P-B2 Performance of WHO immunological response to predict virological failure in patients with severe versus moderate immunosuppression at antiretroviral therapy initiation. (January 2016) - Herbas Ekat, Martin
Abstract : Objectives: To evaluate sensitivity and specificity of WHO-immunological criteria (CI) to predict virological failure (EV) among patients with severe (who have high incidence of opportunistic infections) versus moderate immunosuppression at ART initiation. Methods: HIV-positive patients naive to ART follow-up between January 2004 and December 2011, at Ambulatory Treatment Center of Brazzaville(CTA), Congo, and Age ≥18 years on ART since ≥12 months with combination of 2NRTIs plus 1INNTI; Were divided into 2 groups: G1 = severe CD4 50% drop from CD4 count peak and CD4 cell count lower than baseline. Sensitivity of CI to predict EV was analyzed across level of viral load ≥1000 copies per milliliter. Results: We included 329 patients in G1 and 216 in G2. The median values at baseline were: Age: 44 years [Inter Quartile Range (IQR): 3–50] versus 43 years (IQR: 37–51), P = 0.99; CD4: 104 cells per cubic millimeter (IQR: 53–162) versus 264 cells per cubic millimeter (IQR: 230–303), P < 0.00, prior AIDS illness: 72.9% versus 64.4%, P = 0.02. Over the 8-year study period, in 12-month follow-up incidence rate of opportunistic infections was 3 versus 1.2 per 100 person-years, P < 0.001 and 16.9% versus 16%, P = 0.49, 10.3% versus 9%, P = 0.42 patients respectively had confirmed virological and immunological failure in G1 and G2 respectively, only 7 (2.13%) versus 3 patients (1.38%) met both the IC and EV. Performance of CI was: sensitivity: 27.9% (95% CI: 17 to 40) versus 48%(95% CI: 34 to 67), specificity: 88.5% (95% CI: 84 to 92) versus 83.5%(95% CI: 77 to 89), PPV: 38.8% (95% CI: 25 to 54) versus 47% (95% CI: 33 to 62), NPV: 82.4% (95% CI: 78 to 87) value 84% (95% CI: 78 to 89) respectively in G1 and G2. Conclusions: Severe immunosuppression at initiation of ART is not associated with the low sensitivity of WHO-immunological criteria. Viral load, reference tools for the diagnosis of failure should be available in resource-constrained settings.