Cloning and Gene Mapping of the Chromosome 13q14 Region Deleted in Chronic Lymphocytic Leukemia

Frequent deletions and loss of heterozygosity in a segment of chromosome 13 (13q14) in cases of B-cell chronic lymphocytic leukemia (CLL) have suggested that this malignancy is caused by inactivation of an unknown tumor suppressor gene located in this region. Toward the identification of the putative CLL tumor suppressor, we have constructed a high-resolution physical map of YAC, PAC, and cosmid contigs covering 600 kb of the 13q14 genomic region. In addition to densely positioned genetic markers and STSs, this map was further annotated by localization of 32 transcribed sequences (ESTs) using a combination of exon trapping, direct cDNA selection, sample sequencing of cosmids and PACs, and homology searches. On the basis of these mapping data, allelic loss analyses at 13q14 using CLL tumor samples allowed narrowing of the genomic segment encompassing the putative CLL gene to <300 kb. Twenty-three ESTs located within this minimally deleted region are candidate exons for the CLL-associated tumor suppressor gene.     

The Transcription Map of the 13q14 Region Frequently Deleted in B-cell Chronic Lymphocytic Leukemia

Deletions in the region located between the STS markers D13S1168 and D13S25 on chromosome 13 are the most frequent genomic changes in patients with B-cell chronic lymphocytic leukemia (B-CLL). After sequencing of this region, two novel candidate genes were identified: C13orf1(chromosome 13 open reading frame 1) and PLCC (putative large CLL candidate). Analysis of the repeat distribution revealed two subregions differing in composition of repetitious DNA and gene organization. The interval D13S1168–D13S319 contains 131 Alu repeats accounting for 24.8% of its length, whereas the interval GCT16C05–D13S25, which is no more than 180 kb away from the former one is extremely poor in Alu repeats (4.1% of the total length). Both intervals contain almost the same amount of the LINE-type repeats L1 and L2 (20.3 and 21.24%, respectively). In the chromosomal region studied, 29 Alu repeats were found to belong to the evolutionary young subfamily Y, which is still capable of amplifying. A considerable proportion of repeats of this type with similar nucleotide sequences may contribute to the recombinational activity of the chromosomal region 13q14.3, which is responsible for its rearrangements in some tumors in humans.     

Developing Molecular Signatures for Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is a clonal malignancy of mature B cells that displays a great clinical heterogeneity, with many patients having an indolent disease that will not require intervention for many years, while others present an aggressive and symptomatic leukemia requiring immediate treatment. Although there is no cure for CLL, the disease is treatable and current standard chemotherapy regimens have been shown to prolong survival. Recent advances in our understanding of the biology of CLL have led to the identification of numerous cellular and molecular markers with potential diagnostic, prognostic and therapeutic significance. We have used the recently developed digital multiplexed gene-expression technique (DMGE) to analyze a cohort of 30 CLL patients for the presence of specific genes with known diagnostic and prognostic potential. Starting from a set of 290 genes we were able to develop a molecular signature, based on the analysis of 13 genes, which allows distinguishing CLL from normal peripheral blood and from normal B cells, and a second signature based on 24 genes, which distinguishes mutated from unmutated cases (LymphCLL Mut). A third classifier (LymphCLL Diag), based on a 44-gene signature, distinguished CLL cases from a series of other B-cell chronic lymphoproliferative disorders (n = 51). While the methodology presented here has the potential to provide a "ready to use" classification tool in routine diagnostics and clinical trials, application to larger sample numbers are still needed and should provide further insights about its robustness and utility in clinical practice.     

