Beyond Cytomegalovirus and Epstein-Barr Virus: a Review of Viruses Composing the Blood Virome of Solid Organ Transplant and Hematopoietic Stem Cell Transplant Recipients.

Viral primary infections and reactivations are common complications in patients after solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) and are associated with high morbidity and mortality. Among these patients, viral infections are frequently associated with viremia. Beyond the usual well-known viruses that are part of the routine clinical management of transplant recipients, numerous other viral signatures or genomes can be identified in the blood of these patients. The identification of novel viral species and variants by metagenomic next-generation sequencing has opened up a new field of investigation and new paradigms. Thus, there is a need to thoroughly describe the state of knowledge in this field with a review of all viral infections that should be scrutinized in high-risk populations. Here, we review the eukaryotic DNA and RNA viruses identified in blood, plasma, or serum samples of pediatric and adult SOT/HSCT recipients and the prevalence of their detection, with a particular focus on recently identified viruses and those for which their potential association with disease remains to be investigated, such as members of the Polyomaviridae, Anelloviridae, Flaviviridae, and Astroviridae families. Current knowledge of the clinical significance of these viral infections with associated viremia among transplant recipients is also discussed. To ensure a comprehensive description in these two populations, individuals described as healthy (mostly blood donors) are considered for comparative purposes. The list of viruses that should be on the clinicians' radar is certainly incomplete and will expand, but the challenge is to identify those of possible clinical significance.

Graft γδ TCR Sequencing Identifies Public Clonotypes Associated with Hematopoietic Stem Cell Transplantation Efficacy in Acute Myeloid Leukemia Patients and Unravels Cytomegalovirus Impact on Repertoire Distribution.

Although the impact of donor graft composition on clinical outcomes after hematopoietic stem cell transplantation (HSCT) has been studied, little is known about the role of intragraft γδ TCR repertoire on clinical outcomes following HSCT. Using a high-throughput sequencing platform, we sought to analyze the TCR γ-chain (TRG) repertoire of γδ T cells within donor stem cell grafts and address its potential impact on clinical response in the corresponding patients. A total of 20 peripheral blood stem cell grafts were analyzed, and donors were classified as CMV+/- The respective acute myeloid leukemia recipients were followed for disease relapse and acute graft-versus-host disease (aGvHD) development post-HSCT. In all samples, TRG repertoire showed a reduced diversity and displayed overrepresented clones. This was more prominent in grafts from CMV+ donors, which presented a more private repertoire, lower diversity, skewed distribution, and reduced usage of the V9-JP pairing. Grafts given to nonrelapse patients presented a more public repertoire and increased presence of long sequence clonotypes. Variable-joining gene segment usage was not associated with aGvHD development, but a higher usage of V2-JP1 pairing and lower usage of V4-J2/V5-J2/V8-JP2 were observed in grafts given to nonrelapse patients. Our work identified five private overrepresented and one public CDR3 sequence (CATWDGPYYKKLF) associated with CMV infection, in addition to 12 highly frequent public sequences present exclusively in grafts given to nonrelapse patients. Our findings show that, despite CMV infection reshaping the TRG repertoire, TRG composition is not associated with aGvHD development, and several public sequences are associated with clinical remission.

Effect of different human tissue processing techniques on SARS-CoV-2 inactivation-review.

The safety of the tissue transplant recipient is a top priority for tissue banks, and the emergence of the new coronavirus SARS-CoV-2 has raised significant concerns about the risks of releasing tissue for clinical use. In the present study, we conducted a literature review about the potential infectivity of SARS-CoV-2 in different biological tissues and the influence of various tissue processing and sterilization procedures on viral inactivation. The search revealed that SARS-CoV-2 binds to the human angiotensin-converting enzyme receptor to penetrate human cells. These receptors are present in skin cells, musculoskeletal tissue, amniotic membranes, cardiovascular tissue and ocular tissues, including the cornea. In general, we found that coronaviruses are stable at low temperatures, and inactivated upon exposure to extreme heat and pH. Notably, gamma irradiation, which has already been employed to inactivate SARS and MERS, could be useful for sterilizing skin, amnion and musculoskeletal tissues against SARS-CoV-2. We conclude that due to the limited information about the effects of physical and chemical tissue processing methods on viral neutralization, rigorous donor screening is still essential for tissue transplant recipient safety.

Estimated impact of hepatitis C-positive lung donor utilization on US donor lung supply.

