Only 45% of the IL-2 patients who experienced bacterial pneumonia received further dosing cycles of rIL-2 subsequently. The Kaplan–Meier table showing the time to bacterial pneumonia in the IL-2 and control arms

is shown in Figure 2. Overall, as shown in Table 3a, in the multivariate model, baseline risk factors for bacterial pneumonia were older age (HR per 10 years increase in age 1.34; 95% CI 1.14–1.59; P=<0.001), IDU (HR 1.78; 95% CI 1.09–2.90; P=0.02), VL ≥500 HIV-1 RNA copies/mL Selleckchem APO866 (HR 2.02; 95% CI 1.46–2.81; P=<0.001) and history of recurrent bacterial pneumonia as an ADI (HR 5.38; 95% CI 2.86–10.11; P=<0.001). Asian ethnicity was associated with a decreased risk of bacterial pneumonia (HR 0.17; 95% CI 0.05–0.56; P=0.003). In the multivariate analysis of bacterial pneumonia events in the IL-2 arm, the baseline associations were similar to the overall findings, Asian ethnicity was protective (HR 0.10; 95% CI 0.01–0.74; P=0.02);

being older (HR 1.46; 95% CI 1.15–1.85; P=0.002), having detectable plasma VL (HR 2.27; 95% CI 1.45–3.55; P=<0.001) and having a prior history of recurrent bacterial pneumonia (HR 4.46; 95% CI 1.72–11.54; P=0.002) were associated with increased pneumonia risk. However, IDU was not associated with an increased pneumonia risk (HR 1.46; 95% CI 0.72–2.96; P=0.30). Consistent with the overall findings, in control patients, IDU (HR 2.11; 95% CI 1.06–4.20; P=0.03), recurrent bacterial pneumonia (HR 5.61; 95% CI 2.38–13.24; P≤0.001) and detectable plasma VL (HR 1.85; 95% CI 1.13–3.03; INK 128 purchase P=0.01) were associated with a

significantly increased hazard for pneumonia. In contrast to the overall findings, there was only a trend towards decreased risk with Asian ethnicity (HR 0.27; 95% CI 0.06–1.11; P=0.07) and a trend towards increased risk with older age (HR 1.26; 95% CI 0.99–1.61; P=0.06). As shown in Table 3b, higher proximal VL on study (HR for 1 log10 higher VL 1.28; 95% CI 1.11–1.47; P≤0.001) and receipt of rIL-2 within the last 180 days (HR 1.72; 95% CI 1.12–2.65; P=0.01) were predictors of increased risk for a bacterial pneumonia event; higher proximal CD4 cell count 4-Aminobutyrate aminotransferase was associated with decreased risk (HR 0.94; 95% CI 0.89–1.00; P=0.04). When adjusted for baseline predictors (age, IDU, ethnicity and history of recurrent bacterial pneumonia) and time-updated CD4 cell count and VL, the hazards for IL-2 patients cycling within 180 days and ≥180 days of a bacterial pneumonia event were 1.66 (95% CI 1.07–2.60; P=0.02) and 0.98 (95% CI 0.70–1.37; P=0.90), respectively, compared with the control arm. In years 1 and 2 in the IL-2 group, the hazard for bacterial pneumonia when rIL-2 cycling was <30, 30–119 and 120–179 days, compared with receipt ≥180 days previously, was 2.59 (95% CI 0.88–7.62; P=0.08), 1.74 (95% CI 0.70–4.30; P=0.23) and 1.21 (95% CI 0.36–4.04; P=0.75), respectively.