Topical imiquimod for recurrent acyclovir-resistant HSV infection

Recalcitrant ulcerative genital herpes in an immunocompetent individual treated successfully with imiquimod

BACKGROUND

This case report describes the successful use of imiquimod to treat genital herpes in an immunocompetent individual with acyclovir-resistant HSV.

CASE REPORT

A 32 year old male patient, presented with asymptomatic non-healing ulcers over the genital region for 2 years. The ulcers initially responded to acyclovir but became persistent after a few months. He also received multiple courses of antibiotics. On examination, the patient had bilateral inguinal lymphadenopathy and multiple painless ulcers over the coronal sulcus. Routine investigations were normal. The patient was treated with oral and intravenous acyclovir but showed no response. He was then started on topical imiquimod cream applied on alternate days. After one week, the patient presented with pain, redness, burning sensation, and fresh ulcer over the glans which were suspected to be imiquimod-induced irritant reaction or ulcer. Imiquimod was withheld for one week and then restarted at a twice-weekly schedule. After 1 month and 7 days of treatment with imiquimod at a twice-weekly schedule, there was healing of the ulcers.

CONCLUSION

This case report illustrates the efficacy of imiquimod cream as a topical treatment for genital herpes simplex in an immunocompetent patient who had previously been unresponsive to treatment with acyclovir.

Is imiquimod a promising drug to treat oral mucosa diseases? A scoping review and new perspectives

Imiquimod (IMQ) is a chemotherapeutic and immunostimulant drug that is applied topically, demonstrating antitumor and antiviral activities. The objective of this review was to compile data on the off-label use of IMQ in oral mucosal diseases. IMQ has exhibited effectiveness in the treatment of various oral mucosal conditions, including oral carcinogenic lesions, neoplasms, HPV-related lesions and autoimmune disorders. Although IMQ holds promise as a potential strategy for addressing oral mucosal lesions, it is important to note that significant side effects have been frequently reported. Nonetheless, it is crucial to develop and test new technological systems, such as the combination of nanotechnology with innovative drug delivery platforms. These advancements aim to minimize side effects and prolong the drug's contact time with the mucosa, preventing its removal by salivary flow.

Therapeutic outcomes and prognostic factors in patients with hypertrophic herpes simplex infection treated with imiquimod: A systematic review and meta-analysis of individual patient data from case reports and case series

Hypertrophic herpes simplex (HHS) often has atypical presentations, such as a hypertrophic mass or ulcers, with chronic courses. This situation poses a diagnostic challenge and results in delayed treatment. Imiquimod was used as a treatment for HHS by several studies, but the therapeutic outcomes varied. This systematic review and meta-analysis of individual patient data was conducted to investigate the therapeutic outcomes and prognostic factors of imiquimod treatment for patients with HHS. Biomedical databases (Embase, PubMed, Medline, Cochrane Controlled Trials Register, and ClinicalTrials.gov) were searched for all types of clinical studies reporting the complete cure rate and the time to complete response to imiquimod therapy between 1926 and 2021. Quantitative analysis of individual patient data was performed using multivariable flexible parametric survival regression with cluster variance correction. A total of 12 019 articles were identified and screened for eligibility. Twenty-five studies (21 case reports and four case series) with a combined total of 42 patients were included. The complete cure rate for imiquimod treatment was estimated at 88.1%. The median time to complete response was 60 days (95% confidence interval 35-70). Combined treatment, male sex, and an age less than 50 years were identified as significant prognostic factors for a shorter time to complete cure. A severe local reaction was reported in 2.3%. Imiquimod therapy has high effectiveness and safety in curing HHS. Patients who were male or younger than 50 years or whose treatments were combined with thymidine kinase-dependent antivirals had the best prognoses and were more likely to respond to treatment.

Pathobiology and treatment of viral keratitis

Keratitis is one of the most prevalent ocular diseases manifested by partial or total loss of vision. Amongst infectious (viz., microbes including bacteria, fungi, amebae, and viruses) and non-infectious (viz., eye trauma, chemical exposure, and ultraviolet exposure, contact lens) risk factors, viral keratitis has been demonstrated as one of the leading causes of corneal opacity. While many viruses have been shown to cause keratitis (such as rhabdoviruses, coxsackieviruses, etc.), herpesviruses are the predominant etiologic agent of viral keratitis. This chapter will summarize current knowledge on the prevalence, diagnosis, and pathobiology of viral keratitis. Virus-mediated immunomodulation of host innate and adaptive immune components is critical for viral persistence, and dysfunctional immune responses may cause destruction of ocular tissues leading to keratitis. Immunosuppressed or immunocompromised individuals may display recurring disease with pronounced severity. Early diagnosis of viral keratitis is beneficial for disease management and response to treatment. Finally, we have discussed current and emerging therapies to treat viral keratitis.

