Wikipedia

Thrombocytopenia

Inhematology,thrombocytopeniais a condition characterized by abnormally low levels ofplatelets(also known as thrombocytes) in theblood.[2]Low levels of platelets in turn may lead to prolonged or excessivebleeding.It is the most commoncoagulation disorderamongintensive care patientsand is seen in a fifth of medical patients and a third of surgical patients.[3]

Thrombocytopenia
Other namesThrombocytopaenia, thrombopenia
A photomicrograph of the blood showing thrombocytopenia
SpecialtyHematology
CausesBone marrow not making enough platelets, body destroying platelets, spleen holding too many platelets[1]
Diagnostic methodComplete blood count[1]
TreatmentNone,immunosuppressants,platelet transfusion,surgical removal of the spleen[1]

A normal human platelet count ranges from 150,000 to 450,000 platelets/microliter (μL) of blood.[4]Values outside this range do not necessarily indicate disease. One common definition of thrombocytopenia requiring emergency treatment is a platelet count below 50,000/μL.[5]Thrombocytopenia can be contrasted with the conditions associated with an abnormallyhighlevel of platelets in the blood –thrombocythemia(when the cause is unknown), andthrombocytosis(when the cause is known).[6][7]

Signs and symptoms

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Petechiae on the lower leg from thrombocytopenia
Right upper limb with purpura caused by thrombocytopenia in person withseptic shock

Thrombocytopenia usuallyhas no symptomsand is picked up on a routinecomplete blood count.Some individuals with thrombocytopenia may experience external bleeding, such asnosebleedsor bleedinggums.Some women may have heavier or longerperiodsor breakthrough bleeding.Bruising,particularlypurpurain the forearms andpetechiaein the feet, legs, andmucous membranes,may be caused by spontaneous bleeding under the skin.[8][9]

Eliciting a full medical history is vital to ensure the low platelet count is not secondary to another disorder. Ensuring that the other blood cell types, such asred blood cellsandwhite blood cells,are not also suppressed, is also important.[8] Painless, round, and pinpoint (1 to 3 mm in diameter) petechiae usually appear and fade, and sometimes group to formecchymoses.Larger than petechiae, ecchymoses are purple, blue, or yellow-green areas of skin that vary in size and shape. They can occur anywhere on the body.[8]

A person with this disease may also complain ofmalaise,fatigue,and general weakness (with or without accompanying blood loss). Acquired thrombocytopenia may be associated with the use of certain drugs. Inspection typically reveals evidence of bleeding (petechiae or ecchymoses), along with slow, continuous bleeding from any injuries or wounds. Adults may have large, blood-filledbullaein the mouth.[10]If the person's platelet count is between 30,000 and 50,000/μL, bruising with minor trauma may be expected; if it is between 15,000 and 30,000/μL, spontaneous bruising will be seen (mostly on the arms and legs).[11]

Causes

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Thrombocytopenia can be inherited or acquired.[12]

Decreased production

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Abnormally low platelet production may be caused by:[13]

Increased destruction

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TTP

Abnormally high rates of platelet destruction may be due to immune or nonimmune conditions, including:[15]

Medication-induced

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These medications can induce thrombocytopenia through direct myelosuppression:[16]

Other causes

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Diagnosis

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Laboratory tests for thrombocytopenia might includefull blood count,liver enzymes,kidney function,vitamin B12levels, folic acid levels,erythrocyte sedimentation rate,and peripheral blood smear. If the cause for the low platelet count remains unclear, abone marrow biopsyis usually recommended to differentiate cases of decreased platelet production from cases of peripheral platelet destruction.[22]

Thrombocytopenia in hospitalized alcoholics may be caused byspleen enlargement,folate deficiency,and most frequently, the direct toxic effect of alcohol on production, survival time, and function of platelets.[23]Platelet count begins to rise after 2 to 5 days' abstinence from alcohol. The condition is generally benign, and clinically significant hemorrhage is rare.[citation needed]

In severe thrombocytopenia, a bone marrow study can determine the number, size, and maturity of themegakaryocytes.This information may identify ineffective platelet production as the cause of thrombocytopenia and rule out a malignant disease process at the same time.[24]

