الفهرس 
B-CELL chrONIC LYMPHOCYTIC LEUKEMIAOnly 14 pages are availabe for public view
 |  | from | 233 |  |  |
| | | from | 233 | | |
Abstract
Although the pathogenesis of B-cell chronic lymphocytic leukemia remains largely unknown, several investigators have focused on the role of cytogenetic aberrations which may contribute to defective apoptosis, deregulation of cell cycle regulatory genes and expansion of the malignant clone.
Numerous studies aimed at determining reliable prognostic markers capable of predicting the progression and outcome of the disease, such as chromosomal analysis by conventional cytogenetics and interphase fluorescence in situ hybridization, CD38 expression, and examination of bone marrow infiltration pattern.
Therefore, our study aimed to evaluate the efficiency of conventional cytogenetic analysis (CCA) and fluorescence in situ hybridization (FISH) in detection of trisomy 12 in B-CLL using PB/BM samples and bone marrow trephine biopsy sections. Moreover, assessment of the impact of trisomy 12 on patient’s prognosis and disease outcome was done.
The present study included 30 B-CLL patients; 23 males and 7 females with male to female ratio of 3.3 : 1. Their ages ranged from 49 -71 years, with a mean of 58.5 ± 6.6.
Conventional cytogenetic analysis using G-banding yielded successful karyotyping in 24/30 (80%) of patients. Out of the 24 cases with successful mitosis, only 17/24 (70.8%) cases had chromosomal abnormalities. Trisomy 12 was detected in 3/24 (12.5%). 7/24 (29.2%) cases had del 13q14, 2/24 (8.3%) cases had del 6q and 1/24 (4.1%) of cases had isolated 11q23 rearrangement, 14q rearrangement, t(8;14) or del 17p.
In the current work, FISH analysis using CEP 12 probe, our data indicated that trisomy 12 was detected in 6/30 (20%) of patients when FISH was applied on their peripheral blood or bone marrow aspirates. Percent of the cases positive for trisomy 12 was increased to 7 (23%) when FISH was applied to their trephine sections.
Out of these positive cases, only three were compatible with the karyotypic analysis. The remaining 4 cases showed failed karyotyping, indicating the high efficiency, sensitivity and diagnostic accuracy achieved by applying the additional interphase cytogenetic approach. This also indicates that it was more useful and informative when applied on bone marrow sections than on peripheral blood samples or bone marrow aspirates.
In the present work, positive B-CLL cases for trisomy 12 were shown to be associated with known poor predicted prognosis as well as poor disease outcome. It was shown to be an independent prognostic factor.
In conclusion, trisomy 12 was associated with a proliferative, more aggressive disease and poor disease outcome. This emphasizes its importance as a chromosomal abnormality that can predict the behavior of the disease.
Moreover, trephine sections are good substitution for PB/BM samples for FISH application, yielding more accurate results.