RBC and BLEEDING DISORDERS

RBC and Bleeding Disorders• NORMAL

–Anatomy, histology

–Development

–Physiology

• ANEMIAS–Blood loss: acute, chronic

–Hemolytic

–Diminished erythropoesis

• POLYCYTHEMIA

• BLEEDING DISORDERS

TABLE 13‐2 ‐‐ Adult Reference Ranges for Red Blood Cells*

Measurement (units) Men WomenHemoglobin (gm/dL) 13.6–17.2 12.0–15.0

Hematocrit (%) 39–49 33–43

Red cell count (106 /µL) 4.3–5.9 3.5–5.0

Reticulocyte count (%) 0.5–1.5

Mean cell volume (µm3 ) 82–96

Mean corpuscular hemoglobin (pg) 27–33

Mean corpuscular hemoglobin concentration (gm/dL)

33–37

RBC distribution width 11.5–14.5

WHERE is MARROW?• Yolk Sac: very early embryo

• Liver, Spleen: NEWBORN

• BONE– CHILDHOOD: AXIAL SKELETON & APPENDICULAR SKELETON BOTH HAVE RED (active) MARROW

– ADULT: AXIAL SKELETON RED MARROW, APPENDICULAR SKELETON YELLOW MARROW

MARROW FEATURES• CELLULARITY

• MEGAKARYOCYTES

• M:E RATIO

• MYELOID MATURATION

• ERYTHROID MATURATION

• LYMPHS, PLASMA CELLS

• STORAGE IRON, i.e., HEMOSIDERIN

• “FOREIGN CELLS”

MARROW“DIFFERENTIATION”

ANEMIAS*• BLOOD LOSS

–ACUTE–CHRONIC

• IN‐creased destruction (HEMOLYTIC)

• DE‐creased production

* A good definition would be a decrease in OXYGEN CARRYING CAPACITY, rather than just a decrease in red blood cells, because you need to have enough blood cells THAT FUNCTION, and not just enough blood cells.

Features of ALL anemias

• Pallor, where?• Tiredness• Weakness

• Dyspnea, why?• Palpitations• Heart Failure (high output), why?

Blood LossAcute: trauma

Chronic: lesions of gastrointestinal tract, gynecologic disturbances. The features of chronic blood loss anemia are the same as iron deficiency anemia, and is defined as a situation in which the production cannot keep up with the loss

HEMOLYTIC• HEREDITARY

– MEMBRANE disorders: e.g., spherocytosis

– ENZYME disorders: e.g., G6PD deficciency

– HGB disorders (hemoglobinopathies)

• ACQUIRED– MEMBRANE disorders (PNH)

– ANTIBODY MEDIATED, transfusion or autoantibodies

– MECHANICAL TRAUMA

– INFECTIONS

– DRUGS, TOXINS

– HYPERSPLENISM

IMPAIRED PRODUCTION• Disturbance of proliferation and differentiation of stem cells: aplastic anemias, pure RBC aplasia, renal failure

• Disturbance of proliferation and maturation of erythroblasts

• Defective DNA synthesis:  (Megaloblastic)

• Defective heme synthesis:    (Fe)

• Deficient globin synthesis: (Thalassemias)

MODIFIERS• MCV, microcytosis, macrocytosis

• MCH 

• MCHC, hypochromic

• RDW, anisocytosis

HEMOLYTIC ANEMIAS• Life span LESS than 120 days• Marrow hyperplasia (M:E), EPO+

• Increased catabolic products, e.g., bilirubin, serum HGB, hemosiderin

HEMOLYSIS• INTRA‐vascular (vessels)• EXTRA‐vascular (spleen)

M:E Ratio normally 3:1

HEREDITARY SPHEROCYTOSIS

Genetic defects affecting ankyrin, spectrin, usually autosomal dominant

Children, adults

Anemia, hemolysis, jaundice, splenomegaly, gallstones (what kind?)