Treatment

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Treatment is guided by the severity and specific cause of the disease. Treatment focuses on eliminating the underlying problem, whether that means discontinuing drugs suspected to cause it or treating underlying sepsis. Diagnosis and treatment of serious thrombocytopenia is usually directed by ahematologist.Corticosteroidsmay be used to increase platelet production.Lithium carbonateor folate may also be used to stimulate platelet production in the bone marrow.[25]

Platelet transfusions

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Platelet transfusionsmay be suggested for people who have a low platelet count due to thrombocytopenia.[26]

Thrombotic thrombocytopenic purpura

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Treatment ofthrombotic thrombocytopenic purpura(TTP) is a medical emergency, since the associatedhemolytic anemiaand platelet activation can lead to kidney failure and changes in the level of consciousness. Treatment of TTP was revolutionized in the 1980s with the application ofplasmapheresis.According to theFurlan–Tsai hypothesis,[27]this treatment works by removingantibodiesagainst thevon Willebrand factor-cleavingproteaseADAMTS-13.The plasmapheresis procedure also adds active ADAMTS-13 proteaseproteinsto the patient, restoring a normal level of von Willebrand factor multimers. Patients with persistent antibodies against ADAMTS-13 do not always manifest TTP, and these antibodies alone are not sufficient to explain how plasmapheresis treats TTP.[28]

Immune thrombocytopenic purpura

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Main article:Immune thrombocytopenic purpura
Oral petechiae/purpura - immune thrombocytopenic purpura

Many cases ofimmune thrombocytopenic purpura(ITP), also known as idiopathic thrombocytopenic purpura, can be left untreated, and spontaneous remission (especially in children) is not uncommon. However, counts under 50,000/μL are usually monitored with regular blood tests, and those with counts under 10,000/μL are usually treated, as the risk of serious spontaneous bleeding is high with such low platelet counts. Any patient experiencing severe bleeding symptoms is also usually treated. The threshold for treating ITP has decreased since the 1990s;hematologistsrecognize that patients rarely spontaneously bleed with platelet counts greater than 10,000/μL, although exceptions to this observation have been documented.[29][30]

Thrombopoetin analogues have been tested extensively for the treatment of ITP. These agents had previously shown promise, but had been found to stimulate antibodies againstendogenousthrombopoietinor lead tothrombosis.Romiplostim(trade name Nplate, formerly AMG 531) was found to be safe and effective for the treatment of ITP in refractory patients, especially those whorelapsedfollowing splenectomy.[31]

Heparin-induced thrombocytopenia

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Main article:Heparin-induced thrombocytopenia

Discontinuation of heparin is critical in a case of heparin-induced thrombocytopenia (HIT). Beyond that, however, clinicians generally treat to avoid thrombosis.[32]Treatment may include adirect thrombin inhibitor,such aslepirudinorargatroban.Other "blood thinners"sometimes used in this setting includebivalirudinandfondaparinux.Platelet transfusionsare not routinely used to treat HIT because thrombosis, not bleeding, is the primary problem.[33]Warfarinis not recommended until platelets have normalized.[33]

Congenital amegakaryocytic thrombocytopenia

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Bone marrow/stem cell transplants are the only known cures for this genetic disease. Frequent platelet transfusions are required to keep the patient from bleeding to death before the transplant can be performed, although this is not always the case.[34]

Human-induced pluripotent stem cell-derived platelets

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Human-induced pluripotent stem cell-derived platelets is a technology currently being researched by the private sector, in association with theBiomedical Advanced Research and Development Authorityand theU.S. Department of Health and Human Services,that would create platelets outside the human body.[35]

Neonatal thrombocytopenia

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Thrombocytopenia affects a few newborns, and its prevalence in neonatal intensive care units is high. Normally, it is mild and resolves without consequences. Most cases affect preterm birth infants and result from placental insufficiency and/or fetal hypoxia. Other causes, such as alloimmunity, genetics, autoimmunity, and infection, are less frequent.[36]

