특발성 호산구증가 증후군에서 FIP1L1-PDGFRA융합유전자와 염색체이상의 증명

Abstract

Background: Idiopathic hypereosinophilic syndrome is a rare disorder characterized by persistent eosinophilia of unknown origin often associated with multiple organ dysfunction as a result of infiltration by tissue eosinophils and the toxic effects of their released granule contents. Chronic eosinophilic leukemia is a rare hematologic malignancy difficult to distinguish from idiopathic hypereosinophilic syndrome. The WHO recommendation to diagnosis chronic eosinophilic leukemia in case of proven clonality, and idiopathic hypereosinophilic syndrome in the remaining cases. Methods: I investigated 13 patients fulfilling WHO criteria for IHES, using nested RT-PCR for FIP1L1-PDGFRA fusion gene and cytogenetic study for evaluation of clonality. Results: The median age of patients was 53.2 years (range, 24~73) and male to female ratio was 11:2. In only three patients, clonal karyotype abnormalities were seen: 46,XY,1,der(1;7)(q10;p10)[20], 46,XO ?Y[5], 46,XY[15], 46, XX, inv(19)(q13p12)[20]. However, all patients were not detected FIP1L1-PDGFRA fusion gene. Eleven patients had symptomatic eosinophilic liver disease at first presentation. Two patients involved gastrointestinal tract and 1 patients involved lung and heart, respectively. Six of the 12 patients treated with steroid had responses and chronic eosinophilic syndrome responded poorly to steroids rather than idiopathic hypereosinophilic syndrome(0% vs 66.7%). Conclusions: The 46,XY,1,der(1;7)(q10;p10)[20], 46,XO ?Y[5], 46,XY[15], 46, XX, inv(19)(q13p12)[20] involving the cells of the eosinophilic lineage are three novel chromosome abnormalities occurring in chronic eosinophilic leukemia. These findings indicated that cytogenetic and molecular genetic analysis should be performed to distinguish from idiopathic hypereosinophilic syndrome to chronic eosinophilic leukemia.