The availability of highly effective direct-acting antiviral agents (DAAs) for hepatitis C virus (HCV) infection has led to reports of safely transplanting HCV+ donor lungs into HCV- candidates. However, it remains unclear how the ability to use HCV+ donor lungs for lung transplant could affect the number of donor lungs available for transplant. Using Scientific Registry of Transplant Recipient data, we identified all deceased organ donors within the United States from March 1, 2015, to February 28, 2018, and stratified by HCV status. A donor prediction model for lung donation was derived and validated within HCV- donors and applied to HCV+ donors to estimate the number of acceptable HCV+ lung donors. Of 29 481 eligible donors, 2054 (7.0%) were HCV+ donors with 82 HCV+ donors' lungs being used for transplant during the study period. The prediction model for donor lung donation (specificity 92.6%, sensitivity 65.6%) estimated 248 HCV+ donors (75 nonviremic, 173 viremic) were acceptable for lung transplant during the study period, suggesting that 166 acceptable HCV+ lung donors were discarded. The ability to transplant lungs from HCV+ organ donors would lead to an estimated nationwide increase of at least 55 donor lungs per year, including 44 from HCV viremic donors.

Transplantation during the COVID-19 pandemic: nothing noble is accomplished without danger.

The global health crisis due to the fast spread of coronavirus disease (COVID-19) has caused major disruption in all aspects of healthcare. Transplantation is one of the most affected sectors, as it relies on a variety of services that have been drastically occupied to treat patients affected by COVID-19. With this report from two transplant centers in Italy, we aim to reflect on resource organization, organ allocation, virus testing and transplant service provision during the course of the pandemic and to provide actionable information highlighting advantages and drawbacks.To what extent can we preserve the noble purpose of transplantation in times of increased danger? Strategies to minimize risk exposure to the transplant population and health- workers include systematic virus screening, protection devices, social distancing and reduction of patients visits to the transplant center. While resources for the transplant activity are inevitably reduced, new dilemmas arise to the transplant community: further optimization of time constraints during organ retrievals and implantation, less organs and blood products donated, limited space in the intensive care unit and the duty to maintain safety and outcomes.

Risk factors of de novo hepatitis B virus infection in pediatric hepatitis B core antibody positive liver graft recipients under prophylactic therapy.

BACKGROUND AND AIM: We aim to investigate the risk factors of de novo hepatitis B virus (HBV) infection in pediatric liver transplantation recipients receiving hepatitis B core antibody positive grafts and to evaluate the efficacy of our prophylactic strategies. METHODS: One hundred thirty-nine pediatric recipients receiving hepatitis B core antibody positive grafts operated from September 2016 to September 2018 were retrospectively enrolled, and all the patients received prophylactic treatment to prevent de novo HBV infection. Donor and recipient features, operative information along with graft, and recipient outcomes were compared between recipients with or without de novo HBV infection. Univariate and multivariate analyses were applied to identify the risk factors of de novo HBV infection. RESULTS: The mean follow-up time was 23.5 ± 15.7 months, and the overall incidence of de novo HBV infection was 3.6%. Recipients with de novo HBV infection showed equal graft and recipient outcome compared with the recipients without de novo HBV infection during the follow-up time. Recipient preoperative hepatitis B surface antibody titer of < 1000 IU/L (odds ratio [OR] = 9.652, P = 0.024), graft HBV DNA of > 1000 copies (OR = 9.050, P = 0.032), and intraoperative fresh-frozen plasma transfusion of > 400 mL (OR = 10.462, P = 0.023) were identified as independent risk factors for de novo HBV infection. CONCLUSION: Hepatitis B core antibody positive grafts can safely be used in pediatric liver transplantation under rational prophylactic therapy.

Evaluating for Human Herpesvirus 6 in the Liver Explants of Children With Liver Failure of Unknown Etiology.

