Asymptomatic serum cryptococcal antigenemia and early mortality during antiretroviral therapy in rural Uganda

University of California, San Francisco, San Francisco, California, United States
Tropical Medicine & International Health (Impact Factor: 2.33). 08/2007; 12(8):929-35. DOI: 10.1111/j.1365-3156.2007.01874.x
Source: PubMed


To evaluate the association between a positive serum cryptococcal antigen (CRAG) test at baseline and mortality during the first 12 weeks on antiretroviral therapy (ART). Cryptococcal meningitis is a leading cause of HIV-related mortality in Africa, but current guidelines do not advocate CRAG testing as a screening tool.
Between May 2003 and December 2004, we enrolled HIV-1 infected individuals into a study of ART monitoring in rural Uganda. CRAG testing was conducted retrospectively on stored pre-ART serum samples of participants whose baseline CD4 cell count was <100 cells/mul and who were without symptoms suggestive of disseminated cryptococcal disease at enrolment.
Of 377 participants, 5.8% had serum CRAG titre >/=1:2. Of these, 23% died during follow-up. Controlling for CD4 cell count, HIV-1 viral load, anaemia, active tuberculosis and body mass index, relative risk of death during follow-up among those with asymptomatic cryptococcal antigenemia at baseline was 6.6 [95% confidence interval (CI) 1.86-23.61, P = 0.0036]. The population attributable risk for mortality associated with a positive CRAG at baseline was 18% (CI 2-33%), similar to that associated with active tuberculosis (19%, CI 1-36%).
Asymptomatic cryptococcal antigenemia independently predicts death during the first 12 weeks of ART among individuals with advanced HIV disease in rural Uganda. Routine screening and provision of azole antifungal therapy prior to or simultaneous with the start of ART should be evaluated for the potential to prevent mortality in this population.

