Pediatric Hematology/Oncology Flashcards
How is anemia defined physiologically?
Hemoglobin level too low to meet cellular oxygen demands
What is an example of anemia despite a ‘high’ hemoglobin level?
A 2-year-old child with cyanotic congenital heart disease who has a Hgb of 14 gm/dL and Hct of 40%
What is an example of no anemia despite a ‘low’ hemoglobin level?
A 2-month-old thriving premature infant with Hgb 7.5 gm/dL
How is anemia defined practically?
Hemoglobin level at least 2 standard deviations below mean value for age, gender, and race
What factors determine hemoglobin values in normal children?
Age, gender, race, degree of sexual maturation, altitude, heredity
What is the recommended method for evaluating lead poisoning?
Venous blood lead level (BLL)
What BLL is considered abnormal and warrants intervention?
≥ 5
What are reticulocytes?
Young RBCs in circulation, still with residual RNA
How are reticulocytes characterized?
Larger than normal RBCs, lack central pallor, bluish tint
What additional screening should be done if BLL is elevated?
Screen for iron deficiency
What is the normal percentage of reticulocytes in the RBC population?
0.5-1.5%
What imaging might be considered if a patient is symptomatic for lead poisoning?
Plain abdominal x-ray
How is the absolute reticulocyte count (ARC) calculated?
% retic x RBC count/L
What should be done to manage lead poisoning?
End further exposure to lead
What is the normal range for the absolute reticulocyte count (ARC)?
25,000 – 75,000
Who else should be tested if one household member has elevated BLL?
Household members/children
What public health measure can help manage lead exposure?
Lead abatement program
What does an increased reticulocyte count indicate in the presence of anemia?
Shows bone marrow response
What nutritional elements should be ensured in the diet to manage lead poisoning?
Calcium, vitamin C, iron
What therapy is used for significantly elevated BLL?
Chelation therapy
What does anemia with a low/normal ARC suggest?
Deficient production of RBCs
What is a medical emergency in the context of lead poisoning?
Symptomatic lead intoxication
What does anemia with a high reticulocyte count indicate?
Increased erythropoietic response
What does stable anemia with a low reticulocyte count indicate?
Deficient production (reduced bone marrow response)
What does lead poisoning cause in erythrocytes?
Basophilic stippling
What is physiologic anemia of early infancy?
The smaller the premie, the earlier and lower the hemoglobin nadir
What is elevated in the blood due to lead poisoning?
Free erythrocyte protoporphyrin
What is the definition of neutropenia?
Decrease in the absolute neutrophil count below accepted norms for age.
How is the Absolute Neutrophil Count (ANC) calculated?
ANC = # total WBC * (% PMNs + % bands)
What is the ANC threshold for term newborns up to 1 week?
<3,000
What is the ANC threshold for infants aged 1 week to 2 years?
<1,100
What is the ANC threshold for children, adolescents, and adults?
<1,500
What is the hemoglobin nadir for a term infant at 12 weeks?
9.5 gm/dl
What condition is NOT caused by lead poisoning?
Microcytic anemia
What ANC range indicates mild neutropenia and its associated infectious risk?
1,000-1,500; none
What is a common cause of microcytic anemia in young children with lead poisoning?
Iron deficiency
What is the hemoglobin nadir for a premature infant at 6-8 weeks?
7.0 gm/dl
What dietary deficiency can lead to PICA?
Iron deficiency
What ANC range indicates moderate neutropenia and its associated infectious risk?
500-1,000; minimal
What is the response rate to splenectomy in managing chronic ITP?
60-80%
What can PICA lead to in terms of lead exposure?
Lead ingestion
What is a significant risk associated with post-splenectomy in chronic ITP management?
Sepsis
What ANC level indicates severe neutropenia and its associated infectious risk?
<500; moderate to severe
What are common causes of iron deficiency during childhood?
Blood loss, GI tract issues, cow’s milk, parasitic infection, esophageal varices, anatomic lesions, inflammatory bowel disease, epistaxis, menorrhagia, intrapulmonary or renal loss, idiopathic pulmonary hemosiderosis, chronic intravascular hemolysis
What is the most common cause of neutropenia?
