Management of herpes virus infections following transplantation

Association of Herpes simplex infection with significantly increased risk of head and neck cancer: real-world evidence of about 500,000 patients

BACKGROUND

The role of viral agents in the development of head and neck cancers has remained controversial. While markers of viral origin have been isolated from oral cancer tissues, a causative relationship has yet to be shown. The aim of this study was to evaluate the relationship between head and neck cancers and Herpes simplex virus, one of the most common viral infections of the oral orifice.

METHODS

Here, we conducted a retrospective analysis of two age- and gender-matched cohorts extracted from the real-world database TriNetX on March 10th, 2023, each consisting of 249,272 patients with and without Herpes simplex infections (ICD-10: B00). The diagnoses C00-C14 were analyzed, and risk analysis and Kaplan-Meier survival statics were computed.

RESULTS

The strongest association was found for lip cancer (ICD-10: C00) with a hazard ratio [HR (CI 95% low-high)] of 3.08 (1.77-5.35). A significant association with HR of 1.17 (1.02-1.34) was found for the entire group of head and neck cancers. Confounders like smoking and alcohol dependence were considered using propensity score matching.

CONCLUSION

The surprisingly strong correlation with lip, oral cavity, and pharynx neoplasms sheds new light on supposedly harmless herpes simplex infections, suggesting them as a possible new factor for risk stratification.

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.

Human herpesvirus 8 and Kaposi sarcoma: how should we screen and manage the transplant recipient?

PURPOSE OF REVIEW

HHV-8-associated diseases are rare but potentially fatal in transplant recipients. Important differences exist in the distribution of HHV-8 seroprevalence, which might contribute to the lack of uniform approach to HHV-8. The aim of this review was to discuss recent updates in screening and management of HHV-8 after transplant.

RECENT FINDINGS

Increasing attention has been given to the nonmalignant but potentially fatal inflammatory syndrome caused by HHV-8 in solid organ transplant (SOT) recipients. At-risk groups include HHV-8-IgG D+/R- transplant and HHV-8-positive recipients. Severe cases of donor-derived HHV-8 disease, mainly Kaposi sarcoma, frequently without skin involvement and some diagnosed at autopsy, highlight the need to increase clinicians' awareness, to implement effective preemptive strategies and to perform rapid diagnosis. In HSCT setting, HHV-8-associated disorders are very rare.

SUMMARY

Identification of SOT recipients at risk through reliable serology is warranted and the utility of preemptive management and HHV-8-DNA monitoring should be studied. Clinicians should be aware of severe nonmalignant disorders and of early post-SOT Kaposi sarcoma cases with lymph node or transplanted organ involvement in order to provide prompt diagnosis and treatment. No screening for HHV-8 is warranted after HSCT but rapid diagnosis and reduction of immunosuppression remain fundamental.

Ellagitannins as synergists of ACV on the replication of ACV-resistant strains of HSV 1 and 2

The plant-derived polyphenolic compounds castalagin, vescalagin and grandinin (C-glucosidic ellagitannins containing nonahydroxyterphenoyl) manifested a strong inhibitory effect on the replication of acyclovir-resistant strains of herpes simplex viruses (HSV) type 1 and 2 in MDBK cells in focus forming units (i.e., microscopically registered microplaques) reduction assay and in two variants of cytopathic effect inhibition test. The effect on the acyclovir (ACV)-resistant herpes simplex virus type 1 (HSV-1) strain was markedly higher compared to that on the ACV-resistant herpes simplex virus type 2 (HSV-2). The three compounds showed comparable levels of antiviral activity against ACV-resistant HSV strains, in contrast with previous results where castalagin exerted the highest degree of activity against wild type HSV strains (Vilhelmova et al., 2011). Combinations of ellagitannins and ACV were tested on the ACV-resistant strains of both HSV-1 and 2 and produced synergistic effects that were revealed by applying the three-dimensional approach of Prichard and Shipman (1990). The ellagitannin(s)-ACV combination applied against ACV-resistant HSV-1 produced a much stronger synergistic effect compared to the effect observed against ACV-resistant HSV-2. The study of the effects of the combination ellagitannin(s)-ACF on intact cell monolayers did not show any toxicity resulting from interaction between the two substances. Altogether, the results obtained in this study demonstrate the highly promising potential of these plant polyphenols as antiherpetic agents.

Antimicrobial prophylaxis and outpatient management of fever and neutropenia in adults treated for malignancy: American Society of Clinical Oncology clinical practice guideline

PURPOSE

To provide guidelines on antimicrobial prophylaxis for adult neutropenic oncology outpatients and on selection and treatment as outpatients of those with fever and neutropenia.

