Human Herpesvirus 8 DNA in Serum During Seroconversion in Allogeneic Bone Marrow Transplant Recipients

Hematopoietic stem cell transplantation and the noncytomegalovirus herpesviruses

Although hematopoietic stem cell transplantation (HSCT) and other cellular therapies have significantly improved outcomes in the management of multiple hematological and nonhematological malignancies, the resulting impairment in humoral and cellular response increases the risk for opportunistic infection as an undesirable side effect. With their ability to establish latent infection and reactivate when the host immune system is at its weakest point, the Herpesviridae family constitutes a significant proportion of these opportunistic pathogens. Despite recent advancements in preventing and managing herpesvirus infections, they continue to be a common cause of significant morbidity and mortality in transplanted patients. Herein, we aim to provide and update on herpesvirus other than cytomegalovirus (CMV) affecting recipients of HSCT and other cellular therapies.

Fatal donor-derived Kaposi sarcoma following liver transplantation

Human herpesvirus-8 (HHV8) is a recognised precursor for a number of neoplastic and non-neoplastic processes. Immunosuppressed recipients of both solid organ and haematopoietic stem cell transplants are at risk of life-threatening lytic reactivations of HHV8-infected B-lymphocytes, primary infections after receiving grafts from HHV8-seropositive donors and more rarely by the direct transplantation of malignant Kaposi sarcoma cells seeded within graft tissue. We describe the case of an HHV8-seronegative patient with confirmed, post-orthotopic liver transplant transmission of HHV8 from a seropositive donor with quantitative evidence of viraemia and subsequent development of disseminated visceral and cutaneous Kaposi sarcoma with a rapidly fatal outcome.

Incidence and outcome of Kaposi sarcoma after hematopoietic stem cell transplantation: a retrospective analysis and a review of the literature, on behalf of infectious diseases working party of EBMT

The incidence, the clinical characteristics, and the outcome of Kaposi sarcoma (KS) in patients after hematopoietic stem cell transplantation (HSCT) were assessed. During the period 1987-2018, 13 cases of KS were diagnosed, 3 females and 10 males, median age of 50 years, median time from HSCT of 7 months. KS had an incidence of 0.17% in allogeneic and 0.05% in autologous HSCT. HHV-8 was documented in eight of nine tumor tissue samples assessed. The organ involvement was: skin in nine, lymph nodes in six, oral cavity in four, and visceral in three patients, respectively; seven patients had >1 organ involved. Five patients had immunosuppression withdrawn, whereas four and three patients received radiotherapy and chemotherapy, respectively. Eight patients are alive (median follow-up 48 months, range 5-128), whereas five patients died after a median time of 8 months from the diagnosis of KS. However, no death was caused by KS. We conclude that the incidence of KS after HSCT is very low. Although KS can be managed with the reduction of immunosuppression, visceral forms may require chemotherapy and/or radiotherapy. The low prevalence of KS indicates that screening for HHV-8 serology and surveillance for HHV-8 viremia are not indicated in HSCT patients.

Seroprevalence of human herpesvirus 8 and its impact on the hemoglobin level in patients of end stage of renal diseases

The incidence of Kaposi's sarcoma (KS) is increasing among renal transplant recipients. Patients with end-stage renal disease (ESRD) are immunocompromised and are candidates for renal transplantation, but HHV8 seroprevalence in ESRD patients has not been well documented. A cross-sectional study of 286 ESRD patients and 281 matched subjects without kidney disease was conducted at the First People's Hospital of Huzhou, Zhejiang province to explore the epidemiologic features of HHV8 among ESRD patients in China. Blood samples were collected and HHV8 antibodies and serologic indices were measured. The seroprevalence of HHV8 was 15.3% for ESRD patients and 8.9% for the comparison group. A significant difference in the geometric mean titer (GMT) of the HHV8 antibodies was detected between ESRD patients and the comparison group (617.1 vs 291.7; P = 0.042). The average level of hemoglobin was 11.56 ± 1.78 g/dL for the ESRD group and 13.73 ± 1.42 g/dL for the comparison group, (P > 0.05). Multiple linear regression revealed a negative association between HHV8 infection and plasma hemoglobin concentration (β = -0.682, P = 0.036). We found a higher HHV8 prevalence and a higher level of HHV8 antibody GMT in ESRD patients than the comparison group, which indicate a high risk of posttransplantation KS.

Fulminant anaplastic large cell lymphoma (ALCL) concomitant with primary cytomegalovirus (CMV) infection, and human herpes virus 8 (HHV-8) infection together with Epstein-Barr-virus (EBV) reactivation in a patient with asymptomatic HIV-infection

Background

Most malignant lymphomas in HIV-patients are caused by reactivation of EBV-infection. Some lymphomas have a very rapid fulminant course. HHV-8 has also been reported to be a cause of lymphoma. The role of CMV in the development of lymphoma is not clear, though both CMV and HHV-8 have been reported in tissues adjacent to the tumour in Burkitt lymphoma patients. Here we present a patient with asymptomatic HIV infection, that contracted a primary cytomegalovirus (CMV) infection and human herpes virus 8 (HHV-8) infection. Three weeks before onset of symptoms the patient had unprotected sex which could be possible source of his CMV and also HHV-8 infection He deteriorated rapidly and died with a generalized anaplastic large cell lymphoma (ALCL).

