Foscarnet therapy for severe acyclovir-resistant herpes simplex virus type-2 infections in patients with the acquired immunodeficiency syndrome (AIDS). An uncontrolled trial

STUDY OBJECTIVE: To determine whether trisodium phosphonoformate (foscarnet) is efficacious in treating severe mucocutaneous disease due to acyclovir-resistant herpes simplex virus type-2 (HSV-2) infection in patients with the acquired immunodeficiency syndrome (AIDS). DESIGN: Open-labeled drug administration to patients with AIDS and severe ulcerative disease due to acyclovir-resistant HSV-2 infection. SETTING: Medical floors of acute care hospital. PATIENTS: Four patients with AIDS who developed progressive ulcerative mucocutaneous lesions of the genitals, perineum, perianal region, or finger due to acyclovir-resistant, thymidine-kinase (TK)-negative strains of HSV-2. INTERVENTION: Foscarnet, 60 mg/kg body weight intravenously every 8 hours (with reduced dosage for renal impairment), for 12 to 50 days. MEASUREMENT AND MAIN RESULTS: All patients receiving foscarnet had dramatic improvement in their clinical findings with marked clearing of mucocutaneous lesions and eradication of HSV from mucosal surfaces. CONCLUSION: Foscarnet may be an effective treatment for severe mucocutaneous disease due to acyclovir-resistant, TK-negative strains of HSV-2.     

Foscarnet therapy in five patients with AIDS and acyclovir-resistant varicella-zoster virus infection.

OBJECTIVE: To determine whether foscarnet has potential efficacy in the treatment of acyclovir-resistant mucocutaneous varicella-zoster infection in patients with the acquired immunodeficiency syndrome (AIDS). DESIGN: Open-label study. SETTING: Three university medical centers. PATIENTS: Five patients with AIDS who were infected with thymidine-kinase-deficient or -altered strains of varicella-zoster virus. INTERVENTION: Foscarnet, 40 mg/kg body weight every 8 hours in 1-hour infusions for 10 or more days. MAIN RESULTS: Four patients had healing in response to foscarnet therapy, and each of four tested patients became culture negative for virus during foscarnet therapy. Results of fluorescent antigen testing remained positive during therapy in two patients; one of these patients had concomitant clinical failure but the other patient healed fully. One patient had complete healing despite the emergence of resistance to foscarnet in serial specimens obtained during foscarnet therapy. CONCLUSION: Foscarnet is a potentially effective and tolerable antiviral agent for patients with acyclovir-resistant, varicella-zoster virus infection; however, the optimal dosage and duration of therapy require further study, as does the relation between clinical findings and in-vitro susceptibility results.     

Acyclovir-resistant varicella zoster virus infection after chronic oral acyclovir therapy in patients with the acquired immunodeficiency syndrome (AIDS)

Four patients with human immunodeficiency virus (HIV) infection who received chronic oral acyclovir therapy for suppression of recurrent varicella zoster or herpes simplex virus infection developed persistent disseminated hyperkeratotic papules that failed to heal with intravenous or high-dose oral acyclovir therapy. Varicella zoster virus, resistant to acyclovir in vitro, was isolated from skin lesions of all four patients. Three patients were adults in whom the acquired immunodeficiency syndrome (AIDS) had been diagnosed 12 to 20 months before isolation of acyclovir-resistant varicella zoster virus. The fourth patient was a perinatally HIV-infected child who developed primary varicella infection at age 7 years when profoundly immunosuppressed (absolute CD4+ lymphocyte count less than 50 cells/microL). Mean antiviral susceptibilities (ED50 values) of the four clinical isolates compared with the ED50 values of the reference strain Oka were 85 compared with 3.3 mumol/L for acyclovir, 1.4 compared with 0.8 mumol/L for vidarabine, and 123 compared with 117 mumol/L for foscarnet. When assayed by [125I]-dC plaque autoradiography, 90% to 100% of the viral isolate populations had altered or no measurable thymidine kinase function. Acyclovir-resistant varicella zoster virus infection may complicate long-term oral acyclovir administration in patients with AIDS and may be associated with the appearance of atypical hyperkeratotic papules.     

Characterization of the DNA polymerase and thymidine kinase genesof herpes simplex virus isolates from AIDS patients in whom acyclovirand foscarnet therapy sequentially failed.

