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33 Cards in this Set
- Front
- Back
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mechanisms for thrombocytopenia
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-decreased plt production
-increased plt consumption -increased plt destruction -pooling of larger than normal fraction of plts w/in the spleen |
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stagnation of blood flow as a result of arterial disease of mechanical impendence disturbing the endothelial cell anticoagulant effects
-leads to formation of thrombis clot & hypercoaguable states |
thrombosis
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-defined by plt adhesion to exposed collagen with the endothelium of the vessel wall.
-forms hemostatic plug -plt adhesion mediated by GPIb and vWF |
primary hemostasis
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-decrease in # of circulating plts
-plts <140x10^9/L -caused by defective production of BM |
thromobocytopenia
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-increase # of petechiae
-hemorrhages -increased BT -impaired clot retraction |
thrombocytopenia
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-decreased # of megakaryocytes
-congenital( FA, Maternal infection) -acquired( radiation, alcohol, etc) -BM replacement w/ malignant cells (luekemia, lymphoma, myeloma, myelofibrosis) |
Thrombcytopenia with decreased #of megakaryoctyes
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-hereditary thrombocytopenia
-megaloblastic anemia -di gugliemos erythroluekemia -Proximal nocturnal hemoglobinuria |
Thrombocytopenia with ineffective plt production
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-tissue injury
-obsteric complications -neoplasms -bacterial/ viral infections -intravascular hemolysis |
thrombocytopenia with destruction of plts
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causes:
-inherited/acquired megakaryocytic hypoplasia -inherited/acquried ineffective erythropoiesis -non-immune/immune plt destruction |
cuases of thrombocytopenia
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generally no bleeding manifestations
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mild thromobocytopenia
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no hemorrhagic symptoms unless there is an increase need such as trauma or surgery
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Moderate thrombocytopenia
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May begin seeing bleeding diathesis when count drops to 20x10^9/L
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severe thrombocytopenia
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Increase of BT is ________ proportional to plt count as it drops below 100x10^9/L
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inversely
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-Increase in circulating plt counts
- >1000x10^9/L |
Thrombocytosis
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-result of primary BM disordedr
-caused by clonal proliferation that affects all hematopoeitic cells |
primary thrombocytosis
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Seein in:
-hodgkins lymphonas -PV -Myelofibrosis -CML -Thrombocytopenia |
Secondary thrombocytsosis
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associated with:
-IDA associated w/ chronic blood loss -chronic inflammatory disease -splenectomy -rebound thrombocytosis |
secondary thrombocytosis
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-autoimmune disorder
- ^MPV -dec. plts - ^BM plt production - ^marrow megakaryocyte - Normal BT - associated with IgG |
ITP
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-2-6 yrs old
- sudden onset of thrombocytopenia -often follow rubella, varicella, CMV, toxoplasmosis |
Acute ITP
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- lasts 2-6 wks
- plt= <20x10^9/L - caused by viral attachment of antigenic alteration of plt membrane proteins |
acute ITP
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- IgG coated plts are removed by macrophage in spleen, sometimes needing spleenectomy
-self limiting -can also use corticosteroids for therapy |
acute ITP
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-seen in 20-40 yo
-more common in women -slow asymptomatic thrombocytopenia - last for mos-yrs - plt= 30-80x10^9/L -treament= splenectomy - can use corticosteroids |
chronic ITP
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-caused by excessive deposition of plt aggregates in renal and cerebral vessels
-vascular wall dysfunction disrupts plt membrane -more common in women >35 yrs. |
TTP
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symptoms include:
-MAHA -thrombocytopenia -headaches/seizures -fever -renal disease |
Symptoms of TTP
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-PT normal
-APTT normal -Fibrinogen normal -FDP- normal or positive -^plt aggregating factor -decreased factor inhibitor - decreased PGI2 - abs. of plasminogen activator |
TTP
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-considered if plt count low and no plt Ab can be demonstrated
- manifested in infancy -seen in FA, TAR, Trisomy syndromes, AMT |
inherited megakaryocytic hyperplasia
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- Aplastic anemia--BM supression
-drug toxicity -myelophthistic thrombocytopenia -prolonged hypoxia |
Acquried megakaryocytic hypoplasia
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congenital states:
-may hegglin anomaly -bernard soulier syndrom -wiskott- aldrich syndrome |
acquired megakaryocytic hypoplasia
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-mild anemia/thrombocytopenia
-intraglomerular thrombi formation -vomitting/bloody diarrhea (E.Coli seen) -febrile illness/ jaundice |
HUS
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-Purpura bleeding from mucous membranes
-most frequent in children -adults usually 2nd to: pregnancy, HIV, Organ transplant, mal. hypertension |
HUS
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- ^BUN, ^creatinine, ^hematuria, ^proteinuria
-PT, APTT, D-dimer, FDP normal -Burr cells seen |
HUS
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-all ages
-marked poikylocytosis, shistocytes - ^RDW - ^LD,^indirect bili, dec. haptoglobin |
DIC
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- ^APTT
-^PT - D-dimer positive - FDP positive |
DIC
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