Red Blood Cell Pathology

Front 1

Target cells

Back 1

increased RBC membrane. Hemoglobinopathies, thalassemia, liver disease.

Front 2

Acanthocytes

Back 2

Irregular spicules on surface. Abetalipoproteinemia

Front 3

Spherocytes

Back 3

Decreased RBC membrane. No central area of pallor. Spherocytosis

Front 4

Schistocytes

Back 4

RBC fragments. Microangiopathic hemolytic anemia, trauma

Front 5

Bite cells

Back 5

RBC with removed bits of cytoplasm. G6PDH deficiency.

Front 6

Sickle cells

Back 6

Sickle cell anemia

Front 7

Howell-Jolly bodies

Back 7

Remnants of nuclear chromatin. Severe anemias or patients without spleen

Front 8

Ring sideroblasts

Back 8

Trapped iron in mitochondria. Prussian-blue stain. Sideroblastic anemia

Front 9

Heinz bodies

Back 9

Denatured Hb. G6PDH deficiency

Front 10

Basophilic stipling

Back 10

RNA remnants. Lead poisoning

Front 11

Hypersegmented neutrophil

Back 11

Megaloblastic anemia

Front 12

EPO stimuli

Back 12

Low SaO2 (hypoxemia, anemia < 7gm/Dl, left shifted O2 curve

Front 13

Reticulocytes

Back 13

Immature RBC with no nucleous and bluish color in peripheral blood indicate effective erithropoiesis. Require 24 hours to become mature.

Front 14

Reticulocyte normal and corrected count

Back 14

Normal reticulocyte count is 1.5%. Corrected count is Hct/45 * reticulocyte count. >3% --> marrow responds well. <3% marrow is not well. If polychromasia (shift cells) divide corrected count by two because shift cells take double the time to mature

Front 15

Signs of anemia

Back 15

Palpitations, dizziness, angina, pallor, weakness

Front 16

Hypochromic RBCs

Back 16

Increased central pallor

Front 17

MCV < 80

Back 17

Iron deficiency, thalassemia, AOD, Sideroblastic

Front 18

MCV 80-100, low reticulocyte count

Back 18

Marrow failure, aplastic anemia, leukemia, renal failure, AOD

Front 19

MCV 80-100, high reticulocyte count

Back 19

Sickle cell, G6PDH deficiency, spherocytosis, AIHA, PNH

Front 20

MCV > 100

Back 20

Folate or B12 deficiency

Front 21

Causes of iron deficiency anemia

Back 21

Ulcers, menstrual bleeding, left colon cancer, elderly and poor children, malabsorption, gastrectomy, hookworm, Plummer-Vinson

Front 22

Low serum iron, % saturation and serum ferritin with high TIBC

Back 22

Iron deficiency anemia

Front 23

Low serum iron, TIBC and % saturation with high serum ferritin

Back 23

AOCD

Front 24

High serum iron, serum ferritin and % saturation with low TIBC

Back 24

Sideroblastic anemia

Front 25

AOCD

Back 25

Iron is trapped in bone marrow macrophages due to high levels of IL-1 and lactoferrin. High ferritin and low TIBC.

Front 26

HbA

Back 26

α2β2

Front 27

HbF

Back 27

α2γ2

Front 28

Hb Barts

Back 28

γ4

Front 29

HbH

Back 29

β4

Front 30

α-thalassemia

Back 30

Carrier has one α gene deletion, asymptomatic. Α-Thal trait has two deletions. HbH disease three deletions with high HbH and Heinz bodies. Hydrops fetalis, four deletions, lethal, high Hb Barts

Front 31

β-thalassemia

Back 31

Minor, asymptomatic, 8% HbA2 and 5% HbF. Major - develop symptoms 6 months after birth as HbF declines, jaundice, bilirubin gallstones, secondary hemochromatosis due to life-long transfusions, CHF, crecut skull x-ray, target cells. 90% HbF and HbA2

Front 32

HbA2

Back 32

α2δ2

Front 33

Lead poisoning anemia

Back 33

Sideroblastic anemia. Lead denatures ferrochelatase, ALA dehydrse and ribonuclease (coarse basophilic stipling). Ringed sideroblasts and basophilic stipling. Lead colic, peripheral neuropahty, cerebral edema, learning disabilities, bone in epiphysis on x-rays. high serum Pb, high urine δ-ALA, high serum iron, ferritin and %saturation with low TIBC. Risk fators: Pb paint, battery factory, pottery painter.

