Prognostic importance of anaemia in HIV type-1-infected patients starting antiretroviral therapy: collaborative analysis of prospective cohort studies

Abstract

Background: In HIV type-1-infected patients starting highly active antiretroviral therapy (HAART), the prognostic value of haemoglobin when starting HAART, and of changes in haemoglobin levels, are not well defined.

Methods: We combined data from 10 prospective studies of 12,100 previously untreated individuals (25% women). A total of 4,222 patients (35%) were anaemic: 131 patients (1.1%) had severe (<8.0 g/dl), 1,120 (9%) had moderate (male 8.0-<11.0 g/dl and female 8.0- < 10.0 g/dl) and 2,971 (25%) had mild (male 11.0- < 13.0 g/ dl and female 10.0- < 12.0 g/dl) anaemia. We separately analysed progression to AIDS or death from baseline and from 6 months using Weibull models, adjusting for CD4+ T-cell count, age, sex and other variables.

Results: During 48,420 person-years of follow-up 1,448 patients developed at least one AIDS event and 857 patients died. Anaemia at baseline was independently associated with higher mortality: the adjusted hazard ratio (95% confidence interval) for mild anaemia was 1.42 (1.17-1.73), for moderate anaemia 2.56 (2.07-3.18) and for severe anaemia 5.26 (3.55-7.81). Corresponding figures for progression to AIDS were 1.60 (1.37-1.86), 2.00 (1.66-2.40) and 2.24 (1.46-3.42). At 6 months the prevalence of anaemia declined to 26%. Baseline anaemia continued to predict mortality (and to a lesser extent progression to AIDS) in patients with normal haemoglobin or mild anaemia at 6 months.

Conclusions: Anaemia at the start of HAART is an important factor for short- and long-term prognosis, including in patients whose haemoglobin levels improved or normalized during the first 6 months of HAART.

Figure 1

Kaplan Meier estimates of the cumulative probability of AIDS (left panels) and death (right panels) according to anaemia at baseline (upper panels) or anaemia at 6 months (lower panels). See table 1 for definitions of mild, moderate and severe anaemia.

Webfigure 1

Hazard ratios for progression to AIDS or death by septiles of haemoglobin levels. Median (range) haemoglobin levels in men were: septile 1: 10.6 g/dl (4.1 to 11.6 g/dl); septile 2: 12.3 g/dl (11.7 to 12.8 g/dl); septile 3: 13.2 g/dl (12.9 to 13.5 g/dl); septile 4: 13.9 g/dl (13.6 to 14.1 g/dl); septile 5: 14.4 g/dl (14.2 to 14.7 g/dl); septile 6: 15.0 g/dl (14.7 to 15.3 g/dl); septile 7: 15.9 g/dl (15.4 to 22.6 g/dl). Median (range) haemoglobin levels in women were: septile 1: 9.2 g/dl (2.1 to 10.0 g/dl); septile 2: 10.6 g/dl (10.1 to 11.0 g/dl); septile 3: 11.5 g/dl (11.1 to 11.8 g/dl); septile 4: 12.1 g/dl (11.8 to 12.4 g/dl); septile 5: 12.7 g/dl (12.4 to 12.9 g/dl); septile 6: 13.2 g/dl (13.0 to 13.6 g/dl); septile 7: 14.2 g/dl (13.7 to 18.0 g/dl).