Infection-associated neutropenia
What preventive measures are needed before and after splenectomy for chronic ITP?
Vaccinations prior to surgery and prophylactic antibiotics following
What is the complete response rate to Rituximab in chronic ITP management?
30%
Why does excessive cow’s milk intake predispose to iron deficiency?
Contains minimal iron, iron poorly absorbed, leads to reduced intake of other foods, may cause GI bleeding
What are some mechanisms of infection-associated neutropenia?
Increased utilization, complement mediated margination, marrow suppression/failure, direct effect, cytokine/chemokine induced margination, antibody formation
Name two additional immunosuppressant agents used in chronic ITP management.
Mycophenolate mofetil, 6-mercaptopurine
What are the causes of iron deficiency during adolescence?
Rapid growth, blood loss, menstrual, gastrointestinal and renal in athletes, pregnancy, H. pylori infection
What does iron deficiency increase in the context of lead poisoning?
Lead absorption from the intestine
What do thrombopoietic agents do in chronic ITP management?
Stimulate bone marrow production of platelets
What is the most common cause of microcytic hypochromic anemia during childhood?
Iron deficiency
What are two broad categories of hemoglobin disorders?
Quantitative and qualitative disorders
What is an example of a quantitative hemoglobin disorder?
Thalassemia
What characterizes immune neutropenias of childhood?
Marrow production normal to increased, storage pool normal to decreased, increase in turnover of neutrophils, vascular compartment decreased
What is an example of a qualitative hemoglobin disorder?
Structural variants or hemoglobinopathies
What are the risk factors for lead poisoning?
Increased susceptibility in younger children, incomplete blood-brain barrier, higher prevalence of iron deficiency, exposure to lead
What is Diamond Blackfan Anemia (DBA)?
Congenital/inherited anemia
What are the categories of immune neutropenias of childhood?
Chronic benign neutropenia of childhood, alloimmune, autoimmune, drug-induced
List three thrombopoietic agents used in chronic ITP management.
Eltrombopag (Promacta), Romiplostim (NPlate), Avatrombopag (Doptelet)
What are common sources of lead exposure?
Peeling paint in housing built before 1970s, lead dust
What is Transient Erythroblastopenia of Childhood (TEC)?
Acquired anemia
What is the function of Fostamatinib in chronic ITP management?
Syk (spleen tyrosine kinase) inhibitor
What are the three major systems affected by lead poisoning?
Nervous system, heme biosynthetic pathway, renal system
What is the mechanism of chronic benign neutropenia of childhood?
Anti-neutrophil antibody
What is a common cause of anemia in children with viral illness?
TEC
What is the peak age for acute ITP in children?
2-4 years
What are the clinical presentations of lead poisoning?
Most are asymptomatic
What is the peak age for chronic ITP in adults?
15-40 years
What is the median age at diagnosis for chronic benign neutropenia of childhood?
8-11 months
What is the typical age range for diagnosis of TEC?
1-4 years
What is the age range for AML in children?
1 – 15 years
What are the effects of lead poisoning on the nervous system?
Decreased IQ, cognitive effects, seizures, encephalopathy
What is the male-to-female ratio for acute ITP?
1:1
What is the typical age for diagnosis of DBA?
<1 year
How many AML cases are diagnosed annually in the US?
750 cases
What is the male-to-female ratio for chronic ITP?
1:2-3
What percentage of leukemia cases in children does AML represent?
10%
What percentage of DBA patients have congenital anomalies?
30-50%
How does lead poisoning affect the heme biosynthetic pathway?
Interferes with several enzymatic steps, decreased hgb synthesis at BLLs of 40, hemolytic anemia at BLL >70
How common is antecedent infection in acute ITP?
Common 1-3 weeks prior
How common is antecedent infection in chronic ITP?
Unusual
What percentage of leukemia-related deaths in children is due to AML?
30%
What is the hemoglobin level at diagnosis for DBA?
