title: Loss of heterozygosity at the human leukocyte antigen locus in thymic epithelial tumors.
abstract: BACKGROUND
  To study the relationship between loss of heterozygosity (LOH) at the human leukocyte antigen (HLA) locus and the pathogenicity and clinicopathological features of thymic epithelial tumors (TET).
  
  
  METHODS
  Tumor and adjacent normal tissues were isolated from 36 TET patients. Five microsatellite loci (D6S1666, D6S265, D6S273, DS6276, and D6S291) within the HLA locus were amplified by polymerase chain reaction. DNA sequencing was used to measure the frequency of microsatellite LOH.
  
  
  RESULTS
  LOH was identified in at least one locus in 83.6% of TET patients. LOH frequency at D6S1666, D6S265, D6S273, D6S276, and D6S291 was 44.4%, 16.7%, 30.5%, 38.9%, and 36.1% respectively. There was no significant association between LOH frequency in TET with tumor severity, or in the presence or absence of myasthenia gravis.
  
  
  CONCLUSIONS
  D6S1666, D6S265, D6S273, DS6S276, and D6S29 are sensitive loci for studying microsatellite LOH in TET. LOH within the HLA complex is implicated in the occurrence and development of TET, with the HLA-DQA1 gene likely involved. However, an understanding of the relationship between LOH and the clinicopathological features of TET requires a larger sample size than that of the present study.
authors.affiliation: Deparment of Cardiothoracic Surgery, Tianjin Medical University General Hospital Tianjin, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Deparment of Hematology and Oncology, Tianjin Medical University General Hospital Tianjin, China.
authors.forename: Guojin
authors.initials: G
authors.lastname: Wang
authors.affiliation: Deparment of Cardiothoracic Surgery, Tianjin Medical University General Hospital Tianjin, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Deparment of Cardiothoracic Surgery, Tianjin Medical University General Hospital Tianjin, China.
authors.forename: Yimei
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Deparment of Cardiothoracic Surgery, Tianjin Medical University General Hospital Tianjin, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Deparment of Cardiothoracic Surgery, Tianjin Medical University General Hospital Tianjin, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Wang
authors.affiliation: Deparment of Cardiothoracic Surgery, Tianjin Medical University General Hospital Tianjin, China.
authors.forename: Yuanguo
authors.initials: Y
authors.lastname: Wang
keywords: Human leukocyte antigen (HLA); loss of heterozygosity (LOH); microsatellite; thymic epithelial tumor (TET)