Herpes Virus Infections Other than Cytomegalovirus in the Recipients of Hematopoietic Stem Cell Transplantation

This review discusses the epidemiologic and clinical aspects of herpes viruses other than cytomegalovirus in patients who have undergone hematopoietic stem cell transplantation.

A case of an atypical resistant granulomatous HSV-1 and HSV-2 ulceration in an AIDS patient treated with intralesional cidofovir

We report a case of a granulomatous skin lesion in an AIDS patient whereby biopsy revealed both HSV-1 and HSV-2. This lesion was resistant to acyclovir and successfully treated with intralesional cidofovir without recurrence to date. This is the only known reported case of a granulomatous skin lesion in an HIV patient, whereby both HSV-1 and HSV-2 were isolated.

AT-533, a Hsp90 inhibitor, attenuates HSV-1-induced inflammation

Inflammatory events are tightly associated with the death caused by Herpes simplex virus 1 (HSV-1) infection of the brain. Heat shock protein 90 (Hsp90) is a molecular chaperone that is stimulated in response to many stressful conditions (e.g., inflammation and hypoxia) and Hsp90 inhibitors are suggested to be potent inhibitors of the inflammatory response. The aim of this study was to investigate the effect of Hsp90 inhibitor AT-533 on HSV-1-induced inflammation. AT-533 at a non-antiviral concentration was found to show a prominent inhibitory effect on the production of cytokines induced by HSV-1 infection, such as tumor necrosis factor α (TNF-α), interleukin 6 (IL-6) and interleukin 1β (IL-1β). Mechanically, HSV-1 early infection induced inflammation through NF-κB signaling and NLRP3 inflammasome activation, as illustrated by the nuclear translocation of NF-κB and the enhanced cleavage of caspase-1. Besides, HSV-1 enhanced the interaction between NLRP3 and Hsp90. Moreover, AT-533 reduced the nuclear translocation of NF-κB and inflammasome activation via inhibiting the chaperone function of Hsp90. Furthermore, AT-533 inhibited the cleavage of pro-IL-1β to mature IL-1β in a NLRP3-independent manner. In summary, AT-533 may be a promising therapeutic strategy in HSV-1-infected inflammation management.

Herpes simplex virus infections in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of HSV in the pre- and post-transplant period. A majority of transplant recipients are seropositive for HSV-1 or 2. Compared with immunocompetent persons, SOT recipients shed HSV more frequently, have more severe clinical manifestations, and are slower to respond to therapy. Most HSV infection is diagnosed on clinical grounds, but patients may present with atypical lesions and/or other clinical manifestations. Acquisition from the donor is rare. Polymerase chain reaction is the preferred diagnostic test unless culture is needed for resistance testing. For limited mucocutaneous lesions, oral therapy can be used; however, in severe, disseminated, visceral or CNS involvement, acyclovir doses of up to 10 mg/kg every 8 hours intravenously should be initiated. Acyclovir-resistant HSV is less common in SOT patients than in HSCT and can be treated with foscarnet, though other novel therapies are currently under investigation. HSV-specific prophylaxis should be considered for all HSV-1 and HSV-2-seropositive organ recipients who are not receiving antiviral medication for CMV prevention that has activity against HSV.

Recalcitrant hypertrophic herpes genitalis in HIV-infected patient successfully treated with topical imiquimod

Herpes Simplex Virus type 2 is the primary cause of genital ulceration worldwide. The presence of atypical features like deep ulcerations, hypertrophic, or pseudotumoural lesions or unusual location can be a marker for co-infection with HIV. These immunocompromised patients are usually resistant to the conventional antiviral treatment. We present a case of an HIV-infected patient with hypertrophic herpes genitalis, refractory to conventional oral antiviral therapy, who was successfully treated with a combination of oral valcyclovir and topical application of 5% imiquimod.

