No Role for Kaposi Sarcoma-Associated Herpesvirus in Pediatric Idiopathic Pulmonary Hypertension

Abstract

Idiopathic pulmonary hypertension (IPHT) is a rare but progressive disease with devastating outcomes, especially in children. The etiology is unknown. A recent study reported a potential role of Kaposi sarcoma-associated herpesvirus in the pathogenesis of IPHT in adults. Our goal was to test if this association exists in pediatric patients. The pathology specimen database of the Children's Hospital of Pittsburgh from 1980-2004 was searched, and all patients with a diagnosis of IPHT were enrolled. Lung tissues containing the characteristic plexiform lesion from all patients were selected and stained with antibody to latent nuclear antigen (LNA-1) of Kaposi sarcoma-associated herpesvirus. To avoid false-negative results, three different positive controls were utilized. Eighteen patients were identified; 3 had familial pulmonary hypertension, and 2 had persistent pulmonary hypertension of infancy. Patients' ages varied from 3 days to 17 years, and the female-to-male ratio was 2:1. No positive history of HIV or of parents with HIV was identified. The Heath-Edwards grade of pulmonary hypertension was between 3-5. All patients died: 11 from the disease, and the remaining 7 died after receiving a lung transplant. Immunohistochemical staining with LNA-1 antibody showed no staining of either endothelial or smooth muscle cell nuclei in any of the patients' lung tissues, while all three positive control specimens showed the characteristic intranuclear granular, punctate staining pattern. Our results do not support a role for Kaposi sarcoma-associated herpesvirus in the pathogenesis of pediatric IPHT.