COAGULATION DISORDERS (Platelet disorders) (Thrombocythopathy (CONGENITAL,…
COAGULATION DISORDERS (Platelet disorders)
morphology –plt <150,000
auto [or rare allo] antibody against PLT, hla [+/-]
viral [HIV, HCV], bacterial [HbP] tests
vitamins: vit b12
treat the cause
HUS, TTP –CAUSAL AND PLASMAFERESIS / FFP (fresh frozen plasma), ECULISUMAB
PLT TRUNSFIUSION –ONLY IN bleeding
Ineffective hematopoiesis –d. vit b12, MDS
Drugs, Infections, Cyclic
Immunologic & Nonimmunologic
Immune thrombocytopenic purpura (ITP)
Thrombocytopenia is due to immune destruction of platelets
commonly in age group 2–6 years
has an acute onset with mucocutaneous bleeding
less acute than in children.
seen in women and may be associated with other autoimmune disorders such as SLE, thyroid disease and autoimmune haemolytic anaemia (Evans’ syndrome).
also seen in patients with chronic lymphocytic leukaemia and solid tumours, and after infections with viruses such as HIV.
Platelet autoantibodies are detected in about 60–70% of patients.
haemorrhage is rare and is seen only in severe thrombocytopenia.
bruising, purpura, epistaxis and menorrhagia are common.
Splenomegaly is rare.
The only blood count abnormality is thrombocytopenia.
do not usually require treatment.
corticosteroids, intravenous immunoglobulin (i.v. IgG) and anti-D are effective; i.v. IgG is effective in >80% of children
Platelet counts >30 × 109/L generally require no treatment unless they are about to undergo a surgery.
First-line therapy: oral corticosteroids, fail to respond to corticosteroids--> splenectomy, i.v. IgG.
Second-line therapy: splenectomy
Third-line therapy: high- dose corticosteroids, intravenous immunoglobulin, Rh0(D) immune globulin (anti-D), vinca alkaloids, danazol, immunosuppressive agents
PLT [<30-50 g/l] –immunosupresive:
steroids –encotron 1 mg/kg / dexametason 1 x 40 mg iv 4 days,
solumedrol 1mg/kg iv [1,2,3,5]
immunoglobulins –2 x 1 g/kg iv
other immunosupresants: endoxan, csa, mmf, asathioprin…
dansol, anti RhD, splenectomy
Hypersplenism Secvestration in Spleen
Post-transfusion purpura (PTP)
Neonatal alloimmune thrombocytopenia
Posttheraputic / DRUGS
Heparin-induced thrombocytopenia (HIT)
antibodies are formed against the heparin-platelet factor 4 complex.
Mostly occurs with unfractionated heparin
Main complication of HIT is venous thrombosis—DVT or PE.
Diagnostic tests: antiplatelet factor IV antibody or serotonin release assay, autoantibodies [hep2].
Treatment: stop heparin, thrombin inhibitors in case of thrombosis.
HIT type1:Heparin directly causes platelet aggregation; seen <48 hours after initiating heparin; no treatment is needed.
HIT type 2: Heparin induces antibody-mediated injury to platelet; seen 3 to 12 days after initiating heparin; heparin should be discontinued immediately.
Thrombotic Thrombocytopenic Purpura (TTP)
rare disorder of platelet consumption
Patients have lack functional ADAMTS13, a protease that cleaves vWF
Hemolytic anemia (microangiopathic)
Acute renal failure
Fever, Fluctuating, transient neurologic signs
Corticosteroids and splenectomy
Platelet transfusions are contraindicated.
PT and PTT are normal.
TTP=HUS+fever+ altered mental status
HUS=microangiopathic hemolytic anemia + thrombocytopenia + renal failure
reduced platelet production in the bone marrow (central), excessive peripheral destruction of platelets
Cutaneous bleeding (PLT <20,000): petechiae, purpura, ecchymoses.
Mucosal bleeding (PLT <5,000): epistaxis, menorrhagia, hemoptysis, bleeding in GI and genitourinary tracts
Excessive bleeding after procedures or surgery (PLT 20,000–70,000)
DRUGS : ASA, CLOPIDOGREL, ABCIKSYMAB, DECTRANS, ANTIBIOTICS
SECENDERY IN: Myeloproliferative disorders, URAEMIA, LIVER DESEASE, Paraproteinaemias (multiple myeloma)
PSEUDO VWD [GPIb]
WISCKOTT - ALDRICH SYNDROME
GLANZMANN thrombasthenia [GPIIb/IIIa]
lack of platelet membrane glycoprotein IIb–IIIa complex resulting in defective fibrinogen binding and failure of platelet aggregation.
Bernard–Soulier syndrome [GPIb/IX/V]
lack of platelet membrane glycoprotein Ib–IX–V complex (the binding site for VWF), causing failure of platelet adhesion and moderate thrombocytopenia.
Storage pool disease/GRAY PLT [Alfa–Granulations]
lack of the storage pool of platelet dense bodies, causing poor platelet function.
AGREGATION [ADP, COLAGEN, EPINEFRIN, ADRENALIN, TRAP, RISTOCETIN]
Platelet transfusions, VIIa–NOVOSEVEN, SCT
associated with excessive bruising and bleeding and, in some of the acquired forms, with thrombosis.
platelet count is normal or increased and the bleeding time is prolonged.
abnormality in platelet function
Reactive (most cases):
Iron deficiency, Splenectomy, Rebound thrombocytosis, Inflammatory diseases, Malignancy (GI, lung)
Autonomous: Splenectomy (loss of a major site of platelet destruction), Essential thrombocytosis, MPD (PV), CML