Intravenous Foscarnet With Topical Cidofovir for Chronic Refractory Genital Herpes in a Patient With AIDS

Few case reports have documented the use of topical cidofovir for refractory genital herpes simplex virus (HSV) ulcers in human immunodeficiency virus (HIV) infected patients. This drug formulation lacks a standardized concentration or even a procedural outline as to how it should be compounded. We aim to discuss the utilization of topical cidofovir in addition to presenting a procedural means of compounding it for treatment of refractory genital HSV ulcers. Our patient completed 21 days of intravenous foscarnet and 13 days of topical cidofovir with clinical improvement in the penile and scrotal ulcers. Genital herpes is a concern in patients with HIV because it generally manifests as a persistent infection. Physicians should be aware that when patients fail to respond to the conventional treatment regimens for genital HSV in a timely manner, other options are available, such as topical cidofovir as an adjuvant to systemic antivirals.

Clinical characteristics of hypertrophic herpes simplex genitalis and treatment outcomes of imiquimod: a retrospective observational study

OBJECTIVE

Atypical presentations of herpes simplex genitalis are becoming more frequent. The aim of this study was to investigate the atypical clinical manifestations and treatment of this infection.

METHODS

The charts of patients with herpes simplex genitalis who attended our clinics between January 2009 and December 2013 were reviewed retrospectively.

RESULTS

Of 294 patients, 147 (50%) were male with a mean (standard deviation, SD) age of 48.3 (16.8) years. An ulcerative lesion was the most common symptom (48.3%), followed by vesicle clusters (36.4%). The mean duration of symptoms at first visit was 6 days. Oral acyclovir was administered to 87.6% of patients. Hypertrophic manifestations were observed in 4.8% (14/294) of patients; 50% (7/294) were male, with a mean age of 44.5 (SD 9) years. All patients with hypertrophic manifestations were infected with HIV. Hypertrophic manifestations had a mean duration of onset of 53.3 days. Acyclovir was prescribed to 11 (78.6%) patients. The mean duration to cure was 40.9 days. Topical imiquimod was given in six resistant cases (42.9%) as adjunctive therapy.

CONCLUSIONS

Atypical manifestations of herpes simplex genitalis require careful consideration because their frequency is rising, particularly in patients with HIV infection. Although acyclovir is important in their treatment, imiquimod provides an additional benefit in resistant cases.

Herpes simplex virus drug-resistance: new mutations and insights

PURPOSE OF REVIEW

Acyclovir (ACV) is the first-line treatment for the management of herpes simplex virus 1 (HSV-1) and 2 (HSV-2) diseases. Long-term administration of the drug for the treatment of chronic infections in the immunocompromised host can lead to the development of ACV-resistance. This review provides an update of the mutations linked to drug-resistance and issues to be considered in the management of HSV infections refractory to antiviral therapy.

RECENT FINDINGS

Recent data have shown that HSV drug-resistance should be taken into account not only in immunocompromised individuals but also in immunocompetent persons when HSV infections involve 'immune-privileged sites'. Thus, drug-resistance typing is recommended in cases of ACV unresponsive herpetic keratitis and herpes simplex encephalitis. Several issues regarding HSV drug-resistance were highlighted by recent studies. Phenotypic and genotypic antiviral resistance may vary not only from different compartments but also over time, highlighting the importance of characterizing longitudinal HSV isolates from all sites. Combination therapy should be considered when viruses with distinct phenotype/genotype are identified at one or at distinct body sites.

SUMMARY

Surveillance of HSV drug-resistance is highly recommended in immunocompromised patients and in immunocompetent individuals with infections implicating 'immune-privileged sites' to rationally adapt antiviral treatment.

Recalcitrant pseudotumoral anogenital herpes simplex virus type 2 in HIV-infected patients: evidence for predominant B-lymphoplasmocytic infiltration and immunomodulators as effective therapeutic strategy

BACKGROUND

In patients with human immunodeficiency virus (HIV) infection, genital herpetic lesions may be extensive and tend to persist for longer periods; in addition, atypical hypertrophic, ulcerative, or pseudotumor forms have been reported, frequently showing resistance to acyclovir (ACV) treatment.

METHODS

Between 2003 and 2011, 10 HIV-1-infected patients presenting with chronic pseudotumoral anogenital herpes simplex type 2 (HSV-2) infections were studied.

