Endothelial damage caused by cytomegalovirus and human herpesvirus-6

Infection with cytomegalovirus (CMV) or human herpesvirus-6 (HHV-6) may have a role in vascular endothelial damage after bone marrow transplantation (BMT). In total, 41 patients who underwent BMT were classified into four groups (12, 10, 7, and 12 patients who were infected with both CMV and HHV-6, CMV alone, HHV-6, and neither virus, respectively). Levels of thrombomodulin, plasminogen activator inhibitor-1, and cyclic GMP were 7.5+/-1.7 FU/ml, 76.4+/-24.1 ng/ml, and 9.51+/-1.1 pmol/ml, respectively, in the patients with both viruses, while the respective values were 2.9+/-0.67 FU/ml, 33.8+/-8.09 ng/ml, and 2.90+/-1.4 pmol/ml in patients infected with CMV alone, 4.8+/-0.96 FU/ml, 47.7+/-9.21 ng/ml, and 5.48+/-0.55 pmol/ml in patients with HHV-6 alone, and 1.6+/-0.39, 17.5+/-7.88 ng/ml, and 0.45+/-0.3 in those with neither virus. All three markers were significantly higher in the three groups with at least one virus than in the uninfected patients (P<0.05), and were also higher in patients with HHV-6 alone than in those with CMV alone (P<0.05). These results suggest that infection by CMV or HHV-6 causes vascular endothelial injury, with HHV-6 having a stronger effect than CMV, and combined infection having a stronger effect than either virus alone. Such viral infection may be a cause of thrombotic microangiopathy after BMT.