV effect of Vδ2^neg γδ T cells, unexpected indirect effects of these cells have been also observed in the context of kidney transplantation. CMV-induced Vδ2^neg γδ T cells have been involved in surveillance of malignancy subsequent to long-term immunosuppression. Moreover, CMV-induced CD16+ γδ T cells are cell effectors of antibody-mediated rejection of kidney transplants, and represent a new physiopathological contribution to the well-known association between CMV infection and poor graft survival. All these basic and clinical studies paved the road to the development of a future γδ T cell-based immunotherapy. In the meantime, γδ T cell monitoring should prove a valuable immunological biomarker in the management of CMV infection.

Randomized trial of valganciclovir versus valacyclovir prophylaxis for prevention of cytomegalovirus in renal transplantation

BACKGROUND AND OBJECTIVES

Both valganciclovir and high-dose valacyclovir are recommended for cytomegalovirus prophylaxis after renal transplantation. A head-to-head comparison of both regimens is lacking. The objective of the study was to compare valacyclovir prophylaxis with valganciclovir, which constituted the control group.

DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS

In a randomized, open-label, single-center trial, recipients of renal transplants (recipient or donor cytomegalovirus-seropositive) were randomly allocated (1:1) to 3-month prophylaxis with valacyclovir (2 g four times daily) or valganciclovir (900 mg daily). Enrollment occurred from November of 2007 to April of 2012. The primary end points were cytomegalovirus DNAemia and biopsy-proven acute rejection at 12 months. Analysis was by intention to treat.

RESULTS

In total, 119 patients were assigned to valacyclovir (n=59) or valganciclovir prophylaxis (n=60). Cytomegalovirus DNAemia developed in 24 (43%) of 59 patients in the valacyclovir group and 18 (31%) of 60 patients in the valganciclovir group (adjusted hazard ratio, 1.35; 95% confidence interval, 0.71 to 2.54; P=0.36). The incidence of cytomegalovirus disease was 2% with valacyclovir and 5% with valganciclovir prophylaxis (adjusted hazard ratio, 0.21; 95% confidence interval, 0.01 to 5.90; P=0.36). Significantly more patients with valacyclovir prophylaxis developed biopsy-proven acute rejection (18 of 59 [31%] versus 10 of 60 [17%]; adjusted hazard ratio, 2.49; 95% confidence interval, 1.09 to 5.65; P=0.03). The incidence of polyomavirus viremia was higher in the valganciclovir group (18% versus 36%; adjusted hazard ratio, 0.43; 95% confidence interval, 0.19 to 0.96; P=0.04).

CONCLUSIONS

Valganciclovir shows no superior efficacy in cytomegalovirus DNAemia prevention compared with valacyclovir prophylaxis. However, the risk of biopsy-proven acute rejection is higher with valacyclovir.

Porcine cytomegalovirus infection is associated with early rejection of kidney grafts in a pig to baboon xenotransplantation model

BACKGROUND

Recent survivals of our pig-to-baboon kidney xenotransplants have been markedly shorter than the graft survivals we previously reported. The discovery of high levels of porcine cytomegalovirus (pCMV) in one of the rejected xenografts led us to evaluate whether this reduction in graft survival might be because of the inadvertent introduction of pCMV into our α1,3-galactosyltransferase gene knockout swine herd.

METHODS

Archived frozen sections of xeno-kidney grafts over the past 10 years were analyzed for the presence of pCMV, using real-time polymerase chain reaction. Three prospective pig-to-baboon renal transplants using kidneys from swine delivered by cesarean section (C-section) and raised in isolation were likewise analyzed.

RESULTS

Kidney grafts, from which 8 of the 18 archived samples were derived were found to be pCMV-negative, showed a mean graft survival of 48.3 days and were from transplants performed before 2008. None showed signs of disseminated intravascular coagulopathy and were lost because of proteinuria or infectious complications. In contrast, 10 of the archived samples were pCMV positive, were from kidney transplants with a mean graft survival of 14.1 days, had been performed after 2008, and demonstrated early vascular changes and decreased platelet counts. Three prospective xenografts from swine delivered by C-section were pCMV negative and survived an average of 53.0 days.

CONCLUSIONS

Decreased survivals of α1,3-galactosyltransferase gene knockout renal xenografts in this laboratory correlate temporally with latent pCMV in the donor animals and pCMV in the rejected xeno-kidneys. Transmission of pCMV to swine offspring may be avoided by C-section delivery and scrupulous isolation of donor animals.