A Low Frequency of Losses in 11q Chromosome Is Associated with Better Outcome and Lower Rate of Genomic Mutations in Patients with Chronic Lymphocytic Leukemia

To analyze the impact of the 11q deleted (11q-) cells in CLL patients on the time to first therapy (TFT) and overall survival (OS), 2,493 patients with CLL were studied. 242 patients (9.7%) had 11q-. Fluorescence in situ hybridization (FISH) studies showed a threshold of 40% of deleted cells to be optimal for showing that clinical differences in terms of TFT and OS within 11q- CLLs. In patients with ≥40% of losses in 11q (11q-H) (74%), the median TFT was 19 months compared with 44 months in CLL patients with <40% del(11q) (11q-L) (P<0.0001). In the multivariate analysis, only the presence of 11q-L, mutated IGHV status, early Binet stage and absence of extended lymphadenopathy were associated with longer TFT. Patients with 11q-H had an OS of 90 months, while in the 11q-L group the OS was not reached (P = 0.008). The absence of splenomegaly (P = 0.02), low LDH (P = 0.018) or β2M (P = 0.006), and the presence of 11q-L (P = 0.003) were associated with a longer OS. In addition, to detect the presence of mutations in the ATM, TP53, NOTCH1, SF3B1, MYD88, FBXW7, XPO1 and BIRC3 genes, a select cohort of CLL patients with losses in 11q was sequenced by next-generation sequencing of amplicons. Eighty % of CLLs with 11q- showed mutations and fewer patients with low frequencies of 11q- had mutations among genes examined (50% vs 94.1%, P = 0.023). In summary, CLL patients with <40% of 11q- had a long TFT and OS that could be associated with the presence of fewer mutated genes.     

A Case of Fatal Strongyloidiasis in a Patient with Chronic Lymphocytic Leukemia and Molecular Characterization of the Isolate

Strongyloides stercoralis is a human intestinal parasite which may lead to complicated strongyloidiasis in immunocompromised. Here, a case of complicated strongyloidiasis in a patient with chronic lymphocytic leukemia is reported. Presence of numerous S. stercoralis larvae in feces and sputum confirmed the diagnosis of hyperinfection syndrome in this patient. Following recovery of filariform larvae from agar plate culture of the stool, the isolate was characterized for the ITS1 region of ribosomal DNA gene by nested-PCR and sequencing. Albendazole therapy did not have cure effects; and just at the beginning of taking ivermectin, the patient died. The most important clue to prevent such fatal consequences is early diagnosis and proper treatment.     

High Mitochondrial DNA Stability in B-Cell Chronic Lymphocytic Leukemia

Background

Chronic Lymphocytic Leukemia (CLL) leads to progressive accumulation of lymphocytes in the blood, bone marrow, and lymphatic tissues. Previous findings have suggested that the mtDNA could play an important role in CLL.

Methodology/Principal Findings

The mitochondrial DNA (mtDNA) control-region was analyzed in lymphocyte cell DNA extracts and compared with their granulocyte counterpart extract of 146 patients suffering from B-Cell CLL; B-CLL (all recruited from the Basque country). Major efforts were undertaken to rule out methodological artefacts that would render a high false positive rate for mtDNA instabilities and thus lead to erroneous interpretation of sequence instabilities. Only twenty instabilities were finally confirmed, most of them affecting the homopolymeric stretch located in the second hypervariable segment (HVS-II) around position 310, which is well known to constitute an extreme mutational hotspot of length polymorphism, as these mutations are frequently observed in the general human population. A critical revision of the findings in previous studies indicates a lack of proper methodological standards, which eventually led to an overinterpretation of the role of the mtDNA in CLL tumorigenesis.

Conclusions/Significance

Our results suggest that mtDNA instability is not the primary causal factor in B-CLL. A secondary role of mtDNA mutations cannot be fully ruled out under the hypothesis that the progressive accumulation of mtDNA instabilities could finally contribute to the tumoral process. Recommendations are given that would help to minimize erroneous interpretation of sequencing results in mtDNA studies in tumorigenesis.     