Methods

A Caucasian homosexual male with asymptomatic human immunodeficiency virus (HIV) infection contracted a primary cytomegalovirus (CMV) infection and human herpes virus 8 (HHV-8) infection. He deteriorated rapidly and died with a generalized anaplastic large cell lymphoma (ALCL). Clinical and laboratory records were compiled. Immunohistochemistry was performed on lymphoid tissues, a liver biopsy, a bone marrow aspirate and the spleen during the illness and at autopsy. Serology and PCR for HIV, CMV, EBV, HHV-1–3 and 6–8 was performed on blood drawn during the course of disease.

Results

The patient presented with an acute primary CMV infection. Biopsies taken 2 weeks before death showed a small focus of ALCL in one lymph node of the neck. Autopsy demonstrated a massive infiltration of ALCL in lymph nodes, liver, spleen and bone marrow. Blood samples confirmed primary CMV- infection, a HHV-8 infection together with reactivation of Epstein- Barr-virus (EBV).

Conclusion

Primary CMV-infection and concomitant HHV-8 infection correlated with reactivation of EBV. We propose that these two viruses influenced the development and progression of the lymphoma. Quantitative PCR blood analysis for EBV, CMV and HHV-8 could be valuable in diagnosis and treatment of this type of very rapidly developing lymphoma. It is also a reminder of the importance of prevention and prophylaxis of several infections by having protected sex.

Immunodeficiency-associated viral oncogenesis

Several viruses with different replication mechanisms contribute to oncogenesis by both direct and indirect mechanisms in immunosuppressed subjects after solid organ transplantation, after allogeneic stem cell transplantation, or with human immunodeficiency virus (HIV) infection. Epstein-Barr virus (EBV), human papillomavirus (HPV), Kaposi sarcoma herpesvirus (KSHV), human T-cell lymphotropic virus type 1 (HTLV-1) and Merkel cell polyoma virus (MCV) are the main viruses associated with the development of cancer in immunosuppressed patients. Besides being a main cause of immunodeficiency, HIV1 has a direct pro-oncogenic effect. In this review, we provide an update on the association between the condition of acquired immunodeficiency and cancer risk, specifically addressing the contributions to oncogenesis of HPV, MCV, KSHV, HTLV-1, and EBV.

Human herpesvirus 8 seroconversion in a population-based cohort of men in Tobago

Human herpesvirus 8 (HHV-8) is the causal agent of Kaposi's sarcoma (KS). In Tobago, KS is not common; however, HHV-8 seropositivity has been reported to be 39.9% in men with prostate cancer compared to <22.9% in healthier women and men. To understand HHV-8 transmission, we examined HHV-8 seroconversion and seroreversion, and risk factors for these changes in Tobago men. Serum specimens from a sub-cohort of Tobago Prostate Survey men, aged 40-81 years (n = 381/442), were collected at baseline and a subsequent visit between 3 and 9 years and tested for HHV-8 seropositivity using an immunofluorescence assay for antibodies against HHV-8 lytic antigens. Poisson distribution was used to calculate HHV-8 seroconversion and seroreversion rates and their 95% confidence intervals. Differences in baseline characteristics between HHV-seroconverters versus persistent HHV-8 seronegative men and HHV-8 seroreverters versus HHV-8 seropositive men were examined. HHV-8 seropositivity was 12.3% (N = 381) at baseline, with HHV-8 seropositivity significantly higher in increasing age groups, 40-49 (4.0%) to 70-81 (37.5%) years (P-value trend <0.0001). HHV-8 seroconversion and seroreversion rates were 0.23 per 100 person-years (95% C.I., 0.06-0.58) and 2.42 per 100 person-years (95% C.I., 0.89-5.26), respectively. There were significantly more HHV-8 seroconverters who reported "ever smoked cigarettes of >6 months" at baseline compared to HHV-8 persistent seronegative men (P-value = 0.03). Baseline characteristics of HHV-8 seroreverters did not differ from persistent seropositive men. Low HHV-8 seroconversion and seroreversion rates were found. Data suggest that HHV-8 transmission occurred at earlier ages, <40 years, in Tobago men.

