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Thrombocytopenia
Classification and external resources
ICD-10 D69.6, P61.0
ICD-9 287.3, 287.4, 287.5
OMIM 188000 313900
DiseasesDB 27522
MedlinePlus 000586
MeSH D013921

Thrombocytopenia (or -paenia, or thrombopenia in short) is the presence of relatively few platelets in blood. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The International Statistical Classification of Diseases and Related Health Problems 10th Revision ( ICD -10) is a coding of diseases and signs symptoms abnormal findings P00-P96 - Certain conditions originating in the Perinatal period (P00-P04 Fetus and newborn affected by maternal factors and by complications of pregnancy labour and The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. The Mendelian Inheritance in Man project is a Database that catalogues all the known Diseases with a genetic component, and—when possible—links them The Diseases Database is a free Website that provides information about the relationships between medical conditions Symptoms, and Medications. MedlinePlus, with the MedlinePlus Medical Encyclopedia, is a website network containing Health information from the world's largest medical Library Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Platelets, or Thrombocytes, are small cytoplasmic bodies derived from cells They circulate in the Blood of Mammals and are involved Blood is a specialized Bodily fluid that delivers necessary substances to the body's cells such as nutrients and oxygen—and transports Waste products

Generally speaking, in humans, a normal platelet count ranges from 150,000 and 450,000 per mm3 (microlitre). [1] These limits, however, are determined by the 2. 5th lower and upper percentile, and a deviation does not necessarily imply any form of disease. A percentile is the value of a variable below which a certain percent of observations fall The number of platelets in a blood sample also decreases rather quickly with time and a low platelet count may be caused by a delay between sampling and analysis.

Contents

Signs and symptoms

Often, low platelet levels do not lead to clinical problems; rather, they are picked up on a routine full blood count (or CBC, complete blood count ). A complete blood count ( CBC) also known as full blood count ( FBC) or full blood exam ( FBE) or blood panel, is A complete blood count ( CBC) also known as full blood count ( FBC) or full blood exam ( FBE) or blood panel, is Occasionally, there may be bruising, particularly purpura in the forearms, nosebleeds and/or bleeding gums. Purpura (from the Latin purpura, meaning "purple" is the appearance of red or purple discolorations on the Skin, caused by Bleeding underneath Epistaxis (or a nosebleed in Plain English) is the relatively common occurrence of Hemorrhage from the Nose, usually noticed when the blood drains The gingiva (sing and plur: gingiva) or gums, consists of the Mucosal tissue that lies over the Alveolar bone.

It is vital that a full medical history is elicited, to ensure the low platelet count is not due to a secondary process. It is also important to ensure that the other blood cell types red blood cells, and white blood cells, are not also suppressed. Red blood cells are the most common type of Blood cell and the Vertebrate body's principal means of delivering Oxygen to the body tissues via the Blood

Diagnosis

Laboratory tests might include: full blood count, liver enzymes, renal function, vitamin B12 levels, folic acid levels, erythrocyte sedimentation rate, and peripheral blood smear. A complete blood count ( CBC) also known as full blood count ( FBC) or full blood exam ( FBE) or blood panel, is Liver function tests (LFTs or LFs which include liver enzymes, are groups of Clinical biochemistry laboratory blood assays designed to give information about the Renal function, in Nephrology, is an indication of the state of the Kidney and its role in Renal physiology. Folic acid (also known as Vitamin M and Folacin) and Folate (the Anionic form are forms of the water-soluble Vitamin B9 The erythrocyte sedimentation rate (ESR also called a sedimentation rate, sed rate, or Biernacki Reaction, is the rate at which Red blood cells

If the cause for the low platelet count remains unclear, bone marrow biopsy is often undertaken, to differentiate whether the low platelet count is due to decreased production or peripheral destruction. Bone marrow examination refers to the pathologic analysis of samples of Bone marrow obtained by bone marrow biopsy (often called a Trephine biopsy

Causes

Decreased platelet counts can be due to a number of disease processes:

Decreased production

Increased destruction

Medication-induced

The most comprehensive list of thrombocytopenia-inducing medications is maintained by Dr. Sepsis is a serious medical condition characterized by a whole-body inflammatory state (called a Systemic inflammatory response syndrome or SIRS caused An infection is the detrimental Colonization of a host Organism by a foreign Species. Bone marrow is the flexible tissue found in the hollow interior of Bones In adults marrow in large bones produces new Blood cells It constitutes 4% of The megakaryocyte is a Bone marrow cell responsible for the production of blood Platelets necessary for normal blood Clotting Megakaryocytes normally Platelets, or Thrombocytes, are small cytoplasmic bodies derived from cells They circulate in the Blood of Mammals and are involved TAR Syndrome ( Thrombocytopenia with Absent radius) is a rare Genetic disorder which is characterized by the absence of the radius bone in Fanconi anemia (FA is a genetic disease that affects children and adults from all ethnic backgrounds Bernard-Soulier syndrome (BSS also called hemorrhagiparous thrombocytic dystrophy, is an Autosomal recessive bleeding disorder that causes a deficiency Gray platelet syndrome, or platelet alpha-granule deficiency, is a rare congenital bleeding disorder caused by a reduction or absence of the Platelet alpha-granules Alport syndrome is a Genetic disorder characterized by Glomerulonephritis, endstage kidney disease and hearing loss Idiopathic thrombocytopenic purpura (ITP is the condition of having a low Platelet count ( Thrombocytopenia) of no known cause ( Idiopathic) Thrombotic thrombocytopenic purpura ( TTP or Moschcowitz disease) is a rare disorder of the blood-coagulation system causing extensive microscopic In Medicine, hemolytic-uremic syndrome (or haemolytic-uraemic syndrome, abbreviated HUS is a disease characterized by Microangiopathic hemolytic anemia Disseminated intravascular coagulation ( DIC) also known as consumptive coagulopathy, is a pathological activation of Coagulation (blood clotting mechanisms Paroxysmal nocturnal hemoglobinuria (PNH sometimes referred to as Marchiafava-Micheli syndrome, is a rare acquired potentially life-threatening disease of the blood characterised Antiphospholipid syndrome (APS or APLS or antiphospholipid antibody syndrome is a disorder of Coagulation, which causes blood clots ( Thrombosis) in both Systemic lupus erythematosus ( SLE or lupus,) is a chronic autoimmune disease that can be fatal though with recent medical advances fatalities are becoming Neonatal Alloimmune Thrombocytopenia ( NAITP or NAIT or NAT for short or feto-maternal alloimmune thrombocytopenia, FMAITP Splenomegaly is an enlargement of the Spleen, which usually lies in the left upper quadrant (LUQ of the Human abdomen. James George at Ohio State University at this website, though last updated in 2004. A small subset of drug-induced thrombocytopenia culprits:

Drug name
Heparin
Valproic acid
Quinidine
Abciximab
Sulfonamide antibiotics
Interferons
Measles-mumps-rubella vaccine
Glycoprotein IIb/IIIa inhibitors
Clopidogrel
Vancomycin [2][3]
Linezolid
Famotidine
Mebeverine
Tinidazole/Metronidazole

Treatment

Treatment is guided by etiology and disease severity. The main concept in treating thrombocytopenia is to eliminate the underlying problem, whether that means discontinuing suspected drugs that cause thrombocytopenia, or treating underlying sepsis. Diagnosis and treatment of serious thrombocytopenia is usually directed by a hematologist. Hematology ( American English) or haematology ( British English) is the branch of biology (physiology Pathology, Clinical laboratory

Specific treatment plans often depend on the underlying etiology of the thrombocytopenia. Etiology (alternatively aetiology, aitiology) is the study of causation.