CD11c在慢性淋巴细胞白血病诊断中的意义

目的:探讨CD11c抗原在慢性淋巴细胞白血病(chronic lymphocytic leukemia,CLL)中的表达及在临床诊断中的价值,以及CD11c抗原表达与患者的遗传学异常及预后参数的相关性。方法:采用多参数流式细胞术(flow cytometry,FCM)检测200例CLL患者、49例套细胞淋巴瘤(mantle cell lymphoma,MCL)患者CD11c的表达率和平均荧光强度(mean fluorescence intensity,MFI);并比较CLL患者CD11c的表达与预后参数ZAP-70和CD38表达的关系;同时采用荧光原位杂交(fluorescence in situ hybridization,FISH)技术检测CLL患者的P53缺失、13q14缺失、ATM缺失、6q23缺失、+12以及IGH重排,比较CD11c~+CLL患者与CD11c~-CLL患者遗传学特点。结果:CLL患者中CD11c阳性率为49.5%(99/200),MFI中位值为2.06(1.00～7.34);而MCL患者中CD11c阳性率为6.12%(3/49),MFI中位值为2.00(1.97～2.54)。CD11c在CLL中的表达率明显高于MCL,(x~2=30.62,P0.05)。CD11c~+CLL患者的ZAP-70和CD38阳性率均明显高于CD11c~-CLL患者(x~2=15.472,P0.05;x~2=11.556,P0.05),差异有统计学意义。而CLL患者的CD11c表达率与P53缺失、13q14缺失、ATM缺失、6q23缺失、+12、IGH重排的结果均无统计学差异。结论:CD11c对于辅助诊断CLL有重要价值,尤其有助于CLL和MCL的诊断和鉴别诊断。     

Trisomy 13 with a 13q14q translocation.

A sporadic case of Patau syndrome with 46,XY,14-,t(13q14q)+ karyotype is reported in a 2-month-old child. Dermatoglyphic and cytogenetic findings of the propositus and cytogenetic study of his parents are presented.     

Clustering of Expression Data in Chronic Lymphocytic Leukemia Reveals New Molecular Subdivisions

Although the identification of inherent structure in chronic lymphocytic leukemia (CLL) gene expression data using class discovery approaches has not been extensively explored, the natural clustering of patient samples can reveal molecular subdivisions that have biological and clinical implications. To explore this, we preprocessed raw gene expression data from two published studies, combined the data to increase the statistical power, and performed unsupervised clustering analysis. The clustering analysis was replicated in 4 independent cohorts. To assess the biological significance of the resultant clusters, we evaluated their prognostic value and identified cluster-specific markers. The clustering analysis revealed two robust and stable subgroups of CLL patients in the pooled dataset. The subgroups were confirmed by different methodological approaches (non-negative matrix factorization NMF clustering and hierarchical clustering) and validated in different cohorts. The subdivisions were related with differential clinical outcomes and markers associated with the microenvironment and the MAPK and BCR signaling pathways. It was also found that the cluster markers were independent of the immunoglobulin heavy chain variable (IGVH) genes mutational status. These findings suggest that the microenvironment can influence the clinical behavior of CLL, contributing to prognostic differences. The workflow followed here provides a new perspective on differences in prognosis and highlights new markers that should be explored in this context.     

High Viral Loads of Epstein-Barr Virus DNA in Peripheral Blood of Patients with Chronic Lymphocytic Leukemia Associated with Unfavorable Prognosis

Epstein-Barr virus (EBV) is a ubiquitous γ-herpesvirus that infects more than 90% of the world population. The potential involvement of EBV in the clinical course of chronic lymphocytic leukemia (CLL) remains unexplained. The aim of this study was to determine whether EBV-DNA load in the peripheral blood mononuclear cells (PBMCs) of CLL patients may influence heterogeneity in the course of the disease. The study included peripheral blood samples from 115 previously untreated patients with CLL (54 women and 61 men) and 40 healthy controls (16 women and 24 men). We analyzed the association between the EBV-DNA load in PBMCs and the stage of the disease, adverse prognostic factors, and clinical outcome. Detectable numbers of EBV-DNA copies in PBMCs were found in 62 out of 115 CLL patients (53.91%). The EBV-DNA copy number/μg DNA was significantly higher in patients who required early implementation of treatment, presented with lymphocyte count doubling time <12 months, displayed CD38-positive or ZAP-70-positive phenotype, and with the del(11q22.3) cytogenetic abnormality. Furthermore, the EBV-DNA copy number/μg DNA showed significant positive correlation with the concentrations of lactate dehydrogenase (LDH) and beta-2-microglobulin. We have shown that in CLL patients, higher EBV-DNA copy number predicted shorter survival and shorter time to disease progression, and it was associated with other established unfavorable prognostic factors. This suggests that EBV may negatively affect the outcome of CLL.     

