CCR5 antagonists in the treatment of treatment-experienced patients infected with CCR5 tropic HIV-1.

CCR5 antagonists are a newly developed class of antiretroviral drugs which inhibit viral entry into the host cell by binding to the predominant HIV coreceptor. Data on the use of these new drugs in treatment-experienced HIV patients are emerging. Clinical trials on maraviroc and vicriviroc in pretreated patients recruited more than 1300 individuals. Interim results of these studies indicate that pretreated patients infected with CCR5-tropic viruses benefit from their use in optimized combination regimens. Maraviroc reduces the HIV-1 viral load in patients with previous triple-class failure by 1.96 log10 copies/ml versus 0.99 log10 copies/ml in placebo; vicriviroc shows potency by dose depending viral decrease of 1.51-1.68 log10 copies/ml compared to 0.29 log10 in placebo. As expected, CCR5 antagonists do not reduce viral load in patients harbouring CXCR4-tropic or dual/mixed tropic viruses. Nevertheless, since a considerable percentage of late-stage HIV patients still bear CCR5-tropic viruses, the use of CCR5 antagonists appears promising in properly selected treatment-experienced patients.

Epidemiology of HHV-8 infection in HIV-positive patients with and without Kaposi sarcoma: diagnostic relevance of serology and PCR.

BACKGROUND: Kaposi's sarcoma (KS) remains the most common neoplasm in HIV-infected patients. Human herpesvirus 8 (HHV-8) infection is etiologically associated with KS. Diagnostic procedures with regard to HHV-8 infection are not routinely performed in HIV-infected patients; diagnostic and prognostic value of HHV-8 serology or PCR are unknown in this setting. Epidemiological data concerning HHV-8 infection of HIV-infected patients in Germany are rare. OBJECTIVES: To assess prevalence of HHV-8 infection in a cohort of HIV-infected patients with and without KS in Germany and to correlate this to manifestations and clinical course of KS. STUDY DESIGN: HHV-8 serology was performed in 483 patients in routine care for HIV-infection in northern Germany. HHV-8 DNA was analyzed by PCR in peripheral blood mononuclear cells (PBMC) of 293 patients; in a subgroup multiple samples were analyzed. History and manifestations of KS were recorded. RESULTS: HHV-8 antibodies were detected using IFT in 91% of 33 patients with KS and 52% of 398 patients without KS. In 36 of 293 (12.3%) patients HHV-8 DNA was detected in PBMC. In general, HHV-8 DNA was not continuously detected when multiple samples from the same patient were analyzed. Patients with KS history were more likely to be PCR positive than those without (45.5% versus 7.8%). In patients with active KS HHV-8 DNA was detected more frequently than in patients with disease remission. HHV-8 DNA was not detected in serologically negative patients. However, three patients with KS history in full remission for several years were seronegative. CONCLUSIONS: HIV-infected patients were frequently found to be positive for HHV-8 antibodies. The number of patients positive for viral DNA in PBMC was much smaller. Single PCR-examinations were of little value for prognosis, but repeated detection of HHV-8 DNA represents an increased risk of disease activity.

Reappearance of HIV multidrug-resistance in plasma and circulating lymphocytes after reintroduction of antiretroviral therapy.

BACKGROUND: After the discontinuation of antiretroviral therapy in HIV-infected patients with highly resistant virus, the detectability of viral resistance mutations quickly decreases. To which extent this represents a true loss of resistance or rather a detectability phenomenon remains unclear. OBJECTIVES: To monitor virologic response and resistance pattern during a non-strategic treatment interruption in the presence of highly drug-resistant viral strains. STUDY DESIGN: We performed serial genotypic resistance analyses on viral DNA isolated from a patient with a multidrug-resistant human immunodeficiency virus infection who discontinued and later on reintroduced antiretroviral therapy. Sequencing was performed on viral DNA from plasma as well as DNA from circulating leukocytes. RESULTS: While under combination antiretroviral therapy with two nucleosidic reverse transcriptase inhibitors, a non-nucleosidic reverse transcriptase inhibitor and a protease inhibitor, the viral load of the patient was around five logs. Genotypic resistance to all available agents was detected during this time. Antiretroviral therapy was then interrupted, and 14 weeks later an almost complete reversion of the virus to wild type was observed. After introduction of a new antiretroviral therapy regimen, the reappearance of nearly all of the formerly present resistance mutations had to be noted within 6 weeks, including mutations without known relation to any of the drugs in the new regimen. CONCLUSIONS: We obviously observed not the de novo appearance of a complex resistance pattern under just 6 weeks of potent antiretroviral therapy, but a reappearing archival strain of the virus. This finding provides evidence for subdetectable persistence of resistant variants during treatment interruptions. Therefore, resistance analyses from peripheral blood performed in times of treatment interruptions should be interpreted with caution as they may provide incomplete information about the resistance profile soon after reintroduction of therapy.

Profile of maraviroc: a CCR5 antagonist in the management of treatment-experienced HIV patients.

Maraviroc is the first and, so far, the only licensed representative of the class of chemokine receptor type 5 (CCR5) inhibitors used for the treatment of human immunodeficiency virus (HIV) infection. Its safety and efficacy were demonstrated in several clinical trials, and its use was approved in 2007 by the responsible authorities. Some specific issues are correlated with maraviroc and its use. It is the only drug in the antiretroviral armamentarium, which does not interact with the viral enzymes but with a human receptor. Hence, it is able to be long-term effective only if the infecting virus uses, exclusively, the CCR5 receptor. Occurrence and detection of the CCR5 tropism are some of the great challenges of maraviroc use in treatment-experienced patients. Although up to 80% of naive patients harbor CCR5-tropic virus, the occurrence of CXCR4 or other tropisms increases with the duration of HIV infection and treatment. Nonetheless, maraviroc is a potent medication for eligible patients and helps to improve the outcome of antiretroviral treatment (ART) of HIV infection.

Progressive multifocal leukencephalopathy in patients on highly active antiretroviral therapy: survival and risk factors of death.

OBJECTIVE: To describe the clinical course and risk factors of death in highly active antiretroviral therapy (HAART)-treated patients with progressive multifocal leukencephalopathy (PML); to evaluate the efficacy of cidofovir in addition to HAART. METHODS: Retrospective multicenter cohort study of PML in HIV-1-infected patients. Diagnosis of PML was confirmed by histology or by positive polymerase chain reaction for JC virus (JCV) in cerebrospinal fluid (CSF) or was made by typical radiologic and clinical findings. RESULTS: Thirty-five cases of PML were identified. The diagnosis was made by histology (9 cases), detection of JCV in CSF (17 cases), and by radiologic findings (9 cases). Upon manifestation of PML, 15/35 patients had never received HAART, and 11/35 were on HAART for >6 months (median 1126 days). In 9/35 cases, clinical manifestation of PML occurred within 6 months after initiation of HAART. All patients received HAART after PML diagnosis. After a median follow-up of 553 days (range 28-2694 days), the median survival time was not reached. In 12 patients who were treated concomitantly with cidofovir, cumulative survival was significantly shorter than in patients without cidofovir (P = 0.03). Patients in whom PML was diagnosed while on HAART demonstrated a trend toward a shorter survival than HAART-naive patients (P = 0.15). CONCLUSIONS: PML continues to occur in HIV-1-infected patients even when they are treated with HAART. Patients developing PML on HAART had a trend toward a shorter median survival compared with treatment-naive patients, and cidofovir therapy was not associated with improved survival in this cohort.