-
Clinical Microbiology and Infection :... Sep 2023Cytomegalovirus (CMV) is an opportunistic pathogen responsible for substantial morbidity after solid organ transplantation and haematopoietic stem cell transplantation.... (Review)
Review
BACKGROUND
Cytomegalovirus (CMV) is an opportunistic pathogen responsible for substantial morbidity after solid organ transplantation and haematopoietic stem cell transplantation. Treatment of CMV disease involves a two-pronged approach with antiviral drug treatment coupled with strategies to minimize the intensity of immune suppression.
OBJECTIVES
This narrative review examines the evidence for the current treatment of CMV disease in transplant recipients, including the use of oral antiviral drugs.
SOURCES
Literature search was performed on PubMed with keywords cytomegalovirus, transplantation, ganciclovir, valganciclovir, maribavir, letermovir, cidofovir, and foscarnet.
CONTENT
Intravenous and oral valganciclovir are the standard first-line treatment of cytomegalovirus disease after transplantation. Oral maribavir has demonstrated superior efficacy and safety over CMV DNA polymerase inhibitors for the treatment of refractory or resistant CMV infection. Transplant patients with severe and life-threatening CMV disease, those with very high viral load, and patients with impaired gastrointestinal absorption should still be treated initially with intravenous antiviral drugs, including ganciclovir and foscarnet. Criteria for the safe transition from intravenous therapies to oral antiviral drugs include achieving clinical improvement and satisfactory decline in viral load. Recurrence of CMV viremia and disease is common, particularly among transplant patients who are lymphopenic and have impaired CMV-specific immunity.
IMPLICATIONS
Oral antiviral drugs for the treatment of CMV infection and disease in transplant recipients have improved the CMV landscape, because they reduce the cost and mitigate the inconvenience and risks related to prolonged hospitalization and the need for long-term intravascular access. However, their antiviral efficacy should be complemented by an intentional strategy of reducing the degree of immune suppression to allow for immunologic recovery that ensures durable control of CMV infection.
Topics: Humans; Antiviral Agents; Cytomegalovirus; Valganciclovir; Foscarnet; Transplant Recipients; Ganciclovir; Cytomegalovirus Infections
PubMed: 36963566
DOI: 10.1016/j.cmi.2023.03.020 -
JAMA Dermatology Oct 2023
Topics: Male; Humans; Foscarnet; Penile Diseases; Antiviral Agents; Ulcer; Skin Diseases; Penis
PubMed: 37647057
DOI: 10.1001/jamadermatol.2023.2592 -
Journal of Virology Aug 2023The APOBEC3 family of DNA cytosine deaminases comprises an important arm of the innate antiviral defense system. The gamma-herpesviruses Epstein-Barr virus and Kaposi's...
The APOBEC3 family of DNA cytosine deaminases comprises an important arm of the innate antiviral defense system. The gamma-herpesviruses Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus and the alpha-herpesviruses herpes simplex virus (HSV)-1 and HSV-2 have evolved an efficient mechanism to avoid APOBEC3 restriction by directly binding to APOBEC3B and facilitating its exclusion from the nuclear compartment. The only viral protein required for APOBEC3B relocalization is the large subunit of the ribonucleotide reductase (RNR). Here, we ask whether this APOBEC3B relocalization mechanism is conserved with the beta-herpesvirus human cytomegalovirus (HCMV). Although HCMV infection causes APOBEC3B relocalization from the nucleus to the cytoplasm in multiple cell types, the viral RNR (UL45) is not required. APOBEC3B relocalization occurs rapidly following infection suggesting the involvement of an immediate early or early (IE/E) viral protein. In support of this possibility, genetic (IE1 mutant) and pharmacologic (cycloheximide) strategies that prevent the expression of IE/E viral proteins also block APOBEC3B relocalization. In comparison, the treatment of infected cells with phosphonoacetic acid, which interferes with viral late protein expression, still permits A3B relocalization. These results combine to indicate that the beta-herpesvirus HCMV uses an RNR-independent, yet phenotypically similar, molecular mechanism to antagonize APOBEC3B. IMPORTANCE Human cytomegalovirus (HCMV) infections can range from asymptomatic to severe, particularly in neonates and immunocompromised patients. HCMV has evolved strategies to overcome host-encoded antiviral defenses to achieve lytic viral DNA replication and dissemination and, under some conditions, latency and long-term persistence. Here, we show that HCMV infection causes the antiviral factor, APOBEC3B, to relocalize from the nuclear compartment to the cytoplasm. This overall strategy resembles that used by related herpesviruses. However, the HCMV relocalization mechanism utilizes a different viral factor(s) and available evidence suggests the involvement of at least one protein expressed at the early stages of infection. This knowledge is important because a greater understanding of this mechanism could lead to novel antiviral strategies that enable APOBEC3B to naturally restrict HCMV infection.