A Molecular Score by Quantitative PCR as a New Prognostic Tool at Diagnosis for Chronic Lymphocytic Leukemia Patients

Background

Several markers have been proposed to predict the outcome of chronic lymphocytic leukemia (CLL) patients. However, discordances exist between the current prognostic factors, indicating that none of these factors are totally perfect.

Methodology/Principal Findings

Here, we compared the prognostic power of new RNA-based markers in order to construct a quantitative PCR (qPCR) score composed of the most powerful factors. ZAP70, LPL, CLLU1, microRNA-29c and microRNA-223 were measured by real time PCR in a cohort of 170 patients with a median follow-up of 64 months (range3-330). For each patient, cells were obtained at diagnosis and RNA was extracted from purified CD19 cells. The best markers were included in a qPCR score, which was thereafter compared to each individual factor. Statistical analysis showed that all five RNA-based markers can predict treatment-free survival (TFS), but only ZAP70, LPL and microRNA-29c could significantly predict overall survival (OS). These three markers were thus included in a simple qPCR score that was able to significantly predict TFS and OS by dividing patients into three groups (0/3, 1-2/3 and 3/3). Median TFS were >210, 61 and 24 months (P<0.0001) and median OS were >330, 242 and 137 months (P<0.0001), respectively. Interestingly, TFS results were also confirmed in Binet stage A patients (P<0.0001). When compared to other classical factors, this score displays the highest univariate Cox hazard ratio (TFS: HR = 9.45 and OS: HR = 13.88) but also provides additional prognostic information.

Conclusions

In our hands, this score is the most powerful tool for CLL risk stratification at the time of diagnosis.     

Deoxyribonucleic Acid Polymerase Activity Associated with a Plasma Particulate Fraction from Patients with Chronic Lymphocytic Leukemia

Plasma from two cases of chronic lymphocytic leukemia have been examined for deoxyribonucleic acid (DNA) polymerase activity. In both cases, detectable enzyme activity was present. In the plasma from a patient known to have chronic lymphocytic leukemia for 10 years, the enzyme activity was sufficiently high to study product formation, buoyant density of the enzyme activity, deoxyribonucleoside triphosphate requirements, and kinetics of DNA synthesis. These studies are presented in this report.     

The Pathogenesis of Chronic Lymphocytic Leukemia

The pathogenesis of chronic lymphocytic leukemia was examined in a series of 88 cases observed during a 15-year period. In untreated cases the trend of the absolute lymphocyte counts followed two main patterns. In the type I trend, the counts rose throughout the observation period; in the type II trend, the tendency to rise ceased and the counts stabilized above and below a mean value, the stationary trend being maintained for months or years. The type II trend was associated with relatively benign disease. The development of lymphocytosis was correlated with the progression of lymphadenopathy. It is suggested that lymphocytosis may result from the physiological process of recirculation and that the accumulation of lymphocytes may result from the proliferation of a single slightly abnormal cell-line. The abnormal cells might survive an unusually long time because they are unable to respond to stimuli which cause normal lymphocytes to transform.     

