Despite affecting millions of people throughout the world (and growing), sickle cell disease remains without a cure, and treatments are only somewhat effective. In 1995, researchers showed that hydroxyurea, a chemotherapy drug, was capable of decreasing the frequency and severity of chest crisis attacks, during which pain and oxygen deprivation in the lungs are common. Still, concerns over possible long-term harms had kept doctors from widely recommending the drug to patients. A new study, however, has just demonstrated that hydroxyurea is capable of improving the lung function of children diagnosed with the disease.

Sickle cell is a genetic disorder involving an abnormality in the oxygen-transporting protein hemoglobin, found in red blood cells. This mutation leads to a curved, sickle-like shape that gives the disease its name. Though it is relatively rare in the United States, affecting about 100,000 Americans, sickle cell is the most commonly inherited genetic disorder in people of African descent — about 1 of every 365 black or African-American births are affected. Signs of the disorder usually become noticeable around 5 or 6 months of age, and include swelling of the hands and feet, fatigue from anemia, and acute chest crises.

“Persons with sickle-cell disease experience an annual decline in lung function that starts in childhood,” said Dr. Anya McLaren, lead author of the study and respiratory medicine fellow at The Hospital for Sick Children in Toronto, Canada, in a press release.

McLaren told Medical Daily that past studies had shown favorable outcomes of hydroxyurea on acute chest crises, and that the new study is unique. “This study looks at how hydroxyurea impacts lung health over time in children and is the first of its kind,” she said.

The research involved 94 participants between the ages of 6 and 20 years old. The patients received treatment and then researchers tracked their blood count, hemoglobin F levels, and liver and renal functions for four years. They also looked at two separate levels of lung function: FEV1, which measures how quickly a person can move air in and out of their lungs, and FEF25-75, which can help clinicians determine if there is an obstruction in the airway. McLaren said hydroxyurea improved annual pulmonary function in the children by more than one-third.

Despite numerous studies detailing the effectiveness of hydroxyurea, physicians seem loath to use it. Used to treat certain types of cancer, the drug has been known to cause side effects including nausea, vomiting, and some more serious effects, such as chest pain and mood changes.

“Hydroxyurea has myelosuppressive effects and possible malignancy,” McLaren told Medical Daily, referring to the drug’s ability to decrease bone marrow activity and fears that the drug could lead to cancer. “This has not been shown to date in the sickle cell population as far as I know,” she added.

McLaren explained that education about the favorable safety profile and efficacy of the medication is paramount for patients, parents, and physicians to feel comfortable with hydroxyurea. Evidence of its positive effects on lung function will hopefully help with this.

“In combination with the established safety data, it hopefully will promote physician recommendations for hydroxyurea initiation and encouragement of compliance,” she concluded.

Source: McLaren A, Klingel M, Behera S, Kirby-Allen M, Odame I, Grasemann H. Effect of Hydroxyurea on Pulmonary Function Decline in Children with Sickle Cell Disease. ATS International Conference. 2016.