BACKGROUND: Liver failure of unknown etiology (LFUE) has a transplant-free survival rate <25%. Human herpesvirus 6 (HHV-6) may be associated with LFUE, but studies are limited by small sample size. METHODS: We identified all children who underwent liver transplant for LFUE at a single quaternary children's hospital; 51/65 cases could be age matched with controls (children who underwent liver transplant for metabolic liver disease). Quantitative polymerase chain reaction for HHV-6 was performed on DNA from formalin-fixed paraffin-embedded liver explant tissue. RESULTS: HHV-6 was detected in 34/51 cases (66.7%) and 19/51 controls (37.3%) (P = .005). Average HHV-6 viral load was 213207 copies/106 cells in positive cases (range: 7293-1102030) and 38115 copies/106 cells in positive controls (range: 1382-122375) (P = .0008). HHV-6 was present significantly more often in cases compared to controls in patients younger than 6 years. In particular, in patients younger than 3 years, HHV-6 was present in 13/27 cases (48.1%) and 2/27 controls (7.4%) (P = .0009). CONCLUSIONS: HHV-6 was detected in liver explants significantly more often and in higher quantities in children transplanted for LFUE compared to controls, suggesting HHV-6 should be evaluated in young children who present with LFUE.

Yellow fever and orthotopic liver transplantation: new insights from the autopsy room for an old but re-emerging disease.

AIMS: The clinical spectrum of yellow fever (YF) ranges from asymptomatic to fulminant hepatitis. During the sylvatic YF epidemic in the metropolitan area of São Paulo, Brazil in 2018, seven orthotopic liver transplantations (OLTs) were performed in our institution to treat fulminant YF hepatitis. Three patients recovered, while four patients died following OLT. The autopsy findings of all these cases are presented herein as the first description of YF in transplanted patients. METHODS AND RESULTS: All patients were men, aged 16-40 years, without vaccination to YF virus (YFV). All organs were examined, with tissue sampling for histopathological analysis. Detection of YF virus antigens (YFV Ag) was performed with two primary antibodies (mouse polyclonal anti-YFV antibody directed to wild strain and a goat anti-YF virus antibody), and RT-PCR assays were utilised to detect YFV-RNA. All the cases depicted typical findings of YF hepatitis in the engrafted liver. The main extrahepatic findings were cerebral oedema, pulmonary haemorrhage, pneumonia, acute tubular necrosis and ischaemic/reperfusion pancreatitis. Of the four cases, the YVF Ag was detected in the heart in one case, liver and testis in three cases, and the kidney and spleen in all four cases. All four cases had YF virus RNA detected by RT-PCR in the liver and in other organs. CONCLUSIONS: Infection of the engrafted liver and other organs by YFV, possibly combined with major ischaemic systemic lesions, may have led to the death of four of the seven patients undergoing OLT.

Aggressive Epstein-Barr virus-negative B-cell post-transplant lymphoproliferative disorder in a hepatitis C-negative liver transplant recipient who received a hepatitis C-positive graft: Implications for D+/R- hepatitis C virus seroconversion.

Post-transplant lymphoproliferative disorder (PTLD) is an uncommon, but well-described complication after liver transplantation. Most recently, Hepatitis C virus (HCV) has been implicated in the development of PTLD. A HCV-negative 62-year-old man with autoimmune hepatitis received a HCV nucleic acid amplification test-positive liver graft from a 73-year-old brain-dead donor (D+/R-). After his recovery from the operation, the patient was treated for HCV and achieved an undetectable viral load. He was readmitted 6 months after transplant with a spontaneous perisplenic hematoma, weight loss, failure to thrive, low-grade fevers, and abnormal liver function tests. He had a rapid clinical deterioration and expired shortly after admission. His liver biopsy demonstrated EBV-negative monomorphic B-cell PTLD. Our case is the first to report an aggressive early-onset EBV-negative monomorphic B-cell PTLD in a HCV D+/R- liver transplant. This case illustrates the paucity of knowledge on HCV seroconversion and its involvement in EBV-negative monomorphic B-cell PTLD development.

Use of Hepatitis C-Positive Liver Grafts in Hepatitis C-Negative Recipients.

As the demand for liver transplantation continues to rise, the scarcity of liver donor grafts has led to the use of extended criteria grafts for liver transplantation in select group of patients. Hepatitis C-seropositive liver grafts have been used primarily in hepatitis C-positive recipients, with studies showing non-inferior outcomes when compared to hepatitis C-negative grafts. Studies suggest that hepatitis C serology status of the donor liver does not influence the patient or graft outcomes in the recipient. These results advocate for offering hepatitis C-positive grafts to all patients awaiting liver transplantation regardless of their hepatitis C status. However, some concerns persist regarding the ethics of potentially introducing a new infection into a patient that could progress to chronic liver disease following liver transplantation. The recent approval of direct-acting antiviral therapy offers a solution to this dilemma, as it has changed the landscape of hepatitis C management by making it a curable disease. In this review, we shall discuss the current evidence regarding the use of hepatitis C-seropositive donor grafts in hepatitis C-positive and hepatitis C-negative patients.

