Topical Cidofovir and Cryotherapy - combination treatment for recalcitrant molluscum contagiosum in a patient with HIV infection

Cutaneous Applications of the Antiviral Drug Cidofovir: A Review

Background/Objectives: Cidofovir, an antiviral drug approved for cytomegalovirus retinitis, has emerged as an alternative treatment option for virally induced cutaneous and mucocutaneous conditions, as well as being trialed as a treatment for select neoplasms. In this review, we highlight the existing evidence, clinical uses, and rationale of using cidofovir for the treatment of cutaneous pathologies. Methods: A PubMed database literature search was conducted to identify relevant articles for inclusion in this review. Results: Cidofovir has several cutaneous applications in various formulations including intravenous, topical, and subcutaneous administrations. Primarily through case reports, case series, and retrospective reviews, cidofovir has demonstrated efficacy in treating a variety of virally induced conditions-verruca vulgaris, herpes simplex virus, molluscum contagiosum-as well as in adjuvant treatment for select neoplasms. The drug has shown efficacy in immunocompromised and immunocompetent adults and children alike. Conclusions: The body of literature supports the use of cidofovir as an effective and well-tolerated treatment for many viral cutaneous pathologies, and encourages further study for its use as an adjuvant therapy for neoplastic disease.

Cantharidin for the treatment of molluscum contagiosum: a prospective, double-blinded, placebo-controlled trial

Our aim was to study the effects and safety of cantharidin in the treatment of molluscum contagiosum (MC), we conducted a prospective, double-blinded, placebo-controlled, randomized clinical trial to evaluate the safety and efficacy of topical cantharidin for treatment of pediatric MC in an academic ambulatory care center. Twenty-nine children aged 5-10 with a diagnosis of MC were enrolled to receive treatment with cantharidin or placebo. The main outcome measure was complete clearance of all molluscum lesions. In contrast to previous retrospective observational studies, the performance of cantharidin treatment over 2 months was not substantially better than the performance of placebo. The scope of follow-up was limited to five visits over 2 months of treatment. A longer follow-up period might have captured a greater effect of cantharidin. Over a 2 month period, the magnitude of the cantharidin treatment effects in the target population are, at best, not large. This study provided objective unbiased estimates of the magnitude of cantharidin treatment effects and provided important prospective safety data. Our subjects experienced minimal side effects when treated with cantharidin.

Recurrent giant molluscum contagiosum immune reconstitution inflammatory syndrome (IRIS) after initiation of antiretroviral therapy in an HIV-infected man

We describe an HIV-infected South African man who experienced two distinct episodes of disseminated giant molluscum contagiosum immune reconstitution inflammatory syndrome (IRIS) over a six-year period. The first episode of molluscum contagiosum IRIS occurred with rapid virologic suppression following antiretroviral therapy initiation. The second episode occurred during a rapid increase in CD4 cells following stable viral suppression with second-line antiretroviral therapy. His molluscum contagiosum lesions then completely resolved during a reduction in CD4 count, despite maintaining virologic suppression. Nearly one year after the resolution of his giant molluscum contagiosum IRIS lesions, he maintains an undetectable viral load, but his level of immune deficiency has not improved. In the absence of well-controlled therapeutic trials, molluscum contagiosum IRIS presents important management challenges.

Disseminated atypical molluscum contagiosum as a presenting symptom of HIV infection

Atypical forms of molluscum contagiosum may be challenging to diagnose and are found in immunocompromised patients where they indicate severe impairment of cellular immunity. We report a case of disseminated atypical molluscum contagiosum which was the first sign of HIV infection and AIDS disease in a 38-year-old male patient. The lesions – painless, flesh-colored and violaceous papules and nodules – spread systematically for previous 3 years. They were located on the face, forearms, in the groins and in the genital region. Serologic tests for HIV-1 and hepatitis C virus were positive. CD4+ T–cells count was 80/mm³. The skin biopsy showed intracytoplasmic molluscum bodies. Atypical, recalcitrant, disseminated or facial molluscum contagiosum requires immediate HIV testing. In our patient, both the opportunity for early diagnosis and the institution of effective therapy were missed.

[Usefulness of topical cidofovir treatment for recalcitrant molluscum contagiosum in immunocompromised children]

Molluscum contagiosum (MC) is common and often numerous and recalcitrant in immunocompromised children. The response to available treatments is frequently unsatisfactory. Cidofovir is a nucleoside analog of the deoxycytidine antiviral drug approved for the intravenous treatment of cytomegalovirus retinitis in AIDS patients. We report four cases of children, 5-8 years old, who developed extensive MC in the context of chemotherapy for acute lymphoid leukemia and who were treated with a cream containing cidofovir 1%. In all patients, the lesions began to regress within 2 to 4 months. For three patients, complete regression was observed in 7 to 9 months, and the children remained clear of recurrence. For one patient, partial regression was obtained after 17 months of treatment. No side effects have been observed. Treatment of MC in immunocompromised children is difficult because the usual treatments are inappropriate. Successful use of either topically or intralesionally administered cidofovir in several virally induced cutaneous diseases has been demonstrated and recently documented in the treatment of MC in immunocompromised adults. Conversely, its use in children is not documented. Although intravenous use of cidofovir may lead to severe adverse effects, one single case of a systemic side effect has been reported after topical use at a greater concentration, but no changes in laboratory data were observed. Topical cidofovir offers an effective and well-tolerated therapeutic alternative option for the treatment of MC in immunosuppressed children.

