Effect of hydroxyurea therapy on pneumococcal pneumonia. (A) Mean overall survival of SCA mice receiving hydroxyurea (squares) or saline (circles) or mock-transplanted mice receiving saline (triangles) after pneumococcal challenge (*P < .01 compared with SCD saline by Mantel-Cox log rank test). n = 31, SCA saline; n = 35, SCA hydroxyurea; n = 21, mock transplanted from at least 3 independent experiments; P = .0028 for SCA saline vs SCA hydroxyurea. No significant difference (P = .12) observed between mock-transplanted and SCD hydroxyurea groups. (B) Survival of nontransplanted wild-type mice (C57/bl6) receiving hydroxyurea (squares) or saline (circles) after pneumococcal challenge. n = 15/group (P = .93; statistical comparisons by Mantel-Cox log rank). Bacteria were introduced by intranasal administration in 25 μL of saline: 5 to 8 × 105 CFUs for transplanted mice and 2 × 106 CFUs for nontransplanted C57/bl6 mice. Representative Xenogen images of bioluminescent pneumococci indicating the progression of disease in (C) saline- and (D) hydroxyurea-treated SCA mice at 24 hours after challenge. Color intensity correlates with bacterial density (blue indicates low titer; and red, high titer).
