CD4 and infection: Age at the time of diagnosis (HR = 1.003, 95% CI = 1.000–1.006), smoking (HR = 2.338, 95% CI = 1.236–4.424), baseline Scr ≥5.74 mg/dl (HR = 2.153, 95% CI = 1.323–3.502), CD4+ T cell< 281 ul (HR = 1.813, 95% CI = 1.133–2.900), and use of intravenous CYC were independent risk factors of infection.