Detection of DNA of lymphotropic herpesviruses in plasma of human immunodeficiency virus-infected patients: frequency and clinical significance

Prevalence of HHV-6 Detection Among People Living with HIV: A Systematic Review and Meta-Analysis

Human herpesvirus 6 (HHV-6) is a ubiquitous virus with significant implications for immunocompromised individuals, particularly people living with HIV (PLWH). This study aimed to estimate the prevalence of HHV-6 detection in blood samples among PLWH using molecular diagnostic techniques. A systematic literature search was conducted across multiple databases until September 2024, including studies that reported HHV-6 detection in blood samples of PLWH through molecular methods. The meta-analysis calculated pooled prevalence rates using a random-effects model and assessed study quality, with additional analyses for outlier identification and influential study effects. Twelve studies met the inclusion criteria, and the random-effects model estimated the prevalence of HHV-6 detection at 11.7% (95% CI: 4.3-21.8%), with considerable heterogeneity. Influence diagnostics identified one study as influential, and after its exclusion, the recalculated pooled prevalence was 8% (95% CI: 4.4-12.4%), with reduced but still considerable heterogeneity. This meta-analysis highlights the prevalence of HHV-6 detection in PLWH, emphasizing the need for ongoing research to explore the clinical implications and factors influencing viral detection as well as the implications of this coinfection on the treatment and overall health of PLWH.

Plasma mcfDNA Sequencing May Improve Usual Care Diagnostics to Detect HHV-8 Among Outpatient People with Advanced HIV

Background

Human herpesvirus-8 (HHV-8), or Kaposi sarcoma (KS)-associated herpesvirus (KSHV), causes severe disease in people with profound immunosuppression. Yet, diagnosing KS can be challenging given the diverse manifestations and current limited usual care diagnostic methods (UC; polymerase chain reaction, histopathology).

Methods

Pathogen-agnostic plasma microbial cell-free DNA sequencing was applied to banked samples from 116 outpatients included in 2 previous prospective studies of patients with antiretroviral treatment-naïve, advanced HIV (CD4 count ≤100 cells/μL). We then reviewed clinical and laboratory data for any people who tested positive for HHV-8 by mcfDNA sequencing or UC at baseline.

Results

HHV-8 was detected in 21 (18%) outpatients with advanced HIV by any method, with males comprising the majority (86%) and one-third originally from non-US countries (including Africa, Central America, and the Caribbean). Adding mcfDNA sequencing to UC proportionally increased HHV-8 detection by 38%, while also identifying in 18 (86%) people other microbes of potential interest, including common herpesviruses, Mycobacterium tuberculosis, and Pneumocystis jirovecii.

Conclusions

Plasma mcfDNA sequencing may improve UC in detection of HHV-8 infection, especially in immunocompromised outpatients, in whom early detection may facilitate appropriate management to prevent severe KS disease. The potential added benefit of the detection of other pathogens by mcfDNA sequencing may be particularly relevant for this population.

Predictors of seropositivity for human herpesvirus type 8 in patients with mild cirrhosis

The high seroprevalence of human herpesvirus type 8 (HHV-8) in moderate or severe cirrhotics appears to be associated with male sex, hepatitis B virus (HBV) infection, alcoholism, and disease severity. The status of HHV-8 infection in mild cirrhotics remains unclear. Plasma samples collected from 93 mild cirrhotics and 93 age- and sex-matched healthy controls were analyzed for HHV-8 antibody and HHV-8 DNA. Mild cirrhotics had higher seropositivity for HHV-8 antibodies than healthy controls (P=0.0001). Univariate logistic regression analysis revealed that an age ≥55 years (odds ratio (OR) 2.88, P=0.02), hepatitis C virus (HCV) infection (OR 3.42, P=0.01), and hepatitis activity (OR 4.10, P=0.004) were associated with HHV-8 seropositivity in cirrhotics. Stepwise multivariate logistic regression analysis confirmed that age ≥55 years (adjusted OR (aOR) 1.92, P=0.04) and hepatitis activity (aOR 3.55, P=0.005) were independent factors. The rate of hepatitis activity was higher in HCV-infected than in HBV-infected patients (P<0.0001) and in women than in men (P=0.0001). Cirrhotics who were seropositive for HHV-8 or HCV or had hepatitis activity were significantly older (P=0.02, <0.0001 and <0.0001, respectively). Plasma samples from all participants were negative for HHV-8 DNA. HHV-8 antibody titers in mild cirrhotics also markedly exceeded those in controls (P<0.0001), as did those in patients ≥55 years old vs. younger patients (P=0.01), those in patients with vs. without HCV infection (P=0.0008), and those in patients with vs. without hepatitis activity (P=0.0005). Mild cirrhotics had high HHV-8 seroprevalence and HCV infection, and, in particular, old age and hepatitis activity were predictors.

