Evaluation of an infectivity standard for real-time quality control of human immunodeficiency virus type 1 quantitative micrococulture assays. Participating Laboratories of The AIDS Clinical Trials Group

Can home-made injectable opiates contribute to the HIV epidemic among injection drug users in the countries of the former Soviet Union?

AIMS

Home-made preparation of heroin is common in countries of the former Soviet Union (FSU), and the addition of blood during its preparation and the use of contaminated syringes to distribute it may play a role in the rapid spread of HIV-1 among injecting drug users (IDUs). This study was designed to determine the viability of HIV-1 during these procedures.

SETTING

Field observations of home-made opiate manufacture in four FSU countries were used to develop a consensus protocol to replicate manufacture in the laboratory that included the addition of human blood contaminated with HIV-1.

DESIGN AND MEASUREMENT

Following the addition of HIV-1-contaminated blood during manufacture or storage, we attempted to recover viable HIV-1. The recovery was measured by propagation of the virus in stimulated white blood cells from uninfected donors.

FINDINGS

In experiments in which HIV-1 contaminated blood was added during manufacture, no viable HIV-1 was recovered. In experiments in which chornaya was introduced into HIV-contaminated syringes, the percentage of syringes containing viable HIV-1 was reduced. The reduction appeared to be related to the interaction of HIV-1 contaminated blood with a component of the poppies. While HIV-contaminated syringes used to dispense or inject home-made opiates might transmit HIV, the ability of chornaya to reduce HIV viability seems to make this route of transmission less efficient.

CONCLUSIONS

The epidemic of HIV-1 among IDUs in the FSU resulted more probably from recognized injection risk behaviors-including sharing syringes and drug solutions--than from opiate solutions harboring viable HIV-1.

Survival of human immunodeficiency virus type 1 after rinsing injection syringes with different cleaning solutions

Bleaching of syringes has been advocated to prevent HIV transmission among injection drug users (IDUs). Several reports indicate that IDUs use household products to disinfect syringes instead of bleach. To test their disinfection efficacy, we performed syringe-rinsing simulations with a range of agents used by IDUs trying to disinfect their syringes. No viable HIV-1 was recovered from syringes rinsed with bleach diluted 1:10. Bleach stored at 37 degrees C and rubbing alcohol performed better than water and the other liquids tested, but less well than bleach 1:10. Rinsing syringes with the other liquids was similar to rinsing with water alone. Increasing the rinsing volume did not always increase the effect of rinsing, but the addition of a second rinse consistently increased rinsing efficacy. Bleaching remains the most effective disinfectant among those tested. It is important that IDUs learn the proper techniques for bleach storage and syringe decontamination. Other household products are not effective disinfectants and should be avoided. Because access to sterile syringes may be restricted by laws, public policy, and police practices, bleach retains its importance in the control of the HIV-1 epidemic among IDUs.

Transendothelial migration of leukocytes carrying infectious HIV-1: an indicator of adverse prognosis

OBJECTIVE

To ascertain the likelihood that perivascular leukocyte infiltrates are sites for replication and dissemination of HIV-1.

DESIGN AND METHODS

We measured the ability of HIV patients' peripheral blood mononuclear leukocytes to migrate through confluent endothelial monolayers in vitro and infect phytohemagglutinin-stimulated allogeneic lymphoblasts. We also measured the ability of migratory leukocytes to transmit virus to uninfected leukocytes that have localized outside an endothelial barrier, and the subsequent ability of these newly infected cells to reverse-migrate back across the endothelial barrier - a process that might facilitate reentry of infected cells into the circulation and dissemination of the virus to distant sites.

RESULTS

Leukocytes from 27 out of 63 unselected patients spontaneously carried infectious virus across endothelial barriers. On follow-up, these 27 patients were frequently observed to develop uncontrolled viremia, despite treatment, and be hospitalized for secondary infections. Migratory leukocytes transmitted HIV to both T lymphocytes and non-T cells that had previously crossed the endothelial barrier. Either cell type could subsequently reverse-migrate carrying virus back across this barrier.

CONCLUSIONS

Reverse-migration of HIV-1 infected leukocytes out of perivascular reservoirs may provide a way to disseminate HIV-1 and expand the body burden of virus in some patients receiving highly active antiretroviral therapy.

Chemokine/CD4 receptor density ratios correlate with HIV replication in lymph node and peripheral blood of HIV-infected individuals

OBJECTIVES

Lymphoid tissue is a major reservoir for virus replication in HIV-infected subjects. The relationship of CCR5 and CXCR4 coreceptor density and HIV replication in peripheral blood mononuclear cells (PBMC) and lymph node (LN) mononuclear cells (LNMC) of HIV-infected subjects was examined.