Thrombocytopenia that starts after the first 72 hours, since birth is often the result of underlyingsepsisornecrotizing enterocolitis.[36]In the case of infection,polymerase chain reactiontests may be useful for rapid pathogen identification and detection of antibiotic-resistance genes. Possible pathogens include viruses (e.g.cyt Omega lovirus,[36]rubella virus,[36]HIV[36]), bacteria (e.g.Staphylococcusspp.,[37]Enterococcusspp.,[37]Streptococcus agalactiae,[36]Listeria monocytogenes,[36]Escherichia coli,[36][37]Haemophilus influenzae,[36]Klebsiella pneumoniae,[37]Pseudomonas aeruginosa,[37][38]Yersinia enterocolitica[38]), fungi (e.g.Candidaspp.[37]), andToxoplasma gondii.[36]The severity of thrombocytopenia may be correlated with pathogen type; some research indicates that the most severe cases are related to fungal orGram-negativebacterial infection.[37]The pathogen may be transmitted during[39]or before birth, bybreast feeding,[40][41][42]or during transfusion.[43]Interleukin-11is being investigated as a drug for managing thrombocytopenia, especially in cases of sepsis or necrotizing enterocolitis.[36]

References

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  1. ^abc"Thrombocytopenia".National Heart, Lung, and Blood Institute (NHLBI).U.S. Department of Health and Human Services.Archivedfrom the original on 25 November 2020.Retrieved4 January2018.
  2. ^Deutschman CS, Neligan PJ (2010).Evidence-based Practice of Critical Care.Elsevier Health Sciences.ISBN978-1416054764.Archivedfrom the original on 2023-01-11.Retrieved2015-04-30.
  3. ^Marini JJ, Dries DJ (2019).Critical care medicine: the essentials and more.Philadelphia: Wolters Kluwer.ISBN978-1-4963-0291-5.OCLC1060947164.
  4. ^"Platelet count".MedlinePlus Medical Encyclopedia.U.S. National Library of Medicine.Archivedfrom the original on 2015-04-05.Retrieved2015-05-01.
  5. ^"What Is Thrombocytopenia?".National Heart, Lung, and Blood Institute (NHLBI).U.S. Department of Health and Human Services.Archivedfrom the original on 2015-05-18.Retrieved2015-05-01.
  6. ^Schafer AI (March 2004). "Thrombocytosis".The New England Journal of Medicine.350(12): 1211–1219.doi:10.1056/NEJMra035363.PMID15028825.
  7. ^"Thrombocythemia and Thrombocytosis".National Heart, Lung, and Blood Institute (NHLBI).U.S. Department of Health and Human Services.Archivedfrom the original on 14 June 2019.Retrieved5 August2020.
  8. ^abcBhatia MP."B.E. Project on Platlet Count Using Image Processing Techniques"(PDF).BTP_Report.Archived(PDF)from the original on 10 September 2016.Retrieved30 November2014.
  9. ^Houghton AR, Gray D (2010).Chamberlain's Symptoms and Signs in Clinical Medicine 13th Edition, An Introduction to Medical Diagnosis.CRC Press.ISBN9780340974254.Archivedfrom the original on 2023-01-11.Retrieved2015-05-01.
  10. ^Interpreting Signs and Symptoms.Lippincott Williams & Wilkins. 2007. p. 293.ISBN9781582556680.
  11. ^Rosdahl CB, Kowalski MT (2008).Textbook of Basic Nursing.Lippincott Williams & Wilkins.ISBN9780781765213.Archivedfrom the original on 2023-01-11.Retrieved2015-05-01.
  12. ^"What Causes Thrombocytopenia?".National Heart, Lung, and Blood Institute (NHLBI).U.S. Department of Health and Human Services.Archivedfrom the original on 2 December 2014.Retrieved4 December2014.
  13. ^Fiebach NH, Barker LR, Burton JR, Zieve PD (2007).Principles of Ambulatory Medicine.Lippincott Williams & Wilkins.ISBN9780781762274.Retrieved2015-04-30.