Topics: Humans; Infant, Newborn; Cytidine Deaminase; Cytomegalovirus; DNA Replication; DNA, Viral; Epstein-Barr Virus Infections; Herpesviridae Infections; Herpesvirus 1, Human; Herpesvirus 4, Human; Immediate-Early Proteins; Minor Histocompatibility Antigens; Ribonucleotide Reductases; Viral Proteins; Virus Replication
PubMed: 37565748
DOI: 10.1128/jvi.00781-23 -
Antiviral Research Jul 2023Cytomegalovirus (CMV) is a significant human pathogen, especially for immunocompromised patients, often treated with one or more antiviral drugs. Although the prevalence...
Cytomegalovirus (CMV) is a significant human pathogen, especially for immunocompromised patients, often treated with one or more antiviral drugs. Although the prevalence of resistance is low, the impact of drug resistant CMV infections on patient outcomes is high and genotypic testing is recommended when resistance is suspected. To assess the prevalence of CMV drug resistance mutations among samples submitted for genotypic testing, 2750 patient sample results were analyzed. Testing was performed by sequencing for ganciclovir (GCV), cidofovir (CDV), foscarnet (FOS), maribavir (MBV) and/or letermovir (LMV) resistance conferring mutations. Of the 2750 patient samples, 826 (30.04%) had resistance to one or more anti-CMV drug. Resistance mutations were most common in UL97, with 27.64% and 9.96% of samples having GCV and MBV mutations, respectively. Resistance mutations in UL54 were less common, with 6.11%, 5.98% and 1.76% of samples having GCV, CDV and FOS mutations, respectively. For LMV, resistance mutations in UL56 were present in 7.17% of samples, with mutations at codon 325 representing 80.95% of the observed LMV resistance mutations. Resistance to two drugs was identified in 215 samples and to 3 or more drugs in 35 samples. While a high prevalence of CMV resistance mutations was identified, this must be taken in the context of healthcare providers submitting samples from patients with suspected resistant CMV strains. For these patients, rapid monitoring for resistance allows treatment modifications based on objective results rather than empiric drug selection, which is particularly relevant given the presence of mutations conferring resistance to more than one drug.
Topics: Humans; Cytomegalovirus; Prevalence; Transplant Recipients; DNA-Directed DNA Polymerase; Viral Proteins; Antiviral Agents; Ganciclovir; Foscarnet; Cidofovir; Drug Resistance, Viral; Mutation; Benzimidazoles
PubMed: 37150409
DOI: 10.1016/j.antiviral.2023.105623 -
Oral Diseases Apr 2024Herpes Simplex Virus (HSV) type 1 (HSV-1) and type 2 (HSV-2) are among the most common human viral pathogens, affecting several billion people worldwide. Although in... (Review)
Review
Herpes Simplex Virus (HSV) type 1 (HSV-1) and type 2 (HSV-2) are among the most common human viral pathogens, affecting several billion people worldwide. Although in healthy patients clinical signs and symptoms of HSV infection are usually mild and self-limiting, HSV-infections in immunocompromised patients are frequently more aggressive, persistent, and even life-threatening. Acyclovir and its derivatives are the gold standard antiviral drugs for the prevention and treatment of HSV infections. Although the development of acyclovir resistance is a rather uncommon condition, it may be associated with serious complications, especially in immunocompromised patients. In this review, we aim to address the problem of drug resistant HSV infection and discuss the available alternative therapeutic interventions. All relative studies concerning alternative treatment modalities of acyclovir resistant HSV infection published in PubMed between 1989 to 2022 were reviewed. Long-term treatment and prophylaxis with antiviral agents predisposes to drug resistance, especially in immunocompromised patients. Cidofovir and foscarnet could serve as alternative treatments in these cases. Although rare, acyclovir resistance may be associated with severe complications. Hopefully, in the future, novel antiviral drugs and vaccines will be available in order to avoid the existing drug resistance.