STAT3 activation by KSHV correlates with IL-10, IL-6 and IL-23 release and an autophagic block in dendritic cells

Kaposis's sarcoma associated herpesvirus (KSHV) has been reported to infect, among others, monocytes and dendritic cells DCs impairing their function. However, the underlying mechanisms remain not completely elucidated yet. Here we show that DC exposure to active or UV-inactivated KSHV resulted in STAT3 phosphorylation. This effect, partially dependent on KSHV-engagement of DC-SIGN, induced a high release of IL-10, IL-6 and IL-23, cytokines that in turn might maintain STAT3 in a phosphorylated state. STAT3 activation also correlated with a block of autophagy in DCs, as indicated by LC3II reduction and p62 accumulation. The IL-10, IL-6 and IL-23 release and the autophagic block could be overcome by inhibiting STAT3 activation, highlighting the role of STAT3 in mediating such effects. In conclusion, here we show that STAT3 activation can be one of the molecular mechanisms leading to KSHV-mediated DC dysfunction, that might allow viral persistence and the onset of KSHV-associated malignancies.

How I treat HHV8/KSHV-related diseases in posttransplant patients

Posttransplantation human herpesvirus-8 (HHV8)/Kaposi sarcoma herpesvirus (KSHV) primary infection and/or reactivations are associated with uncommon and sometimes fatal, neoplastic, and non-neoplastic diseases. HHV8-related clinical manifestations notably range from Kaposi sarcoma (KS) to either primary effusion lymphoma or multicentric Castleman disease B-cell malignancies, and from polyclonal HHV8-positive plasmacytic lymphoproliferative disorders to bone marrow failure and peripheral cytopenias, associated or not with hemophagocytic syndromes, and to acute hepatitis syndromes. We reviewed the patient series reported in the literature and summarized clinical management aspects, in terms of diagnosis, follow-up, and treatment. We described typical clinical presentations and histopathologic diagnostic features of these diseases, and we discussed the role of HHV8-specific serologic, molecular, and immunologic assays, particularly focusing on recent data from HHV8-specific T-cell monitoring in posttransplantation KS patients. We finally discussed actual therapeutic options, namely, the reduction or discontinuation of immunosuppressive therapy or the switch from calcineurin inhibitors to mTOR inhibitors, as alternatives to antineoplastic chemotherapy, along with the use of antiherpesvirus agents as prophylactic or therapeutic measures, and treatment with rituximab in posttrans-plantation multicentric Castleman disease patients and non-neoplastic HHV8-associated syndromes.

HHV-8-related visceral Kaposi's sarcoma following allogeneic HSCT: report of a pediatric case and literature review

An HHV-8-related visceral KS was diagnosed in a 10-yr-old boy after partially matched allogeneic HSCT. This complication occurred 463 days after HSCT and involved tonsils, lymph nodes, hard palate, lung, skin, and paranasal sinuses. Treatment with pegylated liposomal doxorubicin induced long-term remission (33 months) of this disease. HHV-8 infection is quite frequent after HSCT, but KS, and especially its visceral form, is a very rare complication, and its association with HHV-8 has been documented even less frequently. However, our observation suggests that HHV-8-related KS should be taken into consideration in the differential diagnosis of late post-HSCT complications.

Transmission of human herpesvirus 8: an update

PURPOSE OF REVIEW

Human herpesvirus 8 is associated with neoplastic diseases in the immunocompromised host, including Kaposi's sarcoma, multicentric Castleman disease and primary effusion lymphoma. Acquisition and control of human herpesvirus 8 infection have not yet been fully elucidated. This review focuses on the most recent findings on human herpesvirus 8 transmission.

RECENT FINDINGS

Horizontal transmission by saliva appears the most common route not only in families in endemic regions, but also among high-risk groups in Western countries. Vertical, sexual, and blood and transplant-related transmission, however, remain of significant concern worldwide. Novel approaches to standardize and optimize the assessment of human herpesvirus 8 infection have been reported. New insights on the host immune cell mechanisms devoted to the control of human herpesvirus 8 infection have also been presented.

SUMMARY

The increasing knowledge about the routes of human herpesvirus 8 transmission, which appear now more similar to those of other more ubiquitous human herpesviruses (i.e. Epstein-Barr virus and cytomegalovirus), the growing efforts in improving laboratory diagnosis and the caution in the research of new biological associations are the major recent findings. They constitute a fundamental background for directing more appropriate future research and achieving more stringent evidence useful for the control of human herpesvirus 8 spread and for the management of human herpesvirus 8-related diseases.

Kaposi's sarcoma triggered by endogenous HHV-8 reactivation after non-myeloablative allogeneic haematopoietic transplantation

Human herpesvirus 8 (HHV-8) is causally associated with Kaposi's sarcoma (KS). KS is most frequently observed in HIV patients and in solid organ transplant recipients. The role of HHV-8 in allogeneic haematopoietic cell transplantation (HCT) remains to be determined. Here we describe a case in which KS concomitantly occurred with CMV reactivation after a non-myeloablative allogeneic HCT and presented with skin lesions, but not visceral involvement. Skin biopsy confirmed the diagnosis and ruled out graft versus host disease or disease recurrence. Molecular findings indicated viral reactivation of the recipient's primary infection. Tumour lesions completely receded when immunosuppression was tapered. Prevalence studies in donors and recipients are needed to determine the clinical impact of HHV-8 in HCT.