Glucose‐6‐Phosphate Dehydrogenase (G6PD) Deficiency

• A‐ and Mediterranean are most significant types

FEATURES of G6PD Defic.• Genetic: Recessive, X‐linked

• Can be triggered by foods (fava beans), oxidant substances drugs (primaquine, chloroquine), or infections

• HGB can precipitate as HEINZ bodies

• Acute intravascular hemolysis can occur:–Hemoglobinuria

–Hemoglobinemia

–Anemia

Sickle Cell Disease• Classic hemoglobinopathy

• Normal HGB is α2 β2:       β‐chain defects (Val‐>Glu)

• Reduced hemoglobin “sickles” in homozygous

• 8% of American blacks are heterozygous

Clinical features of HGB‐S disease

• Severe anemia

• Jaundice

• PAIN (pain CRISIS)

• Vaso‐occlusive disease: EVEREWHERE, but clinically significant bone, spleen (autosplenectomy)

• Infections: Pneumococcus, Hem. Influ.

THALASSEMIAS• A WIDE VARIETY of diseases involving GLOBIN synthesis, COMPLEX genetics

• Alpha or beta chains deficient synthesis involved

• Often termed MAJOR or MINOR, depending on severity,  silent carriers and “traits” are seen

• HEMOLYSIS is uniformly a feature, a microcytic anemia

• A “crew cut” skull x‐ray appearance may be seen

Hemoglobin H Disease• Deletion of THREE alpha chain genes• HGB‐H is primarilly Asian

• HGB‐H has a HIGH affinity for oxygen

• HGB‐H is unstable and therefore has classical hemolytic behavior

HYDROPS FETALIS• FOUR alpha chain genes are deleted, so this is the MOST SEVERE form of thalassemia

• Many/most never make it to term

• Children born will have a SEVERE hemolytic anemia as in the erythroblastosis fetalis of Rh disease:– Pallor (as in all anemias)

– Edema (hence the name “hydrops”)

– Massive hepatosplenomegaly (hemolysis)

Paroxysmal Nocturnal Hemoglobinuria  (PNH)

• ACQUIRED, NOT INHERITED like all the previous hemolytic anemias were

• ACQUIRED mutations in phosphatidylinositol glycan A (PIGA)

• It is “P” and “N” only 25% of the time

GlycosylphosPhatidylInositol

Immunohemolytic Anemia• All of these have the presence of antibodies and/or compliment present on RBC surfaces

• NOT all are AUTOimmune, some are caused by drugs

• Antibodies can be–WARM (IgG)

–COLD AGGLUTININ (IgM)

–COLD HEMOLYSIN (paroxysmal) (IgG)

IMMUNOHEMOLYTIC ANEMIAS• WARM  (IgG), will NOT hemolyze at room temp

– Primary Idiopathic (most common)– Secondary (Tumors, especially leuk/lymph, drugs)

• COLD AGGLUTININS:  (IgM), WILL hemolyze at room temp– Mycoplasma pneumoniae, HIV, mononucleosis

• COLD HEMOLYSINS: (IgG) Cold Paroxysmal Hemoglobinuria, hemo‐LYSIS in body, ALSO often follows mycoplasma pneumoniae

COOMBS TEST• DIRECT: Patient’s CELLS are tested for surface Ab’s

• INDIRECT: Patient’s SERUM is tested for Ab’s.

HEMOLYSIS/HEMOLYTIC ANEMIAS DUE TO RBC TRAUMA

• Mechanical heart valves breaking RBC’s

• MICROANGIOPATHIES:–TTP–Hemolytic Uremic Syndrome

NON‐Hemolytic Anemias:i.e., DE‐creased Production

• “Megaloblastic” Anemias

• B12 Deficiency (Pernicious Anemia)

• Folate Deficiency

• Iron Deficiency

• Anemia of Chronic Disease

• Aplastic Anemia

• “Pure” Red Cell Aplasia

• OTHER forms of Marrow Failure

MEGALOBLASTIC ANEMIAS• Differentiating megaloblasts (marrow) from macrocytes (peripheral smear, MCV>94)

• Impaired DNA synthesis

• For all practical purposes, also called the anemias of B12 and FOLATE deficiency

Decreased intake

Inadequate diet, vegetarianism

Impaired absorption

Intrinsic factor deficiency

Pernicious anemia

Gastrectomy

Malabsorption states

Diffuse intestinal disease, e.g., lymphoma, systemic sclerosis

Ileal resection, ileitis

Competitive parasitic uptake

Fish tapeworm infestation

Bacterial overgrowth in blind loops and diverticula of bowel

Increased requirement

Pregnancy, hyperthyroidism, disseminated cancer

Vit‐B12 Physiology• Oral ingestion

• Combines with INTRINSIC FACTOR in the gastric mucosa

• Absorbed in the terminal ileum

• DEFECTS at ANY of these sites can produce a MEGALOBLASTIC anemia

Please remember that ALL megaloblastic anemias are also MACROCYTIC (MCV>94 or MCV~100), and that not only are the RBC’s BIG, but so are the neutrophils, and neutrophilic precursors in the bone marrow too, and even more so, HYPERSEGMENTED!!!