Chronic Lymphocytic Leukemia Patients Have a Preserved Cytomegalovirus-Specific Antibody Response despite Progressive Hypogammaglobulinemia

Chronic lymphocytic leukemia (CLL) is characterized by progressive hypogammaglobulinemia predisposing affected patients to a variety of infectious diseases but paradoxically not to cytomegalovirus (CMV) disease. Moreover, we found reactivity of a panel of CLL recombinant antibodies (CLL-rAbs) encoded by a germ-line allele with a single CMV protein, pUL32, despite differing antibody binding motifs. To put these findings into perspective, we studied prospectively relative frequency of viremia, kinetics of total and virus-specific IgG over time, and UL32 genetic variation in a cohort of therapy-naive patients (n=200). CMV-DNA was detected in 3% (6/200) of patients. The decay of total IgG was uniform (mean, 0.03; SD, 0.03) and correlated with that of IgG subclasses 1-4 in the paired samples available (n=64; p<0.001). Total CMV-specific IgG kinetics were more variable (mean, 0,02; SD, 0,06) and mean decay values differed significantly from those of total IgG (p=0.034). Boosts of CMV-specific antibody levels were observed in 49% (22/45) of CMV-seropositive patients. In contrast, VZV- and EBV-specific IgG levels decayed in parallel with total IgG levels (p=0.003 and p=0.001, respectively). VZV-specific IgG even became undetectable in 18% (9/50) of patients whereas CMV-specific ones remained detectable in all seropositive patients. The observed CMV-specific IgG kinetics were predicated upon the highly divergent kinetics of IgG specific for individual antigens - glycoprotein B-specific IgG were boosted in 51% and pUL32-specific IgG in 32% of patients. In conclusion, CLL patients have a preserved CMV-specific antibody response despite progressive decay of total IgG and IgG subclasses. CMV-specific IgG levels are frequently boosted in contrast to that of other herpesviruses indicative of a higher rate of CMV reactivation and antigen-presentation. In contrast to the reactivity of multiple different CLL-rAbs with pUL32, boosts of humoral immunity are triggered apparently by other CMV antigens than pUL32, like glycoprotein B.     

Chronic Lymphocytic Leukemia Cells in a Lymph Node Microenvironment Depict Molecular Signature Associated with an Aggressive Disease

Chronic lymphocytic leukemia (CLL) cells survive longer in vivo than in vitro, suggesting that the tissue microenvironment provides prosurvival signals to tumor cells. Primary and secondary lymphoid tissues are involved in the pathogenesis of CLL, and the role of these tissue microenvironments has not been explored completely. To elucidate host–tumor interactions, we performed gene expression profiling (GEP) of purified CLL cells from peripheral blood (PB; n = 20), bone marrow (BM; n = 18), and lymph node (LN; n = 15) and validated key pathway genes by real-time polymerase chain reaction, immunohistochemistry and/or TCL1 trans-genic mice. Gene signatures representing several pathways critical for survival and activation of B cells were altered in CLL cells from different tissue compartments. Molecules associated with the B-cell receptor (BCR), B cell–activating factor/a proliferation-inducing ligand (BAFF/APRIL), nuclear factor (NF)-κB pathway and immune suppression signature were enriched in LN-CLL, suggesting LNs as the primary site for tumor growth. Immune suppression genes may help LN-CLL cells to modulate antigen-presenting and T-cell behavior to suppress antitumor activity. PB CLL cells overexpressed chemokine receptors, and their cognate ligands were enriched in LN and BM, suggesting that a chemokine gradient instructs B cells to migrate toward LN or BM. Of several chemokine ligands, the expression of CCL3 was associated with poor prognostic factors. The BM gene signature was enriched with antiapoptotic, cytoskeleton and adhesion molecules. Interestingly, PB cells from lymphadenopathy patients shared GEP with LN cells. In Eμ-TCL1 transgenic mice (the mouse model of the disease), a high percentage of leukemic cells from the lymphoid compartment express key BCR and NF-κB molecules. Together, our findings demonstrate that the lymphoid microenvironment promotes survival, proliferation and progression of CLL cells via chronic activation of BCR, BAFF/APRIL and NF-κB activation while suppressing the immune response.     

Spontaneous Immunity Against the Receptor Tyrosine Kinase ROR1 in Patients with Chronic Lymphocytic Leukemia

Background

ROR1 is a receptor tyrosine kinase expressed in chronic lymphocytic leukemia (CLL) and several other malignancies but absent in most adult normal tissues. ROR1 is considered an onco-fetal antigen. In the present study we analysed spontaneous humoral and cellular immunity against ROR1 in CLL patients.

