[Incidence and causes of hypereosinophilia (corrected) in the patients of a university hospital].
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.
Kim
Da Woon
DW
Department of Laboratory Medicine, Chonnam National University Medical School, Dong-Gu, Gwangju, Korea.
Shin
Myung Geun
MG
Yun
Hyeong Kee
HK
Kim
Soo Hyun
SH
Shin
Jong Hee
JH
Suh
Soon Pal
SP
Ryang
Dong Wook
DW
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
C479818:FIP1L1 protein, human; D039221:mRNA Cleavage and Polyadenylation Factors; D020796:Receptor, Platelet-Derived Growth Factor alpha