PERNICIOUS ANEMIA• MEGALOBLASTIC anemia• LEUKOPENIA and HYPERSEGS• JAUNDICE• NEUROLOGIC posterolateral spinal tracts• ACHLORHYDRIA• Can’t absorb B12• LOW serum B12• Flunk Schilling test, i.e., can’t absorb B12, using a radioactive tracer

FOLATE DEFICIENCY MEGALOBLASTIC AMEMIAS

• Decreased Intake: diet, etoh‐ism, infancy• Impaired Absorption: intestinal disease• DRUGS: anticonvulsants, BCPs, CHEMO• Increased Loss: Hemodialysis• Increased Requirement: Pregnancy, infancy• Impaired Usage

Fe Deficiency Anemia• Due to increased loss or decreased ingestion, almost always, in USA, nowadays, increased loss is the reason

• Microcytic (low MCV), Hypochromic (low MCHC)

• THE ONLY WAY WE CAN LOSE IRON IS BY LOSING BLOOD

Fe

Transferrin

Ferritin (GREAT test)

Hemosiderin

Clinical Fe‐Defic‐Anemia

• Adult men: GI Blood Loss

• PRE menopausal women: menorrhagia

• POST menopausal women: GI Blood Loss

2 BEST lab tests:• Serum Ferritin

•Prussian blue hemosiderin stain of marrow (also called an “iron” stain)

Anemia of Chronic Disease*•CHRONIC INFECTIONS•CHRONIC IMMUNE DISORDERS

•NEOPLASMS• LIVER, KIDNEY failure

* Please remember these patients may very very much look like iron deficiency anemia, BUT, they have ABUNDANT STAINABLE HEMOSIDERIN in the marrow!

APLASTIC ANEMIAS• ALMOST ALWAYS involve platelet and WBC suppression as well

• Some are idiopathic, but MOST are related to drugs, radiation

• FANCONI’s ANEMIA is the only one that is inherited, and NOT acquired

• Act at STEM CELL level, except for “pure” red cell aplasia

APLASTIC ANEMIAS

APLASTIC ANEMIAS• CHLORAMPHENICOL

• OTHER ANTIBIOTICS

• CHEMO

• INSECTICIDES

• VIRUSES– EBV

–HEPATITIS

–VZ

MYELOPHTHISIC  ANEMIAS

• Are anemias caused by metastatic tumor cells replacing the bone marrow extensively

POLYCYTHEMIA• Relative  (e.g., hemoconcentration)

• Absolute

– POLYCYTHEMIA VERA (Primary)  (LOWEPO)

– POLYCYTHEMIA  (Secondary) (HIGH EPO)• HIGH ALTITUDE

• EPO TUMORS

• EPO “Doping”

• CVAC, the trendy California bubble pods

P. VERA•A “myeloproliferative” disease

•ALL cell lines are increased, not just RBCs

BLEEDING DISORDERS(aka, Hemorrhagic “DIATHESES”)• Blood vessel wall abnormalities √

• Reduced platelets √

• Decreased platelet function √

• Abnormal clotting factors √

• DIC (Disseminated INTRA‐vascular Coagulation)

VESSEL WALL ABNORMALITIES(NON‐thrombotic cytopenic purpuras)

• Infections, especially, meningococcemia, and rickettsia

• Drug reactions causing a leukocytoclastic vasculitis

• Scurvy, Ehlers‐Danlos, Cushing syndrome

• Henoch‐Schönlein purpura (mesangial deposits too)

• Hereditary hemorrhagic telangiectasia

• Amyloid

THROMBOCYTOPENIAS

• Like RBCs:–DE‐creased production–IN‐creased destruction–Sequestration (Hypersplenism)

–Dilutional

• Normal value 150K‐300K

DE‐CREASED PRODUCTION

• APLASTIC ANEMIA

• ACUTE LEUKEMIAS

• ALCOHOL, THIAZIDES, CHEMO

• MEASLES, HIV

• MEGALOBLASTIC ANEMIAS

• MYELODYSPLASTIC SYNDROMES

IN‐CREASED DESTRUCTION

• AUTOIMMUNE (ITP)