Materials and Methods

Antibodies against ROR1 were analysed in 23 patients and 20 healthy donors by ELISA and Western blot. Purified serum IgG from patients was tested for cytotoxicity against CLL cells using the MTT viability assay. A cellular immune response against ROR1 derived HLA-A2 restricted 9 aa and 16 aa long peptides were analysed using peptide loaded dendritic cells co-cultured with autologous T cells from CLL patients (n = 9) and healthy donors (n = 6). IFN-γ, IL-5 and IL-17A-secreting T cells were assessed by ELISPOT and a proliferative response using a H3-thymidine incorporation assay.

Results

The majority of CLL patients had antibodies against ROR1. Significantly higher titers of anti-ROR1 antibodies were noted in patients with non-progressive as compared to progressive disease. The extracellular membrane-close ROR1 KNG domain seemed to be an immunodominant epitope. Ten patients with high titers of anti-ROR1 binding antibodies were tested for cytotoxicity. Five of those had cytotoxic anti-ROR1 antibodies against CLL cells. ROR1-specific IFN-γ and IL-17A producing T cells could be detected in CLL patients, preferentially in non-progressive as compared to patients with progressive disease (p<0.05).

Conclusion

ROR1 seemed to spontaneously induce a humoral as well as a T cell response in CLL patients. The data support the notion that ROR1 might be a specific neo-antigen and may serve as a target for immunotherapy.     

聚焦慢性淋巴细胞白血病治疗药物

过去的10 年,慢性淋巴细胞白血病（CLL）的治疗策略已发生变化,其疗法已有长足进展,即从仅可治标性缓解病痛发展到能致病情完全缓解、最大限度根除疾患和提高存活率。Rituxan（rituximab）的开发及其在免疫化疗中的应用使抗CLL 疗法发生了改变,该药已成为目前用于小于65 岁患者的黄金标准治疗药物。然而,基于Rituxan 的免疫化疗仍仅局限用于两类常见CLL 病例——老年患者和具并发症及高危患者的治疗。再者,在为期两年的一线和二线治疗中,约有25% 和50% 的CLL 患者会复发,且已有数年缓解的患者对后续治疗的疗效较差。因此,对于CLL 的治疗,仍远不能满足需求。早期研究发现,B 细胞受体（BCR）信号通路与CLL 的发生和发展以及治疗后的高反应率与病情持续缓解有关联。鉴于此,靶向BCR信号通路的小分子药物得以快速发展。Imbruvic（ibrutinib）是首个口服Bruton 酪氨酸激酶（BTK）抑制剂,近期经快速审批上市,用于治疗复发/ 顽固性恶性淋巴瘤,但其长期生存率数据目前尚不成熟。眼下,新疗法面临着多个挑战：其需提供更高的反应率,特别是对老年患者和具并发症及高危患者,且需克服当前疗法造成的耐药性。目前,唯一的CLL 根治疗法是同种异体造血干细胞移植（HSCT）,但其并不适用于大多数CLL 患者。而目前CLL 的标准治疗方案是化学免疫疗法,适用于小于65 岁的患者,但老龄或高危患者的治疗选择是有限的。因此,最终的问题是针对CLL 的小分子疗法是否能达到根治目的,期望随着在鉴定与CLL 发病机制和预后相关的细胞遗传学及分子变化方面取得进展,能促进下一代靶向疗法的快速发展。新型靶向性小分子抑制剂,如Imbruvica 和idelablisib,已展现出对CLL 的显著治疗作用。综述CLL 治疗领域重大行业投资和研发的主要市场博弈者和交易亮点。     

Opposite Prognostic Significance of Cellular and Serum Circulating MicroRNA-150 in Patients with Chronic Lymphocytic Leukemia