The antiviral activity and mechanism of action of (S)-[3-hydroxy-2-(phosphonomethoxy)propyl] (HPMP) nucleosides

One class of compounds that has shown promise as antiviral agents are the (S)-[3-hydroxy-2-(phosphonomethoxy)propyl] (HPMP) nucleosides, members of the broader class of acyclic nucleoside phosphonates. These HPMP nucleosides are nucleotide analogs and have been shown to be effective inhibitors of a wide range of DNA viruses. Prodrugs of these compounds, which achieve higher levels of the active metabolites within the cell, have an expanded activity spectrum that also includes RNA viruses and retroviruses. Because they are analogs of natural nucleotide substrates, HPMP nucleosides are predicted to target polymerases (DNA polymerases, RNA polymerases and reverse transcriptases), resulting in the inhibition of viral genome replication. Previous work using the replicative enzymes of different viruses including human cytomegalovirus (HCMV) and vaccinia virus DNA polymerases and human immunodeficiency virus type 1 (HIV-1) reverse transcriptase has shown that the activated forms of these compounds are substrates for viral polymerases and that incorporation of these compounds into either the primer strand or the template strand inhibits, but does not necessarily terminate, further nucleic acid synthesis. The activity of these compounds against other viruses that do not encode their own polymerases, like polyoma viruses and papilloma viruses, suggests that host cell DNA polymerases are also targeted. This complex mechanism of action and broad activity spectrum has implications for the development of resistance and host cell genome replication, and suggests these compounds may be effective against other viruses such as influenza virus, respiratory syncytial virus and Dengue virus. This class of nucleotide analogs also points to a potential avenue for the development of newer antivirals.

Molluscum Contagiosum and Chronic Vulval Ulceration as the First Manifestations of HIV Infection – A Case Report / Molluscum contagiosum i hronične vulvalne ulceracije kao prve manifestacije HIV infekcije – prikaz slučaja

Molluscum contagiosum is a very common, benign, often self-limiting skin disease caused by Molluscum contagiosum virus, member of the poxvirus family. Genital ulcers in HIV positive women are usually acute or subacute, mostly idiopathic or aphtous. Sixty percent of cases are caused by herpes simplex virus syphilis or chancroid. We present a 31-yearold woman with a 2.5 month history of vulval ulceration and a several month history of molluscum contagiosum in the pubic region, neck and face. After she was admitted to our department, the patient underwent physical examination using enzyme-linked immunosorbent assay, and an immunoblot test for HIV 1/2. Both tests were positive. Thereafter, the patient was referred to an infectologist who recommended application of 5% imiquimod cream 3 times per week for molluscum contagiosum and acyclovir 3x400 mg/day. Considering that there are more accepted indications for HIV testing, we agree with other authors that all adults with molluscum contagiosum or chronic genital ulceration should be tested for HIV serology.

Cidofovir Activity against Poxvirus Infections

Cidofovir [(S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine, HPMPC] is an acyclic nucleoside analog approved since 1996 for clinical use in the treatment of cytomegalovirus (CMV) retinitis in AIDS patients. Cidofovir (CDV) has broad-spectrum activity against DNA viruses, including herpes-, adeno-, polyoma-, papilloma- and poxviruses. Among poxviruses, cidofovir has shown in vitro activity against orthopox [vaccinia, variola (smallpox), cowpox, monkeypox, camelpox, ectromelia], molluscipox [molluscum contagiosum] and parapox [orf] viruses. The anti-poxvirus activity of cidofovir in vivo has been shown in different models of infection when the compound was administered either intraperitoneal, intranasal (aerosolized) or topically. In humans, cidofovir has been successfully used for the treatment of recalcitrant molluscum contagiosum virus and orf virus in immunocompromised patients. CDV remains a reference compound against poxviruses and holds potential for the therapy and short-term prophylaxis of not only orthopox- but also parapox- and molluscipoxvirus infections.

