CRP and Increased total leukocyte count: Hospitalized patients with non-O blood groups appear to have lower systolic blood pressure during PUUV infection compared to patients with blood group O. In pairwise analysis, the only significant difference in blood pressure was detected between blood groups O and B. Patients with blood group O have also less severe leukocytosis without a difference in CRP value, but more severe thrombocytopenia when compared with patients with non-O blood groups.