Frequent deletions at 11q23 and 13q14 in B cell prolymphocytic leukemia (B-PLL)

Abstract

Deletions of the long arm of chromosomes 11 and 13 are the most frequent structural chromosome aberrations in various types of lymphoproliferative disorders. However, these regions have not been studied so far in B cell prolymphocytic leukemia (B-PLL). We have investigated the incidence of 13q deletions in 18 B-PLL cases by fluorescence in situ hybridization (FISH), using molecular probes for the RB1 and D13S25 loci. Chromosome 11q deletions were evaluated by FISH using the yeast artificial chromosome (YAC) clone 755b11 from the chromosome 11q22.3-q23.1 region, which has been previously shown to be deleted in 20% of cases of chronic lymphocytic leukemia. Chromosome 11q23 deletions were found in 7/18 (39%) cases of B-PLL. Monoallelic loss of RB1, D13S25 and BRCA2 was present in 10/18 (55%), 6/18 (33%) and 3/18 (16%) of the cases, respectively. All the cases with D13S25 and BRCA2 deletion showed RB1 loss. Deletions of 13q14 and 11q23 are frequent chromosome aberrations in B-PLL and, in contrast to CLL, there is a preferential loss of RB1 with respect to the D13S25 locus suggesting that allelic loss of the RB1 gene may play a role in the pathogenesis of B-PLL. Leukemia (2000) 14, 427-430.

Surface antigen expression in chronic lymphocytic leukemia: clustering analysis, interrelationships and effects of chromosomal abnormalities

“…It is interesting to note that 11q23 deletion is also frequent in B cell prolymphocytic leukemia, which ususally has a fast progression. 36 A recent cDNA mRNA profiling analysis from this same patient cohort revealed some interesting gene expression patterns concerning CD14, CD25, CD79b. 37 CD25 mRNA was upregulated in 11q deletion patients.…”

Proliferation-dependent expression and phosphorylation of pRB in B cell non-Hodgkin's lymphomas: dependence on RB1 copy number

“…Studies of the 13q14 deletions in lymphoid neoplasia have indicated that RB1 may not be the affected gene in B cell NHL, 7,9 however, this situation may be different in other haematological neoplasms. 46,47 If the RB1 gene was the main target in the cases with 13q14…”

How I treat prolymphocytic leukemia

“…Only a few cytogenetic studies have been reported in B-PLL because of the rarity of the disease and the difficulty of obtaining prolymphocytes in metaphase. [50][51][52][53] Use of B-cell mitogens might increase the detection rate of cytogenetic changes. Complex karyotypic changes are common.…”

“…Using interphase FISH, 13q14 deletions, 17p deletions, and monoallelic 11q23 deletions can be identified, but trisomy 12 is rare. 51 Other abnormalities described include 6qϪ, t(6;12), and structural aberrations of 1p and 1q. 50 Although t(11;14) has previously been described in B-PLL, it is clear now that these cases represent a leukemic phase of MCL, for which this is the "hallmark" translocation.…”