HTLV-1 myelopathy after renal transplant and antiviral prophylaxis: the need for screening.

The human T-lymphotropic virus type 1 (HTLV-1) is a RNA retrovirus that infects a minimum of 5-10 million people worldwide. Transmission by cell-containing blood products and solid organ transplantation has been reported. Clinical disease occurs in about 5-10% of infected individuals and consists mainly in adult T cell leukemia and HTLV-1-associated myelopathy (HAM). We present a 54-year-old woman who underwent kidney transplant from cadaveric donor in March 2015. Donor also underwent cornea extraction for another recipient (corneal transplant protocol includes HTLV-1/2 serology). Twenty-four hours after completion of kidney transplant donor, HTLV-1 serology was revealed positive. Following experts' recommendations, once donor seropositivity was demonstrated, antiviral prophylaxis including zidovudine and raltegravir was initially given to our patient, in spite of which the patient developed HAM. Once the diagnosis of HAM was established, antiretroviral therapy was restarted, and intravenous pulses of methylprednisolone were periodically administered with transient initial improvement. Later on, the patient experienced neurological deterioration becoming wheelchair dependent. Since the occurrence of this case, HTLV-1 screening has become mandatory for solid organ transplantation in the Spanish province of Navarra, and the same should happen worldwide.

Changes in Utilization and Discard of Hepatitis C-Infected Donor Livers in the Recent Era.

The impact of interferon (IFN)-free direct-acting antiviral (DAA) hepatitis C virus (HCV) treatments on utilization and outcomes associated with HCV-positive deceased donor liver transplantation (DDLT) is largely unknown. Using the Scientific Registry of Transplant Recipients, we identified 25 566 HCV-positive DDLT recipients from 2005 to 2015 and compared practices according to the introduction of DAA therapies using modified Poisson regression. The proportion of HCV-positive recipients who received HCV-positive livers increased from 6.9% in 2010 to 16.9% in 2015. HCV-positive recipients were 61% more likely to receive an HCV-positive liver after 2010 (early DAA/IFN era) (aRR:1.45 1.611.79 , p < 0.001) and almost three times more likely to receive one after 2013 (IFN-free DAA era) (aRR:2.58 2.853.16 , p < 0.001). Compared to HCV-negative livers, HCV-positive livers were 3 times more likely to be discarded from 2005 to 2010 (aRR:2.69 2.993.34 , p < 0.001), 2.2 times more likely after 2010 (aRR:1.80 2.162.58 , p < 0.001) and 1.7 times more likely after 2013 (aRR:1.37 1.682.04 , p < 0.001). Donor HCV status was not associated with increased risk of all-cause graft loss (p = 0.1), and this did not change over time (p = 0.8). Use of HCV-positive livers has increased dramatically, coinciding with the advent of DAAs. However, the discard rate remains nearly double that of HCV-negative livers. Further optimization of HCV-positive liver utilization is necessary to improve access for all candidates.

Hepatitis C Virus RNA Persists in Liver Explants of Most Patients Awaiting Liver Transplantation Treated With an Interferon-Free Regimen.

We assessed the presence of hepatitis C virus (HCV) RNA in liver explants from 39 patients awaiting liver transplantation who were treated with an interferon-free regimen and had undetectable serum HCV RNA at the time of liver transplantation. Interestingly, HCV RNA was detected in most liver explants (67%). Patients with HCV RNA-positive explants had received shorter courses of treatment, and HCV RNA was undetectable in serum for shorter periods before transplantation compared to patients with HCV RNA-negative explants (P = .014 and P = .013, respectively). Levels of HCV RNA in explants were significantly higher in patients with a relapse of HCV infection than patients who responded to treatment (P = .016), but most patients (85%) with residual HCV-RNA in the explant achieved a sustained virologic response after receiving their liver transplant.

Cytomegalovirus infection management in solid organ transplant recipients across European centers in the time of molecular diagnostics: An ESGICH survey.

