Post on 21-Apr-2017
AnaemiaDR. AAMIR FAROOQM. PHIL. PATHOLOGYdr.aamirfarooq@hotmail.com
TerminologyMCV: Average volume of individual cell
MCV=MCHC: Its average conc. of Hb in individual erythrocyte
MCHC
MCH: It tells us about total Hb.
MCH=
AnaemiaAbsolute fall in haematocrit, erythrocyte count and Hb concentrationClinical signs depends upon amount of blood lostPale mucus membranesIncrease in heart rateLow oxygen carrying capacityExercise intoleranceLab Finding: Decrease in Hb, RBCs count and PCV.
Classification
Morphological CharacteristicsEtiologyBone Marrow Response
Morphological CharacteristicsDecreased (Microcytic)
Normal (Normocytic)
Increased (Macrocytic)
MCV
Decreased (Hypochromic)
Normal (Normochromic)
Increased (Hyperchromic)
MCHC
ClassificationAnaemia MCV MCHC
Normocytic, Normochromic Normal Normal
Normocytic, Hypochromic Normal Decreased
Macrocytic, Normochromic Increased Normal
Macrocytic, Hypochromic Increased Decreased
Microcytic, Normochromic Decreased Normal
Microcytic, Hypochromic Decreased Decreased
Classification
MCV, MCHC and AnaemiaMCV increases….. Immature cells in circulation…..bone marrow compensation…… regenerative anaemia.MCV decreases…… hyper mature cellsMCV Normal……. May be regenerative or non-regenerativeMCHC increases….. Excessive intravascular haemolysisMCHC decreases…… excessive loss of blood/ iron deficiency in diet.MCHC Normal……..haemorrhages…..iron available…..Hb formation
Etiological ClassificationHaemorrhagic
Haemolytic
Bone marrow depression
Haemorrhagic AnaemiaLoss of blood due to: accident Fracture surgery internal haemorrhagesBlood sucking parasites
AcuteChronic
AcuteInitiallyAll parameter normal……… hypoxia………. Epinephrine release…….. Spleenic contraction……..hyperviscoucity due to old RBCs…… PCV increase up to 80%2-3 hours post-haemorrhagesInterstitial fluid absorption……. PCV decreases….. hypoproteinemia….. Thrombocytosis to stop haemorrhages.48 hours post-haemorrhagesPlasma protein at normal level
Cont.…72 hoursPolychromatic/ reticulocytes….. Remain in circulation for 2-3 weeksThen patient recover to normal condition
Reticulocytes remain in circulation for 2-3 weeks…… iron deficiency or persistent haemorrhages in body.
ChronicBlood parasites, ulcers or haemorrhages.All parameters reduced before appearing of clinical signsPersistent thrombocytosis and regenerative response is lessHypoproteinemia and hypovolemia may or may not developDeficiency of iron…..regenerative response is lessInternal and external haemorrhages…………. Regenerative response more and less respectively
Haemolytic Anaemia
Break down (lysis) of Erythrocytes.1. Intravascular2. Extravascular
Clinical FindingsEvidence of haemorrhages are absentPlasma protein is normal or slightly increasedMCH and MCHC increasedAcute cases----------- neutrophilocytosisChronic cases--------- monocytosisincreased bilirubin------------- Icterus may be presentMorphological abnormalities in erythrocytes e.g. Heinz bodies, erythrocytes containing parasites etc.
Anaplasma
Babasia
Heinz Bodies
NormalErythrocytes
Extravascular HaemolysisLysis of RBCs outside the blood vesselsLab findings:oHaemoglobinemia and haemoglobinuria absentoBilirubin highoBone marrow response presentoNeutrophilic leucocytosis (acute), monocytic leucocytosis (chronic)
EtiologyAntibodies and C3b mediated haemolysisImmune mediated haemolytic anaemia (IMHA)Anaemia by some infectious agent or drugsDeformities of ErythrocytesReduced glycolysis and low ATP productionSplenomegaly/increased macrophages activity
Antibodies and C3b mediated haemolysisAg exposed
on RBCsLymphoid system
recognition
Formation of Ag-Ig complex
Complement system activation
Macrophages recognize it
IMHAMechanism not exactly knownRBCs recognized as AgIgs produced against RBCs.May be caused by bacteria, virus or medication.
Anaemia by some infectious agent or drugsInfectionMycobacterium hemolyticum
Hidden Receptor Exposed / Cell Membrane Changed
Deformities of ErythrocytesChanges in Cell Membrane
Internal Viscosity is High..... Spherocytes
Enter in spleen
Phagocytosis
Low production of ATPSuch cells predisposed to phagocytosisReduction is accelerated in pyruvate kinase and phosphofructokinase deficiency
SplenomegalySpleen enlargedMacrophage activity increased
Intravascular HaemolysisBreak down of erythrocytes inside the blood vesselLab Findings:oRegenerative response 2-3 post-haemolysisoHaemoglobinuria and haemoglobinemiaoIncreased bilirubinoAbnormal erythrocytes e.g. eccentrocytes, spherocytes or blood parasite etc.