RESULTS

All patients developed chronic, hypertrophic HSV-2 anogenital lesions with multilesional presentation in 7 cases and involvement of 2 anatomical sites in 6 of them. At the time of diagnosis, the median CD3(+)CD4(+) absolute blood count was 480.5 cells/µL (range, 165-632 cells/µL), whereas the plasma HIV load was undetectable in all cases. Histopathologic analysis of lesion biopsies showed a moderately dense dermal polytypic plasma cell infiltrate. Detection of HSV-2 by culture and/or polymerase chain reaction was positive for all patients, with evidence for ACV-resistant strains in 6 of 8 cases. In addition, viral resistance to ACV was found only in HSV-2 isolated from ulcerative lesions, whereas purely pseudotumoral ones harbored sensitive strains. Durable control was observed with HSV DNA polymerase inhibitors in only 2 cases, and the immunomodulators imiquimod and thalidomide allowed 5 patients to reach sustained complete response.

CONCLUSIONS

HSV-2-related pseudolymphoma in HIV-infected patients is characterized by a predominant polyclonal lymphoplasmacytic infiltration, and is frequently refractory to antiherpetic drugs. Immunomodulatory therapeutic strategies using thalidomide showed consistent efficacy, and should be considered early during the course of disease.

Resistance of herpes simplex viruses to nucleoside analogues: mechanisms, prevalence, and management

Herpes simplex viruses (HSV) type 1 and type 2 are responsible for recurrent orolabial and genital infections. The standard therapy for the management of HSV infections includes acyclovir (ACV) and penciclovir (PCV) with their respective prodrugs valacyclovir and famciclovir. These compounds are phosphorylated by the viral thymidine kinase (TK) and then by cellular kinases. The triphosphate forms selectively inhibit the viral DNA polymerase (DNA pol) activity. Drug-resistant HSV isolates are frequently recovered from immunocompromised patients but rarely found in immunocompetent subjects. The gold standard phenotypic method for evaluating the susceptibility of HSV isolates to antiviral drugs is the plaque reduction assay. Plaque autoradiography allows the associated phenotype to be distinguished (TK-wild-type, TK-negative, TK-low-producer, or TK-altered viruses or mixtures of wild-type and mutant viruses). Genotypic characterization of drug-resistant isolates can reveal mutations located in the viral TK and/or in the DNA pol genes. Recombinant HSV mutants can be generated to analyze the contribution of each specific mutation with regard to the drug resistance phenotype. Most ACV-resistant mutants exhibit some reduction in their capacity to establish latency and to reactivate, as well as in their degree of neurovirulence in animal models of HSV infection. For instance, TK-negative HSV mutants establish latency with a lower efficiency than wild-type strains and reactivate poorly. DNA pol HSV mutants exhibit different degrees of attenuation of neurovirulence. The management of ACV- or PCV-resistant HSV infections includes the use of the pyrophosphate analogue foscarnet and the nucleotide analogue cidofovir. There is a need to develop new antiherpetic compounds with different mechanisms of action.

Antiviral drug resistance: mechanisms and clinical implications

Antiviral drug resistance is an increasing concern in immunocompromised patient populations, where ongoing viral replication and prolonged drug exposure lead to the selection of resistant strains. Rapid diagnosis of resistance can be made by associating characteristic viral mutations with resistance to various drugs as determined by phenotypic assays. Management of drug resistance includes optimization of host factors and drug delivery, selection of alternative therapies based on knowledge of mechanisms of resistance, and the development of new antivirals. This article discusses drug resistance in herpesviruses and hepatitis B.

Herpes simplex virus and human papillomavirus genital infections: new and investigational therapeutic options

Human papillomavirus and Herpes simplex virus are the most common genital viral infections encountered in clinical practice worldwide. We reviewed the literature focusing on new and experimental treatment modalities for both conditions, based on to the evidence-based data available. The modalities evaluated include topical agents such as immune response modifiers (imiquimod, resiquimod, and interferon), antivirals (penciclovir, cidofovir, and foscarnet), sinecatechins, microbiocidals (SPL7013 gel, and PRO 2000 gel), along with experimental (oligodeoxynucleotides), immunoprophylactic, and immunotherapeutic vaccines.

Antiviral drug resistance: mechanisms and clinical implications

Antiviral drug resistance is an increasing concern in immunocompromised patient populations, where ongoing viral replication and prolonged drug exposure lead to the selection of resistant strains. Rapid diagnosis of resistance can be made by associating characteristic viral mutations with resistance to various drugs as determined by phenotypic assays. Management of drug resistance includes optimization of host factors and drug delivery, selection of alternative therapies based on knowledge of mechanisms of resistance, and the development of new antivirals. This article discusses drug resistance in herpesviruses and hepatitis B.