• POST‐TRANSFUSION (NEONATAL)

• QUINIDINE, HEPARIN, SULFA

• MONO, HIV

• DIC

• TTP

• “MICROANGIOPATHIC”

THROMBOCYTOPENIAS• ITP (Idiopathic Thrombocytopenic Purpura)

• Acute Immune

• DRUG‐induced• HIV associated• TTP, Hemolytic Uremic Syndrome

• ADULTS AND ELDERLY

• ACUTE OR CHRONIC

• AUTO‐IMMUNE

• ANTI‐PLATELET ANTIBODIES PRESENT

• INCREASED MARROW MEGAKARYOCYTES

• Rx: STEROIDS

ACUTE  ITP• CHILDREN• Follows a VIRAL illness (~ 2 weeks)• ALSO have anti‐platelet antibodies• Platelets usually return to normal in a few months

DRUGS• Quinine• Quinidine• Sulfonamide antibiotics

•HEPARIN

• BOTH DE‐creased production AND IN‐creased destruction factors are present

Thrombotic  Microangiopathies

• BOTH are very SERIOUS CONDITIONS with a HIGH mortality:– TTP (THROMBOTIC THROMBOCYTOPENIC PURPURA)

– H.U.S. (HEMOLYTIC UREMIC SYNDROME)

• These can also be called “consumptive” coagulopathies, just like a DIC

“QUALITATIVE” platelet disorders

• Mostly congenital (genetic):–Bernard‐Soulier syndrome (Glycoprotein‐1‐b deficiency)

–Glanzmann’s thrombasthenia (Glyc.‐IIB/IIIA deficiency)

– Storage pool disorders, i.e., platelets mis‐function AFTER they degranulate

• ACQUIRED:  ASPIRIN, ASPIRIN, ASPIRIN

BLEEDING DISORDERS due toCLOTTING FACTOR DEFICIENCIES

• NOT spontaneous, but following surgery or trauma

• ALL factor deficiencies are possible

• Factor VIII and IX both are the classic X‐linked recessive hemophilias, A and B, respectively

• ACQUIRED disorders often due to Vitamin‐K deficiencies

• von Willebrand disease the most common, 1%

von Willebrand Disease• 1% prevalence, most common bleeding disorder

• Spontaneous and wound bleeding

• Usually autosomal dominant

• Gazillions of variants, genetics even more complex

• Prolonged BLEEDING TIME, NL platelet count

• vWF is von Willebrand Factor, which complexes with Factor VIII, it is the von Willebrand Factor which is defective in von Willebrand disease

• Usually BOTH platelet and FactorVIII‐vWF disorders are present

HEMOPHILIA A• The “classic” HEMOPHILIA

• Factor VIII decreased

• Co‐factor of Factor IX to activate Factor X

• Sex‐linked recessive

• Hemorrhage usually NOT spontaneous

• Wide variety of severities

• Prolonged PTT (intrinsic) only• Rx: Recombinant Factor VIII

HEMOPHILIA B• The “Christmas” HEMOPHILIA

• Factor IX decreased

• Sex‐linked recessive

• Hemorrhage usually NOT spontaneous

• Wide variety of severities

• Prolonged PTT (intrinsic) only• Rx: Recombinant Factor IX

DIC, Disseminated INTRA‐vascular, Coagulation

• ENDOTHELIAL INJURY

• WIDESPREAD FIBRIN DEPOSITION

• HIGH MORTALITY

• ALL MAJOR ORGANS COMMONLY INVOLVED

DIC, Disseminated INTRA‐vascular, Coagulation

• Extremely SERIOUS condition

• NOT a disease in itself but secondary to many conditions– Obstetric: MAJOR OB complications, toxemia, sepsis, abruption

– Infections: Gm‐, meningococcemia, RMSF, fungi, Malaria

– Many neoplasms, acute promyelocytic leukemia

– Massive tissue injury: trauma, burns, surgery

• “Consumptive” coagulopathy

Common Coagulation TESTS• PTT (intrinsic)• PT INR (extrinsic)

• Platelet count, aggregation• Bleeding Time, so EASY to do

• Fibrinogen• Factor Assays

RBC LAB

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