Front 34

Iron overload anemia

Back 34

Sideroblastic anemia with ringed sideroblasts. Alcoholism (MCC), pyridoxine deficiency (required by ALA synthase), isoniazid treatment. High serum iron, % saturation, ferritin and decreased TIBC.

Front 35

Factors that induce and prevent sickling

Back 35

Deoxygenation of Hb/right shifting dissociation curve (acidosis), increasing HbS concentration (dehydration), low O2 tension (altitude and renal medulla). HbF left shifts dissociation curve and prevent sickling (hydroxeurea Rx)

Front 36

Pathophysiology of sickle cell disease

Back 36

Valine subsitutes glutamic acid in position 6 of β Hb chain causing sickling and thrombi that occlude vessels (painful crisis), hand-foot swelling, autosplenectomy with Howell-Jolly bodies and increased risk of infections by encapsulated orgainsms, Salmonella osteomyelitis, parvovirus B19 aplastic crisis.

Front 37

Pathophysiology of G6PDH deficiency

Back 37

Mutation causes defective protein folding with low G6PDH activity and low levels od reduced gluthathione needed to neutralize ROS. Oxidative stress, oxidative drugs (primaquine, sulfonamides, anti-TB), bacterial infections and fava beans cause red cell damage and hemolysis with Heinz body formation (seen with methylene blue or crystal violet stains)

Front 38

Pathophysiology of spherocytosis

Back 38

Spectrin defect with decrease in RBC membrane leads to circular RBCs which are removed by macrophages in the spleen (extravascular hemolysis). Triad of anemia, splenomegaly and jaundice with risk of bilirubinate gallstones. Increased osmotic fragility test.

Front 39

Pathophysiology of AIHA

Back 39

IgG autoantibodies against Rh antigens on RBC with macrophage removal in spleen cause splenomegaly. Differentiate from hereditary spherocytosis with positive direct Coombs test

Front 40

Pathophysiology of PNH

Back 40

Low levels of decay accelerating factor (DAF) are not able to normally inhibit C3 convertase with increased sensitivity of cells to complement lysis. Slow breathing at night (retains CO2) and exercise produce acidosis which activates the complement system with pancytopenia and increased risk of aplastic anemia, leukemia and venous thrombosis

Front 41

Direct Coomb's test

Back 41

Detects IgG or C3 on surface of RBCs. Positive in AIHA, negative in hereditary spherocytosis.

Front 42

Indirect Coomb's test

Back 42

Detects autoantibodies in the serum. Often positive in AIHA

Front 43

Pathophysiology of microangiopathic hemolytic anemia

Back 43

RBCs are damaged by calcium in stenotic valves (aortic stenosis MCC), fibrin clots in DIC and platelet plugs in ITP and HUS. Presence of schistocytes.

Front 44

Sites for reabsorption of iron, folate and B12

Back 44

Iron: duodenum (Bilroth II, vitamin c deficiency and malabsorption syndromes produce deficiency). Folate: jejunum (contraceptives and alcohol decrease absorption). B12: terminal ileum (pernicious anemia, Crohn's and terminal ileum resection decrease absorption)

Front 45

Pathophysiology of megaloblastic anemia

Back 45

Methyl THF is needed to make methylcobalamine to convert homocysteine into methione by methylTHF-homocysteine methyl transferase (requires cobalamine). Methylene THF is required by thymidilate synthetase to make nucleic acids. B12 is needed by methylmalonyl CoA mutase to make succinyl CoA.Tetrahydrofolate is made by dihydrofolate reductase (blocked by methotrexate and trimethropin). Deficiency of folate or B12 produces megaloblastic anemia with hypersegmented neutrophils (no nucleic acid synthesis), homocystinuria and methylmalonic aciduria.

Front 46

Causes of folate deficiency

Back 46

Alcoholism (not beer), pregnancy, methotrexate, trimetrhoprim, phentoyn, birth control pills, celiac disease, leukemia

Front 47

Causes of B12 deficiency

Back 47

Pernicious anemia, pure vegan diet, Crohn's disease, chronic pancreatitis (cant cleave R factor from saliva which protects B12), D. latum

Front 48

Schilling's test

Back 48

Non-radioactive intramuscular B12 to saturate transcobalamin followed by radioactivee oral B12. No radioactive B12 detected in 24h urine confirms B12 absorption deficiency. Correct with intrinsic factor (pernicious anemia), pancreatic enzymes (chronic pancreatitis) or antibiotics (bacterial overgrowth)