Survival after a very low (< 5 x 10(6)/l) CD4+ T-cell count in individuals infected with HIV

[Predictors of progression and death in patients with advanced HIV infection in the era of highly active antiretroviral therapy]

INTRODUCTION

To assess the factors associated with progression of infection and death in HIV-positive patients with severe immunodepression in the era of highly active antiretroviral therapy (HAART).

METHODS

We studied 146 HIV-infected patients with < 100 x 10(6)/L CD4+ lymphocytes and positive cytomegalovirus (CMV) serology enrolled between December 1997 and October 1998 and prospectively followed a median of 12.1 months. The main outcome measures were progression of HIV infection, defined as the appearance of a new AIDS-defining disease (CDC category C) or death. HIV viral load, lymphocyte count (CD4+ and CD8+), HAART administration and other clinical variables were evaluated at baseline. CMV viremia (determined by PCR) and HAART efficacy were recorded during follow-up.

RESULTS

Progression was observed in 40% of patients and 17% died. Factors associated with progression or death were CD4+ lymphocyte count less than 50 x 10(6)/L, CD8+ lymphocyte count less than 500 x 10(6)/L, HIV viral load more than 300,000 copies RNA/mL, CMV viremia, and absence or inefficacy of HAART. In the multivariate model, absence of HAART and low CD4+ and CD8+ counts remained statistically associated with progression, but the only variable associated with death was CMV viremia.

CONCLUSIONS

In patients with advanced HIV infection, CD4+ and CD8+ cell count and HAART were the most important factors related to progression, and CMV viremia was the strongest predictor of death.

Cytofluorometric methods for assessing absolute numbers of cell subsets in blood. European Working Group on Clinical Cell Analysis

The enumeration of absolute levels of cells and their subsets in clinical samples is of primary importance in human immunodeficiency virus (HIV)+ individuals (CD4+ T- lymphocyte enumeration), in patients who are candidates for autotransplantation (CD34+ hematopoietic progenitor cells), and in evaluating leukoreduced blood products (residual white blood cells). These measurements share a number of technical options, namely, single- or multiple-color cell staining and logical gating strategies. These can be accomplished using single- or dual-platform counting technologies employing cytometric methods. Dual-platform counting technologies couple the percentage of positive cell subsets obtained by cytometry and the absolute cell count obtained by automated hematology analyzers to derive the absolute value of such subsets. Despite having many conceptual and technical limitations, this approach is traditionally considered as the reference method for absolute cell count enumeration. As a result, the development of single-platform technologies has recently attracted attention with several different technical approaches now being readily available. These single-platform approaches have less sources of variability. A number of reports clearly demonstrate that they provide better coefficients of variation (CVs) in multicenter studies and a lower chance to generate aberrant results. These methods are therefore candidates for the new gold standard for absolute cell assessments. The currently available technical options are discussed in this review together with the results of some cross-comparative studies. Each analytical system has its own specific requirements as far as the dispensing precision steps are concerned. The importance of precision reverse pipetting is emphasized. Issues still under development include the establishment of the critical error ranges, which are different in each test setting, and the applicability of simplified low-cost techniques to be used in countries with limited resources.

Gender and survival after AIDS in Rio de Janeiro, Brazil

The relation between gender and survival after a diagnosis of AIDS was studied in a cohort of patients with HIV infection in Rio de Janeiro, Brazil. During the study period, 124 of 617 patients (20%) developed AIDS. Of this group, 91 patients were men and 33 were women. There were no gender related differences regarding the access to antiretroviral therapy or to prophylaxis for Pneumocystis carinii pneumonia. Survival was shorter among women (hazard ratio [HR] = 4.43; p < .001) after adjustment for age and AIDS-defining condition. Adjusting for CD4+ and CD8+ counts reduced the difference between genders (HR = 3.33; p = .017). These results suggest that survival after an AIDS diagnosis may be shorter among women than men in Brazil. Further studies are needed to determine the factors that may be negatively influencing the prognosis of women with AIDS in Brazil.