Natural History of Sickle Cell Disease and Other Hemolytic Disorders

Under this study, NIH physicians will evaluate and treat patients with sickle cell disease and other hemolytic disorders (diseases involving damage to red blood cells) in order to learn more about the diseases and the painful attacks and lung complications that are often associated with them. Patients in this study will not receive experimental therapy, but will be given standard medical care. Patients who meet the medical criteria for another NIH protocol may be offered participation in that study, but are not obligated to enroll in it.

Patients 5 years of age and older with known or suspected sickle cell disease, sickle cell trait or another anemia or red blood cell disorder such as thalassemia may be eligible for this study. Participants will be admitted to the NIH Clinical Center as an inpatient or outpatient for evaluation and treatment. In addition to a physical examination, evaluation may include the following types of tests and procedures:

• Routine blood and urine tests, including a 24-hour urine collection
• Blood test for genetic analysis to look for genes that may be relevant to the development of sickle cell anemia or other hemolytic disorders
• X-rays, if needed, to evaluate the patient's condition
• Computerized tomography (CT) scans or magnetic resonance imaging (MRI), or both, as needed to examine the lungs, brain, or heart and to measure blood flow in these organs.
• Echocardiogram (heart ultrasound) to determine if there is high blood pressure in the lungs
• Pulmonary (lung) function tests and cardiopulmonary (heart and lung) exercise test to evaluate breathing and exercise capacity to determine if there are lung or heart problems associated with the patient's condition.
• Heart catheterization to measure blood pressures in the heart and lung blood vessels will be offered if the results of clinical evaluation or echocardiogram suggest the presence of high blood pressure in the lungs. For this procedure, the patient is given a local anesthetic, and a catheter (plastic tube) is inserted into a vein in the arm, thigh, chest, or neck until it passes through the right side of the heart. When the catheter is in place, a tiny balloon at the end of the catheter is inflated, temporarily blocking the blood flow and allowing the physician to measure pressure in the lung artery system.
• Ventilation-perfusion scan to measure breathing and circulation in all areas of the lungs. For the perfusion scan, radioactive albumin is injected into a vein and the patient is placed on a table that is positioned under the scanner. The lungs are scanned to detect the location of the radioactive particles as blood flows through the lungs. The ventilation scan is performed by scanning the lungs while the patient inhales a radioactive gas. A mask is placed over the nose and mouth, and the patient breathes the gas while sitting or lying on the table beneath the arm of the scanner. The gas is breathed out entirely in a matter of minutes and is removed from the room by a special exhaust system.

Patients are offered treatment for high blood pressure in the lungs. The medicines used are approved by the Food and Drug Administration for patients with pulmonary hypertension.