title: Estimation of diagnosis and prognosis in ET by assessment of CALR and JAK2V617Fmutations and laboratory findings: a meta-analysis.
abstract: BACKGROUND
  Essential thrombocythemia (ET) is a benign disease with slow progress in which thrombosis is a cause of mortality. JAK2V617Fand calreticulin (CALR) are the most frequent mutations in this disease. In this systematic review and meta-analysis, we compared the prevalence of JAK2V617Fand CALR mutations in ET and examined the incidence of thrombosis and other hematologic indices.
  
  
  METHODS
  After choosing MeSH keywords, including essential thrombocythemia, JAK2V617F, calreticulin, prognosis, and diagnosis, as well as searching Medline/PubMed and Scopus, 12 papers were selected. Data were pooled, and summary prevalence and OR were estimated using either a random-effects model or a fixed-effects model.
  
  
  RESULTS
  The frequency of JAK2V617Fand CALR shows heterogeneity in Caucasian population [JAK2V617I2% = 84.3, P < 0.001, 95% CI 0.56 (0.51-0.61)], [CALR I2% = 96.1, P < 0.001, 95% CI 0.23 (0.15-0.31)]. The prevalence of JAK2V617Fand CALR was 0.57 (95% CI 0.53-0.61), I2% = 79.3 and 0.22 (95% CI 0.16-0.27), I2% = 94, respectively. JAK2V617Fpositive ET was associated with increasing odds of thrombosis [OR 2.35 (95% CI 1.83-3.02), P < 0.001]. The incidence of splenomegaly was not statistically different between these two mutations. Hemoglobin, platelet, and WBC count did not affect the risk of thrombosis.
  
  
  CONCLUSIONS
  Detection of CALR mutation is helpful for molecular diagnosis of ET patients as well as JAK2V617F. Due to reduction of thrombosis in CALR-positive patients, it can be stated that such patients have less thrombotic disorders and better prognosis relative to patients bearing JAK2V617Fmutation. Therefore, detection of mutation in CALR and JAK2V617Fmay contribute to diagnosis and prognosis of ET patients.
authors.affiliation: Thalassemia & Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: N
authors.initials: N
authors.lastname: Saki
authors.affiliation: Thalassemia & Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: R
authors.initials: R
authors.lastname: Shirzad
authors.affiliation: Thalassemia & Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: F
authors.initials: F
authors.lastname: Rahim
authors.affiliation: Thalassemia & Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. amalsaki@gmail.com.|Department of Biostatistics and Epidemiology, School of Public Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. amalsaki@gmail.com.
authors.forename: A
authors.identifier: http://orcid.org/0000-0002-0952-5861
authors.initials: A
authors.lastname: Saki Malehi
mesh_terms: D037282:Calreticulin / Q000235:genetics*; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics*; D009154:Mutation; D011379:Prognosis; D013920:Thrombocythemia, Essential / Q000175:diagnosis* / Q000235:genetics*
chemical_list: C576483:CALR protein, human; D037282:Calreticulin; C507924:JAK2 protein, human; D053614:Janus Kinase 2
keywords: Calreticulin; Diagnosis; Essential thrombocythemia; JAK2V617F; Meta-analysis; Prognosis; Thrombosis