  14. ^Almazni I, Stapley R, Morgan NV (2019) Inherited Thrombocytopenia: Update on genes and genetic variants which may be associated With bleeding. Front Cardiovasc Med
  15. ^Rodak BF, Fritsma GA, Keohane E (2013).Hematology: Clinical Principles and Applications.Elsevier Health Sciences.ISBN9780323292696.Archivedfrom the original on 2023-01-11.Retrieved2015-04-30.
  16. ^Gresele P, Fuster V, Lopez JA, Page CP, Vermylen J (2007).Platelets in Hematologic and Cardiovascular Disorders: A Clinical Handbook.Cambridge University Press.ISBN9781139468763.Retrieved2015-04-30.
  17. ^Tan GC, Stalling M, Dennis G, Nunez M, Kahwash SB (2016)."Pseudothrombocytopenia due to Platelet Clumping: A Case Report and Brief Review of the Literature".Case Reports in Hematology.2016:3036476.doi:10.1155/2016/3036476.PMC5164902.PMID28044112.
  18. ^Waldmann C, Soni N, Rhodes A (2008).Oxford Desk Reference: Critical Care.Oxford University Press.ISBN9780199229581.Archivedfrom the original on 2023-01-11.Retrieved2015-05-01.
  19. ^Greer JP, Arber DA, Glader B, List AF, Means RT, Paraskevas F, Rodgers GM (2013).Wintrobe's Clinical Hematology.Lippincott Williams & Wilkins.ISBN9781469846224.Archivedfrom the original on 2023-01-11.Retrieved2015-05-01.
  20. ^"Niemann-Pick disease".Genetics Home Reference.U.S. National Library of Medicine.Archivedfrom the original on 2018-09-24.Retrieved2020-06-12.
  21. ^"Niemann-Pick - Symptoms and causes".Mayo Clinic.Archivedfrom the original on 2020-08-04.Retrieved2020-06-12.
  22. ^"How Is Thrombocytopenia Diagnosed?".National Heart, Lung, and Blood Institute (NHLBI).U.S. Department of Health and Human Services.Archivedfrom the original on 2015-05-25.Retrieved2015-05-19.
  23. ^Lieber CS (2012).Medical and Nutritional Complications of Alcoholism: Mechanisms and Management.Springer Science & Business Media.ISBN9781461533207.Archivedfrom the original on 2023-01-11.Retrieved2020-10-10.
  24. ^Hillyer CD, Abrams CS, Shaz BH, Roshal M, Zimring JC, Abshire TC (2009).Transfusion Medicine and Hemostasis: Clinical and Laboratory Aspects.Elsevier.ISBN9780080922300.Retrieved2015-05-01.
  25. ^Lawrence PF, Bell RM, Dayton MT (2012-10-31).Essentials of General Surgery.Lippincott Williams & Wilkins.ISBN9780781784955.Archivedfrom the original on 2023-01-11.Retrieved2020-10-10.
  26. ^Estcourt LJ, Malouf R, Hopewell S, Doree C, Van Veen J, et al. (Cochrane Haematological Malignancies Group) (April 2018)."Use of platelet transfusions prior to lumbar punctures or epidural anaesthesia for the prevention of complications in people with thrombocytopenia".The Cochrane Database of Systematic Reviews.2018(4): CD011980.doi:10.1002/14651858.CD011980.pub3.PMC5957267.PMID29709077.
  27. ^Chapman K, Seldon M, Richards R (February 2012)."Thrombotic microangiopathies, thrombotic thrombocytopenic purpura, and ADAMTS-13".Seminars in Thrombosis and Hemostasis.38(1): 47–54.doi:10.1055/s-0031-1300951.PMID22314603.
  28. ^"How Is Thrombotic Thrombocytopenic Purpura Treated?".National Heart, Lung, and Blood Institute (NHLBI).U.S. Department of Health and Human Services.Archivedfrom the original on 2015-05-01.Retrieved2015-05-20.
  29. ^Thrombocytopenic Purpura: New Insights for the Healthcare Professional: 2013 Edition: ScholarlyPaper.ScholarlyEditions. 2013-07-22.ISBN9781481662420.Archivedfrom the original on 2023-01-11.Retrieved2015-05-20.
