Hematology is the study of blood and abnormalities of the cells and proteins (plasma) that comprise blood. Because blood is a complicated organ, there is a wide range of hematologic disorders and diseases. In fact, since each disorder is so specialized and unique, blood is sometimes the only common link between the different disorders and diseases.
At the Children’s Cancer Hospital, a team of hematologists treats pediatric and adolescent patients with non-malignant blood disorders each Tuesday morning at the Robin Bush Child and Adolescent Clinic.
The hematologic diagnoses most often seen are bone marrow failure syndromes, neutropenia, anemia, erythrocytosis, thrombocytopenia (primarily immune thrombocytopenic purpura, or ITP), thrombocytosis, rare immune-related problems, and other rare hematologic disorders. The hematologists also provide expert consultation on blood clotting abnormalities such as hemostasis and thrombosis.
Children and adolescents with hemostasis and thrombosis disorders, but no evidence of cancer, are seen at another location. Additionally, children diagnosed with sickle cell anemia may be evaluated as transplant candidates in the Children’s Cancer Hospital.
Bone Marrow Failure Syndromes
Shwachman-Diamond syndrome is a gastroenterological (digestive system) genetic condition that is often accompanied by bone marrow hypoplasia (underdevelopment of bone marrow) or aplasia (lack of development of bone marrow). The patient’s digestive system symptoms manifest because of a defect in pancreatic enzyme production. Constitutional short stature (underdeveloped growth) may also be present. Persons with Shwachman-Diamond syndrome may be at higher risk to develop leukemia or complete bone marrow failure, making some — particularly those with a human leukocyte antigen (HLA) matched sibling genotype — bone marrow transplant candidates.
Diamond Blackfan anemia is a rare disorder of red blood cell (RBC) production, are treated with steroids or chronic packed red blood cell (PRBC) transfusions. These patients receive bone marrow transplants only when a matched sibling is available. In the past, the Diamond Blackfan patients who had to receive chronic transfusions became iron overloaded, a toxic life threatening condition for vital organs such as the liver, heart and pancreas. Removal of the iron by chemical binding (chelation) is required to avoid this toxicity. Up until recently, the only effective iron chelator required continuous subcutaneous (below the skin) or intravenous infusion for ten hours each day. Since January of 2006, an oral chelator has been on the market, improving the quality of life for almost anyone on chronic transfusion.
Aplastic anemia is the severest of bone marrow failure syndromes with trilineage (red blood cell, white blood cell and platelet) deficiencies. These patients typically become packed red blood cell (PRBC) and platelet transfusion-dependent and are invariably susceptible to overwhelming infection. Initially, immune suppressive medical therapy such as antithymocyte globulin (ATG) and cyclosporine may be tried, particularly if a bone marrow transplant is not feasible. The hematology team coordinates closely with the bone marrow transplant team to enable patients who have identified donors and are, therefore, candidates for bone marrow transplant, to access this potentially life-saving therapy.
Neutropenia is a deficiency of infection-fighting white blood cells, most commonly caused by chemotherapy used to treat childhood cancer. However, other rare causes may be inherited or acquired without cancer or chemotherapy. These are the diseases evaluated by the hematology service. Neutropenia may be clinically insignificant as with benign neutropenia of children or neutropenia of African Americans, or it may threaten life as with severe congenital neutropenia (Kostmann’s syndrome). The creation of a drug, granulocyte colony stimulating factor (G-CSF), 20 years ago has significantly extended and improved the quality of life of those with Kostmann’s. However, up to one-third of those with Kostmann’s syndrome will develop leukemia.
Immune thrombocytopenic purpura (ITP): The majority of patients seen in the Children’s Cancer Hospital hematology clinic with thrombocytopenia have immune thrombocytopenic purpura (ITP). One in 600 – 700 children will develop ITP during childhood. ITP typically follows a viral infection that causes the child’s body to make antibodies that attack the body’s platelets. This results in the platelet count decreasing, which causes an increase in bruising and bleeding. In 85% of ITP cases in pre-pubertal children, the disorder resolves itself with or without treatment. However, the remaining 15% (usually adolescents and adults) have chronic ITP.
Kostmann’s syndrome (severe congenital neutropenia)
Acquired & Congenital Thrombocytopenias
Hemoglobinopathies & Thalassemias
Symptoms vary according to the different blood disorders. Infants are screened at birth for hemoglobinopathies to detect sickle cell anemia before symptoms are even present.
Symptoms for ITP include bruising or skin bleeding while some blood disorders cause pain, infections, and/or swelling in the hands and/or feet.
A standard complete blood count test can detect abnormalities in the blood such as low red blood cell counts, white blood cell counts and platelets. However, each blood disorder has different diagnostic tests that provide more details for an accurate diagnosis.
Treatments for blood disorders have come a long way in the past two decades. Diseases that were once fatal are now controllable due to the development of new therapies. Blood disorders may be treated with drug therapies, bone marrow transplantation, and/or cellular therapies such as blood transfusions and cell growth stimulants. Although many blood disorders are chronic diseases, most patients are able to maintain a normal life while living with their disease.