Detection of the t(14;18) chromosomal translocation by interphase cytogenetics with yeast-artificial-chromosome probes in follicular lymphoma and nonneoplastic lymphoproliferation.
OBJECTIVE
The aim of this study was to establish a fluorescence in situ hybridization (FISH) technique for the detection of t(14;18)(q32;q21), characteristic for follicular lymphoma (Kiel classification: centroblastic centrocytic [cb-cc] lymphoma).


METHODS
After the FISH system had been established, parallel studies of lymph node biopsy specimens from 30 patients with cb-cc lymphoma and from 32 patients with nonneoplastic lymphoproliferation were performed by means of chromosome analysis, polymerase chain reaction (PCR), and FISH analysis. Two differently labeled yeast-artificial-chromosome (YAC) probes that contained the entire bcl-2 gene and the C-region of the immunoglobulin H (IgH) gene, respectively, were used to detect t(14;18) by FISH.


RESULTS
The presence of the translocation is indicated by a red (Cy3)/green (fluorescien isothiocyanate [FITC]) double signal, which corresponds to the IgH/bcl-2 fusion gene, whereas in normal cells the signals are separate. Control studies showed that the double signal is visible in less than 1% of normal cells. FISH analysis was able to identify the t(14;18) in all cases of cb-cc lymphoma we studied. All bcl-2 breakpoints can be detected. Combined immunophenotyping and interphase cytogenetics demonstrated that t(14;18) was restricted to CD22+ B lymphocytes and never occurred in CD3+ T lymphocytes. In four of 32 cases of nonneoplastic lymphoproliferation, t(14;18) was also detected.


CONCLUSIONS
FISH turned out to be the most sensitive method to detect t(14;18). Our FISH results confirm PCR data from other groups that found evidence for the presence of t(14;18) in nonneoplastic lymphoproliferation. It needs to be determined whether, in morphologically nonneoplastic processes, t(14;18) is associated with an increased risk for the development of non-Hodgkin's lymphoma.
Poetsch
M
M
Department of Human Genetics, University of Kiel, Germany.
Weber-Matthiesen
K
K
Plendl
H J
HJ
Grote
W
W
Schlegelberger
B
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes; D018244:Chromosomes, Artificial, Yeast / Q000235:genetics*; D002883:Chromosomes, Human, Pair 14 / Q000235:genetics*; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D015342:DNA Probes / Q000235:genetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007399:Interphase; D008224:Lymphoma, Follicular / Q000235:genetics* / Q000473:pathology; D008232:Lymphoproliferative Disorders / Q000235:genetics; D008297:Male; D008875:Middle Aged; D014178:Translocation, Genetic / Q000235:genetics*
D015342:DNA Probes