63 Neutropenia and Neutrophilia Flashcards
Neutropenia refers to an absolute blood neutrophil count (total leukocyte count per microliter × percent of neutrophils) that is less than _____ standard deviations (SDs) below the normal mean of the population.
2 standard deviations (SDs)
Agranulocytosis indicate severe neutropenia, that is, counts less than _________
0.5 × 109/L
For children from 1 month to 10 years old, neutropenia is defined as a blood neutrophil count _____________
less than 1.5 × 109/L.
For individuals older than age 10 years, neutropenia is defined as a count _____________
less than approximately 1.8 × 109/L
In persons of African descent, neutropenia is associated with what blood type
Duffy null phenotype
Individuals with neutrophil counts less than ___________ are at substantially greater risk, but the frequency of infections varies considerably, depending on the cause and duration of neutropenia.
less than 0.5 × 109/L
General mechanisms of neutropenia
(a) hypoplastic neutropoiesis,
(b) ineffective neutropoiesis (resulting from exaggerated apoptosis of neutrophils or their precursors)
(c) accelerated removal or utilization of circulating neutrophils
(d) shifts of cells from the circulating to the marginal blood pools
(e) a combination of these mechanisms
The most frequent cause of neutropenia
Cytotoxic drugs
Neutropenia is caused by mutations in the HAX-1 gene
Kostmann syndrome
- Mutations lead to accelerated apoptosis of myeloid cells, as well as neurologic abnormalities.
The majority of patients with sporadic or autosomal dominant severe congenital neutropenia have heterozygous mutations of the gene for _________________
Neutrophil elastase (also called ELANE)
Patients with ELANE mutations who demonstrate a clear maturation arrest at the level of _______________
Promyelocytes
TRUE OR FALSE
Most G-CSF receptor mutations are acquired as part of the evolution to myelodysplasia or acute myelogenous leukemia.
TRUE
Most G-CSF receptor mutations are acquired as part of the evolution to myelodysplasia or acute myelogenous leukemia.
A very effective therapy for all of the recognized subtypes of severe congenital neutropenia, increasing the neutrophil counts and reducing recurrent fevers and infections
G-CSF
***Approximately 5% of patients do not respond to G-CSF.
G-CSF acts to increase the neutrophil counts by enhancing expression of a critical transcription factor for granulopoiesis ______
C/EBPβ (CCAAT/enhancer binding protein β)
Aside from GCSF, the only other therapy known to improve the clinical course of congenital neutropenia
Hematopoietic transplantation
TRUE OR FALSE
G-CSF therapy is effective in most patients with neutropenia associated with immunodeficiency syndromes
TRUE
G-CSF therapy is effective in most patients with neutropenia associated with immunodeficiency syndromes
TRUE OR FALSE
In acquired disorders neutropenia in neonates of hypertensive mothers, the presence of neutropenia is a strong negative predictor for sepsis
FALSE
In acquired disorders neutropenia in neonates of hypertensive mothers, the ABSENCE of neutropenia is a strong negative predictor for sepsis
Nutritional Deficiencies causing neutropenia
Cobalamin or Folate deficiency
Copper deficiency
A rare acquired disorder causing severe selective neutropenia.
Pure white cell aplasia
This neutropenia is a distinct syndrome predominantly affecting young adult women ages 18–35 years; the female-to-male ratio is approximately 8 to 1.
The patients have no chromosomal abnormalities or other evidence of myelodysplasia.
Chronic Idiopathic Neutropenia in Adults
The greatest concern in Chronic Idiopathic Neutropenia
Evolution to lymphoid malignancies
Antigens with the clearest associations of autoantibodies and neutropenia
NA-1 and NA-2 (FcγRIII or CD16)
The disorder results from transplacental passage of maternal (Ig G antibodies that bind to the infant’s neutrophil-specific antigens, usually the FcγRIIIb (HNA1 or CD16b) isotype inherited from the infant’s father.
Alloimmune Neonatal Neutropenia
Alloimmune Neonatal Neutropenia usually lasts _________ until the passively acquired antibody is lost
2–4 months