Thrombotic thrombocytopenic purpura (TTP)

Treatment of thrombotic thrombocytopenic purpura is a medical emergency, since the hemolytic anemia and platelet activation can lead to renal failure and changes in the level of consciousness. Thrombotic thrombocytopenic purpura ( TTP or Moschcowitz disease) is a rare disorder of the blood-coagulation system causing extensive microscopic Hemolytic anemia is Anemia due to Hemolysis, the abnormal breakdown of Red blood cells (RBCs either in the Blood vessels (intravascular hemolysis Renal failure or kidney Treatment of TTP was revolutionized in the 1980s with the application of plasmapheresis. Thrombotic thrombocytopenic purpura ( TTP or Moschcowitz disease) is a rare disorder of the blood-coagulation system causing extensive microscopic Plasmapheresis (from the Greek plasma, something molded and apheresis, taking away is the removal treatment and return of (components of Blood According to the Furlan-Tsai hypothesis [4] [5] , this treatment theoretically works by removing antibodies directed against the von Willebrand factor cleaving protease, ADAMTS-13. Antibodies (also known as immunoglobulins, abbreviated Ig) are Gamma globulin Proteins that are found in Blood or other Bodily Von Willebrand factor (vWF is a Blood Glycoprotein involved in Hemostasis. A protease is any Enzyme that conducts Proteolysis, that is begins protein Catabolism by Hydrolysis of the Peptide bonds that link ADAMTS13 ( a disintegrin and metalloproteinase with a thrombospondin type 1 motif member 13)—also known as von Willebrand factor-cleaving protease (VWFCP—is a The plasmapheresis procedure also adds active ADAMTS-13 protease proteins to the patient, restoring a more physiological state of von Willebrand factor multimers. Plasmapheresis (from the Greek plasma, something molded and apheresis, taking away is the removal treatment and return of (components of Blood ADAMTS13 ( a disintegrin and metalloproteinase with a thrombospondin type 1 motif member 13)—also known as von Willebrand factor-cleaving protease (VWFCP—is a A protease is any Enzyme that conducts Proteolysis, that is begins protein Catabolism by Hydrolysis of the Peptide bonds that link Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Von Willebrand factor (vWF is a Blood Glycoprotein involved in Hemostasis. Patients with persistent antibodies against ADAMTS-13 do not always manifest TTP, and these antibodies alone are not sufficient to explain the how plasmapheresis treats TTP. Thrombotic thrombocytopenic purpura ( TTP or Moschcowitz disease) is a rare disorder of the blood-coagulation system causing extensive microscopic Plasmapheresis (from the Greek plasma, something molded and apheresis, taking away is the removal treatment and return of (components of Blood Thrombotic thrombocytopenic purpura ( TTP or Moschcowitz disease) is a rare disorder of the blood-coagulation system causing extensive microscopic

Idiopathic thrombocytopenic purpura (ITP)

Main article: Idiopathic thrombocytopenic purpura

Many cases of ITP can be left untreated, and spontaneous remission (especially in children) is not uncommon. Idiopathic thrombocytopenic purpura (ITP is the condition of having a low Platelet count ( Thrombocytopenia) of no known cause ( Idiopathic) However, counts of under 50,000 are usually monitiored with regular blood tests, and those with counts of under 10,000 are usually treated, as the risk of serious spontaneous bleeding is high with a platelet count this low. Any patient experiencing severe bleeding symptoms is also usually treated. The threshold for treating ITP has decreased since the 1990s, and hematologists recognize that patients rarely bleed with platelet counts greater than ten thousand, though there are documented exceptions to this observation. Treatments for ITP include:

Thrombopoetin analogues have been tested extensively for the treatment of ITP. Prednisone is a synthetic Corticosteroid drug that is usually taken orally but can be delivered by Intramuscular injection and can be used for a great number Corticosteroids are a class of Steroid hormones that are produced in the Adrenal cortex. A splenectomy is a procedure that involves the removal of the Spleen by operative means Danazol is a derivative of the synthetic Steroid Ethisterone, a modified Testosterone. Rituximab, sold under the trade names Rituxan, MabThera and Reditux, is a chimeric Monoclonal antibody against the protein CD20 These agents had previously shown promise but had been found to stimulate antibodies against endogenous thrombopoeitin or lead to thrombosis. Thrombosis is the formation of a blood Clot ( Thrombus) inside a Blood vessel, obstructing the flow of Blood through the Circulatory