2-6 g/dL
What are the renal effects of lead poisoning?
Renal tubular dysfunction, chronic interstitial nephritis
Describe the onset of bleeding in acute ITP.
Abrupt
What is the overall survival rate for children with AML?
50%
What is the median length of illness for chronic benign neutropenia of childhood?
20 months
What are the gastrointestinal effects of lead poisoning?
Lead colic – vomiting, abdominal pain, constipation
What is the hemoglobin level at diagnosis for TEC?
3-9 g/dL
What is the white blood cell count in DBA?
Normal
Describe the onset of bleeding in chronic ITP.
Insidious
What is the platelet count in acute ITP?
<20,000/μl
Describe the therapy approach for AML in children.
Very short and very aggressive
What is the usual ANC level in chronic benign neutropenia of childhood?
<500
What are the endocrine effects of lead poisoning?
Decreased vitamin D metabolism with increased lead level
How is lead poisoning evaluated?
Venous blood lead level (BLL); routine screening recommended
What is considered an abnormal blood lead level (BLL)?
BLL ≥ 5
What additional screening is recommended if blood lead levels are elevated?
Screen for iron deficiency
What is the white blood cell count in TEC?
Normal to decreased
What is the platelet count in chronic ITP?
30,000 - 80,000/μl
What drugs are used during the induction phase of AML therapy?
High dose Ara-C, doxorubicin
What is the typical result of an antibody test in chronic benign neutropenia of childhood?
Positive
What percentage of acute ITP cases involve severe bleeding?
<10%
What is the platelet count in DBA?
Normal
What options are available during the consolidation phase of AML therapy?
More Ara-C or BMT if a match is available
What does the bone marrow show in chronic benign neutropenia of childhood?
Normal to increased myeloid series with a decrease at the band and/or seg level; some show earlier arrest
What is the platelet count in TEC?
Normal
Is there a maintenance phase in AML therapy for children?
No, it did not work
What percentage of chronic ITP cases involve severe bleeding?
Usually mild bleeding
Is the mean corpuscular volume (MCV) increased in DBA?
Yes
What is the incidence of cerebral hemorrhage in acute ITP?
<1%
What is the incidence of cerebral hemorrhage in chronic ITP?
3%
What imaging might be considered if symptomatic for lead poisoning?
Plain abdominal x-ray
What is the hemorrhagic death rate in acute ITP?
<1%
What is the mortality rate due to toxic death during AML chemotherapy?
7 – 9%
Is the mean corpuscular volume (MCV) increased in TEC?
No
Is hemoglobin F increased in DBA?
Yes
What is the hemorrhagic death rate in chronic ITP?
4%
What is the first step in managing lead poisoning?
End further exposure to lead
What is the second most common cancer in children?
Brain tumors
Is hemoglobin F increased in TEC?
No
What is the management approach for chronic benign neutropenia of childhood?
Supportive care; small risk for infection; G-CSF may be required in some patients with infections
What is the duration of acute ITP?
2-6 weeks
What nutritional measures can help manage lead poisoning?
Ensure adequate intake of calcium, vitamin C, iron and avoid fasting
What is the duration of chronic ITP?
Months to years
What is the most common type of solid neoplasm in children?
Brain tumors
What is the course of DBA?
Prolonged transfusion support or steroid therapy
What is the spontaneous remission rate in acute ITP?
83%
What therapy is used for significantly elevated lead levels?
Chelation therapy
What is the mechanism of cyclic neutropenia?
Apoptosis in precursors and cyclic hematopoiesis
What is the course of TEC?
Spontaneous recovery within weeks to months
What is the urgency of symptomatic lead intoxication?
It is a medical emergency
How many new brain tumor diagnoses are there annually in children?
3000-3500
What is the spontaneous remission rate in chronic ITP?
2%
What is the response rate to splenectomy in acute ITP?
71%
What is the 5-year survival rate for children with brain tumors?
60-70%
What are the two main types of leukocytes?
Granulocytes and mononuclear phagocytes
What is the response rate to splenectomy in chronic ITP?
66%