In addition, the results of certain laboratory tests (e.g., lactate dehydrogenase (LDH), >600 IU/L; hypoxemia (PaO2, <60 mm Hg); C-reactive protein (CRP), 10 mg/dl; and leukopenia <5000/mm3) have been associated with greater mortality from infection by influenza A/H1N1 virus [7, 8]. This evidence concerns the gene CRP and Decreased total leukocyte count.