Hematology I Flashcards
What is anemia?
decrease in RBCs, HCT, or Hb
Erythropoiesis occurs in the:
bone marrow
Erythropoietin comes from:
the juxtaglomerular (JG) cells of the kidney
EPO is produced in response to:
decreased O2
increased androgens
RBC lifespan:
120 days
RBCs cleared by:
spleen, liver, bone marrow phagocytic cells
Heme is degraded into:
bilirubin
% of RBCs renewed daily:
0.5-1.5%
Mechanisms of anemia:
Blood loss
Decreased absorption
Deficient erythropoeisis
Excessive hemolysis
Hx risk factors for anemia:
Diet, menstruation, alcoholism, Rx drugs, cancer, COPD, marathon running, family hx of bleeding disorder.
S/sx of anemia:
Weakness, fatigue, SOB, DOE, angina, syncope, drowsiness, seeing spots.
[vertigo, HA, tinnitus, pica, RLS, amenorrhea, menorrhagia, loss of libido, GI complaints]
Signs of hemolysis:
jaundice, pruritis, dark urine (bilirubin, urobilinogen)
Anemia PE:
orthostatis BP (supine, seated, standing)
Inspect conjunctiva, palms, mucus membranes, skin color
Inspect nails (blueness, ridges, spooning, clubbing)
Cardiovascular exam
Microcytic causes:
Iron deficiency, thalassemia, Hb-synthesis defects, copper deficiency, zinc/lead poisoning, alcohol
Macrocytic causes:
B12/folate deficiency, chemo, alcoholism, HIV anti-retrovirals, myelodysplastic disorder, impaired DNA synth
Normocytic anemia causes:
blood loss, deficient EPO
Most common anemia:
iron deficiency
Iron deficiency anemia s/sx:
Mild - fatigue, HA, irritability, loss of stamina, pallor, difficult concentration.
Severe - pica, glossitis, cheilosis, spooning, tachycardia, dyspnea, RLS, glossal pain, xerostomia, alopecia
Increases non-heme iron absorption:
ascorbic acid
Daily iron requirement:
25mg/day (most from recycle/reabsorption)
Iron storage forms/locations:
Hemosiderin - liver, marrow
Ferritin - liver, marrow, spleen, RBCs, serum
Most frequent cause of iron deficiency anemia:
Men - chronic bleed (UC, colon cancer, PUD, ASA use)
Women - menstruation, repeated pregnancy
Dx for iron deficient anemia:
Stool occult blood
Iron absorption test
CBC w/peripheral smear, serum iron, TIBC, serum ferritin
Sideroblastic anemias are:
inadequate or abnormal utilization of marrow iron, with adequate stores. hereditary or 2° to drug/toxin (reversible)
RBC appearance in sideroblastic anemia:
Polychromatophilic, stippled, targeted RBCs
Dx for sideroblastic anemia:
CBC w/peripheral smear, iron, ferritin, BM bx, erythrocyte protoporphyrin, genetic studies
Causes of anemia of chronic dz:
infection, inflammatory, neoplastic dz, trauma, heart failure, DM
BM responsiveness to EPO mediated by cytokines:
IL-1 beta & TNF-alpha
Hypoproliferative anemias are:
low marrow activity d/t lack of EPO or ability of BM to respond; seen in thyroid regulation disorders, panhypopituitarism
Aplastic anemias are:
pancytopenia of all cell lines, or pure red cell aplasia
Causes of aplastic anemias:
chemical exposure (drugs, pesticides, anti-cancer agents)
infections (parvo, HIV, hepatitis, EBV, CMV)
Genetic inability to clear toxins
Fanconi’s anemia (inherited)
S/sx of aplastic anemia:
sudden acute onset or insidious, pallor, tachycardia, fatigue, dizziness
Thrombocytopenia (petechiae, ecchymosis, bleeding gums, ocular fundi)
Labs for aplastic anemia:
CBC w/peripheral smear, iron, reticulocytes, BM bx
Myelophthisic anemia is:
marrow replaced by tumor, granuloma, fibrosis, or lipid storage dz
S/sx of myelophthisic anemia:
Fatigue (early, severe), splenomegaly, night sweats, low fever, bone pain
Could be asx
Labs for myelophthisic anemia:
CBC w/peripheral smear, BM bx
Macrocytic anemia is:
due to defective DNA synthesis
causes of macrocytic anemia:
alcoholism, folate or B12 deficiency, chemo, hypothyroid, liver dz
Anemia d/t B12/folate deficiency:
megaloblastic anemia
S/sx of macrocytic anemia:
Usu none until severe
Then neuro signs (stocking/glove neuropathy, dementia)
Glossitis, diarrhea, muscle wasting
Labs/dx for macrocytic anemia:
CBC w/peripheral smear, B12 (& PMN count), folate
Causes of hemolytic anemia:
Intrinsic:
abnormal RBC membranes
RBC metabolism disorder
Hemoglobinopathies
Extrinsic:
Hypersplenism
Toxic exposure
Autoimmune dz
Mechanical injury (prosthetic valves, DIC, TTP)
Infectious agents (malaria, C. Perfringens)
S/sx of hemolytic anemia:
May be acute, chronic, or episodic
Rapid onset pallor
Acute hemolytic crisis (uncommon) - fever, chills, back/abd pain, prostration, shock
Severe hemolysis: jaundice, splenomegaly, cholelithiasis
Labs/dx for hemolytic anemia:
Peripheral smear - spherocytosis
Bilirubin, LDH, ALT
Autoimmune hemolytic anemia is:
making antibodies to RBCs; may be severe & fatal
Warm antibody hemolytic anemia:
>37°C more common in women spontaneous or from viral inf, immune deficiency, drugs, SLE, CLL, lymphoma primarily in the spleen mild splenomegaly
Cold antibody hemolytic anemia:
<37°C
commonly from infections (mycoplasma pneumoniae)
1/2 are idiopathic chronic
primarily in the liver
acrocyanosis, Raynauds, scleral icterus, splenomegaly
Dx test for autoimmune hemolytic anemia:
Coombs - direct antiglobulin test
Hereditary spherocytosis & elliptocytosis are:
congenital RBC membrane defects; autosomal dominant
S/sx of hereditary -cytosis anemias:
Jaundice Splenomegaly Cholelithiasis Hepatomegaly (maybe) Anemia sx
Stomatocytosis is:
Rare, congenital (severe) or acquired (EtOH) RBC membrane disorders, display increased fragility
Show straight or rectangular central pallor
Hypophasphatemia is:
d/t low phosphate, RBCs depleted of ATP -> rigid
small, spheroid RBCs
G-6-P deficiency:
reduces energy available to maintain RBC membrane integrity
d/t abnormal enzymes, genetic polymorphism, drug sensitivity
x-linked
12% of African-American males fully express
S/sx of G-6-P deficiency:
episodic
sudden onset jaundice, pallor, dark urine, anemia sx
may have back/abd pain
may lead to renal failure
Labs/dx of G-6-P deficiency:
G6P assay
Sickle cell anemia:
Chronic hemolytic anemia; African descent; homozygous inheritance of Hb S gene
(trait - heterozygous, varying expression)
S/sx of sickle cell anemia:
painful bony crises renal damage punched out leg ulcers splenic infarcts aplastic crises anemia usually severe developmental delays avascular necrosis of femoral head abd pain with vomiting neurological disturbance splenomegaly
Sever complications of sickle cell:
death by middle age, usu d/t infection, pulmonary emboli, vessel occlusion
S/sx of sickle cell trait:
myalgia
hematuria during hypoxia
Hemoglobin C dz:
genetic hemoglobinopathy; African descent; may be assoc with sickle cell
S/sx of hemoglobin C dz:
bone pain
splenomegaly
jaundice (mild)
anemia
Thalassemia:
inherited defects in rate of synthesis of globin chains
ineffective erythropoiesis & low RBC production
Mediterranean, African, SE Asian, Pacific Islanders
may occur with sickle cell anemia
Thalassemia major:
homozygous
most serious - beta thalassemia (autosomal dominant)
usually fatal
Thalassemia minor:
heterozygous
milder dz
may be asx
S/sx of thalassemia:
heart failure failure to thrive splenomegaly jaundice leg ulcers gallstones thick zygomatic and cranial bones
Leukopenia:
absolute decrease in number of WBCs circulating;
may be pancytopenia or one line;
<4000 c/mm
Define neutropenia:
decrease in neutrophils (PMNs/granulocytes)
main defense against bacterial & fungal infections
Neutropenia - normal resistance range:
> 1500/mm whites
>1200/mm blacks
Neutropenia - mild risk:
1000-1500/mm
Neutropenia - moderate risk:
500-1000/mm
Neutropenia - severe risk:
<500/mm
Neutropenia - rapidly fatal range:
<200/mm
S/sx of neutropenia:
sx only occur w/infection -
fever (may be only sign)
cellulitis, liver abscess, furunculosis, pneumonia, septicemia
rash & LA if drug induced
Intrinsic neutropenia:
due to defects in myeloid cells or precursors; rare; congenital, chronic idiopathic, benign
Secondary neutropenia:
drug induced (chemo); unpredictable, idiosyncratic bone marrow infiltration - cancer, myelofibrosis hypersplenism infection, sepsis (childhood virus, HIV) alcoholism autoimmune - esp SLE folate/B12 deficiency leukemia transfusion
Lymphocytopenia:
reduction in lymphocytes
<2yo
Lymphocytes account for what % of WBCs?
20-40%
30% - NLMEB
Lymphocytes include:
T cells (75%) & B cells (25%)
65% of T cells are CD4
Causes of lymphocytopenia:
infectious disease - TB, HIV, SARS, hep, EBV, CMV
dietary deficiency
Iatrogenic - immunosuppression, chemo, radiation
systemic dz w/autoimmune - SLE, RA, sarcoid, cushing
Other - EtOH, zinc deficiency
S/sx of lymphocytopenia:
signs of primary illness
absent/diminished tonsils or lymph nodes
palpable LA if tumors are the cause
hematologic dz - jaundice, pallor, petechiae, splenomegaly
recurrent viral/fungal/parasitic infection
Normal platelet count:
140-440K/uL
Platelet lifespan:
7-10 days
destroyed by spleen
Causes of thrombocytopenia:
failure of production increased sequestration, destruction, dilution quinine drugs liver dz DIC pregnancy, preeclampsia ITP (idiopathic thrombocytopenia purpura) HIV
RBC size:
microcytic 95