  30. ^"Idiopathic thrombocytopenic purpura (ITP)".MedlinePlus Medical Encyclopedia.U.S. National Library of Medicine.Archivedfrom the original on 2015-04-06.Retrieved2015-05-20.
  31. ^"Nplate (romiplostim) for subcutaneous injection".fda.gov.Archivedfrom the original on 2016-03-11.Retrieved2015-05-02.
  32. ^Warkentin TE, Greinacher A (2007-07-23).Heparin-Induced Thrombocytopenia.CRC Press.ISBN9781439826423.Archivedfrom the original on 2023-01-11.Retrieved2023-08-25.
  33. ^abAhmed I, Majeed A, Powell R (September 2007)."Heparin induced thrombocytopenia: diagnosis and management update".Postgraduate Medical Journal.83(983): 575–582.doi:10.1136/pgmj.2007.059188.PMC2600013.PMID17823223.
  34. ^Smit-Sibinga CH (2010-05-10).Neonatology and Blood Transfusion.Springer Science & Business Media.ISBN9780387236001.Archivedfrom the original on 2023-01-11.Retrieved2015-05-20.
  35. ^Clark D (2019-10-02)."New technology may aid emergency preparedness".Homeland Preparedness News.Archivedfrom the original on 2019-10-05.Retrieved2019-10-23.
  36. ^abcdefghijkRoberts I, Murray NA (September 2003)."Neonatal thrombocytopenia: causes and management".Archives of Disease in Childhood. Fetal and Neonatal Edition.88(5): F359–F364.doi:10.1136/fn.88.5.F359.PMC1721612.PMID12937037.
  37. ^abcdefgGuida JD, Kunig AM, Leef KH, McKenzie SE, Paul DA (June 2003). "Platelet count and sepsis in very low birth weight neonates: is there an organism-specific response?".Pediatrics.111(6 Pt 1): 1411–1415.doi:10.1542/peds.111.6.1411.PMID12777561.
  38. ^abPacifico L, Chiesa C, Mirabella S, Panero A, Midulla M (March 1987). "Early-onset Pseudomonas aeruginosa sepsis and Yersinia enterocolitica neonatal infection: a unique combination in a preterm infant".European Journal of Pediatrics.146(2): 192–193.doi:10.1007/BF02343233.PMID3569360.S2CID20198866.
  39. ^Rempen A, Martius J, Hartmann AA, Wecker I (1987). "Transmission rate of Ureaplasma urealyticum, Mycoplasma spp., Gardnerella vaginalis, B-streptococci, Candida spp. and Chlamydia trachomatis from the mother to the newborn".Archives of Gynecology and Obstetrics.241(3): 165–170.doi:10.1007/BF00931313.PMID3324978.S2CID11251976.
  40. ^Olver WJ, Bond DW, Boswell TC, Watkin SL (July 2000)."Neonatal group B streptococcal disease associated with infected breast milk".Archives of Disease in Childhood. Fetal and Neonatal Edition.83(1): F48–F49.doi:10.1136/fn.83.1.F48.PMC1721104.PMID10873172.
  41. ^Kotiw M, Zhang GW, Daggard G, Reiss-Levy E, Tapsall JW, Numa A (2003). "Late-onset and recurrent neonatal Group B streptococcal disease associated with breast-milk transmission".Pediatric and Developmental Pathology.6(3): 251–256.doi:10.1007/s10024-001-0276-y.PMID12687430.S2CID20696142.
  42. ^Gastelum DT, Dassey D, Mascola L, Yasuda LM (December 2005)."Transmission of community-associated methicillin-resistant Staphylococcus aureus from breast milk in the neonatal intensive care unit".The Pediatric Infectious Disease Journal.24(12): 1122–1124.doi:10.1097/01.inf.0000189983.71585.30.PMID16371885.
  43. ^Jagielski M, Rastawicki W, Kałuzewski S, Gierczyński R (2007)."[Yersiniosis--unappreciated infectious disease]"[Yersiniosis – unappreciated infectious diseases](PDF).Przeglad Epidemiologiczny(in Polish).56(1): 57–64.PMID12150068.Archived fromthe original(PDF)on 2011-10-03.Retrieved2011-04-10.
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