BACKGROUND: Scant information is available about how transplant centers are managing their use of quantitative molecular testing (QNAT) assays for active cytomegalovirus (CMV) infection monitoring in solid organ transplant (SOT) recipients. The current study was aimed at gathering information on current practices in the management of CMV infection across European centers in the era of molecular testing assays. METHODS: A questionnaire-based cross-sectional survey study was conducted by the European Study Group of Infections in Immunocompromised Hosts (ESGICH) of the Society of Clinical Microbiology and Infectious Diseases (ESCMID). The invitation and a weekly reminder with a personal link to an Internet service provider (https://es.surveymonkey.com/) was sent to transplant physicians, transplant infectious diseases specialists, and clinical virologists working at 340 European transplant centers. RESULTS: Of the 1181 specialists surveyed, a total of 173 responded (14.8%): 73 transplant physicians, 57 transplant infectious diseases specialists, and 43 virologists from 173 institutions located at 23 different countries. The majority of centers used QNAT assays for active CMV infection monitoring. Most centers preferred commercially available real-time polymerase chain reaction (RT-PCR) assays over laboratory-developed procedures for quantifying CMV DNA load in whole blood or plasma. Use of a wide variety of DNA extraction platforms and RT-PCR assays was reported. All programs used antiviral prophylaxis, preemptive therapy, or both, according to current guidelines. However, the centers used different criteria for starting preemptive antiviral treatment, for monitoring systemic CMV DNA load, and for requesting genotypic assays to detect emerging CMV-resistant variants. CONCLUSIONS: Significant variation in CMV infection management in SOT recipients still remains across European centers in the era of molecular testing. International multicenter studies are required to achieve commutability of CMV testing and antiviral management procedures.

[Concurrence of acute graft rejection and polyomavirus nephropathy: A clinical case]. / Klinicheskoe nabliudenie sochetaniia ostrogo ottorzheniia transplantata s poliomavirusnoi nefropatiei.

The paper describes a case of diagnosing acute renal graft rejection concurrent with polyomavirus nephropathy. Histochemical and electron microscopic methods were used to examine biopsy specimens, which showed morphological changes occurring in the allograft, the ultrastructural characteristics of polyomavirus and the features of its spread in kidney tissue structures.

[Clinical and morphological signs of viral damage to a kidney transplant]. / Kliniko-morfologicheskie priznaki virusnogo porazheniia pochechnogo transplantata.

AIM: Тo compare morphological changes and results of immunohistochemical (IHC) identification of viruses (polyomaviruses, adenoviruses, and herpesviruses) in the biopsy specimens with their clinical manifestations in recipients of renal transplants. MATERIAL AND METHODS: Morphological and IHC studies were conducted using 71 needle renal transplant biopsy specimens from patients in the study group and 10 renal biopsy specimens from those in the control group. A number of clinical indicators were estimated. RESULTS: IHC examination revealed the expression of adenoviral antigens more commonly in patients with posttransplant nephritis than in recipients without nephritis or in control individuals (p<0.05). The association of patient age and time after kidney transplantation with the severity of viral damage was confirmed: graft loss in children occurred within the first months of surgery (p<0.05). Polyomavirus was detected by PCR in patients with the morphological patterns of polyomavirus nephropathy. Determination of HSV-1 and HSV-2 in the biopsy specimens showed no significant associations with morphological changes. CONCLUSION: By taking into account a variety of factors that influence the development of viral nephritis, morphological and IHC examinations should be combined with evaluation of clinical findings.

Intention-to-treat survival analysis of hepatitis C virus/human immunodeficiency virus coinfected liver transplant: Is it the waiting list?

In human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfected patients, the accelerated severity of liver disease, associated comorbidities, and mortality on the waiting list could change the possibility and results of liver transplantation (LT). Intention-to-treat survival analysis (ITTA) can accurately estimate the applicability and efficacy of LT. The primary objective of this study was to compare the survival of patients with HCV with and without HIV infection. We analyzed a cohort of 199 patients with HCV infection enrolled for LT between 1998 and 2015; 17 were also infected with HIV. The patients with HCV/HIV coinfection had higher mortality on the waiting list than those with HCV monoinfection (35.3% versus 4.6%; P < 0.001). ITTA at 1, 3, and 4 years was 75%, 64%, and 57% for HCV monoinfection and 52%, 47%, and 39% for HCV/HIV coinfection, respectively (Wilcoxon test P < 0.05). The ITTA at 1, 3, 6, and 12 months was 96%, 91%, 87%, and 75% for HCV monoinfection and 76%, 70%, 64%, and 52% for HCV/HIV coinfection, respectively (log-rank P < 0.05; Wilcoxon test P < 0.01). A Cox regression analysis was carried out including all variables with predictive value in the univariate analysis, showing that only donor age > 70 years (hazard ratio [HR] = 3.12; P < 0.05), United Network for Organ Sharing status 1 (HR = 10.1; P < 0.01), Model for End-Stage Liver Disease (HR = 1.13; P < 0.001), and HIV coinfection (HR = 2.65; P < 0.05) had independent negative predictive value for survival. In conclusion, our study indicates that HIV coinfection is a factor in mortality prior to transplantation and associated with higher mortality on the waiting list. Liver Transplantation 22 1186-1196 2016 AASLD.