Herpes simplex virus (HSV) isolates were characterized from 8 AIDS patients in whom acyclovir and foscarnet therapy sequentially failed. The 6 postacyclovir (prefoscarnet) HSV isolates were resistant to acyclovir and susceptible to foscarnet. Of the 9 postfoscarnet isolates, 8 were foscarnet-resistant and acyclovir-susceptible, 1 was resistant to both drugs. Acyclovir- or foscarnet-resistant isolates retained susceptibility to cidofovir. The acyclovir-resistant isolates contained single-base substitutions or frameshift mutations in G or C homopolymer nucleotide repeats of the thymidine kinase gene. In contrast, the foscarnet-resistant strains contained single-base substitutions in conserved (II, III, or VI) or, more rarely, nonconserved (between I and VII) regions of the DNA polymerase (pol) gene. The single isolate exhibiting resistance to acyclovir and foscarnet contained mutations in both genes. In this study of clinical HSV isolates, DNA pol mutations conferring foscarnet resistance were not associated with decreased acyclovir or cidofovir susceptibility.     

The effect of foscarnet (phosphonoformate) on human immunodeficiency virus isolation, T-cell subsets and lymphocyte function in AIDS patients

Foscarnet was administered by continuous intravenous infusion in 15 patients with the acquired immunodeficiency syndrome (AIDS) in an open, uncontrolled study. Mean steady state serum concentrations of foscarnet was 261 mumol/l. Treatment was given for 6-21 days, median 14 days, being interrupted prematurely due to renal function impairment in seven patients, and due to other reasons in three patients. Foscarnet therapy was accompanied by improvement of some, probably cytomegalovirus (CMV) related, symptoms but did not otherwise affect the clinical condition of the patients. The occurrence of positive CMV cultures decreased significantly during therapy. Human immunodeficiency virus (HIV) detection by culture was positive in 70-80% of cultures and was unaffected by foscarnet treatment. Eight patients had detectable, free HIV antigen in serum before therapy, and in five of these HIV antigen disappeared during therapy, but reappeared 4-23 weeks after therapy. No patient lost HIV antigen, except during foscarnet therapy. No patient became HIV antigen positive during foscarnet therapy. Immunological parameters did not change during or after foscarnet therapy. Renal function impairment was seen in 9 patients (95% confidence limits, 32-84%), apparently due to reversible tubular damage. At follow-up, serum creatine was normal in all surviving patients. Concomitant medication may have contributed to the renal side-effects. Severe renal function impairment, i.e. serum creatinine above 0.25 mumol/l, was only seen in patients who at the start of foscarnet therapy were chronically affected by their disease. Thus, foscarnet reduces HIV antigen production in AIDS patients. Renal function impairment limits foscarnet use in AIDS patients, but in individuals with less severe manifestations of HIV infection, this side effect may be less frequent.     

Development of drug-resistant herpes simplex virus infection after haploidentical hematopoietic progenitor cell transplantation.

An unusually high incidence of acyclovir- and foscarnet-resistant herpes simplex virus (HSV) infection was noted after lymphocyte-depleted blood hematopoietic progenitor cell (HPC) transplantation from HLA-haploidentical family donors. Fourteen adults with hematologic malignancies underwent blood HPC transplantation from haploidentical family donors. Pheresis products were stringently depleted of T and B cells by immunomagnetic adsorption, and patients received no immunosuppression after transplantation. HSV reactivation occurred in all 7 evaluable HSV-1- or HSV-2-seropositive patients, at a median of 40 days after transplantation. Susceptibility testing of clinically resistant viral isolates demonstrated acyclovir resistance in all 5 cases tested. Second-line therapy produced only partial responses, and in vitro evidence of foscarnet resistance developed rapidly in all 3 patients treated with foscarnet. Healing of lesions coincided with T-cell recovery. The prolonged immunodeficiency associated with stringent lymphocyte depletion of the graft appears to strongly predispose to emergence of drug-resistant HSV. Furthermore, immune reconstitution is necessary for eradication of infection.     

Mucocutaneous dissemination of acyclovir-resistant herpes simplex virus in a patient with AIDS

Infections caused by herpes simplex virus (HSV) are a significant source of morbidity in immunocompromised patients. Acyclovir is often used prophylactically and therapeutically in patients with human immunodeficiency virus infection. The emergence of acyclovir-resistant strains of HSV capable of causing disease has been recognized. We report a case in which a thymidine kinase-deficient mutant of HSV caused extensive disease in a patient with AIDS. This case emphasizes that virus recovered from nonhealing lesions should be submitted for further study, which may advance our understanding of the interaction between host defense and drug-resistant strains.     

Resistant herpes simplex virus type 1 infection: an emerging concern after allogeneic stem cell transplantation.

