COVID-19-associated thrombocytopenia
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Shakiba Hassanzadeh, MD[2]
Synonyms and keywords:
Overview
Coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus called SARS-CoV-2, which caused a respiratory illness outbreak that was first detected in Wuhan, China.Thrombocytopenia in COVID-19 infection is more common is patients with severe infection and it has been reported that thrombocytopenia upon admission for COVID-19 infection is associated with poor outcome and mortality.Thrombocytopenia is defined by platelet count <150 x <math>10^9</math>/L on CBC.It has several causes such as
Historical Perspective
- Coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus called SARS-CoV-2, which caused a respiratory illness outbreak that was first detected in Wuhan, China.[1][2]
- On January 30, 2020, the outbreak was declared a Public Health Emergency of International Concern.
- On March 12, 2020, the COVID-19 outbreak was declared a pandemic by the World Health Organization (WHO).
Classification
- Thrombocytopenia is defined by platelet count <150 x <math>10^9</math>/L on CBC.[3]
- Classification of thrombocytopenia by platelet count is:[4]
- Mild: between 70,000 and 150,000 x <math>10^9</math>/L
- Severe: less than 20,000 x <math>10^9</math>/L
- Most patients are asymptomatic if the platelet count is 50,000 x <math>10^9</math>/L or greater.[4]
- Patients with platelet count between 30 and 50 x <math>10^9</math>/L rarely have purpura, but may have bleeding with trauma.[4]
- Patients with platelet count between 10 and 30 x <math>10^3</math>/L may have bleeding with minor trauma.[4]
- Patients with platelet count less than 10 x <math>10^3</math>/L have increased risk for spontaneous bleeding, petechiae, and bruising.[4]
- Spontaneous bleeding, which is an emergency, usually occurs in patients with platelet counts less than 5 x <math>10^3</math>/L .[4]
Pathophysiology
The pathogenesis of thrombocytopenia in COVID-19 infection is due to several factors:[5]
- Decrease in primary platelet production due to infection of bone marrow cells by coronaviruses[6] and inhibition of bone marrow growth,[7] which lead to abnormal hematopoietic function.[5]
- Decrease in platelets may also be due to a cytokine storm caused by the COVID-19 infection which results in the destruction of bone marrow progenitor cells.[5]
- Decrease in circulating platelet due to lung injury which causes megakaryocyte fragmentation and decreases platelet production, because lung is a reservoir for megakaryocyte and hematopoieitic progenitor cells and has a role in platelet production.[5][9]
- In addition, decrease in platelets may be due to activation of platelets that result in platelet aggregation and formation of micro-thrombus which increase platelet consumption.[5][10]
Causes
The causes of thrombocytopenia in COVID-19 infection are:[11]
- Attack on hematopoietic stem cells (HSCs)
- Abnormal bone marrow microenvironment
- Decreased production of thrombopoietin (TPO)
- Cellular immunity and cytokine storm
- Lung damage
- Increased platelet consumption
- Increased platelet clearance
- Drug-induced thrombocytopenia (antiviral drugs)
Differentiating Thrombocytopenia from other Diseases
The differential diagnosis to consider in thrombocytopenia include:[12]
- Pseudothrombocytopenia
- Splenomegaly
- Infections (Epstein-Barr virus, cytomegalovirus, hepatitis C, HIV, parvovirus B19, H pylori)
- Drugs (antibiotics, alcohol, chemotherapy, radiation)
- Folate deficiency or vitamin B12 deficiency
- Liver disease
- Bone marrow failure (such as aplastic anemia, Fanconi anemia, and Diamond-Blackfan anemia)
- Hematologic disorders (lymphoma, leukemia, myelodysplastic syndrome)
- Tumor infiltration of bone marrow
- Inherited thrombocytopenias (Bernard-Soulier syndrome, Wiskott-Aldrich syndrome, and thrombocytopenia with absent radii)
- Immune thrombocytopenic purpura (ITP) and drug-induced ITP (such as quinine, NSAIDs, glycoprotein IIb/IIIa inhibitors)
- Heparin-induced thrombocytopenia (HIT)
- Thrombotic thrombocytopenic purpura (TTP)/hemolytic uremic syndrome (HUS)