Topics: Humans; Antiviral Agents; Drug Resistance, Viral; Acyclovir; Herpesvirus 1, Human; Immunocompromised Host; Stomatitis, Herpetic; Herpesvirus 2, Human; Cidofovir; Foscarnet
PubMed: 37279074
DOI: 10.1111/odi.14635 -
Journal of Clinical Virology : the... Oct 2023Antiviral resistance in human herpes simplex viruses (HSV) remains a significant clinical challenge in immunocompromised populations. Although molecular tests have...
BACKGROUND
Antiviral resistance in human herpes simplex viruses (HSV) remains a significant clinical challenge in immunocompromised populations. Although molecular tests have largely replaced viral culture for HSV diagnosis and molecular antiviral resistance testing is available for many viruses, HSV resistance testing continues to rely on phenotypic, viral culture-based methods, requiring weeks for results. Consequently, treatment of suspected HSV resistance remains largely empiric.
METHODS
We used HSV whole genome sequencing and a database of previously characterized HSV acyclovir and foscarnet resistance mutations to evaluate the performance of genotypic antiviral resistance testing among 19 control strains compared to in-house plaque reduction assay (PRA) and 25 clinical isolates sent for reference lab PRA antiviral resistance testing.
RESULTS
Among control strains, 23/29 (79.3%) results were concordant, 5 (17.2%) were indeterminate, and 1 (3.4%) was discordant. Indeterminate results were caused by variants of uncertain significance (VUS), including mutations without published phenotypes and mutations with contradictory results. Among clinical isolates, 14/40 (35%) results were concordant, 17 (42.5%) were indeterminate, and 9 (22.5%) were discordant. All discordant results were in reportedly phenotypically-susceptible HSV-1 strains yet possessed resistance mutations. Three contained resistant subpopulations. 6/8 (75%) discordant phenotypes were concordant with resistant genotypes upon repeat PRA.
CONCLUSIONS
These data support the combination of genotypic and phenotypic testing to diagnose HSV resistance more accurately and likely more rapidly than phenotypic testing alone. Genotypic context of resistance mutations and the ability of viral strains to form plaques in culture may affect phenotypic resistance results, highlighting the limitations of PRA alone as a gold standard method.
Topics: Humans; Antiviral Agents; Herpesvirus 2, Human; Acyclovir; Foscarnet; Herpesvirus 1, Human; Genotype; Drug Resistance, Viral; Herpes Simplex
PubMed: 37586184
DOI: 10.1016/j.jcv.2023.105554 -
The Journal of International Medical... Jan 2024This study aimed to examine the mechanism of hyperphosphatemia-induced vascular calcification (HPVC).
OBJECTIVE
This study aimed to examine the mechanism of hyperphosphatemia-induced vascular calcification (HPVC).
METHODS
Primary human aortic smooth muscle cells and rat aortic rings were cultured in Dulbecco's modified Eagle's medium supplemented with 0.9 mM or 2.5 mM phosphorus concentrations. Type III sodium-dependent phosphate cotransporter-1 (Pit-1) small interfering RNA and phosphonoformic acid (PFA), a Pit-1 inhibitor, were used to investigate the effects and mechanisms of Pit-1 on HPVC. Calcium content shown by Alizarin red staining, expression levels of Pit-1, and characteristic molecules for phenotypic transition of vascular smooth muscle cells were examined.
RESULTS
Hyperphosphatemia induced the upregulation of Pit-1 expression, facilitated phenotypic transition of vascular smooth muscle cells, and led to HPVC in cellular and organ models. Treatment with Pit-1 small interfering RNA or PFA significantly inhibited Pit-1 expression, suppressed phenotypic transition, and attenuated HPVC.
CONCLUSIONS
Our findings suggest that Pit-1 plays a pivotal role in the development of HPVC. The use of PFA as a Pit-1 inhibitor has the potential for therapeutic intervention in patients with HPVC. However, further rigorous clinical investigations are required to ensure the safety and efficacy of PFA before it can be considered for widespread implementation in clinical practice.
Topics: Animals; Humans; Rats; Aorta; Foscarnet; Hyperphosphatemia; RNA, Small Interfering; Transcription Factors; Vascular Calcification; Sodium-Phosphate Cotransporter Proteins, Type III
PubMed: 38180904
DOI: 10.1177/03000605231222156 -
Antiviral Research Aug 2023Data on herpes simplex virus (HSV) polymorphism as well as acyclovir (ACV) and foscarnet (FOS) resistance mutations are not exhaustive and may hinder accurate diagnosis...