Reduced human herpesvirus-8 oropharyngeal shedding associated with protease inhibitor-based antiretroviral therapy

BACKGROUND

Human herpesvirus 8 (HHV-8) replication increases the risk of Kaposi sarcoma (KS). Highly-active antiretroviral therapy (HAART) reduces the incidence of KS, and regimens that contain protease inhibitors (PIs) may be particularly effective.

OBJECTIVE

To determine whether PI-based HAART regimens may more effectively inhibit HHV-8 shedding compared to regimens without PIs.

STUDY DESIGN

Prospective, observational study of 142 HIV-1 and HHV-8 co-infected men conducted in Seattle, Washington. Quantitative HHV-8 PCR testing was performed on daily swabs of the oropharynx, the primary site of HHV-8 replication. Associations between antiretroviral regimen and detection of HHV-8 DNA in swabs were evaluated using generalized estimating equations.

RESULTS

HHV-8 DNA was detected in 3016 (26%) of 11,608 specimens collected. PI-based HAART was associated with a statistically significantly lower frequency of detection (RR 0.2; 95% CI 0.1-0.5) compared to ART-naïve persons, whereas HAART without a PI was not (RR 0.7; 95% CI 0.4-1.3). Compared to ART-naïve persons, there was also a trend toward lower quantities of HHV-8 detected during treatment with HAART regimens that contained a PI. These associations between PIs and measures of HHV-8 shedding could not be attributed to use of nelfinavir, which inhibits HHV-8 replication in vitro, and were independent of CD4 count and HIV plasma viral load (VL).

CONCLUSIONS

HAART regimens that contain PIs appear to decrease HHV-8 shedding compared to NNRTIs. Further study of PI-based HAART is warranted to determine the optimal regimens for prevention and treatment of KS.

Treatment with valacyclovir, famciclovir, or antiretrovirals reduces human herpesvirus-8 replication in HIV-1 seropositive men

Human herpesvirus-8 (HHV-8) replication is a key factor in Kaposi sarcoma, primary effusion lymphoma, and Castleman disease pathogenesis. In vitro data suggest that antivirals inhibit HHV-8 replication, but little data exist in humans. Daily oropharyngeal swabs were analyzed from HIV/HHV-8 dually infected men enrolled in three previous clinical trials of valacyclovir and famciclovir for HIV-1 and/or HSV-2 suppression. Fifty-eight participants contributed 6,036 swabs. HHV-8 was detected in 1,128 (19%) of 6,036 swabs, including 618 (21%) of 2,992 on placebo, 323 (15%) of 2,221 on valacyclovir, and 187 (23%) of 823 on famciclovir. After adjusting for baseline HIV viral load and highly active antiretroviral therapy (HAART) use, an 18% reduction in HHV-8 shedding frequency (IRR 0.822; P = 0.011) was found in participants on valacyclovir and a 30% reduction (IRR 0.700; P < 0.001) on famciclovir. HAART was associated with an 89% (IRR 0.129; P = 0.048) reduction in HHV-8-shedding. Neither antiviral nor antiretroviral therapy was associated with decreased HHV-8 quantity. Valacyclovir and famciclovir were associated with modest but significant reductions in HHV-8 oropharyngeal shedding frequency. In contrast, HAART was a potent inhibitor of HHV-8 replication. Studies of whether antiviral therapy in combination with ART will prevent HHV-8-associated disease appear warranted.

