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All that you didn’t know about platelets !

Dr. M.B. Agarwal, MD, MNAMS

Head, Dept of Haematology

Bombay Hospital Institute of Medical Sciences, Mumbai

CME, Vadodara, Sunday, 27th December 2015

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Spurious thrombocytopenia

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Spurious thrombocytopenia

• Harris (Bengal) syndrome

• EDTA induced platelet agglutination

• Partially clotted blood

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Thrombocytopenia : Different shades

Severity Platelet count (x 109/L) Prevalence (%)

Normal 150 - 400

Inconsequential 100 - 150 40

Mild 75 - 100 30

Moderate 30 - 75 20

Severe < 30 10

Littlewood TJ et al. Br J Haematol. 2015;93:460-463

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Thrombocytopenia : Mechanism

Production Marrow disorders

Liver disorders

Destruction

Infections, sepsis, DIC

Drugs including heparin

Immune-mediated ( ITP )

Sequestration Hypersplenism

Dilution Massive transfusion

Gestational thrombocytopenia

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Infection induced thrombocytopenia

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Infection induced thrombocytopenia

Virus

Dengue, Hanta

CMV, EBV, HCV

HIV - to remember

Bacteria Meningococcemia

Parasites Malaria

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Drug induced thrombocytopenia

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Drugs

Production Chemotherapy

Radiotherapy

Anti-folates

Others

Destruction Heparin

Rifampicin

Quinine

Na-valproate

Others

Warkentin TE et al. Annu. Rev. Med. 2015,50:129-147

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Immune mediated thrombocytopenia

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Pathogenesis of ITP

• Antibody mediated destruction

• T-lymphocyte mediated

• Inadequate production

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What is new

in the treatment of ITP ?

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H. Pylori

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Anti CD20 Antibody

Rituximab

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TPO analogs

•Eltrombopag (Revolade)

•Romiplostim (NPlate)

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Thrombocytopenia with

thrombosis

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Q : One of the following disorders does not cause thrombosis & thrombocytopenia

A. Heparin induced thrombocytopenia

B. Antiphospholipid antibody syndrome

C. Evan’s syndrome

D. Thrombotic thrombocytopenic purpura

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A: One of the following disorders does not cause thrombosis & thrombocytopenia

A. Heparin induced thrombocytopenia

B. Antiphospholipid antibody syndrome

C. Evan’s syndrome

D. Thrombotic thrombocytopenic purpura

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TTP : Pathogenesis

Role of ADAMTS-13

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TTP: Pathogenesis

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Q : One of the following is the best treatment modality for TTP

A. FFP support

B. FFP & platelet support

C. Plasma exchange

D. Rituximab

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A : One of the following is the best treatment modality for TTP

A. FFP support

B. FFP & platelet support

C. Plasma exchange

D. Rituximab

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Plasma exchange for TTP

• It is an emergency

•Plasma exchange & not plasmapheresis

• In emergency : FFP

•Avoid platelet transfusion

•Cryosupernatant

•Follow up with LDH & platelet count

Contreras M et al. Transfusion. 2014;38:796-797

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Investigations

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Investigations

•History

•Examination

•CBC

•Blood film examination

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Q : Give the diagnosis on PS in next slide

A. MAHA

B. Dengue

C. Malaria

D. CMV

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Q : Give the diagnosis on PS in next slide

A. MAHA

B. Dengue

C. Malaria

D. CMV

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A : The film shown to you is diagnostic of

A. MAHA

B. Dengue

C. Malaria

D. CMV

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Blood film examination

•Platelets : Number, size, clumping

•RBC : Schistocytes, spherocytes, parasites

•WBC : Leukocytosis, leukaemia, dysplasia

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Coagulation

•PT, PTT

•Fibrinogen

•D-Dimer

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Blood chemistry

•Haemolysis : Bilirubin, LDH, Haptoglobin

•Hepatic dysfunction : Acute, chronic

•Renal dysfunction : HUS, TTP, DIC, SLE

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USG abdomen for splenic enlargement

and Doppler for portal hypertension

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Bone marrow examination

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Management

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Management - 1

•Treating the cause

•Platelet transfusion

• IVGG, Anti D, steroids

•Antifibrinolytic agents

•NovoSeven

Rintala EOP et al. Crit Care Medicine. 2014;26:965-968

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MCQ : Despite thrombocytopenia, platelet transfusion is most hazardous in

A. TTP & HIT-T

B. ITP & TTP

C. Hypersplenism & DIC

D. HLH & HUS

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MCQ : Despite thrombocytopenia, platelet transfusion is most hazardous in

A. TTP & HIT-T

B. ITP & TTP

C. Hypersplenism & DIC

D. HLH & HUS

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The peril of platelet transfusion

Kruskall MS et al. N Engl J Med. 2013;337:1914-1915

Contraindicated TTP, HIT

Not indicated ITP

Hypersplenism

Indicated Production defects

Others : DIC, dilutional

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Platelet count as the trigger for transfusion

(Clinical judgment is superior to the count)

•Severity

•Associated coagulation defects

•Stability

•Aetiology

Klumpp TR et al. Transfusion. 2014;39:674-681

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