Results of life-supporting galactosyltransferase knockout kidneys in cynomolgus monkeys using two different sources of galactosyltransferase knockout Swine

BACKGROUND

Various durations of survival have been observed in the xenotransplantation of life-supporting α-1,3-galactosyltransferase knockout (GalT-KO) porcine kidneys into nonhuman primates. Although others have demonstrated loss of GalT-KO-transplanted kidneys within 2 weeks, we have reported an average survival of 51 days with the cotransplantation of the kidney and vascularized thymus and an average of 29 days with the kidney alone. To determine the factors responsible for this difference in survival time, we performed xenogeneic kidney transplantations into cynomolgus monkeys with an anti-CD40L-based regimen using two different strains of GalT-KO swine, one derived from MGH miniature swine and the other obtained from Meji University.

MATERIALS AND METHODS

Eight cynomolgus moneys received GalT-KO kidneys. Three kidney grafts were from Massachusetts General Hospital (MGH)-Nippon Institute for Biological Science (NIBS) GalT-KO pigs and five GalT-KO grafts were from MEIJI GalT-KO swine. All cynomolgus recipients were treated identically.

RESULTS

Recipients of kidneys from the MGH GalT-KO kidneys swine, produced by nuclear transfer in Japan, survived an average of 28.7 days, whereas recipients of MEIJI GalT-KO kidneys swine survived an average of 9.2 days. Among the differences between these two groups, one potentially revealing disparity was that the MEIJI swine were positive for porcine cytomegalovirus, whereas the MGH-derived swine were negative.

CONCLUSION

This is the first study comparing renal xenotransplantation from two different sources of GalT-KO swine into nonhuman primates at a single center. The results demonstrate that porcine cytomegalovirus may be responsible for early loss of GalT-KO swine kidney xenografts.

The efficacy and cost-effectiveness of valacyclovir in cytomegalovirus prevention in solid organ transplantation

Prevention of cytomegalovirus infection using antiviral prophylaxis or the pre-emptive therapy approach is an integral part of management of patients after solid organ transplantation. Regarding renal transplantation, valacyclovir is currently the only antiviral agent recommended for prophylaxis as an alternative to valganciclovir. This review article discusses studies documenting the efficacy and safety of valacyclovir prophylaxis as well as those comparing valacyclovir with other prophylactic regimens or with pre-emptive therapy. Also addressed are the economic aspects supporting the cost-effectiveness of valacyclovir prophylaxis and demonstrating lower costs compared with other cytomegalovirus preventive strategies.

Human cytomegalovirus inhibits erythropoietin production

Anemia is a feature of CKD and a complication of renal transplantation, often caused by impaired production of erythropoietin. The kidney is a target organ for human cytomegalovirus (hCMV) in such patients, but it is not known whether hCMV effects erythropoietin production. We found that kidneys from patients with CKD were positive for hCMV protein and that blood levels of hCMV IgG inversely correlated with red blood cell count. In mice, systemic murine cytomegalovirus infection decreased serum erythropoietin levels. In human erythropoietin-producing cells, hCMV inhibited hypoxia-induced expression of erythropoietin mRNA and protein. hCMV early gene expression was responsible, as ultraviolet-inactivated virus had no effect and valganciclovir treatment showed that late gene expression was nonessential. Hypoxia-induced gene transcription is controlled by the transcription factors hypoxia-inducible transcription factor (HIF)-1α and HIF2α, which are constitutively produced but stable only under low oxygen conditions. We found that hCMV inhibited constitutive production of HIF2α mRNA. HIF2α is thought to be the master regulator of erythropoietin transcription. Single-cell analysis revealed that nuclear accumulation of HIF2α was inhibited in hCMV-infected cells, and the extent of inhibition correlated with hCMV protein expression. Our findings suggest that renal hCMV infection could induce or exacerbate anemia in patients.