Human herpesvirus 8-associated neoplasms: the roles of viral replication and antiviral treatment

PURPOSE OF REVIEW

In this review, we highlight the importance of human herpesvirus 8 (HHV-8) lytic replication and the potential for antiviral therapies to prevent or treat HHV-8-related neoplasms.

RECENT FINDINGS

Diseases caused by HHV-8 infection include Kaposi sarcoma, multicentric Castleman disease (MCD), and primary effusion lymphoma (PEL), which occur primarily in patients with HIV infection. Kaposi sarcoma is the most common AIDS-associated malignancy worldwide. MCD and PEL occur less commonly but, like Kaposi sarcoma, are associated with poor treatment outcomes. Like all herpesviruses, HHV-8 is capable of either latent or lytic infection of cells. Although HHV-8 infection of tumor cells is predominately latent, accumulating data point to the importance of both lytic phase viral gene products and production of infectious virus. Antiviral agents that target herpesvirus DNA synthesis, such as ganciclovir, inhibit HHV-8 lytic replication and can prevent Kaposi sarcoma. Several HIV protease inhibitors may interfere with tumor growth and angiogenesis, and one protease inhibitor, nelfinavir, directly inhibits HHV-8 replication in vitro.

SUMMARY

Controlled trials are indicated to determine the clinical utility of antiviral suppression of HHV-8 replication, and identify the optimal antiretroviral regimens, for the prevention and treatment of Kaposi sarcoma.

Valganciclovir for suppression of human herpesvirus-8 replication: a randomized, double-blind, placebo-controlled, crossover trial

BACKGROUND

Human herpesvirus-8 (HHV-8) replication is critical in the induction and maintenance of Kaposi sarcoma, primary effusion lymphoma, and some cases of Castleman disease. In vitro and observational studies suggest that ganciclovir inhibits HHV-8 replication, but no randomized clinical trials have been conducted.

METHODS

A total of 26 men infected with HHV-8 were randomized to receive 8 weeks of valganciclovir administered orally (900 mg once per day) or 8 weeks of placebo administered orally. After a 2-week washout period, participants in each group received the study drug they had not yet taken (either valganciclovir or placebo), for 8 additional weeks. Oral swab samples were collected daily during the study, and HHV-8 and CMV DNA were quantified by real-time PCR.

RESULTS

A total of 16 human immunodeficiency virus (HIV)-positive men and 10 HIV-negative men enrolled in and completed the study. Of the 3,439 swab samples that participants had been expected to provide, 3029 (88%) were available for analysis. HHV-8 was detected on 44% of swabs collected from participants who were receiving placebo, compared with 23% of swabs collected from participants who were receiving valganciclovir (relative risk [RR], 0.54 [95% confidence interval {CI}, 0.33-0.90]; P = .02). Valganciclovir reduced oropharyngeal shedding of cytomegalovirus by 80% (RR, 0.20 [95% CI, 0.08-0.48]; P < .001). Shedding of HHV-8 and shedding of cytomegalovirus were independent. Hematologic, renal, or hepatic toxicities were no more common among participants who received the active drug, compared with those who received placebo, though participants who received valganciclovir reported more days of diarrhea.

CONCLUSIONS

Valganciclovir administered orally once per day is well tolerated and significantly reduces the frequency and quantity of HHV-8 replication.