A investigational medication known as AMG 531 (Romiplostim, trade name Nplate) was found, in early studies, to be safe and effective for the treatment of ITP in refractory patients. [6][7][8] AMG 531 is a peptide that bears no sequence homology with endogenous human thrombopoeitin, so it is not as likely to lead to neutralizing antibodies as previous peptide thrombopoeitin analogues. Peptides (from the Greek πεπτίδια, "small digestibles" are short Polymers formed from the linking in a defined order of α- Amino In Evolutionary biology, homology has come to mean any similarity between characters that is due to their shared ancestry. Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus [9]

Heparin-induced thrombocytopenia and thrombosis (HITT)

Main article: Heparin-induced thrombocytopenia

Discontinuation of heparin is critical in a case of HITT. Heparin-induced thrombocytopenia (HIT with or without thrombosis (HITT is Thrombocytopenia (low Platelet counts due to the administration of Heparin Beyond that, however, clinicians generally treat to avoid a thrombosis, and patients started directly on warfarin after a diagnosis of HITT are at excess risk of venous limb gangrene. Warfarin (also known under the brand names Coumadin, Jantoven, Marevan, and Waran) is an Anticoagulant. For this reason, patients are usually treated with a type of blood thinner called a direct thrombin inhibitor such as the FDA-approved lepirudin or argatroban. An anticoagulant is a substance that prevents coagulation; that is it stops Blood from clotting Direct thrombin inhibitors (DTIs are a class of Medication that act as Anticoagulants (delaying blood clotting) by directly inhibiting the Enzyme Lepirudin ( Refludan) is an Anticoagulant which functions as a Direct thrombin inhibitor. Argatroban is an Anticoagulant that is a small molecule Direct thrombin inhibitor. Other blood thinners sometimes used in this setting that are not FDA-approved for treatment of HITT include bivalirudin and fondaparinux. Bivalirudin ( Angiomax) is a drug that belongs to the Anticoagulant class and acts as a Direct thrombin inhibitor. Fondaparinux (Arixtra is an Anticoagulant medication As shown in the box to the right fondaparinux is a synthetic pentasaccharide Platelet transfusions are not a routine component of the treatment of HITT, since thrombosis, not bleeding, is the usual associated problem in this illness.

Congenital amegakaryocytic thrombocytopenia (CAMT)

Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare inherited disorder. The primary manifestations are thrombocytopenia and megakaryocytopenia, or low numbers of platelets and megakaryocytes. There is an absence of megakaryocytes in the bone marrow with no associated physical abnormalities. [10] The cause for this disorder appears to be a mutation in the gene for the TPO receptor, c-mpl, despite high levels of serum TPO. [11][12] In addition, there may be abnormalities with the central nervous system including the cerebrum and cerebellum which could cause symptoms. In Vertebrates the central nervous system ( CNS) is the part of the Nervous system which is enclosed in the Meninges. The telencephalon (tɛlɛnˈsɛfəlɒn cerebrum, or forebrain is the most Anterior or especially in humans most Dorsal region of the The cerebellum ( Latin: "little brain" is a region of the Brain that plays an important role in the integration of sensory perception [11] The primary treatment for CAMT is bone marrow transplantation.

Bone Marrow/Stem Cell Transplant is the only thing that ultimately cures this genetic disease. Frequent platelet transfusions are required to keep the patient from bleeding to death until transplant is done, although this is not always the case.

One of the few non Medical Research related sources on the web with some information on CAMT is;

There appears to be no generic resource for CAMT patients on the web, and this is potentially due to the rariety of the disease.