Fourteen cases of severe acyclovir-resistant herpes simplex virus type 1 (HSV-1) infection, 7 of which showed resistance to foscarnet, were diagnosed among 196 allogeneic stem cell transplant recipients within a 29-month period. Recipients of unrelated stem cell transplants were at higher risk. All patients received foscarnet; 8 subsequently received cidofovir. Strains were initially foscarnet-resistant in 3 patients and secondarily so in 4 patients. In vitro resistance to acyclovir or foscarnet was associated with clinical failure of these drugs; however, in vitro susceptibility to foscarnet was associated with complete response in only 5 of 7 patients. No strain from any of the 7 patients was resistant in vitro to cidofovir; however, only 3 of 7 patients achieved complete response. Therefore, acyclovir- and/or foscarnet-resistant HSV-1 infections after allogeneic stem cell transplantation have become a concern; current strategies need to be reassessed and new strategies must be evaluated in this setting.     

Serious cytomegalovirus disease in the acquired immunodeficiency syndrome (AIDS). Clinical findings, diagnosis, and treatment

Life-threatening opportunistic cytomegalovirus infection is a complication of the acquired immunodeficiency syndrome (AIDS) that occurs in 7.4% or more of patients with AIDS. Cytomegalovirus retinitis, colitis, esophagitis, and gastritis are the commonest manifestations of severe cytomegalovirus end-organ disease. Extensive trials with intravenous ganciclovir, a nucleoside analogue with myelosuppressive toxicity, have shown that ganciclovir halts the progression of cytomegalovirus retinitis and gastrointestinal disease. Since relapse is common when therapy is discontinued, most patients with AIDS need life-long maintenance therapy. The clinical response to ganciclovir therapy is usually accompanied by diminished shedding of the virus. Based on limited data, foscarnet, a pyrophosphate analogue, also appears to have some efficacy in treating cytomegalovirus infection. Unlike ganciclovir, foscarnet does not cause myelosuppression. An important direction for future clinical research is the development of more effective and less toxic therapy, as well as orally bioavailable drugs for maintenance therapy.     

Acyclovir-resistant genital herpes among persons attending sexually transmitted disease and human immunodeficiency virus clinics

BACKGROUND: Genital herpes is epidemic in the United States; long-term acyclovir therapy is common; and long-term use of antimicrobials in suppressive doses favors development of resistance. OBJECTIVE: To determine the prevalence of and risk factors for acyclovir-resistant genital herpes. METHODS: We identified and attempted to enroll all patients 18 years or older with suspected genital herpes who attended 22 sexually transmitted disease and human immunodeficiency virus (HIV) clinics in the United States between October 1996 and April 1998. We conducted standardized interviews of all consenting patients. Lesions were cultured, and isolates were typed as herpes simplex virus (HSV) 1 or HSV-2 and tested for acyclovir sensitivity (using a 50% inhibitory concentration of 2 microg/mL) by plaque reduction, which was independently confirmed. RESULTS: Herpes simplex virus was isolated from 2088 of 3602 patients, and 90.2% of isolates were HSV-2. Fifteen isolates, all HSV-2, were acyclovir resistant. Three (0.18%) of 1644 HIV-negative patients had acyclovir-resistant isolates (95% confidence interval [CI], 0.04%-0.5%); resistance was associated with oral (P<.006) and topical (P<.001) acyclovir use. Twelve (5.3%) of 226 HIV-positive patients yielded resistant HSV isolates (95% CI, 2.8%-9.1%); resistance was associated with oral acyclovir use (P<.001), duration of the current episode (P<.001), history of recurrent genital herpes (P<.01), and low CD4 cell count (P<.05). CONCLUSIONS: In the 15 years following licensure of acyclovir, resistance to the drug remains low among immunocompetent patients. However, 5% of HIV-positive patients had resistant HSV-2 isolates. Continued surveillance is essential to monitor changes in acyclovir resistance and to characterize the clinical and public health importance of acyclovir-resistant HSV.     

Successful treatment with foscarnet for disseminated varicella-zoster infection after reduced intensity stem cell transplantation in a case of relapsed refractory central nervous system lymphoma

Visceral disseminated varicella-zoster virus (VZV) infection occurred with acute graft-versus-host disease in a 33-year-old Japanese male with non-Hodgkin lymphoma who had undergone allogeneic stem cell transplantation from an HLA-identical sibling after reduced intensity conditioning chemotherapy. Although ganciclovir and acyclovir treatment was effective temporarily, the number of VZV-DNA copies in the blood remained at a high level, and the hepatitis was prolonged. The patient was treated with foscarnet, which led to improvement of the VZV viremia and the hepatic dysfunction. Foscarnet therapy should be considered for acyclovir-resistant VZV infection in the setting of allogeneic hematopoietic stem cell transplantation.     

