Sickle Cell Disease

Sickle Cell Disease (SCD) is a genetically inherited condition that is existent at birth. SCD is inherited when a child obtains two sickle cell genes—one from each parent. SCD is usually discovered at birth as part of newborn screening tests. SCD is considered a blood disorder that specifically affects red blood cells. Red blood cells that are healthy are round/disk shaped cells that easily move through the blood vessels and carry oxygen throughout the body. In SCD, the red blood cells are c-shaped and become hard and sticky causing them to stick to each other or to blood vessel walls obstructing blood flow, which can cause pain and increase the likelihood of infections. Sickle cells have a shortened life span, and therefore, can lead to a shortage of red blood cells in the body.

To find out more about the possible treatments for SCD and to help you make your decision visit sickleoptions.org

Types of Sickle Cell Disease

HBSS

People who have the HbSS genotype inherit a sickle cell gene ("S") from each parent. This form of SCD is usually the most severe and is known as sickle cell anemia.

HBSC

People who have the HbSC genotype inherit one sickle cell gene ("S") from one parent and one abnormal hemoglobin gene ("C") from the other parent. This is usually a less severe form of SCD.

HBS BETA THALASSEMIA

People who have HbS beta thalassemia inherit one sickle cell gene (“S”) from one parent and one beta thalassemia gene from the other parent. Beta thalassemia is another form of anemia. There are two types of beta thalassemia: “0” and “+”. Those with HbS beta 0-thalassemia usually have a severe form of SCD, while those with HbS beta +-thalassemia, usually have a milder form of SCD.

HBSD, HBSE, AND HBSO

People who have the HbSD, HbSE, or HbSO genotype inherit one sickle cell gene ("S") from one parent and one abnormal hemoglobin gene ("D", "E", or "O") from the other parent. This is usually a less severe form of SCD.

HBAS (SICKLE CELL TRAIT)

People who have sickle cell trait have an HbAS genotype meaning they inherited one sickle cell gene (“S”) from one parent and one normal gene (“A”) from the other parent.

Published on 09/02/2011

Our Story: Living with and Managing Sickle Cell Disease (Nicholas H.)

In this video, presented by NHLBI ( a division of NIH) Nicholas H. and his mother, Bridget, talk about life with SCD. Nicholas was diagnosed with SCD soon after he was born. He suffered from hand-foot syndrome as a baby and had his gallbladder and spleen removed at age 5. Penicillin, hydroxyurea, and other medicines have helped him and his family manage the illness and the severe pain crises that can result in hospitalization. Now, 15 and an honor student in school, Nicholas enjoys "hanging out," listening to music, playing video games, wrestling and learning Brazilian jujitsu.

Published on 09/02/2011

Living With and Managing Sickle Cell Disease

This video, presented by NHLBI (a division of NIH) shows how Tiffany, a mother and student, has coped with having SCD. Born with the most severe form of sickle cell disease, sickle cell anemia, Tiffany has lived with the symptoms and complications of this disease her entire life. After giving birth to her daughter, Tiffany became very sick and was admitted to the hospital many times. In 2009, she began treatment with a medicine called Hydroxyurea. Although Tiffany's brother had taken hydroxyurea and had many side effects, Tiffany has had success with the treatment. Her commitment to following her treatment plan and living a healthy lifestyle have helped her manage sickle cell anemia and live a happy, full life.

What is Standard of Care? Overview

Treatment options for SCD are referred to as standard of care. Standard of care includes treatments for sickle cell disease like hydroxyurea, pain management, and blood transfusions. Below are common standard of care options, but these may vary person-to-person.

Hydroxyurea

  • Hydroxyurea is a medicine used to treat cancer and blood diseases
  • It is used in conditions such as polycythemia vera (increased number of red blood cells), essential thrombocytosis (increased number of platelets), and SCD
  • It is the only drug approved by the Food and Drug Administration (FDA) to treat sickle cell disease
  • Hydroxyurea can be administered as a pill or a liquid.

Blood Transfusions

  • Healthy donor red blood cells are given via blood transfusions to help replace unhealthy sickle cells in the blood
  • Frequent blood transfusions can help increase the level of normal red blood cells in the body
  • The body will produce less cells that can sickle when it receives healthy cells, but will still make some sickle cells
  • Blood transfusions are usually given every 4 to 6 weeks and last about 3-4 hours

Pain Management

  • To manage acute vaso-occlusive events (painful episodes), assessments of pain are performed
  • Increased hydration may be recommended
  • In severe pain episodes, intravenous (IV) administration of opioids is common. Anti-inflammatory agents, acetaminophen, antihistamines, and other adjuvant medications can be used with opioids to treat pain
  • Management of mild-to-moderate pain can include NSAIDs or acetaminophen; While management of moderate-to-severe pain can include oral opioids. Pain management can also consist of a combination of nonopioid analgesics with opioids

What is a Bone Marrow Transplant? Hematopoiesis

Bone marrow is spongy tissue found inside the bone where all new blood cells are made. Bone marrow is known as the site of hematopoiesis. In Greek "Hemato" means "blood" and "poiesis" means "to form." When combined, it conveys the meaning "to make blood."

Inside the bone marrow, all blood cells are made from hematopoietic stem cells. These stem cells are divided into the myeloid group and the lymphoid group. The lymphoid group includes t-lymphocyte cells and b-lymphocyte cells. The myeloid group contains red blood cells (erythocytes), megakaryocytes, which form platelets, and white blood cells (monocytes, neutrophils, basophils, and eosinophils). In patients, with SCD the red cells created in the bone marrow are abnormal.

In an attempt to cure SCD unhealthy bone marrow is removed with chemotherapy and replaced with healthy donor stem cells from bone marrow so that healthy cells can be created. Chemotherapy drugs used for bone marrow transplants are a group of medicines that are used to get rid of unhealthy cells in the bone marrow.

How does a Bone Marrow Transplant work?

Once unhealthy bone marrow is removed using chemotherapy, the donor bone marrow stem cells are given using an intravenous line (a central line). If the transplant is successful, the new donor bone marrow will start to create new blood cells. Unlike before, these cells will not sickle. It takes about a year to recover from a bone marrow transplant. Bone marrow transplants for patients with sickle cell disease must be allogenic transplants meaning the new cells come from another person (donor).

Risks Associated with Bone Marrow Transplant

  • Side effects from chemotherapy
  • Acute graft versus host disease (GVHD)
  • Posterior reversible encephalopathy Syndrome (PRES)
  • Infection, skin rash, hair loss, nausea, vomiting, diarrhea, fevers, mouth sores, bleeding
  • Persistent pain and fatigue after transplant
  • Late onset GVHD
  • Risk of infection after transplant
  • Partial or full rejection of bone marrow

Benefits of Bone Marrow Transplant

  • Potentially cure sickle cell disease
  • Potentially prevent new organ damage caused by SCD
  • Potentially improve quality of life and increase chances of living longer