SICKLE CELL DISEASE
Sickle cell disease is a genetically
transmitted blood disorder affecting approximately 72,000 Americans,
(but not exclusively) those of African ancestry. Its primary effect is on
hemoglobin, which is the
protein within red blood cells that carries oxygen
throughout the body. Sickle cell disease can damage virtually every
organ system of
the body, profoundly impacting the life of the affected person.
When the red
blood cells release oxygen, the hemoglobin
stretching the cell into the characteristic sickle shape, which can clog blood vessels.
Sickle cell disease occurs when a child inherits from each parent an altered, or mutated, hemoglobin gene. This results in the red blood cell taking on an abnormal (sickle) shape. Due to their abnormal shape, these sickled red blood cells can clog small blood vessels, impairing blood flow, which can result in pain as well as organ damage.
The most frequent and commonly recognized complication of sickle cell disease is the painful vasoocclusive crisis, which occurs when sickle cells block blood circulation to a particular organ. A vasoocclusive crisis can involve any part of the body, and can cause severe pain in the affected area. Some people with sickle cell disease live with chronic debilitating pain. The pain can be so severe that patients require hospitalization and must be given intravenous (IV) medications.
Other potential complications of sickle cell disease include stroke, increased risk of lif-threatening infection, lung complications, kidney damage, liver and gallbladder disease, chronic skin ulcerations, joint disease, loss of vision, congestive heart failure, impaired growth and development, and complications of pregnancy.
Sickled red blood cells also have a shortened lifespan, so that most patients are anemic (have a low red blood cell count). Some require frequent red blood cell transfusions to manage complications. The course of the disease varies considerably, with some patients spending a great deal of time in the hospital with complications, while others are well most of the time with occasional bouts of illness.
Approximately 8% of African-Americans are carriers of sickle cell disease - because they carry only one sickle cell gene, they have "sickle cell trait." People with sickle cell trait don't experience any symptoms, and often don't know that they carry the gene. A child of two parents with sickle cell trait has a 25% chance of having sickle cell disease and a 50% chance of having sickle cell trait. If one parent has sickle cell disease, and one parent has the trait, each of their children has a 50% chance of having sickle cell disease.
Other forms of sickle cell disease can occur if a child inherits a sickle cell gene from one parent and another abnormal hemoglobin gene from the other. Newborn screening is mandatory in most states, including Delaware, so children affected by sickle cell disease and sickle cell trait should be diagnosed soon after birth, enabling their families to receive prompt education and treatment.
Sickle cell disease likely emerged thousands of years ago. Sickle cell trait provides some protection against malaria, and the disease is thought to have originated in Africa or perhaps the Middle East where malaria is common. Sickle cell disease is also seen in other areas where malaria occurs, such as Italy, Greece, and Central India. The widespread population of people claiming African or Middle Eastern ancestry means sickle cell disease is also seen in North, South, and Central America and the Caribbean.
As medical care has improved, the lifespan and quality of life for patients with sickle cell disease has improved. Average life expectancy is approaching 50 years, and many patients survive well beyond. Despite the challenges of coping with a chronic disease, the majority of patients are able to live active and meaningful lives. Treatment of sickle cell disease requires a medical team with knowledge and expertise about the disease and its complications, based at a center with the variety of subspecialty services needed to respond to the many health problems these patients can encounter. One of the most important aspects of care is educating patients and parents of children with sickle cell about the disease and its treatment. The frequency and severity of complications can be significantly lessened, and quality of life enhanced, by appropriate precautions and preventive care and timely and effective treatment.
History of National Sickle Cell Program
In his health message to Congress in February 1971, President Richard M. Nixon stated that sickle cell disease was a neglected health problem and should be given special priority. Subsequently, Senator Edward Kennedy introduced a bill that was passed by Congress in 1971 as the "National Sickle Cell Disease Control Act." This legislation led to the establishment of a National Sickle Cell Program directed by the National Institutes of Health (NIH) to set up comprehensive centers for the study and prevention of sickle cell disease. Located in university medical schools, these centers were mandated to provide research, patient care, education, screening, counseling, and other support programs regarding the disease. In addition, a special service was created by the Centers for Disease Control and Prevention (CDC) in Atlanta to provide training facilities for laboratory technicians and to monitor the quality of testing for sickle cell disease in the centers and clinics.
This is an exciting time for those involved in the research and treatment of sickle cell disease, as rapid progress is being made in the development of new therapies. Large cooperative studies have shown that administering penicillin prophylaxis to young children with sickle cell disease dramatically reduces the incidence of deadly pneumococcal infections, and that yearly ultrasound screening can predict which children are at highest risk for the devastating complication of stroke, which blood transfusions can effectively prevent. The daily administration of an oral medication, hydroxyurea, has been shown to greatly reduce the incidence and severity of many of the worst complications of sickle cell disease for severely affected patients and to significantly reduce mortality in adult patients. Bone marrow transplantation has emerged as a cure for the disease, and is currently being offered to those most severely affected. As the procedure becomes safer, it will likely become available to more patients.
Research is actively ongoing in many different areas including:
1) Investigating the role nitric oxide might play in the
development of complications in sickle cell disease, and
how changing the levels of this substance in the body might help prevent or treat them.
2) Gaining a better understanding of how environmental and genetic factors affect the severity of the disease.
3) Achieving a cure
through gene therapy.
Need for Community Support
In the United States, sickle cell disease was once regarded as an obscure disease that predominantly affected black Americans. But for approximately 72,000 Americans, the painful crises that interrupt their lives serve as a constant reminder that sickle cell disease presents very real day-to-day challenges. In addition to the physical pain patients face, they can also be challenged with emotional and financial burdens due to limited employment opportunities, escalating health care costs, and inadequate insurance coverage.
By getting the message about sickle cell disease out to the community, Alpha Kappa Alpha works to improve the quality of life for those with the disease, raise awareness, and support efforts to prevent and ultimately cure the disease.