MicroRNAs (or miRs) play a crucial role in chronic lymphocytic leukemia (CLL) physiopathology and prognosis. In addition, circulating microRNAs in body fluids have been proposed as new biomarkers. We investigated the expression of matched cellular and serum circulating microRNA-150 by quantitative real-time PCR (qPCR) from purified CD19⁺ cells or from CLL serums obtained at diagnosis in a cohort of 273/252 CLL patients with a median follow-up of 78 months (range 7–380) and correlated it to other biological or clinical parameters. We showed that miR-150 was significantly overexpressed in CLL cells/serums compared with healthy subjects (P < 0.0001). Among CLL patients, a low cellular miR-150 expression level was associated with tumor burden, disease aggressiveness and poor prognostic factors. In contrast, a high level of serum miR-150 was associated with tumor burden markers and some markers of poor prognosis. Similarly, cellular and serum miR-150 also predicted treatment-free survival (TFS) and overall survival (OS) in an opposite manner: patients with low cellular/serum miR-150 levels have median TFS of 40/111 months compared with high-level patients who have a median TFS of 122/60 months (P < 0.0001/P = 0.0066). Similar results were observed for OS. We also found that cellular and serum miR-150 levels vary in an opposite manner during disease progression and that cellular miR-150 could be regulated by its release into the extracellular space. Cellular and serum levels of miR-150 are associated with opposite clinical prognoses and could be used to molecularly monitor disease evolution as a new prognostic factor in CLL.     

Lipoprotein Lipase SNPs rs13702 and rs301 Correlate with Clinical Outcome in Chronic Lymphocytic Leukemia Patients

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western world and is characterized by a heterogeneous clinical course. This variability in clinical course has spiked the search for prognostic markers able to predict patient evolution at the moment of diagnosis. Markers demonstrated to be of value are the mutation status of the immunoglobulin heavy chain variable region genes (IGHV) and lipoprotein lipase (LPL) expression. High LPL mRNA expression has been associated with short treatment free (TFS) and decreased overall survival (OS) in CLL. The LPL SNPs rs301 (T<C), rs328 (C<G) and rs13702 (T<C) have been associated with various metabolic disorders, but the association with CLL evolution is unknown. Here, in a cohort of 248 patients, we show that patients with the LPL SNP rs13702 wild-type T/T genotype had significantly shorter OS than patients with C/C and T/C genotypes (median time until CLL related death: 90 and 156 months respectively, p=0.008). The same was observed for LPL SNP rs301 (median time until CLL related death T/T: 102 and C/C, T/C: 144 months, p=0.03). Both SNPs rs301 and rs13702 were significantly associated with each other and notably, no association was found between IGHV status and presence of the SNP genotypes, indicating that these LPL SNPs are reliable prognostic markers that could add extra prognostic and predictive information to classical markers and help to improve the management of CLL.     

Clinical and Molecular Characterization of Patients with Distal 11q Deletions

Jacobsen syndrome is caused by segmental aneusomy for the distal end of the long arm of chromosome 11. Typical features include mild to moderate psychomotor retardation, trigonocephaly, facial dysmorphism, cardiac defects, and thrombocytopenia, though none of these features are invariably present. To define the critical regions responsible for these abnormalities, we studied 17 individuals with de novo terminal deletions of 11q. The patients were characterized in a loss-of-heterozygosity analysis using polymorphic dinucleotide repeats. The breakpoints in the complete two-generation families were localized with an average resolution of 3.9 cM. Eight patients with the largest deletions extending from 11q23.3 to 11qter have breakpoints, between D11S924 and D11S1341. This cytogenetic region accounts for the majority of 11q⁻ patients and may be related to the FRA11B fragile site in 11q23.3. One patient with a small terminal deletion distal to D11S1351 had facial dysmorphism, cardiac defects, and thrombocytopenia, suggesting that the genes responsible for these features may lie distal to D11S1351. Twelve of 15 patients with deletion breakpoints as far distal as D11S1345 had trigonocephaly, while patients with deletions distal to D11S912 did not, suggesting that, if hemizygosity for a single gene is responsible for this dysmorphic feature, the gene may lie distal to D11S1345 and proximal to D11S912.