Efficacy of N-methanocarbathymidine in treating mice infected intranasally with the IHD and WR strains of vaccinia virus

N-Methanocarbathymidine [(N)-MCT] is a newly identified inhibitor of orthopoxvirus replication in cell culture and in mice. Limited published animal studies indicated the compound is effective by intraperitoneal (i.p.) route at 10-100 mg/(kg day). More extensive studies using different treatment regimens in intranasally infected mice were conducted in order to further explore the potential of this compound compared to cidofovir in treating vaccinia virus infections. (N)-MCT was given twice a day for 7 days, whereas cidofovir was administered once a day for 2 days, each starting 24h after virus exposure for most experiments. (N)-MCT was not toxic up to 1000 mg/(kg day) by the i.p. treatment route. Oral and i.p. treatment regimens with (N)-MCT were directly compared during a vaccinia virus (IHD strain) infection, indicating that the nucleoside has good oral bioavailability in mice. Treatments by i.p. route with (N)-MCT (100 mg/(kg day)) reduced lung, nasal, and brain virus titers during an IHD virus infection, but not nearly to the same extent as i.p. cidofovir (100 mg/(kg day)). Treatment with both compounds decreased liver, spleen, and kidney virus titers, as well as reduced lung consolidation scores and lung weights. Onset of treatment could be delayed by 2 days with (N)-MCT and by 3 days with cidofovir, providing significant survival benefit during the IHD virus infection. Against a vaccinia virus (WR strain) infection in mice, i.p. (N)-MCT treatment prevented death at 500 mg/(kg day), which was comparable in activity to i.p. cidofovir (100 mg/(kg day)). Significant reductions in tissue virus titers occurred with both treatment regimens. (N)-MCT could be further pursued for its potential to treat orthopoxvirus infections in humans.

Facial lipoatrophy and the place of ultrasound

BACKGROUND

Interest in facial lipoatrophy (LA) has recently intensified; this phenomenon is linked to the rise in the number of people adversely affected by the condition as a side effect of antiretroviral treatment for HIV, combined with the growing number of cosmetic products that claim to be able to correct the appearance of LA. Despite growing awareness of the problem, there is at present no standard and accepted technique with which to assess the severity of LA.

OBJECTIVE

This review explores facial LA, the use of ultrasound in the evaluation of facial LA, its advantages and disadvantages, and will place the technique in the context of other means of assessing regional skin and fat thickness.

METHOD

Review of literature published on PubMed. RESULTS Ultrasound, as with any technique used to assess facial LA, is associated with distinct advantages and disadvantages.

CONCLUSIONS

Studies that use a number of different techniques to evaluate changes in dermal thickness provide the greatest insight into both perceived and actual changes in facial LA. Further investigation into the use of these techniques is warranted, along with a formal consensus of facial LA grades.

Cell line dependency for antiviral activity and in vivo efficacy of N-methanocarbathymidine against orthopoxvirus infections in mice

A novel carbocyclic thymidine analog, N-methanocarbathymidine [(N)-MCT], was evaluated for inhibition of orthopoxvirus infections. Efficacy in vitro was assessed by plaque reduction assays against wild-type and cidofovir-resistant strains of cowpox and vaccinia viruses in nine different cell lines. Minimal differences were seen in antiviral activity against wild-type and cidofovir-resistant viruses. (N)-MCT's efficacy was affected by the cell line used for assay, with 50% poxvirus-inhibitory concentrations in cells as follows: mouse=0.6-2.2 microM, rabbit=52-90 microM, monkey=87 to >1000 microM, and human=39-220 microM. Limited studies performed with carbocyclic thymidine indicated a similar cell line dependency for antiviral activity. (N)-MCT did not inhibit actively dividing uninfected cells at 1000 microM. The potency of (N)-MCT against an S-variant thymidine kinase-deficient vaccinia virus was similar to that seen against S-variant and wild-type viruses in mouse, monkey, and human cells, implicating a cellular enzyme in the phosphorylation of the compound. Mice were intranasally infected with cowpox and vaccinia viruses followed 24h later by intraperitoneal treatment with (N)-MCT (twice a day for 7 days) or cidofovir (once a day for 2 days). (N)-MCT treatment at 100 and 30 mg/kg/day resulted in 90 and 20% survival from cowpox virus infection, respectively, compared to 0% survival in the placebo group. Statistically significant reductions in lung virus titers on day 5 occurred in 10, 30, and 100mg/kg/day treated mice. These same doses were also active against a lethal vaccinia virus (WR strain) challenge, and protection was seen down to 10mg/kg/day against a lethal vaccinia virus (IHD strain) infection. Cidofovir (100mg/kg/day) protected animals from death in all three infections.

Acyclic nucleoside phosphonates: a key class of antiviral drugs

Almost 20 years after the broad antiviral activity spectrum of the first acyclic nucleoside phosphonates was described, several of these compounds have become important therapies for DNA virus and retrovirus infections. Here, we review the discovery and development of acyclic nucleoside phosphonates, focusing on cidofovir and its potential in the treatment of various herpes-, papilloma-, polyoma-, adeno- and pox-virus infections, adefovir for the treatment of hepatitis B and tenofovir for the treatment of AIDS and the prevention of HIV infections.