Infection with herpes simplex virus and cell-mediated immunity after marrow transplant

The relationship between herpes simplex virus (HSV) infection and specific cell-mediated immunity was investigated in 141 patients before and for the first four months after marrow transplant. Sixty-two (82%) of 76 seropositive patients but only one of 65 seronegative patients developed HSV infection. Lymphocyte responses to HSV antigen were suppressed immediately after transplant and subsequently became reactive in those patients with HSV infection. The presence or absence of antibody to HSV in the donor before transplant did not influence the response. Seventy long-term survivors of marrow transplant were also studied. Among 60 patients who had pretransplant serum available for study, 26 (68%) of 38 who had been seropositive before transplant had positive responses compared with none of 22 who had been seronegative. Recovery of responsiveness to HSV antigen after marrow transplant is primarily related to recurrent virus infection and not to the pretransplant immune status of the donor.     

Multiple herpes simplex virus infections with various resistance patterns in a matched unrelated donor transplant recipient.

A 45-year-old matched unrelated BMT recipient had sequential mucocutaneous herpes simplex virus (HSV) type 2 infections. Five months after BMT, a penile lesion occurred and was cured using acyclovir, as expected from in vitro susceptibility results. The same lesion recurred 1 month later but worsened with acyclovir. The HSV isolate was resistant to acyclovir (IC(50) = 105 microM), and a nucleotide (G) was added to the thymidine kinase gene leading to a premature stop codon. The lesion improved markedly with foscarnet. During this treatment a second HSV infection occurred on the buttocks 2 weeks after the first one and healed completely with acyclovir. This course correlated with in vitro results of the buttock HSV isolate which was foscarnet-resistant (IC(50) = 300 microg/ml) and acyclovir-sensitive. Surprisingly, no mutation gene of the foscarnet-resistant isolate was detected in the DNA polymerase gene. This case shows that an HSV acyclovir-resistant infection may be followed by an acyclovir-sensitive one. Determination of antiviral susceptibility is needed to monitor the treatment of various HSV infections in immunocompromised BMT recipients.     

Infections with cytomegalovirus and other herpesviruses in 121 liver transplant recipients: transmission by donated organ and the effect of OKT3 antibodies

One hundred twenty-one adult liver transplant recipients were studied for the incidence, risk factors, and morbidity associated with herpesviruses infections after transplantation. The overall incidence of infection was 59% for cytomegalovirus (CMV), 35% for herpes simplex virus (HSV), 25% for Epstein-Barr virus (EBV), and 7% for varicella-zoster virus (VZV). Primary CMV infection occurred in 46% and reactivation CMV infection in 67% of the susceptible recipients. Symptomatic and disseminated CMV diseases were more common when patients developed primary infection (P less than .01, for both comparisons). The donor organ appeared to be the only important source of CMV infection in seronegative recipients. The use of OKT3 antibodies was associated with disseminated CMV disease in patients with primary infection (P = .04) but not with reactivation infection (P greater than .10). Although most HSV infections were oral or genital reactivations, three cases of HSV hepatitis occurred--one was a primary infection. Symptomatic reactivations of HSV were observed in 53% of HSV-seropositive recipients who received OKT3, versus 31% of seropositive recipients who did not receive OKT3 (P = .05).     

Oral topical cidofovir: novel route of drug delivery in a severely immunosuppressed patient with refractory multidrug-resistant herpes simplex virus infection

We present a case of serious treatment-refractory acyclovir- and foscarnet-resistant herpes simplex virus (HSV) type-1 orolingual infection that responded to oral cidofovir rinses after failure of acyclovir and foscarnet therapy. The use of 3% cidofovir in a saline rinse for refractory mucosal HSV infection appears promising but needs prospective evaluation.     

In vitro sensitivity to acyclovir in genital herpes simplex viruses from acyclovir-treated patients

Genital isolates of herpes simplex virus (HSV) from patients given acyclovir or placebo were tested in vitro for sensitivity to acyclovir. Isolates obtained before therapy were sensitive to acyclovir concentrations of 0.01-19 micrograms/ml, with 86 of 97 isolates inhibited by less than 1 microgram/ml. Before therapy, six patients had isolates of HSV type 2 with ID50 values (concentrations of drug reducing viral cytopathic effect by 50%) of greater than 3 micrograms/ml. Plaque purification revealed mixed populations of virus; some clones were associated with high and some with low rates of acyclovir phosphorylation. Sensitivity to acyclovir decreased in isolates obtained after therapy from four of 25 patients given acyclovir and three of 30 patients given placebo. The occurrence of this change with similar frequency in the two groups suggests that factors other than the use of acyclovir influence the in vitro sensitivity of clinical HSV isolates to this agent. In one patient in whom an acyclovir-resistant, thymidine kinase-negative strain of HSV type 2 emerged during therapy, infection subsequently recurred. The isolate responsible for the recurrence was sensitive to acyclovir and had a high level of acyclovir-phosphorylating activity.     