METHODS

PBMC and cervical LNMC from 12 HIV-infected patients were examined for virological and immunological parameters including chemokine receptor density, HIV plasma and cellular viral load, coreceptor usage and CD38/HLA-DR expression.

RESULTS

The number of CCR5 and CXCR4 molecules on CD4 lymphocytes in the LN were significantly higher than in PBMC. In contrast the number of CD4 molecules/CD4 T cell was higher in PBMC than in LNMC. The CXCR4/CD4 and CCR5/CD4 ratios in the LN were significantly higher than in the PBMC. This was associated with a cellular viral load in the LN that was approximately 110-fold higher than in PBMC. The absolute number of coreceptor molecules per cell did not correlate with the viral load. However, the CCR5/CD4 and CXCR4/CD4 ratios in the LN positively correlated with HIV cellular and plasma RNA. Characterization of the viral isolates suggested an association between clinical isolates using a distinct coreceptor and the upregulation of the corresponding chemokine receptor.

CONCLUSIONS

The ratios of chemokine receptors to CD4 molecules in CD4 T cells from LN is higher than in PBMC and may account for the relative difference in cellular viral load in these compartments. Additionally, the coreceptor/CD4 ratios, particularly in the lymphoid tissue, were highly related to HIV replication.

Neutralization profiles of sera from human immunodeficiency virus (HIV)-infected individuals: relationship to HIV viral load and CD4 cell count

The relationship of the neutralizing activity (NA) profile of sera from human immunodeficiency virus (HIV)-infected individuals to the HIV viral load and the absolute CD4 count was examined. The NA of 24 serum samples against autologous isolates (AI) and HIV type 1 strain MN was examined. Three NA patterns were recognized. Nine sera neutralized both AI and MN (+/+), six sera neutralized MN but not AI (-/+), and nine sera failed to neutralize both AI and MN (-/-). The identification of the three neutralization patterns (+/+, -/+, and -/-) indicated that resistance to neutralization was progressive. A reciprocal relationship between the viral burden of the patients and the NA profiles was observed. The nine subjects with a -/- NA profile had a plasma viral load of > or =5 x 10(4) copies/ml and a cellular viral burden of > or =1,122 infectious units per million viable cells, which were significantly different from those of the other groups (P < 0.02). These patterns were independent of the phenotypic characteristics of the virus. Longitudinally, subjects with a -/- profile at baseline gained their HIV-specific NA by 24 weeks of antiretroviral therapy when this was associated with a >/=1-log(10) decline in the plasma HIV viral load. The sera from week 24 from some patients were able to neutralize both the 24-week and the baseline dominant virus isolates. A change in CD4 cell count of 50 or more in either direction predicted a -/- or +/+ profile. The verification of the autologous NA profile might be important in selecting patients who may benefit from immune-based therapies involving neutralizing monoclonal antibodies.

Anti-HIV type 1 memory cytotoxic T lymphocyte responses associated with changes in CD4+ T cell numbers in progression of HIV type 1 infection

We investigated memory cytotoxic T lymphocyte (CTLm) responses to HIV-1 as a determinant of HIV-1 disease progression, in relation to plasma HIV-1 load and T lymphocyte numbers in a longitudinal study of 14 homosexual men with incident HIV-1 infection. Study participants were selected who exhibited failure of T cell homeostasis, i.e., a downward inflection in CD3+ T cells that occurs in >75% of persons 1.5 to 2.5 years before development of AIDS, and compared with participants who developed low CD4+ T cell counts associated with possible T cell homeostasis failure, a subject who progressed rapidly to AIDS without well-defined T cell inflection, and subjects who had long-term preservation of T cell homeostasis (nonprogressors). High CTLm responses against Gag, but not Pol or Env, soon after seroconversion were associated with a slower loss of CD4+ T cells 1-4 years after seroconversion. Anti-Env CTLm responses decreased in most subjects around the time that T cell homeostasis failed. Plasma HIV-1 RNA increased exponentially (1.59-fold per year) over the 5 years preceding failure of T cell homeostasis, and there was a shift from a non-syncytium-inducing/CCR5 coreceptor phenotype of HIV-1 to a syncytium-inducing/CXCR4 phenotype, regardless of high or increasing levels of anti-HIV-1 CTLm during this time. These observations suggest that decreases in CTLm and increasing virus load are independent factors contributing to HIV-1 disease progression.