- Drug-induced TTP (such as mitomycin C, gemcitabine, oxaliplatin)
- Disseminated intravascular coagulation (DIC)
- Posttransfusion purpura
- Autoimmune-related thrombocytopenia (such as systemic lupus erythematosus (SLE), common variable immunodeficiency (CVID), antiphospholipid antibody syndrome,thyroid disease)
- Mechanical destruction (such as cardiopulmonary bypass, intra-aortic balloon pump)
Epidemiology and Demographics
- Thrombocytopenia is seen in 36.2% of all patients with COVID-19 infection.[13]
- Thrombocytopeniais seen in 57.7% of patients with severe COVID-19 infection compared to 31.6 % of patients with non-severe infection.[13]
Risk Factors
Thrombocytopenia in COVID-19 infection is more common is patients with severe infection compared to patients with non-severe infection.[13]
Screening
- It has been reported that thrombocytopenia upon admission for COVID-19 infection is associated with severe disease and mortality.[14]
- However, there is insufficient evidence to recommend routine screening and monitoring of thrombocytopenia for predicting disease progression in patients with COVID-19 infection and further studies are required.[11]
Natural History, Complications, and Prognosis
Natural History
Thrombocytopenia is associated with an increased risk for severe COVID-19 infection (threefold).[15]
Complications
Complications of thrombocytopenia in patients with severe COVID-19 infection may include:
Prognosis
It has been reported that thrombocytopenia upon admission for COVID-19 infection is independently and strongly associated with poor outcome and mortality.[14]
Diagnosis
Diagnostic Study of Choice
- The diagnostic study of choice for thrombocytopenia is compelete blood count (CBC).
- Thrombocytopenia is defined by platelet count <150 x <math>10^9</math>/L on CBC.[3]
- The median platelet count in COVID-19 patients with thrombocytopenia is 137,500 and 172,000 x <math>10^9</math>/L in severe and non-severe infection, respectively.[13]
History and Symptoms
- The median platelet count in COVID-19 patients with thrombocytopenia is 137,500 and 172,000 x <math>10^9</math>/L in severe and non-severe infection, respectively.[13]
- Most patients are asymptomatic if the platelet count is 50,000 x <math>10^9</math>/L or greater.[4]
- Patients should be questioned about:[3][4]
- Bruising or petechiae
- Bleeding (melena, epistaxis, menorrhagia, hematuria, prolonged bleeding after procedures, gingival bleeding and blood in sputum)
- Past medical history
- Family history
- Medications history
- Immunization history
- Changes in vision
- Rash
- Fever
- Recent travel
- Transfusion history
Physical Examination
- The median platelet count in COVID-19 patients with thrombocytopenia is 137,500 and 172,000 x <math>10^9</math>/L in severe and non-severe infection, respectively.[13]
- Most patients are asymptomatic if the platelet count is 50,000 x <math>10^9</math>/L or greater.[4]
- The physical examination in patients with thrombocytopenia should include checking for:[3]
- Bleeding[16] (epistaxis, bloody sputum, gingival bleeding, menorrhagia, heavy bleeding after invasive procedures or childbirth)[17]
- Unexplained bruising (petechiae, purpura, ecchymosis)
- Hepatosplenomegaly
- Abdominal tenderness
- Urinary tract (check for hematuria)[18]
- Stool for occult blood (evaluation of gastrointestinal and rectal bleeding)
- Retinal hemorrhage on fundoscopic exam (evaluation of central nervous system bleeding)[18]
- Neurologic examination (check for intracranial bleeding)[18]
- Soft tissue or joint bleeding is not associated with thrombocytopenia and other coagulation disorders such as DIC should be checked.[16][18]
Laboratory Findings
- Compelete blood count (CBC): Thrombocytopenia is defined by platelet count <150 x <math>10^9</math>/L on CBC.[3]
- The median platelet count in COVID-19 patients with thrombocytopenia is 137,500 and 172,000 x <math>10^9</math>/L in severe and non-severe infection, respectively.[13]
- Peripheral blood smear: Peripheral blood smear may be helpful if there is suspicion of other disorders that cause thrombocytopenia.
