How is cyclic neutropenia diagnosed? How long are cycles?
Diagnosis is made by obtaining serial neutrophil counts during a 2-3 month period
Cycles last an average of 21 days in 70% of patients
What are the clinical features of ITP?
Illness typically occurs 1-4 weeks after a viral infection
Begins abruptly with cutaneous bleeding or mucous membrane bleeding
Internal bleeding into the brain, kidneys, or GI tract may occur but is rare
In ITP, very low platelet counts (<20,000) or active bleeding warrant treatment with...
What is the second line agent?
IVIG or corticosteroids
Anti-D immunoglobulin is a second-line agent that may aslo be effective
What follow up is recommended beginning at 2 years of age for SS disease patients and why?
Serial transcranial Doppler ultrasound or magnetic resonance angiography to identify patients at risk for stroke
What is polycythemia vera?
A malignancy involving the RBC precursor that occurs during childhood
What is the most common cause of neutropenia during childhood?
What is deficient in scurvy?
What is the management for hemophilia B (Christmas tree disease)?
Factor IX replacement
Why is ferritin not always a reliable marker of iron deficiency anemia?
Because ferritin is also an acute-phase reactant, it may be increased in infection, disease states, and stress
What is the genetic cause of Sickle cell (SS) disease?
SS disease is caused by a single amino acid substitution of valine for gluamic acid on position 6 of the ß-globin chain of Hgb
Mutation results in polymerization of Hgb within the RBC membrane when the RBC is exposed to low oxygen or acidosis
Why do thalessemias lead to increased size of bones in the face and skull?
Both types of thalassemia result in hemolysis that elads to increased bone marrow activity; as marrow activity increases, the marrow spaces enlarge, increasing the size of bones
What are red blood cell aplasias?
A group of congenital or acquired blood disorders characterized by anemia, reticulocytopenia, and a paucity of RBC precursors in the bone marrow
Describe autoimmune neutropenia and isoimmune neutropenia
Autoimmune: A disorder in which antineutrophil antibodies are produced in response to infection, drugs, SLE, and juvenile rheumatoid arthritis
Isoimmune: Passive transfer of antineutrophil antibodies from the mother to her fetus after maternal sensitization by antigens on the fetal neutrophils
What are some clinical manifestations of vitamin K deficiency?
- Oozing from skin puncture wounds
- Bleeding into organs
What are two inherited disorders involving factor VIII of the clotting cascade?
Hemophilia A and von Willebrand's disease
What are some common causes of normocytic, normochromic anemias?
red cell aplasias, and sickle cell anemia
Possible complications of polycythemia are...
Thrombosis and bleeding
What is DIC?
A group of laboratory and clinical features indicative of both accelerated fibrogenesis and fibrinolysis; the initiating event is clotting that leads to consumption of procoagulant factors and resultant hemorrhage
How is SS disease diagnosed?
Usually diagnosed at brth through state newborn screening programs; Hgb Electrophoresis is a highly sensitive and specific test
The Hgb is ______ at birth and reaches the physiologic lowest point between _ and _ months of age in the term infant (between _ and _ months in the preterm infant)
The Hgb is high at birth and reaches the physiologic lowest point between 3 and 4 months of age in the term infant (between 1 and 2 months in the preterm infant)
What laboratory findings are seen in DIC and liver disease?
- Prolonged PT and aPTT
- Elevated fibrin degradation products
What is the management for DIC?
Therapy includes treatment of the underlying cause and transfusions of fibrinogen, FFP, and platelets as needed (same for liver disease); Heparin may be useful if underlying defect cannot be corrected
What is the difference between SS disease and SS trait?
SS disease: result of having 2 genes for Hgb S
SS trait: result of having only one gene for Hgb S; patients are usually asymptomatic without anemia
What are the clinical features of cyclic neutropenia?
Cyclic alterations in neutrophil counts results in regular episodes of neutropenia with resultant infections
Macrocytic (megaloblastic) anemias are characterized by MCV > __
What are the two major causes in children?
Folic acid and Vitamin B12 deficiencies
MCV ( mean corpuscular volume) - average volume and size of individual erythrocytes.
What is the most common acquired platelet abnormality in childhood?
Immune thrombocytopenic purpura (ITP)
What causes the majority of iron deficiency anemia?
Inadequate iron intake
What are some clinical features of moderate anemia?
- Weakness and fatigue
- Decreased exercise tolerance
- Systolic heart murumur
What is the most common hereditary bleeding disorder?
What is it's inheritance pattern?
von Willebrand's disease
How are normocytic, normochromic anemias differentiated (name the lab and the significance of the lab values)?
- Low reticuloyte count: Reflects bone marrow suppression or failure and is consistent with red cell aplsias, pancytopenia, and malignancy
- High reticulocyte count: reflects bone marrow production of RBCs as seen in hemolytic anemias and sickle cell anemia