The association of infection and clinical severity in sickle cell anaemia patients

Sickle cell anaemia (SCA) patients have a high risk of infection. We retrospectively investigated the prevalence of infection among SCA patients from Bahia, Brazil. A total of 1415 SCA patients were studied between 1995 and 2009: 190 (13.4%) had hepatitis C virus (HCV), 67 (4.7%) had human T-lymphotropic virus type I (HTLV-I), 44 (3.1%) had hepatitis B virus (HBV), 40 (2.8%) had Chagas' disease, 11 (0.8%) had human immunodeficiency virus (HIV), and 5 (0.4%) had syphilis. Patients with HCV infection had a higher risk of hospitalisation (OR = 1.52, 95% Cl: 1.07-2.17, P = 0.020), bone disorders (OR = 1.94, 95% Cl: 1.15-3.27, P = 0.011), stroke (OR = 2.17, 95% Cl: 1.12-4.14, P = 0.017), painful crisis (OR = 1.61, 95% Cl: 1.17-2.22, P = 0.004) and leg ulcers (OR = 1.61, 95% Cl: 1.04-3.03, P = 0.031). Patients with HBV infection had a higher risk for bone disorders (OR = 4.90, 95% Cl: 2.08-11.54, P < .010), stroke (OR = 3.01, 95% Cl: 1.29-6.04, P = 0.007), painful crisis (OR = 3.51, 95% Cl: 1.62-7.63, P < 0.001), acute chest syndrome (ACS) (OR = 2.66, 95% Cl: 1.34-5.28, P = 0.004), leg ulcers (OR = 6.60, 95% Cl: 3.37-12.91, P < .001) and vaso-occlusive crisis (OR = 6.34, 95% Cl: 1.96-20.66, P < 0.001). Patients with HTLV-I infection had a high risk for bone disorders (OR = 2.94, 95% Cl: 1.28-6.74, P = 0.011), respiratory failure (OR = 2.66, 95% Cl: 1.26-5.51, P = 0.012), leg ulcers (OR = 3.27, 95% Cl: 1.69-6.11, P < .001), painful crisis (OR = 1.82, 95% Cl: 1.07-3.13, P = 0.025) and ACS (OR = 1.85, 95% Cl: 1.10-3.41, P < .047). SCA patients with HCV infection had increased triglycerides and low-density lipoprotein cholesterol (P = 0.036; P = 0.027), iron serum (P = 0.016) and ferritin (P = 0.007). These results reveal important roles for these infections in SCA patients' clinical outcomes, and studies are warranted to determine the mechanisms utilised by these agents and their involvement in disease severity.