- Other laboratory testings (such as HIV, HCV testing, antibody testing, liver enzymes and liver function testing) are performed if there is suspicion of other disorders that cause thrombocytopenia.
Electrocardiogram
There are no ECG findings associated with COVID-19-associated-thrombocytopenia.
X-ray
There are no x-ray findings associated with COVID-19-associated-thrombocytopenia.
Echocardiography or Ultrasound
There are no echocardiography/ultrasound findings associated with COVID-19-associated-thrombocytopenia.
CT scan
There are no CT scan findings associated with COVID-19-associated-thrombocytopenia.
MRI
There are no MRI findings associated with COVID-19-associated-thrombocytopenia.
Other Imaging Findings
There are no other imaging findings associated with COVID-19-associated-thrombocytopenia.
Other Diagnostic Studies
There are no other diagnostic studies associated with COVID-19-associated-thrombocytopenia. However, bone marrow biopsy may be helpful if there is suspicion of other disorders that cause thrombocytopenia.
Treatment
Medical Therapy
The treatment options for thrombocytopenia in COVID-19 infection include:[19]
- Rituximab,
- Thrombopoietin receptor agonists (eltrombopag, avatrombopag, romiplostim)
- High-dose dexamethasone as an alternative to prednisone
- Intravenous immunoglobulins (IVIg) (1 g/kg on 1 or 2 consecutive days or 0.4 g/kg per day for 5 days)
- Intravenous anti-D (50–75 mg/kg once) (consider potential triggering of DIC or hemolysis)
- Platelet growth factors in patients with bleeding, high risk for bleeding, unresponsive to prednisone (carefully evaluate due to the potential thrombotic events in coronavirus infection)
- Platelet transfusion in refractory visceral or cerebral meningeal hemorrhage
Surgery
The mainstay of treatment for severe thrombocytopenia in COVID-19 infection is medical therapy. Surgery has not been reported to be indicated in thrombocytopenia in COVID-19 infection.
Primary Prevention
There are no established measures for the primary prevention of thrombocytopenia in COVID-19 infection.
Secondary Prevention
There are no established measures for the secondary prevention of thrombocytopenia in COVID-19 infection. However, it may include avoidance of antiviral medications.
References
- ↑ https://www.cdc.gov/coronavirus/2019-ncov/about/index.html. Missing or empty
|title=(help) - ↑ Lu, Jian; Cui, Jie; Qian, Zhaohui; Wang, Yirong; Zhang, Hong; Duan, Yuange; Wu, Xinkai; Yao, Xinmin; Song, Yuhe; Li, Xiang; Wu, Changcheng; Tang, Xiaolu (2020). "On the origin and continuing evolution of SARS-CoV-2". National Science Review. doi:10.1093/nsr/nwaa036. ISSN 2095-5138.
- ↑ 3.0 3.1 3.2 3.3 3.4 Greenberg EM (2017). "Thrombocytopenia: A Destruction of Platelets". J Infus Nurs. 40 (1): 41–50. doi:10.1097/NAN.0000000000000204. PMID 28030481.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 Gauer RL, Braun MM (2012). "Thrombocytopenia". Am Fam Physician. 85 (6): 612–22. PMID 22534274.
- ↑ 5.0 5.1 5.2 5.3 5.4 Xu P, Zhou Q, Xu J (2020). "Mechanism of thrombocytopenia in COVID-19 patients". Ann Hematol. 99 (6): 1205–1208. doi:10.1007/s00277-020-04019-0. PMC 7156897 Check
|pmc=value (help). PMID 32296910 Check|pmid=value (help). - ↑ Yang M, Ng MH, Li CK (2005). "Thrombocytopenia in patients with severe acute respiratory syndrome (review)". Hematology. 10 (2): 101–5. doi:10.1080/10245330400026170. PMID 16019455.
