The major genetic determinants of HIV-1 control affect HLA class I peptide presentation

Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA-viral peptide interaction as the major factor modulating durable control of HIV infection.

Efficacy and Safety of Twice-Daily versus Three-Times Daily Saquinavir Soft Gelatin Capsules as Part of Triple Combination Therapy for HIV-1 Infection

Objective

The objective of this study was to determine whether a triple therapy regimen incorporating twice-daily saquinavir is as effective as a three-times daily regimen.

Methods

This was an open-label, Phase III, multicentre, 48-week study involving 837 HIV-1-infected patients randomised to one of the following: saquinavir soft gel capsule (SGC) 1200 mg three-times daily, plus two nucleoside reverse transcriptase inhibitors (NRTIs) (arm A); saquinavir SGC 1600 mg twice-daily, plus two NRTIs (arm B); saquinavir SGC 1200 mg twice-daily and nelfinavir 1250 mg twice-daily, plus a single NRTI (arm C). The primary outcome measure was the virological response in arm A versus B and in arm A versus C with respect to the percentage of patients whose plasma HIV-1 RNA levels fell below the level of quantification for the Amplicor assay (<400 copies/ml) at weeks 24 and 48.

Results

At 48 weeks, the percentage of patients with plasma HIV-1 RNA levels <400 copies/ml was 47.1% (arm A), 45.3% (arm B) and 42.7% (arm C) in the intention-to-treat analysis. The treatment difference between arm B–arm A was -1.8% (95% confidence intervals -10.1, 6.5) and for arm C–arm A was -4.5% (95% confidence intervals -12.7, 3.7) in the intention-to-treat analysis. These differences fell within the maximum allowable difference (±12%) for arm B compared with arm A. At week 24, the percentage of patients with HIV-1 RNA levels <400 copies/ml was 59.6% (arm A), 57.6% (arm B) and 51.3% (arm C).

Conclusions

A twice-daily triple therapy regimen incorporating saquinavir SGC plus two NRTIs was of equivalent efficacy to the three-times daily regimen studied. All regimens were generally well tolerated.

Antiretroviral hepatotoxicity in human immunodeficiency virus-infected patients

BACKGROUND

Drug hepatotoxicity is a potentially serious adverse reaction of antiretroviral therapy in human immunodeficiency virus-infected patients. The impact of this problem in the routine treatment of patients with human immunodeficiency virus infection is poorly defined.

OBJECTIVES

Our aim was to determine what clinical features are associated with hepatotoxicity in human immunodeficiency virus-infected patients receiving antiretroviral therapy.

METHODS

Consecutive patients in a primary care-based human immunodeficiency virus clinic were evaluated for hepatotoxicity. Clinic records were used to obtain patient characteristics, as well as independent variables including CD4+ count, coexisting hepatitis C and current alcohol use.

RESULTS

Sixty-five patients taking antiretroviral therapy were evaluated. Twenty-four were identified to have antiretroviral hepatotoxicity. An age over 40 years (P=0.019), an absolute CD4+ count of less than 310 cells/mL (P=0.002) and coexisting hepatitis C infection (P=0.035) were significantly associated with hepatotoxicity. Patients older than 40 years had a sevenfold increased risk (risk ratio, 6.9; 95% confidence interval, 1.7-27.3) and those with an absolute CD4+ count of less than 310 cells/mL had a tenfold increased risk (risk ratio, 10.2; 95% confidence interval, 2.5-41.9) for antiretroviral hepatotoxicity, in comparison with those who were younger or who had a greater absolute CD4+ count. Of the eight patients documented to have coexisting hepatitis C infection, six (75%) were in the antiretroviral hepatotoxicity group.

CONCLUSIONS

An age older than 40 years and an absolute CD4+ count of less than 310 cells/mL were significantly associated with antiretroviral-induced hepatotoxicity. The majority of our patients with chronic hepatitis C had hepatotoxicity from antiretroviral therapy.

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.

Human ehrlichiosis diagnosed in Wisconsin

A man developed a febrile illness shortly after he returned to Wisconsin from Florida, where he had received tick bites. This illness was associated with a rash, thrombocytopenia, leukopenia, and elevated hepatic enzymes, and it resolved on doxycycline. Serologic studies confirmed ehrlichiosis, a tick-borne rickettsial intraleukocytic infection endemic to the Southeastern United States. This case expands the spectrum of tick-borne illnesses that must be considered by Wisconsin clinicians.