Long-term outcomes of liver transplantation in patients with hepatitis C infection are not affected by HCV positivity of a donor.

BACKGROUND: The use of HCV-positive livers for HCV-positive recipients is becoming more common. Our aim is to evaluate long-term outcomes in liver transplant recipients transplanted with HCV antibody-positive organs. METHODS: From the Scientific Registry of Transplant Recipients (1995-2013), we selected all adult liver transplant recipients with HCV, and cross-sectionally compared long-term graft loss and mortality rates between those who were transplanted from HCV antibody-positive (HCV+) vs. HCV antibody-negative donors. RESULTS: We included 33,668 HCV+ liver transplant recipients (54.0 ± 7.7 years old, 74.1% male, 71.0% white, 23.6% with liver malignancy). Of those, 5.7% (N = 1930) were transplanted from HCV+ donors; the proportion gradually increased from 2.9% in 1995 to 9.4% in 2013. Patients who were transplanted from HCV+ positive donors were more likely to be discharged alive after transplantation (95.4% vs. 93.9%, p = 0.006), but this difference was completely accounted for by a greater proportion of HCV+ donors in more recent study years (p = 0.10 after adjustment for the transplant year). After transplantation, both mortality in HCV patients transplanted from HCV+ donors (12.5% in 1 year, 24.2% in 3 years, 33.0% in 5 years) and the graft loss rate (2.2% in 1 year, 4.8% in 3 years, 7.5% in 5 years) were similar to those in HCV patients transplanted from HCV-negative donors (all p > 0.05). CONCLUSIONS: Over the past two decades, the use of HCV+ organs for liver transplantation has tripled. Despite this, the long-term outcomes of HCV+ liver transplant recipients transplanted from HCV+ donors were not different from those who were transplanted with HCV-negative organs.

[Carcinogenic viruses in etiopathogenesis of skin cancers in patients after organ transplantation]. / Wirusy onkogenne w etiopatogenezie nowotworów skóry u chorych po przeszczepieniach narzadów.

The latest literature report specifies multifactoral etiology of skin cancer in population of patients after organs transplats. Carcirogenic viruses are one of etiopathogenesis components. Viruses of a vital meaning for skin oncogenesis are called Human papillomavirus - HPV, Human herpesvirus 8 - HHV8 i Merkel cell polyomavirus - MCV. Report on connections exisisting between viruses HPV and skin cancers in the population of patients after organs transplants confirms clinical connection between viruses papillas and cancers centres occuring in similar locations and more frequent appearance of attributes characteristic for HPV infection within the limits of changes in the type of Squamous cell carcinoma (SCC). What's more, coexisting of viruses papillas and SCC is more often noticed in the population of organ recipients than in the population of healthy people. It is not confirmed yet that any specific correlation between subtypes of HPV and greater frequency of morbidity in skin cancers really exist. However, in the population of organ recipients infections of different types of HPV are found within the limits of cancers centres in the case of SCC (63%) as well as in basal cell carcinoma-BCC (55%). DNA of HPV was also fund in healthy parts of organ recipients skin (92-94%). HHV8 is also an oncogenic viruse that influences the development of lymphoma. Infection of that virus may cause ocuuring of Kaposi's sarkoma, which is one of the most frequent types of cancer appearing in population of patients treating by long-term immunosuppression in particular geographical zones. MCV, which belongs to the group called Polyomaviriade, owes a particular meaning in etiopathogenesis of Merkel cell carcinoma - MCC. It is a rare cancer derived from neuroendocrine cells of the basic layers of epidermie. For over 30 years it was supposed that correlation between viruses and skin cancers in population of organ recipient exist. Knowledge of the total viruses influence on skin cancers allows to widen the spectrum of anti-cancers prevention in the future.