Supplements of oral arginine reduced pulmonary hypertension by 15 per cent after five days of therapy in sickle cell patients, report researchers in a journal this week.
The team from the Children's Hospital and Research Center at Oakland and the University of California at San Francisco said that the amino acid arginine could be a "promising new therapy" for the disease with limited treatment options.
Sickle cell disease, an inherited condition that affects black persons almost exclusively, is characterised by sickle-shaped red blood cells and chronic anaemia. Pulmonary hypertension is a serious condition for sickle cell patients and represents an independent predictor of mortality in sickle cell disease.
In a study on 10 patients, oral arginine produced an average 15.2 per cent reduction in estimated pulmonary artery systolic pressure after five days of therapy, reported the researchers in the 5 July issue of the American Journal of Respiratory and Critical Care Medicine.They also found that arginase activity was elevated almost twofold in patients with pulmonary hypertension. The enzyme arginase is thought to compete with nitric oxide synthase, leading to decreased nitric oxide production. Nitric oxide therapy by inhalation has been shown to improve pulmonary hypertension associated with acute chest syndrome in sickle cell disease, noted the study. The increased arginase activity may therefore limit arginine bioavailability.
The one patient who was found to be noncompliant with the study medication, arginine, did not show improvement in their pulmonary hypertension level, added the team, concluding that the findings warrant further study into the supplement's effects on the life-threatening condition.
Arginine is found naturally in foods such as peanuts.