References

  1. ^ Platelet count aka thrombocyte count. Lab Tests Online UK (2004-05-28). "MMIV" redirects here For the Modest Mouse album see " Baron von Bullshit Rides Again " Events 585 BC - A Solar eclipse occurs as predicted by Greek philosopher and scientist Thales, while Alyattes is battling Retrieved on 2008-05-22. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 334 BC - The Greek army of Alexander the Great defeats Darius III of Persia in the Battle of the Granicus.
  2. ^ Howard C, Adams L, Admire J, Chu M, Alred G (1997). "Vancomycin-induced thrombocytopenia: a challenge and rechallenge". Ann Pharmacother 31 (3): 315-8. PMID 9066938.  
  3. ^ NEJM 2007 356:904, PMID available on 3/2/07 "Vancomycin Induced Immune Thrombocytopenia
  4. ^ Furlan M, Lämmle B (2001). "Aetiology and pathogenesis of thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome: the role of von Willebrand factor-cleaving protease". Best Pract Res Clin Haematol 14 (2): 437-54. doi:10.1053/beha.2001.0142. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 11686108.  
  5. ^ Tsai H (2003). "Advances in the pathogenesis, diagnosis, and treatment of thrombotic thrombocytopenic purpura". J Am Soc Nephrol 14 (4): 1072-81. doi:10.1097/01.ASN.0000060805.04118.4C. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 12660343.  
  6. ^ Bussel J, Kuter D, George J, McMillan R, Aledort L, Conklin G, Lichtin A, Lyons R, Nieva J, Wasser J, Wiznitzer I, Kelly R, Chen C, Nichol J (2006). "AMG 531, a thrombopoiesis-stimulating protein, for chronic ITP". N Engl J Med 355 (16): 1672-81. doi:10.1056/NEJMoa054626. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 17050891.  
  7. ^ AMGEN. Amgen Inc () is an international Biotechnology company headquartered in Thousand Oaks California. "Press release: Amgen Statement on Successful Outcome of Romiplostim Panel Meeting", Business Wire via drugs. Business Wire is a company that disseminates full-text News releases from thousands of companies and organizations worldwide to News media, financial markets com, 2008-03-12. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 538 - Witiges, king of the Ostrogoths ends his siege of Rome and retreats to Ravenna, leaving Retrieved on 2008-05-22. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 334 BC - The Greek army of Alexander the Great defeats Darius III of Persia in the Battle of the Granicus.  
  8. ^ "US FDA panel backs Amgen's Nplate against ITP", Reuters, 2008-03-12. This article is primarily about Reuters prior to its 2008 merger with Thomson 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 538 - Witiges, king of the Ostrogoths ends his siege of Rome and retreats to Ravenna, leaving Retrieved on 2008-05-22. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 334 BC - The Greek army of Alexander the Great defeats Darius III of Persia in the Battle of the Granicus.  
  9. ^ Broudy V, Lin N (2004). "AMG531 stimulates megakaryopoiesis in vitro by binding to Mpl". Cytokine 25 (2): 52-60. doi:10.1016/j.cyto.2003.05.001. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 14693160.  
  10. ^ Freedman MH, Estrov Z (1990). "Congenital amegakaryocytic thrombocytopenia: an intrinsic hematopoietic stem cell defect". Am. J. Pediatr. Hematol. Oncol. 12: 225-230.  
  11. ^ a b Ihara K, Ishii E, Eguchi M, Takada H, Suminoe A, Good RA, Hara T (1999). "Identification of mutations in the c-mpl gene in congenital amegakaryocytic thrombocytopenia. ". Proc. Natl. Acad. Sci. 96: 3133–6. doi:10.1073/pnas.96.6.3132. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
  12. ^ Ballmaier M, Germeshausen M, Schulze H, Cherkaoui K, Lang S, Gaudig A, Krukemeier S, Eilers M, Strauss G, Welte K (2001). "C-mpl mutations are the cause of congenital amegakaryocytic thrombocytopenia". Blood. 97: 139–46. doi:10.1182/blood.V97.1.139. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  

External links

The Merck Manual of Diagnosis and Therapy, often called simply The Merck Manual, is the world's best-selling medical textbook

Dictionary

thrombocytopenia

-noun

  1. An abnormally low number of platelets in the blood.
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