Hypoproliferative Anemias Flashcards
identify the causes
microcytic hypochromic anemias - pathogenesis
- due to a cytoplasmic maturation effect - i.e., nuclear maturation / DNA synthesis normal
- leads to decreased Hb maturation
iron deficiency
- leads to what kind of anemia?
- has what main causes?
- microcytic hypochromic anemia
- causes
- dietary deficiency - infant (low Fe in breast milk), teenagers (poor diet), older adults (poverty)
- impaired absorption
- chronic blood loss: almost ALWAYS the cause of iron deficient anemia in: postmenopausal women, older men
- increased requirement
briefly outline iron metabolism in the body
- absorbed in gut
- transported by transferrin to various tissues
- bone (75%): for hematopoiesis
- liver > heart (25%): for storage in the form of ferritin
discuss the clinical presentations of iron deficiency anemia
- specific findings:
- koilonychia - finger nail spooning
- atrophic glossitis
- alopecia
- intestinal malabsorption
- general findings
- pale nail beds
- palor
- -/- thrombocytosis
discuss the RBC characteristics seen in iron deficiency anemia
-
microcytic hypochromic cells
- anisocytosis - high RDW (difference in RBC size)
- poikilocytosis: pencil cell elliptocytes
- DECREASED RETICULOCYTE COUNT
glossitis
specific for either iron deficiency (microcytic hypochromic) or B12 / folate deficiency (macrocytic)
koilonychia (spooning fingernails) - specific for iron deficiency anemia
pale nail beds
see in any anemia
pale nail beds - seen in any anemia
iron deficiency anemia
- microcytic hypochromic cells (with anisocytosis)
- _presence of poikilocytosi_s “pencil cells”
contrast the images
left: normal bone marrow stain - blue stain (pearls stain) highlight normal iron stores in macrophages
right: absence of blue staining in iron deficiency anemia
what factors are used to help dx between the major causes of microcytic hypochromic anemia (iron deficient, chronic disease, sideroblastic) and what do they mean?
- serum iron
- total iron binding capacity (TIBC)- total transferrin concentration
- serum soluble transferrin receptor (SSTR) - presence of serum transferrin, inversely proportional to iron stores
- serum ferritin []: rough approximation of bone marrow iron stores
characterize iron deficiency anemia based on
- serum Fe
- TIBC
- SSTR
- % Sat
- Marrow Fe
what are the m/c anemias?
- iron deficiency
- chronic disease
both microcytic, hypochromic
pathogenesis of anemia of chronic disease
microcytic, hypochromic anemia
-
driven by cytokine dysfunction:
- impaired “hand off” of iron between macrophages and developing RBCs → iron trapped in macrophages → unavailable for heme synthesis
discuss the RBC characteristics of anemia of chronic disease
- RBC morphology - typically microcytic hypochromic. however, no other morphological distinguishers.
- reticulocyte count is low
characterize anemia of chronic disease based on
- serum Fe
- TIBC
- SSTR
- % Sat
- Marrow Fe
sideroblastic anemia - pathogenesis/cause
- abnormal iron metabolism within the RBC itself: iron is sequestered in the developing erythroblast mitochondria → unavailable for Heme synthesis. cause
- hereditary
- myelodysplastic syndromes
sideroblastic anemia - RBC characteristics
- microcytic hypochromic
note: in bone marrow, siderblastic anemia can cause characteristic ringed sideroblasts: ring of dark blue-staining, iron containing mitochondria around nucleus
sideroblastic anemia
increased iron stores (prussian blue stain) in the bone marrow
sideroblastic anemia
“ringed sideroblasts” in the bone marrow: ring of iron around mitochondria
characterize sideroblastic anemia based on
- serum Fe
- TIBC
- SSTR
- % Sat
- Marrow Fe
mego-blastic macrocytic anemia - pathogenesis / causes
-
nuclear defect (vs macrocytic - which is a cytoplasmic defect)
- impaired DNA synthesis defective nuclear maturation → less divisions → ABNORMALLY LARGE RBCS
- m/c cause: lack of VITAMINS necessary for DNA synthesis
- VITAMIN-B12
- FOLATE
- copper deficiency
- m/c cause: lack of VITAMINS necessary for DNA synthesis
- impaired DNA synthesis defective nuclear maturation → less divisions → ABNORMALLY LARGE RBCS