Monoclonal B cell lymphocytosis (MBL) is a hematologic condition wherein small B cell clones can be detected in the blood of asymptomatic individuals. Most MBL have an immunophenotype similar to chronic lymphocytic leukemia (CLL), and “CLL-like” MBL is a precursor to CLL. We used flow cytometry to identify MBL from unaffected members of CLL kindreds. We identified 101 MBL cases from 622 study subjects; of these, 82 individuals with MBL were further characterized. Ninety-one unique MBL clones were detected: 73 CLL-like MBL (CD5+CD20dimsIgdim), 11 atypical MBL (CD5+CD20+sIg+), and 7 CD5neg MBL (CD5negCD20+sIgneg). Extended immunophenotypic characterization of these MBL subtypes was performed, and significant differences in cell surface expression of CD23, CD49d, CD79b, and FMC-7 were observed among the groups. Markers of risk in CLL such as CD38, ZAP70, and CD49d were infrequently expressed in CLL-like MBL, but were expressed in the majority of atypical MBL. Interphase cytogenetics was performed in 35 MBL cases, and del 13q14 was most common (22/30 CLL-like MBL cases). Gene expression analysis using oligonucleotide arrays was performed on 7 CLL-like MBL, and showed activation of B cell receptor associated pathways. Our findings underscore the diversity of MBL subtypes and further clarify the relationship between MBL and other lymphoproliferative disorders.
There is strong and consistent evidence that a genetic component contributes to the etiology of chronic lymphocytic leukemia (CLL). A recent genome-wide association study (GWAS) of CLL identified 7 genetic variants that increased the risk of CLL within a European population.
We evaluated the association of these variants, or variants in linkage disequilibrium (LD) with these variants, with CLL risk in an independent sample of 438 CLL cases and 328 controls.
Of these 7 SNPs, 6 had p-trend < 0.05 and had estimated odds ratios (ORs) that were strikingly comparable to those of the previous study. Associations were seen for rs9378805 (OR = 1.47, 95% CI: 1.19, 1.80, p-trend = 0.0003) near IRF4 and rs735665 near GRAMD1B (OR= 1.47; 95% CI: 1.14, 1.89; p-trend = 0.003). However, no associations (P> 0.05) were found for rs11083846, nor were any found for any SNPs in LD with rs11083846.
Our results confirm the previous findings and further support the role of a genetic basis in the etiology of CLL; however, more research is needed to elucidate the causal SNP(s) and the potential manner in which these SNPs or linked SNPs function in CLL pathogenesis.
IRF4; CLL; genetic association
Monoclonal B-cell lymphocytosis (MBL) is an asymptomatic haematological condition characterized by low absolute levels of B-cell clones with a surface immunophenotype similar to that of chronic lymphocytic leukaemia (CLL). In the general population, MBL increases with age with a prevalence of 5–9% in individuals over age 60 years. It has been reported to be higher among first-degree relatives from CLL families. We report results of multi-parameter flow cytometry among 505 first-degree relatives with no personal history of lymphoproliferative disease from 140 families having at least two cases of CLL. Seventeen percent of relatives had MBL. Age was the most important determinant where the probability for developing MBL by age 90 years was 61%. MBL clustered in certain families but clustering was independent of the number of known CLL cases in a family. As is the case with CLL, males had a significantly higher risk for MBL than did females (p=0.04). MBL patients had significantly higher mean absolute lymphocyte counts (2.4 × 109/l) and B-cell counts (0.53 × 109/l) than those with a normal B-cell immunophenotype. Our findings show that MBL occurs at a very high rate in high risk CLL families. Both the age and gender distribution of MBL are parallel to CLL, implying a shared inherited risk.
chronic lymphocytic leukaemia; high risk families; monoclonal B-cell lymphocytosis; flow cytometry
A recent meta-analysis of three genome-wide association studies of chronic lymphocytic leukaemia (CLL) identified two common variants at the 6p21.31 locus that are associated with CLL risk. To verify and further explore the association of these variants with other non-Hodgkin lymphoma (NHL) subtypes, we genotyped 1196 CLL cases, 1699 NHL cases, and 2410 controls. We found significant associations between the 6p21.31 variants and CLL risk (rs210134: P=0.01; rs210142: P=6.8×10−3). These variants also showed a trend towards association with some of the other NHL subtypes. Our results validate the prior work and support specific genetic pathways for risk among NHL subtypes.
