Thrombocytopenia

From Citizendium, the Citizens' Compendium

Thrombocytopenia is a decrease in the platelet count. The half-life of a platelet in a normal person is about 4 days.^[1]

Contents 1 Classification 1.1 Decreased production of platelets 1.2 Decreased survival of platelets 1.2.1 Immunolologic destruction 1.2.2 Nonimmunolologic destruction 2 Cause/etiology 2.1 Medications 2.2 Infection 3 References 4 External links

Classification

The following classification is proposed by Robbins and Cotran.^[2]

Decreased production of platelets

Decreased survival of platelets

Immunolologic destruction

Autoimmune includes immune thrombocytopenia purpura or Werlhof's Disease. The chronic form in adults is usually caused by antibodies to Platelet glycoprotein GPIIb-IIIa complex or Ib-IX.^[2]

Isoimmune

Drug associated

Infections

Nonimmunolologic destruction

Disseminated intravascular coagulation (DIC)

Giant hemangiomas

Microangiopathic hemolytic anemias (MAHAs) include thrombotic thrombocytopenia purpura (TTP) and hemolytic uremia syndrome (HUS). TTP is usually an inherited or acquired deficiency of von Willebrand factor (vWF) metalloprotease, also called ADAMTS 13.

Cause/etiology

Medications

A systematic review has identified common causes of drug-induced thrombocytopenia.^[3]

Drug-induced thrombocytopenia maybe immune mediated by antibodies against immune complexes of drugs bound to Platelet glycoprotein GPIIb-IIIa complex or Ib/V/IX complexes.^[4] Heparin-induced thrombocytopenia (HIT) is usually caused by antibodies against immune complexes of platelet factor 4 (PF4) and heparin.^[5] Other drugs include vancomycin ^[6] and oxaliplatin^[7]

Infection

Septicemia has been associated with antibody mediated thrombocytopenia.^[8]

References

1. ↑ Fritz E, Ludwig H, Scheithauer W, Sinzinger H (1986). "Shortened platelet half-life in multiple myeloma". Blood 68 (2): 514–20. PMID 3730614.
2. ↑ ^2.0 2.1 Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease. St. Louis, Mo: Elsevier Saunders. ISBN 0-7216-0187-1. 
3. ↑ George JN, Raskob GE, Shah SR, et al (1998). Drug-induced thrombocytopenia: a systematic review of published case reports. Ann. Intern. Med. 129 (11): 886–90. PMID 9867731.
4. ↑ Aster RH, Bougie DW (2007). Drug-induced immune thrombocytopenia. N. Engl. J. Med. 357 (6): 580–7. DOI:10.1056/NEJMra066469. PMID 17687133.
5. ↑ Arepally GM, Ortel TL (2006). Clinical practice. Heparin-induced thrombocytopenia. N. Engl. J. Med. 355 (8): 809–17. DOI:10.1056/NEJMcp052967. PMID 16928996.
6. ↑ Von Drygalski A, Curtis BR, Bougie DW, et al (2007). "Vancomycin-induced immune thrombocytopenia". N. Engl. J. Med. 356 (9): 904–10. DOI:10.1056/NEJMoa065066. PMID 17329697.
7. ↑ Dold FG, Mitchell EP (2003). Sudden-onset thrombocytopenia with oxaliplatin. Ann. Intern. Med. 139 (2): E156. PMID 12859182.
8. ↑ Kelton JG, Neame PB, Gauldie J, Hirsh J (1979). "Elevated platelet-associated IgG in the thrombocytopenia of septicemia". N. Engl. J. Med. 300 (14): 760–4. PMID 423910.

External links

• University of Oklahoma Health Sciences Center's Platelets on the Web. This includes a database of reports of drug-induced thrombocytopenia.