EccentrocytesKeratocytes
Spherocytes Theleria
EtiologyAntibody and Complement mediated/ immune mediated hemolysisPhysical injury to RBCsOxidative injuryOsmotic lysisAlteration in cell membrane of RBCs
Antibody and Complement mediated/ immune mediated hemolysis
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Mechanical damage to Erythrocytes
Increased fibrinEtiology includes: DIC Damaged valves
Oxidative injury
Cont….Heinz bodies increased….. Denatured Hb….. Functional ability reducedCross linkages formed between cell membranes…..disfigure the cellMethemoglobin is formed…… oxygen carrying capacity reduced
Osmotic LysisHypotonic solution administrationHypophosphatemia…..osmosis increased Osmotic diuretics if uncontrolled e.g. diabetes mellitus
Alteration of Cell MembraneEtiology includes:oSnake venomsoCaster beans containing ricinoBlood parasites (babasiasis)
Bone Marrow ResponseSuch anaemia are:Non regenerativeCaused be abnormal bone marrowThey are of two types:I. Reduced erythropoiesisII. Defective erythropoiesis
Reduced ErythropoiesisFactors causing reduced erythropoiesis:1. Chronic disordersChronic inflammationNeoplasm
2. Cytotoxic bone marrow damageBracken fernCytotoxic cancerous drugsestrogen FurazolidonePhenylbutazoneRadiation
Cont.…..3. Deficiency of erythropoietin (EPO)
Chronic renal disease Hypoadrenocortisism Hypoandrogenism Hypopituitarism Hypothyroidism
4. Immune mediated Pure red cell aplasia (PRCA)
Cont.….5. Infections
Ehrlichia spp. Feline leukemia virus Feline panleukopenia virus Parvovirus Trichostrongyles
6. Mylopathies Lymphocytic leukemia Matastatic neoplasm Myloproliferative disease Osteopetrosis, osteosclerosis Myelofibrosis
Defective ErythropoiesisCauses of defective erythropoiesis are:1. Abnormal maturation
Erythremic mylosis Erythroleukemia Myelodysplastic syndrome Macrocytosis of Poodles
2. Abnormal nucleic acid synthesisVit. B12 deficiency, malabsorptionFolic acid deficiency
Cont….3. Disorders of heme synthesisChloramphenicol toxicityCopper deficiency Iron deficiencyLead poisoningMolybdenum poisoningPyridoxine deficiency
Factors required for normal ErythropoiesisPrecursor cells (Stem cells, myloid cells, erythroid cells)Nutrients (B12, folic acid)Stimulation (EPO, IL-3)Micro environment of bone marrowGrowth stimulating factors (G-CSF, GM-CSF)
Bone marrow failurePrimaryIf cause is within the bone marrow e.g. PRCA, aplastic anaemiaSecondary If cause is extra-marrow e.g. Decreased EPO or nutritional factorsBone marrow failure may be selective for erythroid cells (PRCA)
Bone marrow response anaemia1. Inadequacy of precursor cells or erythrpoietic stimulation is
inadequate2. Maturation abnormalities with hypercellular marrow e.g. MDS3. Suboptimal response of marrow following haemorrhages or
hemolysis
Non-regenerative anaemia On the basis of morphology divided into following subtypes:1. Normocytic, normochromic with normal to increased neutrophils2. Normocytic, normochromic with neutropenia3. Microcytic, hypochromic anaemia with variable neutrophils4. Macrocytic, normochromic anaemia
Normocytic, normochromic with normal to increased neutrophils
Normal to increased neutrophils and platelet count and M:E ratio increasedThis type of anaemia includes followings:
1. Decreased EPO which may be due to followings: Chronic renal damage Uremia/ increased BUN Increased BUN leads to inhibition of uptake of EPO by BM, GIT haemorrhages
caused by abnormal platelet function, inhibit erythropoiesis and haemolysis by uremic plasma
Cont.…..2. Anaemia of inflammatory disease (AID) Chronic inflammation/neoplasm…… production of IL-1 α and β, TNF- α,
cytokines and interferon-γ…… depress erythropoiesis Life span of erythrocyte is shortened
3. Endocrinopathies Hypothyroidism, hypoandroginism and hypopituitarism leads to
inhibition of release of EPO from kidneys4. FeLV5. PRCA
Normocytic, normochromic with neutropenia
1. Aplastic anaemia…… a-cellular or fatty bonemarrow Radiation therapy Chloramphenicol, phenylbutazone toxicity Increased activity of cytotoxic T-cells FeLV Plants toxicity (Bracken fern)
2. Myelophthistic anaemiaMyelofibrosisOsteosclerosisMetastatic cancer
Microcytic, hypochromic anaemia with variable neutrophils
Variable neutrophils and platelet countVariable M:E ratioIncludes followings:
1. Iron Deficiency Chronic external blood loss Young growers on complete milk diet have deficiency of iron
2. Pyridoxine deficiency…..cofactor of heme synthesis3. Copper deficiency……. Iron absorption impaired form GIT
Cont….4. Dyserythrpoiesis5. Microcytosis….. No anemia MCV decreased6. Microcytosis without anemia in porto-systemic shunt (PSS)7. Drugs and chemicals like chloramphenicol or lead toxicity
Macrocytic, normochromic anaemiaVariable neutrophils and platelet count. M:E ratio is usually low.Causes includes:
1. Ruminant grazing Co-deficient and Molybdenum rich pastures2. Vit. B12 and folic acid deficiency3. Macrocytosis of poodles4. Congenital dyseythropoisis5. FeLV infection
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