Influence of inflammation as measured by alpha-1-acid glycoprotein on iron status indicators among HIV-positive postpartum Zimbabwean women.

OBJECTIVES: The acute phase response (APR) influences indicators of iron status. A recent WHO/CDC consultation recommended concurrent measurement of alpha-1-acid-glycoprotein (AGP) in surveys to control for the APR, and aid in interpreting iron status. They proposed further exploratory analyses using AGP. We examined whether the APR (measured by AGP) influences the expected relationships between iron status indicators in an HIV-infected population. SUBJECTS: We measured hemoglobin (Hb), serum ferritin (SF), transferrin receptor (TfR), erythropoietin (EPO) and AGP in a cross-sectional survey of 643 HIV-positive Zimbabwean women. RESULTS: SF was significantly higher in APR-positive (AGP>1 g/l) women (P<0.001), in whom there was no association between SF and Hb. TfR was inversely associated with Hb, in both APR-positive and APR-negative women (P<0.001). However, among anemic women (Hb<110 g/l), APR-positive women had marginally lower TfR concentrations (P=0.053). There was no difference in EPO response to decreasing Hb among APR-positive and APR-negative women. CONCLUSIONS: AGP captured the influence of the APR on iron indicators and their relationships with each other. The APR influenced SF and its relationship with Hb as expected. TfR behaved unexpectedly. Although TfR has been promoted as an iron indicator that is uninfluenced by the APR, TfR concentrations were depressed among anemic APR-positive women. Because TfR reflects iron deficiency and erythropoietic activity, pro-inflammatory cytokines associated with the APR may be inhibiting erythropoiesis, which is reflected by lower TfR concentrations. We support the WHO/CDC recommendation that AGP is a useful indicator to assess the influence of the APR on iron status indicators.

Elevated iron stores are associated with HIV disease severity and mortality among postpartum women in Zimbabwe.

OBJECTIVES: The relationship between Fe status and HIV infection is complex and poorly understood. While anaemia is a major complication of HIV infection, higher Fe stores may be associated with disease progression. There is limited and conflicting data available from Africa. DESIGN: Cross-sectional and prospective cohort study. SETTING, SUBJECTS AND METHODS: We examined the association between postpartum Fe status (Hb, serum ferritin (SF) and transferrin receptor (TfR)) and viral load (VL) and HIV-related mortality in 643 HIV-positive Zimbabwean women over a period of 12 months. RESULTS: In non-anaemic women a log10 increase in SF was associated with a 2.3-fold increase in VL (P = 0.019); this association was absent in anaemic women. In prospective analyses, a log10 increase in SF was associated with a 4-fold increase in mortality by 12 months (P = 0.002). Hb was negatively associated with VL (P = 0.001) and mortality (P = 0.047). The adverse associations between SF and both VL and mortality were found at SF concentrations > 45 microg/l (P < 0.05). Controlling for alpha1 acid glycoprotein, a marker of inflammation, attenuated the association between both SF and VL and mortality, but these remained significant. CONCLUSIONS: These results are consistent with the hypothesis that high Fe stores have adverse consequences in HIV infection. If adverse consequences are real, our data suggest that they occur at SF concentrations exceeding those consistent with adequate Fe nutriture.

HIV-1 and HIV-2 prevalence and associated risk factors among postnatal women in Harare, Zimbabwe.

Studies of antenatal women form the predominant source of data on HIV-1 prevalence in Africa. Identifying factors associated with prevalent HIV is important in targeting diagnostic services and care. Between November 1997 and January 2000, 14,110 postnatal women from Harare, Zimbabwe were tested by ELISAs reactive to both HIV-1 and HIV-2; a subset of positive samples was confirmed with assays specific for HIV-1 and HIV-2. Baseline characteristics were elicited and modelled to identify risk factors for prevalent HIV infection. HIV-1 and HIV-2 prevalences were 32.0% (95% CI 31.2-32.8) and 1.3% (95% CI 1.1-1.5), respectively; 4% of HIV-1-positive and 99% of HIV-2-positive women were co-infected. HIV-1 prevalence increased from 0% among 14-year-olds to >45% among women aged 29-31 years, then fell to <20% among those aged>40 years. In multivariate analyses, prevalence increased with parity, was lower in married women than in single women, divorcees and widows, and higher in women with the lowest incomes and those professing no religion. Adjusted HIV-1 prevalence increased during 1998 and decreased during 1999. Age modified the effects of parity, home ownership and parental education. Among older women, prevalence was greater for women who were not homeowners. Among younger women, prevalence increased with parity and low parental education. None of these factors distinguished women co-infected with HIV-2 from those infected with HIV-1 alone. Prevalent HIV-1 infection is associated with financial insecurity and weak psychosocial support. The ZVITAMBO study apparently spanned the peak of the HIV-1 epidemic among reproductive women in Harare.