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Disease progression and survival in HIV-1-infected Africans in London
J Del Amo1, A Petruckevitch, A Phillips
1Medical Research Council UK Centre for Co-ordinating Epidemiological Studies of HIV and AIDS, Department of Sexually Transmitted Diseases, Mortimer Market Centre, London.
Insights
HIV-1 progression to AIDS and death did not differ significantly between African and non-African groups in London. Clinical factors, not ethnicity or viral subtypes, were key determinants of outcomes in these HIV-1 patients.
Area of Science:
- Immunology
- Epidemiology
- Infectious Diseases
Background:
- Human Immunodeficiency Virus type 1 (HIV-1) infection presents diverse clinical trajectories globally.
- Sub-Saharan Africa, a region with high HIV-1 prevalence, predominantly harbors non-B viral subtypes, contrasting with subtypes common in Europe and North America.
Purpose of the Study:
- To investigate potential disparities in the progression to Acquired Immunodeficiency Syndrome (AIDS) and mortality between HIV-1-positive individuals of African and non-African origin residing in London.
- To determine if observed differences are attributable to ethnicity, viral subtypes, or other clinical factors.
Main Methods:
- A retrospective cohort study involving 2048 HIV-1-positive individuals attending major HIV/AIDS centers in London.
- The cohort comprised 1056 individuals of African origin and 992 of non-African origin, with data collected between 1982 and 1995.
Main Results:
- No significant difference was observed in crude survival rates from presentation to death between the two groups (median 82 months for Africans vs. 78 months for non-Africans).
- While Africans showed a trend towards more rapid AIDS progression (HR 1.21), this was not statistically significant after adjusting for covariates (adjusted HR 1.15).
- Tuberculosis as the initial AIDS-Defining Condition (ADC) was associated with a substantial 64% reduction in mortality risk.
Conclusions:
- Observed differences in HIV-1 progression and CD4+ lymphocyte decline between African and non-African individuals in London were not linked to ethnicity or viral subtypes.
- Patient factors such as age, and the clinical and immunological status at presentation or diagnosis of AIDS, were the primary determinants of outcomes.
- Reduced survival in Africa is more likely due to factors like limited healthcare access and environmental pathogen exposure rather than inherent differences in immune deficiency progression based on race or viral subtypes.
Objective:
To examine differences in progression to AIDS and death between HIV-1-positive Africans (most infected in sub-Saharan Africa and therefore with non-B subtypes) and HIV-1-positive non-Africans in London.
Design:
Retrospective cohort study of 2048 HIV-1-positive individuals.
Setting:
HIV-1-infected individuals attending 11 of the largest HIV/AIDS units in London.
Patients:
Subjects were 1056 Africans and 992 non-Africans seen between 1982-1995.
Results:
There were no differences in crude survival from presentation to death between Africans and non-Africans (median 82 and 78 months, respectively; P = 0.22). Africans progressed more rapidly to AIDS [hazard ratio (HR), 1.21; 95% confidence interval (CI), 1.02-1.45] but after adjustment for age, sex, Centers for Disease Control and Prevention category B symptoms and CD4+ lymphocyte count at presentation, year of HIV diagnosis and hospital attended, this difference was no longer significant (adjusted HR, 1.15; 95% CI, 0.93-1.43). Africans with AIDS had a reduced risk of death compared with non-Africans (HR, 0.78; 95% CI, 0.63-0.96) but not after adjustment for age, CD4+ lymphocyte count at AIDS, initial AIDS-defining conditions (ADC) and hospital attended (HR, 0.98; 95% CI, 0.76-1.27). Tuberculosis as the first ADC was associated with a 64% reduction in the risk of death. CD4+ lymphocyte decline was not significantly different between Africans and non-Africans (P = 0.18).
Conclusions:
Differences in progression to AIDS and death and CD4+ lymphocyte decline between HIV-1-infected Africans and non-Africans in London could not be attributed to ethnicity or different viral subtypes. Age and the clinical and immunological stage at presentation, or AIDS, were the major determinants of outcome. Compared with other diagnoses, tuberculosis as the initial ADC was associated with increased survival. Lack of access to health care and exposure to environmental pathogens are the most likely causes of reduced survival with AIDS in Africa, rather than inherently different rates of progression of immune deficiency due to racial differences or viral subtypes.