High prevalence of human cytomegalovirus in carotid atherosclerotic plaques obtained from Russian patients undergoing carotid endarterectomy

Background

Human cytomegalovirus (HCMV) infection is associated with cardiovascular disease (CVD) but the role of this virus in CVD progression remains unclear. We aimed to examine the HCMV serostatus in Russian patients (n = 90) who had undergone carotid endarterectomy (CEA) and controls (n = 82) as well as to determine the prevalence of HCMV immediate early (IE) and late (LA) antigens in carotid atherosclerotic plaques obtained from 89 patients. In addition, we sought to determine whether HCMV infection was associated with inflammatory activity in the plaque by quantifying infiltrating CD3 and CD68 positive cells and 5-LO immunoreactivity.

Methods

HCMV serology was assessed with ELISA and immunohistochemistry staining was performed to detect HCMV antigens, CD3, CD68 and 5-LO reactivity. The Fisher’s exact test was used to compare i) seroprevalence of HCMV IgG between patients and controls and ii) HCMV-positive or –negative to that of CD3, CD68 and 5-LO immunoreactive cells in plaque samples. The student-t test was performed to connote the significance level of mean optical density between patients and controls.

Results

The seroprevalence for HCMV IgG was high in both patients and controls (99% and 98%, respectively). Controls had significantly higher IgG titers for HCMV compared with patients (p = 0.0148). Strikingly, we found a high prevalence of HCMV antigens in atherosclerotic plaques; 57/89 (64%) and 47/87 (54%) were HCMV IE and LA positive, respectively. Most plaques had rather low HCMV reactivity with distinct areas of HCMV-positive cells mainly detected in shoulder regions of the plaques, but also in the area adjacent to the necrotic core and fibrous cap. In plaques, the cellular targets for HCMV infection appeared to be mainly macrophages/foam cells and smooth muscle cells. HCMV-positive plaques trended to be associated with increased numbers of CD68 positive macrophages and CD3 positive T cells, while 5-LO reactivity was high in both HCMV-positive and HCMV-negative plaques.

Conclusions

In Russian patients undergoing CEA, HCMV proteins are abundantly expressed in carotid plaques and may contribute to the inflammatory response in plaques via enhanced infiltration of CD68 and CD3 cells.

A four-year pathology review of the near total face transplant

In December of 2008, our institution performed a near total face transplant. The patient was monitored for signs of rejection assessed by paired skin and mucosa biopsies. The results of histological review of 120 biopsies collected during the first 4 years posttransplant are discussed. All biopsies were stained with hematoxylin and eosin, periodic acid-Schiff, immunohistochemical and TUNEL assays and graded using the Banff 2007 classification. Grade III rejection was diagnosed clinically at weeks 45 and 66, posttransplant; week 45 was determined as folliculitis while the erythema episode at week 66 confirmed an acute rejection (AR) that required hospitalization. The mucosa frequently showed interface inflammation without clinical signs of rejection and was not present in skin biopsies. In all, 34 of the 45 mucosal biopsies (75%) showed these interface changes. Clinical symptoms concurred with skin pathology in two grade III rejections. The mucosa showed histologic signs of rejection more frequently, which may indicate: increased mucosal sensitivity to rejection, a different type or subtype of AR that is specific to the mucosa, or a nonspecific process such as a drug effect. With more data and world experience, the diagnosis of face transplant rejection will be better defined and the Banff classification enhanced.

Updated international consensus guidelines on the management of cytomegalovirus in solid-organ transplantation

Cytomegalovirus (CMV) continues to be one of the most common infections after solid-organ transplantation, resulting in significant morbidity, graft loss, and adverse outcomes. Management of CMV varies considerably among transplant centers but has been become more standardized by publication of consensus guidelines by the Infectious Diseases Section of The Transplantation Society. An international panel of experts was reconvened in October 2012 to revise and expand evidence and expert opinion-based consensus guidelines on CMV management, including diagnostics, immunology, prevention, treatment, drug resistance, and pediatric issues. The following report summarizes the recommendations.

Neither pre-transplant rituximab nor splenectomy affects de novo HLA antibody production after renal transplantation