Data on herpes simplex virus (HSV) polymorphism as well as acyclovir (ACV) and foscarnet (FOS) resistance mutations are not exhaustive and may hinder accurate diagnosis by next-generation sequencing (NGS). Here, we report novel UL23 and UL30 substitutions for HSV1 and HSV2 identified in immunocompromised patients treated for hematological malignancies during the last 6 years of HSV resistance surveillance at the University Hospital of Lyon. For HSV1, 35 novel UL23 substitutions and 52 novel UL30 substitutions were identified. For HSV2, 2 novel UL23 substitutions and 12 novel UL30 substitutions were identified. These results allow to complete the database of HSV1 and HSV2 substitutions, related either to polymorphism or to ACV and FOS resistance.
Topics: Humans; Antiviral Agents; Herpes Simplex; Herpesvirus 1, Human; Viral Proteins; Drug Resistance, Viral; Acyclovir; Foscarnet
PubMed: 37453453
DOI: 10.1016/j.antiviral.2023.105672 -
Retinal Cases & Brief Reports Mar 2024To determine whether maribavir is effective at treating ganciclovir-resistant cytomegalovirus retinitis.
PURPOSE
To determine whether maribavir is effective at treating ganciclovir-resistant cytomegalovirus retinitis.
METHODS
Retrospective case report of a lung-transplant patient with bilateral cytomegalovirus retinitis documented with serum and aqueous humor studies and color fundus photographs.
RESULTS
A 72-year-old lung-transplant patient with active ganciclovir-resistant cytomegalovirus was treated with intravitreal foscarnet therapy in one eye. Retinitis developed in the contralateral eye and was managed with systemic maribavir alone. Active retinitis regressed in both the eye treated with intravitreal foscarnet and the uninjected eye.
CONCLUSION
This patient's results suggest that systemic maribavir is an effective treatment for treatment-resistant cytomegalovirus retinitis.
Topics: Humans; Aged; Cytomegalovirus Retinitis; Valganciclovir; Foscarnet; Retrospective Studies; Ganciclovir; Antiviral Agents; Dichlororibofuranosylbenzimidazole
PubMed: 36730596
DOI: 10.1097/ICB.0000000000001372 -
Yakugaku Zasshi : Journal of the... 2024Quantitative NMR (qNMR), particularly H-qNMR, is useful for determining the absolute purity of organic molecules. However, identifying the target signal(s) for...
Quantitative NMR (qNMR), particularly H-qNMR, is useful for determining the absolute purity of organic molecules. However, identifying the target signal(s) for quantification is difficult, because of the overlap and complexity of organic molecules. Therefore, we focused on the P nucleus, owing to the simplicity of its signals, and investigated the P-qNMR absolute determination method by using organophosphorus drugs, water-soluble cyclophosphamide hydrate (CP), and water-insoluble sofosbuvir (SOF). The optimized and reproducible P-qNMR conditions, such as qNMR sample preparation [i.e., selecting suitable deuterated solvents and a reference standard (RS) for P-qNMR], hygroscopicity and solution stability of the analyte and RS, and qNMR measurements-such as acquisition time, relaxation delay time, and spectral width-were examined. The CP purities determined using P-qNMR agreed well with those for the established H-qNMR method in DO. In contrast, the SOF purity determined using P-qNMR was 1.6% higher than that for H-qNMR in the protic solvent CDOD. Therefore, using a protic solvent, such as CDOD, was not suitable for P-qNMR; the deuterium exchange with the RS for P-qNMR (i.e., phosphonoacetic acid) resulted in a small integrated intensity. Consequently, the aprotic solvent DMSO-d was employed to determine the SOF purity. The data revealed that the SOF purities determined using P-qNMR agreed well with the established H-qNMR values, indicating that the absolute quantification of SOF using both P-qNMR and H-qNMR is possible in DMSO-d. Thus, we established an optimized and reproducible P-qNMR method in validation study across multiple laboratories.
Topics: Organophosphorus Compounds; Dimethyl Sulfoxide; Water; Solvents; Pharmaceutical Preparations
PubMed: 38556308
DOI: 10.1248/yakushi.23-00151-3