The use of antiviral drugs in the prevention and treatment of Kaposi sarcoma, multicentric Castleman disease and primary effusion lymphoma

Kaposi sarcoma-associated herpesvirus [KSHV, also known as human herpesvirus 8 (HHV-8)] is the most recently identified member of the human herpesvirus family. Kaposi sarcoma (KS), primary effusion lymphoma, and multicentric Castleman disease are all associated with KSHV infection. Although the incidence of KS has declined dramatically in areas with access to highly active antiretroviral therapy, it remains the most common AIDS-associated malignancy in the developed world and is one of the most common cancers in developing nations. Current treatment options for KSHV-associated disease are ineffective, unavailable, or toxic to many affected persons. A growing body of basic science, preclinical, and observational data suggests that antiviral medications may play an important role in the prevention and treatment of KSHV-associated disease.

Viral interactions in human lymphoid tissue: Human herpesvirus 7 suppresses the replication of CCR5-tropic human immunodeficiency virus type 1 via CD4 modulation

Human immunodeficiency virus (HIV) infection is often accompanied by infection with other pathogens that affect the clinical course of HIV disease. Here, we identified another virus, human herpesvirus 7 (HHV-7) that interferes with HIV type 1 (HIV-1) replication in human lymphoid tissue, where critical events of HIV disease occur. Like the closely related HHV-6, HHV-7 suppresses the replication of CCR5-tropic (R5) HIV-1 in coinfected blocks of human lymphoid tissue. Unlike HHV-6, which affects HIV-1 by upregulating RANTES, HHV-7 did not upregulate any CCR5-binding chemokine. Rather, the inhibition of R5 HIV-1 by HHV-7 was associated with a marked downregulation of CD4, the cellular receptor shared by HHV-7 and HIV-1. HHV-7-induced CD4 downregulation was sufficient for HIV-1 inhibition, since comparable downregulation of CD4 with cyclotriazadisulfonamide, a synthetic macrocycle that specifically modulates expression of CD4, resulted in the suppression of HIV infection similar to that seen in HHV-7-infected tissues. In contrast to R5 HIV-1, CXCR4-tropic (X4) HIV-1 was only minimally suppressed by HHV-7 coinfection. This selectivity in suppression of R5 and X4 HIV-1 is explained by a suppression of HHV-7 replication in X4- but not in R5-coinfected tissues. These results suggest that HIV-1 and HHV-7 may interfere in lymphoid tissue in vivo, thus potentially affecting the progression of HIV-1 disease. Knowledge of the mechanisms of interaction of HIV-1 with HHV-7, as well as with other pathogens that modulate HIV-1 replication, may provide new insights into HIV pathogenesis and lead to the development of new anti-HIV therapeutic strategies.

Human herpesvirus 8 load in matched serum and plasma samples of patients with AIDS-associated Kaposi's sarcoma

Human herpesvirus 8 (HHV-8) (or Kaposi's sarcoma [KS]-associated herpesvirus) is associated with all forms of KS. HHV-8 DNA load in peripheral blood mononuclear cells (PBMCs) of KS patients has been shown to correlate with the clinical stage of the disease. Studies have been done to assess the HHV-8 viral load in different sample types from KS patients and its clinical relevance. This paper describes the design and evaluation of a quantitative real-time (TaqMan) PCR assay for routine diagnosis of HHV-8 infection. The linear dynamic range was 5 to 5 x 10(6) copies of HHV-8 DNA (r(2) > 0.99). The assay is very sensitive, specific, and easily reproducible (less than 2% variability) and can be used for different clinical samples, such as serum, plasma, and PBMCs. The question of which clinical sample, serum or plasma, is preferable for HHV8 DNA testing was addressed, using this newly developed real-time PCR assay. From 85 patients with diagnosed AIDS-KS, matched plasma and serum samples were collected. Of the 85 patients tested, 35 were positive for HHV-8 DNA in both plasma and serum (41%), 8 were positive in serum but not plasma, and 7 had detectable HHV-8 DNA only in plasma. The HHV-8 load was similar in both plasma and serum, and no significant difference was found. However, more inhibition was seen in the plasma samples with the use of a system quality control, seal herpesvirus type 1. Therefore, our results suggest that serum is the preferred material for HHV-8 load testing, since there is less possible hindrance in the amplification than with plasma.