Flashcards in WBC Disorders Deck (63)
Define severe neutropenia.
Severe neutropenia is generally defined as having an absolute neutrophil count of <500 cells/µL.
How does one calculate the absolute neutrophil count?
Total WBC count x (% neutrophils + % bands)
Why should patients with severe neutropenia be evaluated immediately for any fever?
Children with severe neutropenia are at risk for overwhelming bacterial infection, so if they develop fever, they should be evaluated immediately, blood cultures should be drawn, and they should be started on parenteral broad-spectrum antibiotics.
Name four inherited neutropenia syndromes.
Cyclic neutropenia, severe congenital neutropenia (Kostmann Syndrome), Shwachman-Diamond syndrome, and cartilage-hair hypoplasia.
Name three forms of acquired neutropenia.
Neonatal isoimmune neutropenia, chronic benign neutropenia (autoimmune), and virus/drug-induced neutropenia.
What is the neutropenic cycle in patients with cyclic neutropenia?
Neutropenia occurs at a regular interval of every 21 +/- 3 days, with the neutropenia lasting for 3-5 days.
What is the typical ANC during the neutropenic interval in patients with cyclic neutropenia?
ANC is typically <200 cells/µL
Patients with cyclic neutropenia are at particular risk for sepsis caused by which organism?
What is the recommended management for patients with cyclic neutropenia?
Administration of granulocyte colony stimulating factor (G-CSF) and antibiotics for infections. Oral hygeine is important.
How do patients with cyclic neutropenia typically present when neutropenic?
Fever, aphthous stomatitis, cervical lymphadenitis, and rectal/vaginal ulcers.
What is Kostmann syndrome?
Kostmann Syndrome (severe congenital neutropenia) is a rare autosomal recessive disorder which causes ANC to be <200 cells/µLwith associated monocytosis and eosinophilia. Children are at risk for severe bacterial infections and early death.
What is the typical management for patients with Kostmann syndrome?
High dose granulocyte colony stimulating factor (G-CSF). Bone marrow transplant is curative.
What two genes are mutated in patients with Kostmann syndrome?
ELA2 and HAX1
What gene is mutated in patients with cyclic neutropenia?
What is Shwachman-Diamond syndrome?
Shwachman-Diamond syndrome is an autosomal recessive disorder resulting from mutations in the SBDS gene. Children present with features similar to those found in patients with cystic fibrosis: FTT, steatorrhea due to pancreatic exocrine insufficiency, and recurrent infections. Unique features include neutropenia and metaphyseal dysostoses.
What disease shares many of the same characteristics as Shwachman-Diamond syndrome?
What features of Shwachman-Diamond syndrome differentiate it from cystic fibrosis?
Patients with Shwachman-Diamond syndrome have neutropenia and metaphyseal dysostoses, which are not present in patients with cystic fibrosis.
How is Shwachman-Diamond syndrome usually treated?
Supportive care with pancreatic enzyme replacement and, depending on frequency and severity of infections, G-CSF administration or bone marrow transplant.
What two oncologic conditions are patients with Shwachman-Diamond syndrome at higher risk for?
Myelodysplasic syndrome and AML.
What is Cartilage-Hair Hypoplasia?
An autosomal recessive form of short-limb dysostosis that occurs primarily in children of Amish descent and is characterized by sparse or fine hair. Neutropenia occurs in ~25% of cases and is often accompanied by defects in cell-mediated immunity.
What infection is particularly troublesome for patients with Cartilage-Hair Hypoplasia?
Which autoimmune diseases are more common in patients with Cartilage-Hair Hypoplasia?
Immune Thrombocytopenic Purpura (ITP) and autoimmune hemolytic anemia (AIHA).
What is the treatment of choice for patients with Cartilage-Hair Hypoplasia who have recurrent severe infections?
Bone marrow transplant.
Describe neonatal immune neutropenia.
It is a self-limited disease that occurs when maternal antibodies to fetal neutrophil antigens cross the placenta and destroy fetal neutrophils. The infant develops neutropenia that recovers in 6-12 weeks, but any infection during that time requires quick, appropriate antibiotic therapy.
Describe the risk for infants of mothers who have had children with neonatal isoimmune neutropenia in the past.
All future children of mothers who had a child with neonatal isoimmune neutropenia are also at risk for developing the condition.
What is another name for chronic benign neutropenia?
What is the most common cause of neutropenia in a child who is otherwise healthy?
Chronic benign neutropenia/autoimmune neutropenia
Describe chronic benign neutropenia.
It is characterized by a persistently low ANC of <1,000 cells/µL, which is caused by autoantibodies against granulocytes. The disease is mild and does not usually require treatment.
What is the median age of diagnosis and typical duration of chronic benign neutropenia?
Median age of diagnosis is 8-11 months and the disorder usually lasts about 2 years.