METHODS

A literature search identified relevant studies published in English. Primary outcomes included: development of fever and/or infections in afebrile neutropenic outpatients and recovery without complications and overall mortality in febrile neutropenic outpatients. Secondary outcomes included: in afebrile neutropenic outpatients, infection-related mortality; in outpatients with fever and neutropenia, defervescence without regimen change, time to defervescence, infectious complications, and recurrent fever; and in both groups, hospital admissions, duration, and adverse effects of antimicrobials. An Expert Panel developed guidelines based on extracted data and informal consensus.

RESULTS

Forty-seven articles from 43 studies met selection criteria.

RECOMMENDATIONS

Antibacterial and antifungal prophylaxis are only recommended for patients expected to have < 100 neutrophils/μL for > 7 days, unless other factors increase risks for complications or mortality to similar levels. Inpatient treatment is standard to manage febrile neutropenic episodes, although carefully selected patients may be managed as outpatients after systematic assessment beginning with a validated risk index (eg, Multinational Association for Supportive Care in Cancer [MASCC] score or Talcott's rules). Patients with MASCC scores ≥ 21 or in Talcott group 4, and without other risk factors, can be managed safely as outpatients. Febrile neutropenic patients should receive initial doses of empirical antibacterial therapy within an hour of triage and should either be monitored for at least 4 hours to determine suitability for outpatient management or be admitted to the hospital. An oral fluoroquinolone plus amoxicillin/clavulanate (or plus clindamycin if penicillin allergic) is recommended as empiric therapy, unless fluoroquinolone prophylaxis was used before fever developed.

Excoecarianin, Isolated from Phyllanthus urinaria Linnea, Inhibits Herpes Simplex Virus Type 2 Infection through Inactivation of Viral Particles

Phyllanthus urinaria Linnea (Euphorbiaceae) is one of the traditional medicinal plants widely used by oriental people to treat various diseases. We have previously demonstrated that the acetone extract of P. urinaria inhibits herpes simplex virus type 2 (HSV-2) but not HSV-1 infection. In a continuing effort to clarify the antiviral mechanisms of P. urinaria, we isolated the pure compound excoecarianin from the whole plant of P. urinaria through acetone extraction, and investigated its anti-HSV-1 and HSV-2 activities. Our results indicated that excoecarianin protected Vero cells from HSV-2 but not HSV-1 infection, and its 50% inhibitory concentration (IC₅₀) was 1.4 ± 0.1 μM. The antiviral effective concentration of excoecarianin did not affect the viability or the morphology of Vero cells. Although excoecarianin inhibited HSV-2 infection, the inhibitory effect, however, was most prominent when excoecarianin was concurrently added with the virus. Pretreatment of Vero cells with excoecarianin with removal of the drug prior to infection did not yield any antiviral effects, and the same observation was made for post viral entry treatment. Subsequent studies revealed that excoecarianin inactivated HSV-2 virus particles to prevent viral infection. A synergistic antiviral effect against HSV-2 was also observed when Vero cells were treated with a combination of acyclovir (ACV) and excoecarianin. These results suggested that excoecarianin merits to be further explored as an entry inhibitor against HSV-2 and could potentially be investigated for combinatorial drug treatment with nucleoside analogues such as ACV in therapeutic management of HSV-2 infection.

7-Oxo-4,7-dihydrothieno[3,2-b]pyridine-6-carboxamides: Synthesis and biological activity of a new class of highly potent inhibitors of human cytomegalovirus DNA polymerase

We report a new class of non-nucleoside antivirals, the 7-oxo-4,7-dihydrothieno[3,2-b]pyridine-6-carboxamides, some of which possess remarkable potency versus a broad spectrum of herpesvirus DNA polymerases and excellent selectivity compared to human DNA polymerases. A critical factor in the level of activity is hypothesized to be conformational restriction of the key 2-aryl-2-hydroxyethylamine sidechain by an adjacent methyl group.

ent-Epiafzelechin-(4alpha-->8)-epiafzelechin extracted from Cassia javanica inhibits herpes simplex virus type 2 replication

Herpes simplex virus (HSV) is a ubiquitous organism that causes infections in human populations throughout the world. It causes a variety of diseases ranging in severity from mild to life-threatening. In this study, ent-epiafzelechin-(4alpha-->8)-epiafzelechin (EEE) extracted from the fresh leaves of Cassia javanica L. agnes de Wit (Leguminosae) was investigated for its in vitro anti-HSV-2 activity using XTT and plaque reduction assays. Results showed that EEE inhibited HSV-2 replication in a dose-dependent manner. The IC50 value was 83.8 +/- 10.9 and 166.8 +/- 12.9 microM for XTT and plaque reduction assays, respectively. EEE did not affect the viability and the proliferation of cells at antiviral concentrations. Mechanistic studies demonstrated that EEE prevented HSV-2 from penetrating the cell and also interfered with HSV-2 replication at the late stage of its life cycle. It also disturbed virus attachment but the inhibitory effect was minor. In summary, the conclusion of this study was that EEE exhibits various modes of action in suppressing HSV-2 multiplication.

