NCT00495638

Pulmonary Hypertension, Hypoxia and Sickle Cell Disease

Pulmonary Hypertension and the Hypoxic Response in SCD

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 29 (actual)
• Sponsor: National Heart, Lung, and Blood Institute (NHLBI) · NIH
• Sex: All
• Age: 3 Years – 20 Years
• Healthy volunteers: Accepted

Summary

The study will look at the risk factors for pulmonary hypertension (high blood pressure in the lungs) in children and adolescents with sickle cell anemia (SCA) and examine the role of hypoxia (oxygen shortage) in the disease. In patients with SCA, red blood cells become sickle-shaped and tend to form clumps that get stuck in blood vessels, blocking blood flow to the limbs and organs. Blocked blood vessels can cause pain, serious infections, and organ damage. Many patients with SCA also develop pulmonary hypertension. Children and adolescents with SCA or Chuvash polycythemia (another blood disorder that carries an increased risk for pulmonary hypertension) may be eligible for this study. Participants undergo the following procedures at the beginning (baseline) and end of the study: * History, physical examination and blood tests . * Echocardiography (ultrasound study of heart function). * Transcranial doppler (brain ultrasound study to measure brain blood flow). * Lung function tests. * 6-minute walk (measure of the distance covered in 6 minutes of walking). In addition, patients are followed by telephone or by clinic visits every 6 months for a review of their medical history and medications. A physical examination is also done at 12 months.

Detailed description

The research is designed to determine the prevalence and risk factors of pulmonary hypertension (PHT) in children and adolescents with sickle cell disease (SCD), and to determine the role of the hypoxic response in its pathogenesis. In this regard, proliferative vascular responses mediated by (i) hypoxia inducible factor (HIF)-regulated pathways and (ii) nitric oxide (NO)-scavenging will be compared between patients with SCD and patients with Chuvash polycythemia (CP), another hematological disorder characterized by increased risk for PHT. High throughput microarray and genotyping technologies will be employed to identify candidate gene pholymorphisms involved in pathologic responses to hypoxia in SCD and CP patients with and without PHT.

Conditions

• Chuvash Polycythemia
• Cerebrovascular Disease
• Pulmonary Hypertension
• Sickle Cell Anemia

Timeline

• Start date: 2007-06-28
• Completion: 2014-12-02
• First posted: 2007-07-03
• Last updated: 2019-12-16

Locations

7 sites across 2 countries: United States, Russia