title: [Incidence and causes of hypereosinophilia (corrected) in the patients of a university hospital].
abstract: BACKGROUND
  Eosinophilia may be associated with various primary and reactive conditions. The incidence and the causes of eosinophilia might have been changed according to the changes in the incidence of diseases such as cancer, chronic degenerative diseases, etc. We have conducted a retrospective study to investigate the incidence and causes of eosinophilia.
  
  
  METHODS
  Eosinophilia and hypereosinophilia were defined when absolute eosinophil count was greater than 500/microL and 1,500/microL, respectively. Patient's clinical records were reviewed to find out the underlying clinical conditions responsible for causes of hypereosinophilia. Conventional chromosomal analysis, reverse transcriptase PCR and FISH for gene rearrangement were performed to check the presence of clonal eosinophilia.
  
  
  RESULTS
  Out of 41,137 patients who had a hematology profile performed, 5,019 (12.2%) and 373 patients (0.9%) were found to have eosinophilia and hypereosinophilia, respectively. Among patients with hypereosinophilia, 227 patients (60.9%) had identifiable and/or possible causes. The major causes of hypereosinophilia were malignancy (35.2%), allergy and skin diseases (18.1%), infectious diseases (15.4%), hepatobiliary diseases (7.5%), bone marrow clonal diseases (6.6%) and parasite infections (6.6%). We also found a rare case of FIP1L1-PDGFRalpha positive chronic eosinophilic leukemia combined with light chain multiple myeloma.
  
  
  CONCLUSIONS
  We found a difference in the distribution of causes of hypereosinophilia in comparison with previous Korean studies, and the most common cause of hypereosinophilia in the current study was malignancy. A rare case of clonal eosinophilia (chronic eosinophilic leukemia) associated with multiple myeloma was confirmed using molecular studies.
authors: Department of Laboratory Medicine, Chonnam National University Medical School, Dong-Gu, Gwangju, Korea.
authors: Da Woon
authors: DW
authors: Kim
authors: Myung Geun
authors: MG
authors: Shin
authors: Hyeong Kee
authors: HK
authors: Yun
authors: Soo Hyun
authors: SH
authors: Kim
authors: Jong Hee
authors: JH
authors: Shin
authors: Soon Pal
authors: SP
authors: Suh
authors: Dong Wook
authors: DW
authors: Ryang
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004802:Eosinophilia / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D005260:Female; D006785:Hospitals, University; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics / Q000378:metabolism; D012189:Retrospective Studies; D012737:Sex Factors; D055815:Young Adult; D039221:mRNA Cleavage and Polyadenylation Factors / Q000235:genetics / Q000378:metabolism
chemical_list: C479818:FIP1L1 protein, human; D039221:mRNA Cleavage and Polyadenylation Factors; D020796:Receptor, Platelet-Derived Growth Factor alpha