Inhibition of herpesvirus replication by a series of 4-oxo-dihydroquinolines with viral polymerase activity

Herpesviruses cause a wide variety of human diseases ranging from cold sores and genital herpes to encephalitis, congenital infections and lymphoproliferative diseases. These opportunistic viruses cause major problems in immunocompromised individuals such as transplant recipients, cancer patients, and HIV-infected persons. The current treatment of these infections is not optimal and there is a need for more active, less toxic compounds that might be used in place of or in addition to current therapies. We have evaluated a new series of 4-oxo-dihydroquinolines, which have a different mechanism of action than nucleosides and have activity against multiple herpesviruses. Of the four new compounds evaluated, two (PHA-529311 and PHA-570886) had greater activity than the parent, PHA-183792, against several herpesviruses and one (PHA-568561) was as effective as the parent. A fourth, PHA-243672, was considerably less effective. They had greater efficacy against cytomegalovirus (CMV) than the other herpesviruses tested and also had activity against acyclovir-resistant herpes simplex virus and varicella-zoster virus isolates and ganciclovir or foscarnet-resistant CMV isolates. These results confirm the broad-spectrum efficacy of these compounds against multiple herpesviruses and suggest that members of this class may have a potential role for treatment of a variety of herpesvirus infections.

Examining unmet needs in infectious disease

In the past 30 years, more than 30 new aetiological agents of infectious disease have been identified. Some of these are responsible for entirely novel and life-threatening disorders, such as AIDS, Ebola fever, hantavirus pulmonary syndrome and Nipah virus encephalitis. During the same period, some longstanding infectious diseases (such as tuberculosis) have became resurgent, as a result of a combination of complacency, increased travel and social dislocation, and also increasing drug resistance. This review looks at some of the key unmet needs in this therapeutic area and discusses strategies to address them.

Broad-spectrum antiherpes activities of 4-hydroxyquinoline carboxamides, a novel class of herpesvirus polymerase inhibitors

Through broad screening of the compound library at Pharmacia, a naphthalene carboxamide was identified as a nonnucleoside inhibitor of human cytomegalovirus (HCMV) polymerase. Structure-activity relationship studies demonstrated that a quinoline ring could be substituted for naphthalene, resulting in the discovery of a 4-hydroxyquinoline-3-carboxamide (4-HQC) class of antiviral agents with unique biological properties. In vitro assays with the 4-HQCs have demonstrated potent inhibition of HCMV, herpes simplex virus type 1 (HSV-1), and varicella-zoster virus (VZV) polymerases but no inhibition of human alpha, delta, and gamma polymerases. Antiviral cell culture assays have further confirmed that these compounds are active against HCMV, HSV-1, HSV-2, VZV, and many animal herpesviruses. However, these compounds were not active against several nonherpesviruses representing different DNA and RNA virus families. A strong correlation between the viral DNA polymerase and antiviral activity for this class of compounds supports inhibition of the viral polymerase as the mechanism of antiviral activity. Northern blot analysis of immediate-early and late viral transcripts also pointed to a block in the viral life cycle consistent with inhibition of viral DNA replication. In vitro HCMV polymerase assays indicate that the 4-HQCs are competitive inhibitors of nucleoside binding. However, no cross-resistance could be detected with ganciclovir-resistant HCMV or acyclovir-resistant HSV-1 mutants. The unique, broad-spectrum activities of the 4-HQCs may offer new opportunities for treating many of the diseases caused by herpesviruses.

Infections in recipients of kidney transplants

A review of infections in kidney transplant recipients is presented in this article, beginning with a discussion of the pretransplant infectious diseases evaluation and an overview of the timing of infectious posttransplant, and then focusing on individual types of infection.

Preemptive therapy versus universal prophylaxis with ganciclovir for cytomegalovirus in solid organ transplant recipients

Whether preemptive therapy or universal prophylaxis with ganciclovir is the optimal approach against cytomegalovirus (CMV) remains unresolved. Controversy abounds with respect to the efficacy of preemptive therapy, the reliability of preemptive therapy tools, the logistical difficulties in conducting surveillance monitoring for CMV, the cost of prophylaxis, the effect of prophylaxis on indirect sequelae of CMV and epidemiology of CMV, and the potential for emergence of ganciclovir-resistant CMV. Although neither approach is wholly adequate, a discussion of the relative merits and limitations of the 2 approaches may guide the selection of a rational approach toward prevention of CMV infection in organ transplant recipients.