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    • "These findings are in accordance with the many studies demonstrating improved clinical outcomes and decreased mortality among individuals receiving ART in both developed countries [11]–[18] and RLS [19], [20]. Moreover, we observed lower rates of poor outcomes among individuals with serum cryptococcal antigenemia as compared to previous studies with ART-naïve individuals with a CD4<100 cells/µl [7], [8]. We conjecture that the low rate of mortality and development of cryptococcal meningitis observed among screen positive individuals in this cohort as compared to prior studies with ART-naïve individuals is related to high rates of successful ART receipt at baseline (26 of 31 of CRAG positive individuals), higher CD4 counts at baseline (18 of 31 had CD4>100 cells/µl), and a survivorship bias resulting from a long duration of previous therapy (37 months) [4]. "
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    ABSTRACT: There are limited data on clinical outcomes of ART-experienced patients with cryptococcal antigenemia. We assessed clinical outcomes of a predominantly asymptomatic, ART-experienced cohort of HIV+ patients previously found to have a high (8.4%) prevalence of cryptococcal antigenemia. The study took place at All Africa Leprosy, Tuberculosis and Rehabilitative Training Centre and Black Lion Hospital HIV Clinics in Addis Ababa, Ethiopia. A retrospective study design was used to perform 12-month follow-up of 367 mostly asymptomatic HIV-infected patients (CD4<200 cells/µl) with high levels of antiretroviral therapy use (74%) who were previously screened for cryptococcal antigenemia. Medical chart abstraction was performed approximately one year after initial screening to obtain data on clinic visit history, ART use, CD4 count, opportunistic infections, and patient outcome. We evaluated the association of cryptococcal antigenemia and a composite poor outcome of death and loss to follow-up using logistic regression. Overall, 323 (88%) patients were alive, 8 (2%) dead, and 36 (10%) lost to follow-up. Among the 31 patients with a positive cryptococcal antigen test (titers ≥1∶8) at baseline, 28 were alive (all titers ≤1∶512), 1 dead and 2 lost to follow-up (titers ≥1∶1024). In multivariate analysis, cryptococcal antigenemia was not predictive of a poor outcome (aOR = 1.3, 95% CI 0.3-4.8). A baseline CD4 count <100 cells/µl was associated with an increased risk of a poor outcome (aOR 3.0, 95% CI 1.4-6.7) while an increasing CD4 count (aOR 0.1, 95% CI 0.1-0.3) and receiving antiretroviral therapy at last follow-up visit (aOR 0.1, 95% CI 0.02-0.2) were associated with a reduced risk of a poor outcome. Unlike prior ART-naïve cohorts, we found that among persons receiving ART and with CD4 counts <200 cells/µl, asymptomatic cryptococcal antigenemia was not predictive of a poor outcome.
    PLoS ONE 01/2014; 9(1):e85698. DOI:10.1371/journal.pone.0085698 · 3.23 Impact Factor
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    • "ART alone is insufficient treatment for CrAg-positive HIV-infected persons [10], [12], [13]. Among those with asymptomatic cryptococcal antigenemia, these persons are at high risk of developing symptomatic CM and/or death despite receiving ART [10], [12]. "
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    ABSTRACT: Cryptococcal meningitis is a major cause of HIV/AIDS-related deaths in Africa. Cryptococcosis is a neglected killer. However, meningitis can be prevented by early cryptococcal antigen (CrAg) screening and preemptive antifungal treatment during a prolonged period of detectable, subclinical infection. We determined the prevalence of cryptococcal antigenemia in comparison to CD4 count and clinical symptoms. We surveyed 254 consenting HIV-infected participants to obtain demographic information and clinical history. Serum CrAg was measured by latex agglutination at two sites in the Oromia region of Ethiopia among all persons receiving a CD4 count. Of the 254 participants, 127(50.0%) were ART-naïve, 121(47.6%) were ART-experienced, and 6(2.4%) were ART-defaulters. The prevalence of cryptococcal antigenemia was 10.2% overall being 14.2% among ART-naive, 4.1% among ART-experienced, and 50% (3/6) among ART-defaulters, irrespective of CD4 count. Cryptococcal antigenemia was more frequently detected from ART-naïve patients (p = 0.012) and ART-defaulters (p = 0.001) compared with ART-experienced. Serum CrAg positivity was 20.9% in persons with CD4≤150 cells/µL, 12.2% in 151-200 cells/µL, 5.8% among 201-350 CD4/µL, and none above 350 cells/µL. Potential meningitis symptoms were common in the outpatient cohort irrespective of CrAg-status, with only fever and altered mental status statistically more common in CrAg-positive compared to CrAg-negative persons (P<0.05), yet no symptom had a positive predictive value >33%. We report a 20.9% cryptococcal antigenemia prevalence among those with CD4+ T cells count ≤150 cells/µL, irrespective of ART status, with even higher CrAg prevalence in ART-naïves and ART-defaulters. These groups are target populations for CrAg screening at entry into HIV care.
    PLoS ONE 10/2013; 8(10):e75585. DOI:10.1371/journal.pone.0075585 · 3.23 Impact Factor
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    • "However, the magnitude of the survival difference is substantially below that reported in prior research of individuals with untreated asymptomatic cryptococcal infection. A study from Uganda noted a relative risk of death of 6.6 [95%CI: 1.86, 23.61] (Liechty et al. 2007) and a study from South Africa noted a hazard ratio of 4.75 [95% CI: 2.6, 8.8] and an adjusted hazard ratio of 3.2 [95% CI: 1.5. 6.6] for individuals with asymptomatic cryptococcal infection (Jarvis et al. 2009). "
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    ABSTRACT: Objectives: To test the hypothesis that a screening and treatment intervention for early cryptococcal infection would improve survival among HIV-infected individuals with low CD4 cell counts. Methods: Newly enrolled patients at Family AIDS Care and Education Services (FACES) in Kenya with CD4 ≤ 100 cells/μl were tested for serum cryptococcal antigen (sCrAg). Individuals with sCrAg titre ≥ 1:2 were treated with high-dose fluconazole. Cox proportional hazard models of Kaplan-Meier curves were used to compare survival among individuals with CD4 ≤ 100 cells/μl in the intervention and historical control groups. Results: The median age was 34 years [IQR: 29,41], 54% were female, and median CD4 was 43 cells/μl [IQR: 18,71]. Follow-up time was 1224 person-years. In the intervention group, 66% (514/782) were tested for sCrAg; of whom, 11% (59/514) were sCrAg positive. Mortality was 25% (196/782) in the intervention group and 25% (191/771) in the control group. There was no significant difference between the intervention and control group in overall survival [hazard ratio (HR): 1.1 (95%CI:0.9,1.3)] or three-month survival [HR: 1.0 (95%CI:0.8,1.3)]. Within the intervention group, sCrAg-positive individuals had significantly lower survival rates than sCrAg-negative individuals [HR:1.8 (95%CI: 1.0, 3.0)]. Conclusions: A screening and treatment intervention to identify sCrAg-positive individuals and treat them with high-dose fluconazole did not significantly improve overall survival among HIV-infected individuals with CD4 counts ≤ 100 cells/μl compared to a historical control, perhaps due to intervention uptake rates or poor efficacy of high-dose oral fluconazole.
    Tropical Medicine & International Health 02/2013; 18(4). DOI:10.1111/tmi.12067 · 2.33 Impact Factor
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