Detection of the t(2;5)-associated NPM/ALK fusion cDNA in peripheral blood cells of healthy individuals

Br J Haematol. 1998 Dec;103(4):1138-44. doi: 10.1046/j.1365-2141.1998.01097.x.


The translocation t(2;5), which leads to the fusion of the nucleophosmin gene (NPM) on chromosome 5q35 to the receptor kinase ALK on chromosome 2p23, is found in CD30+ anaplastic large cell lymphomas and some cases of B-cell lymphoma. Hodgkin's disease (HD) is a malignant lymphoma characterized by large multinucleated tumour cells, Hodgkin and Reed-Sternberg (H&RS) cells, surrounded by a dense lymphohistiocytic infiltrate. Our group recently demonstrated NPM/ALK fusion cDNAs by single-cell RT-PCR in < 3% of CD30+ tumour cells in 2/9 cases of HD. To further delineate the relevance of this finding for HD, we studied the occurrence of NPM/ALK fusion genes in peripheral blood cells of healthy donors by RT-PCR. NPM/ALK fusion cDNAs were found by RT-PCR in 14/29 healthy individuals and confirmed by hybridization with a breakpoint-specific oligonucleotide. Due to the low rate of NPM/ALK-positive cells in the peripheral blood of positive individuals, an assignment to a defined cellular subpopulation was not possible. We conclude that NPM/ALK fusion genes are present in peripheral blood cells of healthy donors. After t(14;18) and t(9;22), t(2;5) represents the third example of tumour-associated translocation products in blood cells of apparently healthy donors. The implications of this finding are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Southern
  • Chromosomes, Human, Pair 2 / genetics*
  • Chromosomes, Human, Pair 5 / genetics*
  • DNA, Complementary / genetics*
  • Humans
  • Lymphocyte Subsets / chemistry
  • Lymphocytes / chemistry*
  • Protein-Tyrosine Kinases / genetics*
  • RNA, Messenger / genetics
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • Translocation, Genetic / genetics*


  • DNA, Complementary
  • RNA, Messenger
  • p80(NPM-ALK) protein
  • Protein-Tyrosine Kinases