Altered sensitivity to antiviral drugs of herpes simplex virus isolates from a patient with the acquired immunodeficiency syndrome

Acyclovir (ACV)-resistant herpes simplex virus type 2 (HSV-2) was isolated from a patient with acquired immunodeficiency syndrome after long-term but intermittent ACV therapy. These thymidine kinase-defective isolates were sensitive in vitro to foscarnet. While combined therapy with ACV and interferon produced only partial clinical improvement, the in vitro effect of this combination against an ACV-resistant isolate from the patient was strongly synergistic. A short course (10-12 days) of intravenous foscarnet controlled severe ulceration, and clinical improvement lasted 6 months. After recurrence and further courses of foscarnet, however, the patient responded poorly, and subsequent HSV isolates were resistant to both ACV and foscarnet and hypersensitive to aphidicolin.     

Zidovudine (AZT) for treatment of patients infected with human immunodeficiency virus type 1. An evaluation of effectiveness in clinical practice

To learn about the patterns of use and the effectiveness of zidovudine therapy in clinical practice, we conducted an observational cohort study of 86 patients with human immunodeficiency virus type 1 infection. All patients were followed up for at least 6 months after starting zidovudine (AZT) therapy. Of the 86 patients, 78 (91%) initially received full-dosage zidovudine (1200 mg/d), and eight received a reduced dosage (600 mg/d). During follow-up, the number able to maintain full-dosage zidovudine therapy decreased to 54 (63%) at 3 months and 40 (47%) at 6 months. Thirty-five patients required dosage reductions that lasted at least 7 days and were not preceded by an adverse outcome (death or opportunistic infection). Overall, adverse outcomes occurred for nine (26%) of those with dosage reductions compared with 22 (43%) of 51 patients with no previous dosage change. Even after adjusting for baseline cytopenias and the time of the dosage reductions, adverse outcomes did not occur significantly more often in patients who received reductions in their zidovudine dosage. Our results indicate that full-dosage zidovudine therapy cannot be maintained for most patients infected with human immunodeficiency virus, but that clinicians need not be pessimistic about treatment outcomes when dosage reductions are needed.     

Frequency and significance of acyclovir-resistant herpes simplex virus isolated from marrow transplant patients receiving multiple courses of treatment with acyclovir

The sensitivity to acyclovir of virus isolates from 52 consecutive marrow transplant patients who received acyclovir for herpes simplex virus infections was studied in vitro. The median sensitivity of viruses obtained during first, second, third, and fourth recurrences was similar, and the median duration of virus positivity (three days) was the same for first and second treatment courses. However, acyclovir-resistant virus was recovered from one of 52 patients (1.9%) during the initial treatment course and from two of 22 patients (9.1%) treated for second recurrences. All three strains had reduced thymidine kinase activity. None caused severe infection. Three other patients remained virus-positive during treatment despite the isolation of acyclovir-sensitive virus. Although continuing surveillance is necessary, these data may suggest that acyclovir-resistant virus will not be the cause of significant clinical illness among immunosuppressed patients. In addition, not all instances of "resistance," defined by the persistence of virus during treatment, will be caused by virus strains that are resistant to acyclovir in vitro.     

Cidofovir for treating adenoviral hemorrhagic cystitis in hematopoietic stem cell transplant recipients

Adenovirus (AdV) infection is an important cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients. We treated 16 patients with AdV hemorrhagic cystitis (HC) following HSCT with cidofovir (CDV; 1 mg/kg/day, three times weekly for 3 weeks). Patients included 10 males and six females with a median age of 50 years (range 10-62). Two of the 16 patients were unevaluable because of early death from nonadenoviral causes. CDV therapy cleared AdV from urine in 12 of 14 patients (86%). Of 14 patients, 10 (71%) showed clinical improvements in HC. Among 14 patients, seven (50%) had avoided renal damage, the most important CDV toxicity. One patient previously treated with foscarnet for cytomegalovirus (CMV) required hemodialysis, and CDV treatment was discontinued. In another patient, CDV treatment was discontinued because of grade 2 nephrotoxicity. Four patients became positive for CMV antigenemia while being treated with CDV, and two developed herpes simplex virus (HSV) stomatitis while being treated with CDV. CDV proved effective in treating AdV HC in transplant patients. However, CDV at 1 mg/kg/day given three times weekly failed to prevent breakthrough infection with CMV and HSV in some patients.