By Alexis A. Thompson, MD, MPH, Chief of the Division of Hematology at Children’s Hospital of Philadelphia
Each September brings an opportunity to raise awareness about sickle cell disease (SCD), an inherited hemoglobin disorder that affects approximately 100,000 Americans and causes chronic hemolytic anemia, severe and often debilitating pain, and chronic organ damage — and also shortens life expectancy. With SCD, red blood cells — which are important because they carry oxygen throughout the body — become deformed and rigid, or sickle-shaped, blocking circulation and injuring tissues. SCD was first reported in medical literature over 100 years ago and has often been described as the “first molecular disease” in recognition of early pivotal research findings that have paved the way for discoveries across many areas in medicine and science.
Universal newborn screening in all U.S. states has enabled reliable detection of SCD. Evidence-based interventions such as penicillin prophylaxis can prevent serious infections, and transcranial doppler (TCD) ultrasound can identify children who may be at increased risk for stroke. Hydroxyurea (HU), a medication that induces production of non-sickling fetal hemoglobin and reduces red cell adhesion and inflammation, can be safely introduced in early childhood — and has other benefits across the life span. HU can reduce the severity and frequency of pain and reduce many SCD complications. Today, with early diagnosis and comprehensive care, over 95 percent of children with SCD can survive into adulthood. However, disparities exist across low- and high-income countries.
The last decade has seen transformational advances in the care of individuals living with SCD. Additional treatments that can ameliorate acute and potentially longer-term clinical manifestations of SCD have now been approved. Crizanlizumab, a medication that inhibits red cell adhesion, reduces SCD pain rates when given intravenously once a month. Voxelotor inhibits sickling, improves oxygen delivery to tissues, and relieves anemia in SCD when people take it by mouth once daily. Both of these medicines can be effective with or without HU. Dozens of other agents are currently under investigation at various phases of development, providing hope for more methods to prevent or treat complications of SCD, reduce suffering, and improve survival.
Stem cell transplantation using a well-matched related donor is the only established curative option for SCD — however, most patients lack a suitable donor. Use of alternate donors is showing promise in clinical trials. Gene therapies, which use the patient’s own stem cells to deliver healthy genes or modify the function of other genes to induce production of non-sickling hemoglobin forms, overcome the issue of donor availability. Gene therapies also appear to have durable benefit and fewer side effects — with normalized hemoglobin and elimination of pain.
Newer approaches to managing SCD have improved early detection of complications, and intervention with effective treatments has extended the lives of many individuals living with SCD. These are among the many advances in SCD that we can and should celebrate in National Sickle Cell Awareness Month, yet it is important to acknowledge that long-standing barriers persist. If we don’t acknowledge and eradicate root causes, such as racism and discrimination, efforts to address health disparities will fall short. So, what can be done to bridge this gap?
The U.S. Department of Health and Human Services Office of Minority Health (HHS OMH) commissioned the 2019 National Academies of Sciences, Engineering, and Medicine report Addressing Sickle Cell Disease: A Strategic Plan and Blueprint for Action, which provides an extraordinary overview and a comprehensive set of recommendations for policies, programs, and research to improve the lives of individuals with SCD and sickle cell trait. It also provides opportunities for a diverse community of individuals and organizations invested in this issue to contribute to solutions.
Today there are too few health care providers who are knowledgeable about SCD, especially SCD in adults. In some states, individuals may live far from SCD treatment centers or must seek care in emergency departments from staff that seem ill-informed and uncaring. The transition from pediatric to adult-centered care is often cited as a particularly vulnerable time when changes in providers, health care settings, and insurance coincide with the emergence of serious disease complications. We need more health care facilities and professionals to provide behavioral health services and address other psychosocial issues.
Programs such as the Sickle Cell Disease Treatment Demonstration Program, supported by the Health Resources & Services Administration, seek to enhance education and training of clinicians — particularly primary care physicians and mid-level providers such as nurse practitioners — to improve access to quality care for patients living with SCD. The Centers for Disease Control and Prevention (CDC) supports the Sickle Cell Data Collection program, which awards grants to states, academic institutions, and nonprofit organizations to gather information on SCD prevalence, health outcomes, complications, and treatment. Evidence-informed clinical practice guidelines for managing acute and chronic complications of SCD — such as those established by the American Society of Hematology — are vital resources that should be widely disseminated and implemented by health care providers.
Patients and their families are searching for thoughtful, unbiased information about new treatments. The Sickle Cell Disease Coalition has unbranded, downloadable materials about HU and other medical treatments. The National Institutes of Health (NIH) Cure Sickle Cell Initiative and NIH’s Democratizing Education for Sickle Cell Disease Gene Therapy Project provide accessible and actionable information in multiple formats to help families start conversations with their health care providers and make decisions.
Let us continue to celebrate progress in sickle cell disease. There are many exciting opportunities to make a tangible impact with partnerships across many sectors and ongoing engagement across the entire SCD community.