Plasmacytoid dendritic cells and the control of herpesvirus infections

Type-I interferons (IFN-I) are cytokines essential for vertebrate antiviral defense, including against herpesviruses. IFN-I have potent direct antiviral activities and also mediate a multiplicity of immunoregulatory functions, which can either promote or dampen antiviral adaptive immune responses. Plasmacytoid dendritic cells (pDCs) are the professional producers of IFN-I in response to many viruses, including all of the herpesviruses tested. There is strong evidence that pDCs could play a major role in the initial orchestration of both innate and adaptive antiviral immune responses. Depending on their activation pattern, pDC responses may be either protective or detrimental to the host. Here, we summarize and discuss current knowledge regarding pDC implication in the physiopathology of mouse and human herpesvirus infections, and we discuss how pDC functions could be manipulated in immunotherapeutic settings to promote health over disease.

Treatment of focal epithelial hyperplasia with topical imiquimod: report of three cases

Focal epithelial hyperplasia (Heck disease) is a rare disorder caused by specific types of HPV. It mainly involves oral mucosa and children are affected more frequently. It may persist for years, producing a significant reduction in quality of life. Several treatment modalities such as surgical excision, laser ablation, cryotherapy, electrocauterization, topical, intralesional, systemic interferon, and systemic retinoic acid have been used with inconsistent results and many side effects. Here we report three children of Turkish origin with focal epithelial hyperplasia successfully treated with imiquimod 5% cream. No serious side effects were observed and recurrence did not occur during the 1-year follow-up period.

Severe sepsis and Toll-like receptors

Severe sepsis dominates the mortality of non-cardiac intensive care units. The ingenious Toll-like receptor (TLR) system can recognise many infectious organisms through relatively few receptors to trigger pro-inflammatory and anti-inflammatory cytokine release. Further complexity arises from positive and negative signalling feedback loops. Severe sepsis may be a consequence of an inappropriately excessive response or inadequate endogenous negative feedback. Therapies targeting these pathways are currently being evaluated. Alternatively, in clinical scenarios such as compensatory anti-inflammatory response syndrome, chronic viral sepsis or inadequate vaccine function, TLR signalling may be inadequate. TLR agonists may augment the innate response and are being investigated.

Antimicrobial resistance prevention initiative--an update: proceedings of an expert panel on resistance

Antimicrobial resistance is a growing problem that complicates the treatment of important nosocomial and community-acquired infections. It is a worldwide problem that spans the range of human pathogens, including bacteria, fungi, and viruses. This update from the Antimicrobial Resistance Prevention Initiative (ARPI) provides a review of some important trends in antibiotic, antifungal, and antiviral resistance. Areas of focus include multidrug-resistant bacteria in the hospital setting; the growing problem of community-acquired methicillin-resistant Staphylococcus aureus; triazole and polyene resistance in nosocomial infections caused by non-Candida albicans or Aspergillus species, and the utility of in vitro susceptibility testing for these fungal infections; antiviral resistance in alpha- or beta-herpesviruses causing genital herpes or cytomegalovirus infection in immunocompromised hosts; and concerns about a possible pandemic involving avian influenza A and the importance of minimizing emergence of resistant strains of this highly pathogenic virus. The challenges in each area are different, but the general keys to addressing the growing problem of antimicrobial resistance continue to be responsible antimicrobial stewardship and the development of newer antimicrobial agents.

Antimicrobial resistance prevention initiative--an update: proceedings of an expert panel on resistance

Antimicrobial resistance is a growing problem that complicates the treatment of important nosocomial and community-acquired infections. It is a worldwide problem that spans the range of human pathogens, including bacteria, fungi, and viruses. This update from the Antimicrobial Resistance Prevention Initiative (ARPI) provides a review of some important trends in antibiotic, antifungal, and antiviral resistance. Areas of focus include multidrug-resistant bacteria in the hospital setting; the growing problem of community-acquired methicillin-resistant Staphylococcus aureus; triazole and polyene resistance in nosocomial infections caused by non-Candida albicans or Aspergillus species, and the utility of in vitro susceptibility testing for these fungal infections; antiviral resistance in alpha- or beta-herpesviruses causing genital herpes or cytomegalovirus infection in immunocompromised hosts; and concerns about a possible pandemic involving avian influenza A and the importance of minimizing emergence of resistant strains of this highly pathogenic virus. The challenges in each area are different, but the general keys to addressing the growing problem of antimicrobial resistance continue to be responsible antimicrobial stewardship and the development of newer antimicrobial agents.