The long-term effect of rituximab and splenectomy on de novo HLA antibody production and chronic antibody-mediated rejection after renal transplantation is uncertain. In order to gain insight on this, we studied 92 ABO-incompatible and 228 ABO-identical/compatible consecutive renal transplant patients and determined their de novo HLA antibody production and graft outcome. Patients with pretransplant donor-specific antibodies had been excluded. ABO-incompatible transplants included 30 recipients treated with rituximab, 51 by splenectomy, or 11 with neither, due to low anti-A or -B antibody titer. Graft survival in ABO-identical/compatible patients (97.7% at 5 years) was significantly higher than in ABO-incompatible (87.0% at 5 years), rituximab (96.7% at 3 years), or splenectomy (85.7% at 5 years) patients. Only four patients had clinical chronic antibody-mediated rejection (two each identical/compatible and incompatible). There was no significant difference in prevalence of de novo HLA antibody, including donor-specific and nondonor-specific antibodies among ABO-identical/compatible patients (13.9%), patients receiving rituximab (14.3%) or splenectomy (13.2%), or among those receiving cyclosporine, tacrolimus, mycophenolate mofetil, mizoribine, and everolimus. Renal function remained stable in most recipients with de novo HLA antibody. Thus, neither pretransplant splenectomy nor rituximab treatment has an inhibitory effect on de novo HLA antibody production during medium-term follow-up. Further study on long-term effects is needed.

Vaccination against Streptococcus pneumoniae does not induce antibodies against HLA or MICA in clinically stable kidney transplant recipients

There are concerns in the community that immune activation after vaccination could lead to (subclinical) rejection. Our aim was to define if pneumococcal vaccination induced HLA antibodies using highly sensitive methods. Forty-nine kidney transplant recipients were immunized with Pneumovax 23. The median interval between transplantation and vaccination was 6.5 years, the median serum creatinine concentration 1.3, 1.3 and 1.4 mg/dL pre-vaccination, at month 1 and 15 post-vaccination, respectively. In none of the patients biopsy-proven acute rejection was diagnosed within three years post-vaccination. Pneumococcal, HLA class I and II and major histocompatibility class I-related chain A (MICA) antibodies were determined by Luminex™ technology (xMAP™ Pneumococcal Immunity Panel and LABScreen™ Mixed beads, respectively) and HLA antibodies also by ELISA (Lambda Antigen Tray™). While pneumococcal antibodies were significantly higher at month 1 and 15 post- vs. pre-vaccination (p<0.0001 each), HLA/MICA antibodies remained unchanged as determined by Luminex™ and ELISA. Positive Luminex™ reactions were present in 63%, 67% and 63% (HLA class I), 47%, 47% and 55% (HLA class II) and 29%, 29% and 29% (MICA) pre-vaccination, at month 1 and 15, respectively. In clinically stable kidney transplant recipients there is no evidence for an increase in HLA antibodies after pneumococcal vaccination.

Cytomegalovirus impairs the induction of indoleamine 2,3-dioxygenase mediated antimicrobial and immunoregulatory effects in human fibroblasts

Human fibroblasts provide immunosuppressive functions that are partly mediated by the tryptophan-catabolizing enzyme indoleamine-2,3-dioxygenase (IDO). Moreover, upon stimulation with inflammatory cytokines human fibroblasts exhibit broad-spectrum antimicrobial effector functions directed against various clinically relevant pathogens and these effects are also IDO-dependent. Therefore human fibroblasts are suggested to be involved in the control of immune reactions during infectious diseases. As human cytomegalovirus (HCMV) represents a pathogen frequently found in immunocompromised hosts and IDO is involved in the control of HCMV growth, we here investigated the impact of HCMV infection on IDO-mediated antimicrobial and immunoregulatory effects. We show that infection with HCMV substantially impairs IFN-γ-induced IDO-activity in human fibroblasts in a dose and time dependent fashion. Consequently, these cells are no longer able to restrict bacterial and parasitic growth and, furthermore, loose their IDO-mediated immunosuppressive capacity. Our results may have significant implications for the course of HCMV infection during solid organ transplantation: we suggest that loss of IDO-mediated antimicrobial and immunoregulatory functions during a HCMV infection might at least in part explain the enhanced risk of organ rejection and infections observed in patients with HCMV reactivation after solid organ transplantation.

CMV: Prevention, Diagnosis and Therapy

Cytomegalovirus (CMV) is the most common infection after organ transplantation and has a major impact on morbidity, mortality and graft survival. Optimal prevention, diagnosis and treatment of active CMV infection enhance transplant outcomes, and are the focus of this section. Methods to prevent CMV include universal prophylaxis and preemptive therapy; each has its merits, and will be compared and contrasted. Diagnostics have improved substantially in recent years, both in type and quality, allowing for more accurate and savvy treatment; advances in diagnostics include the development of an international standard, which should allow comparison of results across different methodologies, and assays for cellular immune function against CMV. Therapy primarily involves ganciclovir, now rendered more versatile by data suggesting oral therapy with valganciclovir is not inferior to intravenous therapy with ganciclovir. Treatment of resistant virus remains problematic, but is enhanced by the availability of multiple novel therapeutic agents.