- ↑ Yeager CL, Ashmun RA, Williams RK, Cardellichio CB, Shapiro LH, Look AT; et al. (1992). "Human aminopeptidase N is a receptor for human coronavirus 229E". Nature. 357 (6377): 420–2. doi:10.1038/357420a0. PMC 7095410 Check
|pmc=value (help). PMID 1350662. - ↑ Nardi M, Tomlinson S, Greco MA, Karpatkin S (2001). "Complement-independent, peroxide-induced antibody lysis of platelets in HIV-1-related immune thrombocytopenia". Cell. 106 (5): 551–61. doi:10.1016/s0092-8674(01)00477-9. PMID 11551503.
- ↑ Lefrançais E, Ortiz-Muñoz G, Caudrillier A, Mallavia B, Liu F, Sayah DM; et al. (2017). "The lung is a site of platelet biogenesis and a reservoir for haematopoietic progenitors". Nature. 544 (7648): 105–109. doi:10.1038/nature21706. PMC 5663284. PMID 28329764.
- ↑ Liu X, Zhang R, He G (2020). "Hematological findings in coronavirus disease 2019: indications of progression of disease". Ann Hematol. doi:10.1007/s00277-020-04103-5. PMC 7266734 Check
|pmc=value (help). PMID 32495027 Check|pmid=value (help). - ↑ 11.0 11.1 11.2 11.3 11.4 Zhang Y, Zeng X, Jiao Y, Li Z, Liu Q, Ye J; et al. (2020). "Mechanisms involved in the development of thrombocytopenia in patients with COVID-19". Thromb Res. 193: 110–115. doi:10.1016/j.thromres.2020.06.008. PMC 7274097 Check
|pmc=value (help). PMID 32535232 Check|pmid=value (help). - ↑ Lee EJ, Lee AI (2016). "Thrombocytopenia". Prim Care. 43 (4): 543–557. doi:10.1016/j.pop.2016.07.008. PMID 27866576.
- ↑ 13.0 13.1 13.2 13.3 13.4 13.5 13.6 Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX; et al. (2020). "Clinical Characteristics of Coronavirus Disease 2019 in China". N Engl J Med. 382 (18): 1708–1720. doi:10.1056/NEJMoa2002032. PMC 7092819 Check
|pmc=value (help). PMID 32109013 Check|pmid=value (help). - ↑ 14.0 14.1 Maquet J, Lafaurie M, Sommet A, Moulis G, Covid-Clinic-Toul investigators group. Alvarez M; et al. (2020). "Thrombocytopenia is independently associated with poor outcome in patients hospitalized for COVID-19". Br J Haematol. doi:10.1111/bjh.16950. PMID 32557535 Check
|pmid=value (help). - ↑ Lippi G, Plebani M, Henry BM (2020). "Thrombocytopenia is associated with severe coronavirus disease 2019 (COVID-19) infections: A meta-analysis". Clin Chim Acta. 506: 145–148. doi:10.1016/j.cca.2020.03.022. PMC 7102663 Check
|pmc=value (help). PMID 32178975 Check|pmid=value (help). - ↑ 16.0 16.1 Stasi R (2012). "How to approach thrombocytopenia". Hematology Am Soc Hematol Educ Program. 2012: 191–7. doi:10.1182/asheducation-2012.1.191. PMID 23233580.
- ↑ Ghoshal K, Bhattacharyya M (2014). "Overview of platelet physiology: its hemostatic and nonhemostatic role in disease pathogenesis". ScientificWorldJournal. 2014: 781857. doi:10.1155/2014/781857. PMC 3960550. PMID 24729754.
- ↑ 18.0 18.1 18.2 18.3 Sekhon SS, Roy V (2006). "Thrombocytopenia in adults: A practical approach to evaluation and management". South Med J. 99 (5): 491–8, quiz 499-500, 533. doi:10.1097/01.smj.0000209275.75045.d4. PMID 16711312.
- ↑ Lorenzo-Villalba N, Zulfiqar AA, Auburtin M, Schuhmacher MH, Meyer A, Maouche Y; et al. (2020). "Thrombocytopenia in the Course of COVID-19 Infection". Eur J Case Rep Intern Med. 7 (6): 001702. doi:10.12890/2020_001702. PMC 7279909 Check
|pmc=value (help). PMID 32523922 Check|pmid=value (help).