2013-10-16 Anemia II (Micro- and Normocytic) Flashcards
Best test to determine Fe-deficiency?
ferritin (the bus)
TIBC
measures amount of transferrin (blood borne Fe carrier that only holds 2 Fe molecules)
hepcidin
controls Fe absorption in the duodenum; decr in anemia of chronic dz
iron stores in the body
Hgb (MOST)
Myoglobin
ferritin (“the bus;”in M0s of spleen, liever, marrow)
transferrin (“the car;” TIBC; in circulation)
transferrin saturation lab interpretation
transferrin sat INCR in IRON OVERLOAD (e.g. mhemochromatosis)
transferrin sat DECR in decr supply of Fe from M0s and other stores (e.g. as in anemia of chronic dz)
- Iron def anemia:
- s/sx
- smear findings
- lab findings
s: koilonychia, glossitis, angular cheilosis
sx: pica, RLS
smear: microcytic, hypochromic, anisocytotic, poikilocytotic (weird shapes) RBCs
labs: LOW FERRITIN, low serum Fe, low transferrin sat, incr TIBC
low MCV (microcytes)
low MCH/MCHC (hypochromic)
incr RDW (anisocytosis)
- sideroblastic anemia
- cause
- s/sx
- smear
- lab findings
- tx
- cause: decr heme synth -> excess free Fe;
- -1°: ALA synthase def; MDS
- -2°: Pb poison; B6/Cu def; isoniazid/chloramphenicol; EtOH/Zn/
- s/sx of lead poisoning: Pb-line on gums, lead colic (autonomic dysfxn), insomnia, irritability, psychosis
- smear: ringed sideroblasts (excess Fe)
- lab: high serum Fe, ferritin, transferrin SAT; TIBC (transferrin conc) is LOW/nl; high blood lead level
- tx: ∆ meds/toxins/EtOH; PRBCs; Fe-chelation
- Thalassemias
- genetics
- presentation
- dx
- complications
GENETICS -both: autosomal recessive ALPHA: -decr alpha; excess Beta -dx w/ DNA anaysis b/c electrophoresis nl
BETA
- target cells
- dx w/ hgb electrophoresis
COMPLICATIONS
-both: Fe overload
- anemia of chronic dz
- incidence
- smear
- pathophys
INCIDENCE
—most common normocytic anemia w/ low retic count
—2nd most common anemia overall (after IDA)
SMEAR
—usu normocytic and normchromic (though both can be low)
PATHOPHYS
- chronic disease (infx, inflamm, malig)
- > > cytokines
- > > increases hepcidin
- > > > > > increases storing in M0s (ferritin)
- > > > > > decreases epo, duodenal Fe uptake, Fe release from stores
- aplastic anemia
- normocytic w/ low retic count (less common than anemia of chronic dz)
- pancytopenia (leukopenia and thrombocytopenia bigger concerns!)
- 1°: idiopathic
- 2°: meds (chemo, chloramphenicol, AEDs); toxin (benzene); radiation; viral (Parvovirus B19, EBV)
- anemia of chronic kidney diease
another normocytic w/ low retic
—low epo, blood loss (repeated phleb, machine, uremic plt dsfx)
—shortened RBC life 2° to uremia
endocrinopathies that cause normocytic normochromic anemia
- hypothyr
- hypoparathyr
- panhypopituitarism
- low Test (2° to prostate cancer tx)
intravascular vs. extravascular hemolysis: s/sx/labs
INTRAVASCULAR
- high LDH, low haptoglobin
- hemoglobenemia (red plasma)
- hemoglobulinuria (red pee)
- JAUNDICE
- schistocytes
EXTRAVASCULAR
- still JAUNDICE
- mostly in spleen so no hgb-enmia/uria
- immune hemolytic anemias
Normocytic HYPERchromic –> immune hemolytic anemias
- dx: nl MCV, high RPI, positive COOMBS Test
- tx: fix underlying cause, steroids, immunosupp, rituximab, splenectomy (last resort)
- MAHA - Microangiopathic Hemolytic Anemia
- causes
- s/sx
- labs/smear
Normocytic HYPERchromic –> immune hemolytic anemias
- causes: TTP (ADAMTS13 mutation -> long, potent vWFs), HUS (shiga toxin), HIV, heart valves
- s/sx: DIC, malfunctioning heart valve
- labs/smear: schistocytosis, thrombocytopenia
- PNH
- name
- pathophys
- s/sx
- labs/smear
- tx
Normocytic HYPERchromic –> Membranopathies -> PNH
- NAME:paroxysmal nocturnal hemoglobulinuria
- defect in GPI glycolipid on cell surface makes RBCs susceptible to MAC attack
- dark urine in a.m., incr thrombosis
- labs: flow shows decr CD59 which needs GPI to anchor
- tx: Fe, Folate, eculizumab (C5 inhib), stem cell transplant
- Hereditary Spherocytosis
- pathophys
- labs/smear
- tx
Normocytic hyperchromic –> membranopathies –> herid. spher.
- abnl shape b/c of autosomal dominant mutation in various prots that anchor membrane to cytoskel
- hyperchromic b/c cells shrinking in spleen where eventually removed
- smear shows no donut hole, labs: low h/h, lowish/nl MCV
- tx: splenectomy
- G6PD
- pathophys
- inheritance pattern
- tx
Normocytic, hyperchromic –> G6PD
- enzyme needed to recycle glutathione which protects RBCs from oxidative damage
- x-linked
- avoid exposures
- some drugs that cause hemolytic anemia
normocytic hyperchromic anemia –> hemolytic –> drug-induced
1. penicillin (hapten; ab directed toward Abx-membrane complex)
2. quinidine (deposition of complement via a drug-prot-Ab cmplx)
3. methyldopa (truly autoimmune; role of drug unknown)
BOOK PG. 85
- some infxs that cause haemolytic anemia
normocytic hyperchromic–> hemolytic –> infectious
—malaria
—babesiosis (Ioxodes ticks on Cape Cod)
- Sickle Cell
normocytic hyperchromic–> haemolytic –> SCD
—makes HbS b/o glu –> val ∆
—HbS polymerizes
HEMOLYSIS: jaundice, anemia, pigment gallstones
INFXS: encapsulated organs, bones
VASO-OCCLUSIVE: pain, CP, priapism, avacular hip necrosis, CVAs, retinopathy
APLASTIC EPISODES: with Parvovirus B-19 infection
Work-up for a hemolytic anemia
establish hemolysis: hi retic,; hi LDH/bili, lo hapto check smear: —spherocytes? = extravasc —schistocytes? = intravasc Coombs Test: auto-immune?