Limited impact of cytomegalovirus infection in the long-term outcome of renal and liver transplant

BACKGROUND

The strength of the assumed association of CMV and long term deleterious events in solid organ transplant recipients (SOT) is controversial.

OBJECTIVES

The aim of the present study was to evaluate whether viral replication dynamics during CMV infection or CMV disease may correlate not only with graft dysfunction and survival, but also with other potentially related late events in a long-term followed cohort of kidney (KT) and liver (LT) transplant recipients.

STUDY DESIGN

162 SOT (104 kidney, 58 liver) at our institution (2003-2005) with survival over 180 days and a median follow-up of 71 months (9-86) were analyzed. Using a Cox proportional hazard model, CMV infection (including area under the curve of DNAemia[AUC]) and CMV disease in the first 180 days were evaluated as potential predictors of the following late events (>180 days): mortality, graft dysfunction (GD), graft loss (GL), cardiovascular events (CVE), malignant tumors (MT).

RESULTS

CMV infection occurred in 59% and CMV disease in 8%. Late death occurred in 17%, GD in 45.6%, GL in 14.2%, CVE in 10.5% and MT in 9.9%. We found no significant association between the intensity or duration of CMV viremia (AUC, persistent viremia or untreated CMV viremia) or CMV disease and the development of evaluated late events. According multivariate analysis neither CMV infection (hazard ratio [HR] 2.18 95% CI 0.949-5 p = 0.066) nor CMV disease (HR: 1.72; 95% CI 0.59-5 p = 0.31) were significantly correlated with late mortality.

CONCLUSIONS

Our data do not support that CMV infection or CMV disease contribute significantly to long-term deleterious events in SOT.

Dendritic cell biology in human cytomegalovirus infection and the clinical consequences for host immunity and pathology

Human cytomegalovirus (HCMV), a member of the herpesvirus family, establishes life-long persistence and latency after primary infection and can be reactivated later in life. In immunosuppressed patients, it is an important pathogen that can cause severe disease. HCMV is also thought to play a causative role in inflammatory diseases and cancer. The virus can infect different immune cells, including dendritic cells (DCs) and can take advantage of host immune functions to avoid immune recognition. These characteristics have sparked major interest in understanding HCMV and its interaction with immune cells and their relevance to disease pathogenesis. In this review, we focus on the complex host-pathogen relationship between HCMV and DCs, including the persistence of the virus in these cells, their function in the immune response to HCMV infection and the potential clinical consequences of HCMV infection in DCs.

[In vivo synaptic transmission in the smooth muscle cells of the guinea-pig vas deferens]

BACKGROUND: Brain metastases (BMs) develop by largely unknown mechanisms and cause major morbidity and mortality in patients with solid tumors. Human cytomegalovirus (HCMV) is frequently detected in tumor tissue from patients with different cancers. Here, we aimed to determine the prevalence and potential prognostic role of HCMV in BMs. METHODS: We obtained archived samples of BMs from 41 patients with breast cancer and 37 with colorectal cancer and paired primary tumor tissues from 13 and 12 patients in each respective group. In addition, primary breast cancer tissues from 15 patients were included. HCMV proteins were detected with an immunohistochemical technique and Western blot. HCMV nucleic acids were detected with TaqMan polymerase chain reaction (PCR) assay. RESULTS: HCMV proteins were abundantly expressed in 99% of BM specimens, and in 12 of 13 (92%) paired primary breast cancer specimens. All 12 paired colon cancer samples were positive for HCMV proteins. Protein staining was mainly confined to neoplastic cells. Western blot analysis detected an HCMV-IE reactive protein in 53% of breast cancer specimens, and PCR detected the presence of HCMV DNA and transcripts in 92% and 80% of samples, respectively. Patients with high-level expression of HCMV-IE proteins in their tumors had a shorter time to tumor progression and shorter overall survival. CONCLUSIONS: The prevalence of HCMV proteins and nucleic acids is very high in primary and metastatic tumors and may drive the development of metastatic brain tumors; therefore, this virus may represent a potential therapeutic target in metastatic cancer.