Human Interferon in Viral Diseases

Gemcitabine and interferon-alpha 2b in solid tumors: a phase I study in patients with advanced or metastatic non-small cell lung, ovarian, pancreatic or renal cancer

We performed a phase I study combining gemcitabine and interferon (IFN)- 2b in patients with advanced solid tumors to determine the maximum tolerated dose (MTD) and recommended doses for phase II trials. Five dose levels of gemcitabine (mg/m )/IFN- (x10 IU) were planned: 500/5, 1000/5, 1000/7, 1000/10 and 1200/10. Gemcitabine was given once weekly and IFN 3 x weekly for 3 consecutive weeks followed by 1 week of rest (28-day cycles). Between February 1997 and June 1999, 21 patients with advanced pancreatic ( =3), ovarian ( =1), renal ( =10) and non-small cell lung cancer (NSCLC; =7) were enrolled. The MTD was reached at gemcitabine 1000 mg/m and IFN- 7 x 10 IU, with two of three patients having dose-limiting toxicity (thrombocytopenia). The predominant hematologic toxicities (grade 3/4) were neutropenia and thrombocytopenia (13 and five patients, respectively). Three patients had moderate neutropenic fever and one had grade 4 AST/ALT; none required hospitalization. Of the 18 evaluable patients, responses included one partial response (NSCLC) and 10 stable diseases (eight renal cancer). We conclude that the recommended phase II study regimen is gemcitabine 1000 mg/m and IFN- 5 x 10 IU, every 28 days. The results, particularly those in metastatic renal carcinoma, are encouraging and worthy of further evaluation in phase II trials.

Successful treatment of juvenile laryngeal papillomatosis-related multicystic lung disease with cidofovir: case report and review of the literature

Cidofovir, a nucleoside analog antiviral agent, has been used with moderate success in the treatment of juvenile laryngeal papillomatosis (JLP) by direct intralesional injection. We report the first case where IV cidofovir was used successfully to treat a rare but lethal multicystic lung disease complicating JLP. A 35-year-old woman with a history of JLP requiring multiple laser ablations of laryngeal papillomata each year presented with hemoptysis and was found on CT scan to have bilateral, multiple pulmonary nodules and cysts. The results of BAL fluid analysis demonstrated no evidence of malignancy, and cultures were negative for fungi and mycobacteria. Molecular DNA typing of a biopsy specimen obtained from a laryngeal papilloma confirmed infection with human papilloma virus type 11. She received 12 months of treatment with IV cidofovir followed by 9 months of combined treatmentwith IV cidofovir and subcutaneous interferon-alpha-2A. This therapeutic regime resulted in a markedly decreased requirement for surgical removal of laryngeal papillomata, and CT scanning documented the regression of the lesions in the lung parenchyma that persisted after the discontinuation of therapy. The results of this case demonstrate that cidofovir may be used successfully to treat JLP-related lung disease and suggest that further studies are warranted.

Varicella zoster virus retrobulbar optic neuritis preceding retinitis in patients with acquired immune deficiency syndrome

OBJECTIVE

This study aimed to describe a recently recognized and rare presentation of varicella zoster virus (VZV) retrobulbar optic neuritis preceding retinitis in patients with acquired immune deficiency syndrome and to identify factors that may relate to improved visual outcome.

METHODS

Diagnosis, treatment, and clinical course are described for three eyes of two patients with this viral infection.

RESULTS

Patients had decreased vision, headache, and recent zoster dermatitis. Varicella zoster virus retrobulbar optic neuritis was diagnosed on the bases of clinical, laboratory, and electrophysiologic examination results. Profound vision loss and peripheral retinitis ensued despite intravenous antiviral treatment. Combination intravenous and intravitreous antiviral injections were administered with dramatic visual recovery.

CONCLUSIONS

Varicella zoster virus retrobulbar optic neuritis should be considered in immunocompromised patients with visual loss. Early diagnosis and aggressive combination therapy via systemic and intravitreous routes may enable return of useful vision.

Systemic antiviral drugs used in ophthalmology

Over the past two decades, the recognition of viral enzymes and proteins that can serve as molecular targets of drugs has revolutionized the treatment of viral infections. Beginning with acyclovir, a number of systemically administered agents which are both relatively safe and effective for the treatment of herpetic infections and human immunodeficiency virus (HIV) infections have become widely available. Because of increased numbers of herpes virus infections, as well as the rising epidemic of HIV infections, the ophthalmologist is, more likely than ever before to be involved in the treatment of severe and frequent ocular infections caused by herpes viruses. In addition, the acute retinal necrosis (ARN) syndrome has been demonstrated to be caused by herpes viruses and a once rare retinal infection caused by cytomegalovirus is common in patients with the acquired immunodeficiency syndrome (AIDS). In this article, four systemic antiviral drugs (Vidarabine, Acyclovir, Ganciclovir, and Foscarnet) that have demonstrated usefulness in the treatment of ophthalmic disease are reviewed in detail with regard to their mechanisms, applications, effectiveness, and side effects.

Antiviral agents

In recent years, the antiviral armamentarium has expanded considerably. Currently available agents are virustatic, inhibiting specific steps in the process of viral replication. No agent is active against nonreplicating or latent viruses. Acyclovir is useful in the treatment of genital herpes, herpes simplex encephalitis, mucocutaneous herpetic infection, varicella infection in the immunosuppressed host, and herpes zoster infection in the normal and the immunosuppressed host. It can also be used for prevention of herpesvirus infection in immunocompromised patients. Ganciclovir is indicated for the treatment of cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome (AIDS) and is effective in the management of organ-specific cytomegalovirus infection in other immunocompromised patients. Chronic hepatitis C and condyloma acuminatum due to human papillomavirus respond to therapy with interferon alfa-2b. Patients with human immunodeficiency virus infection and CD4 lymphocyte counts of less than 500 cells/mm3 should be treated with zidovudine. Amantadine is useful in a therapeutic and prophylactic role in the management of influenza A virus infection. With the expanded use of and indications for antiviral therapy, clinically significant resistance to these agents has been encountered with increasing frequency.

The future of antiviral chemotherapy

Over the past two decades, alongside the production of vaccines against many viruses, effective drugs have been developed for many other common viral infections. Initially, many of these drugs were available only for topical application because of their toxicity. However, advances in our knowledge of viral replication and of the molecular and cellular mechanisms of antiviral action have identified virus-specific targets for chemotherapeutic intervention with fewer side effects.