CLL; NHL; SNPs; BAK1; risk locus
Patients with CLL have a variable clinical course. Identification of modifiable characteristics related to CLL-specific survival may provide opportunities for therapeutic intervention. The absolute number of T-cell and natural kill(NK)-cells was calculated for 166 consecutive patients with CLL evaluated by flow cytometry at Mayo Clinic <2 months of diagnosis. The size of the T-cell/NK-cell compartment relative to the size of the malignant monoclonal B-cell(MBC) compartment was evaluated by calculating NK:MBC and T:MBC ratios. Patients exhibited substantial variation in the absolute number of T and NK-cells as well as T:MBC and NK:MBC ratios at diagnosis. Higher T:MBC and NK:MBC ratios were observed among patients with early stage and mutated IgVH genes(all P<0.0003). As continuous variables, both T:MBC ratio(p value=0.03) and NK:MBC ratio(p value=0.02) were associated with time to treatment(TTT). On multivariate Cox modeling including stage, CD38, absolute MBC count, NK:MBC ratio, and T:MBC ratio, the independent predictors of TTT were stage, T:MBC ratio, and NK:MBC ratio. These findings suggest measurable characteristics of the host immune system relate to the rate of disease progression in patients with newly diagnosed CLL. These characteristics can be modified and continued evaluation of immunomodulatory drugs, vaccination strategies, and cellular therapies to delay/prevent disease progression are warranted.
CLL; prognosis; immune system; T-cells; natural killer cells
Non-Hodgkin lymphoma (NHL) is a malignancy of lymphocytes, and there is growing evidence for a role of germline genetic variation in immune genes in NHL etiology.
To identify susceptibility immune genes, we conducted a 2-stage analysis of single nucleotide polymorphisms (SNPs) from 1,253 genes using the Immune and Inflammation Panel. In Stage 1, we genotyped 7,670 SNPs in 425 NHL cases and 465 controls, and in Stage 2 we genotyped the top 768 SNPs on an additional 584 cases and 768 controls. The association of individual SNPs with NHL risk from a log-additive model was assessed using the Odds Ratios (ORs) and 95% confidence intervals (CI).
In the pooled analysis, only the TAP2 coding SNP rs241447 (MAF=0.26; Thr655Ala) at 6p21.3 (OR=1.34, 95%CI 1.17-1.53) achieved statistical significance after accounting for multiple testing (p=3.1 × 10−5). The TAP2 SNP was strongly associated with follicular lymphoma (FL, OR=1.82, 95%CI 1.46-2.26; p=6.9 × 10−8), and was independent of other known loci (rs10484561 and rs2647012) from this region. The TAP2 SNP was also associated with diffuse large B-cell lymphoma (DLBCL, OR=1.38, 95% CI 1.08-1.77; p=0.011), but not chronic lymphocytic leukemia (OR=1.08; 95% CI 0.88-1.32). Higher TAP2 expression was associated with the risk allele in both FL and DLBCL tumors.
Genetic variation in TAP2 was associated with NHL risk overall, and FL risk in particular, and this was independent of other established loci from 6p21.3.
Genetic variation in antigen presentation of HLA class I molecules may play a role in lymphomagenesis.
genetics; non-Hodgkin lymphoma; immune function; single nucleotide polymorphisms
Five laboratories in the Chronic Lymphocytic Leukemia (CLL) Research Consortium (CRC) investigated standardizing and pooling of fluorescence in situ hybridization (FISH) results as a collaborative research project. This investigation used fixed bone marrow and blood cells available from previous conventional cytogenetic or FISH studies in two pilot studies, a one-day workshop, and proficiency test. Multiple FISH probe strategies were used to detect 6q-, 11q-, +12, 13q-, 17p-, and IGH rearrangements. Ten specimens were studied by participants who used their own probes (pilot study 1). Of 312 FISH interpretations, 224 (72%) were true-negative, 74 (24%) true-positive, 6 (2%) false-negative, and 8 (3%) false-positive. In pilot study no. 2, each participant studied two specimens using identical FISH probe sets to control for variation due to probe sets and probe strategies. Of 80 FISH interpretations, no false interpretations were identified. At a subsequent workshop, discussions produced agreement on scoring criteria. The proficiency test that followed produced no false-negative results and 4% (3/68) false-positive interpretations. Interpretation disagreements among laboratories were primarily attributable to inadequate normal cutoffs, inconsistent scoring criteria, and the use of different FISH probe strategies. Collaborative organizations that use pooled FISH results may wish to impose more conservative empiric normal cutoff values or use an equivocal range between the normal cutoff and the abnormal reference range to eliminate false-positive interpretations. False-negative results will still occur, and would be expected in low-percentage positive cases; these would likely have less clinical significance than false positive results. Individual laboratories can help by closely following rigorous quality assurance guidelines to ensure accurate and consistent FISH studies in their clinical practice and research.
Increased ZAP-70 expression predicts poor prognosis in chronic lymphocytic leukemia (CLL). Current methods for accurately measuring ZAP-70 expression are problematic, preventing widespread application of these tests in clinical decision making. We therefore used comprehensive DNA methylation profiling of the ZAP-70 regulatory region to identify sites important for transcriptional control.
Patients and Methods
High-resolution quantitative DNA methylation analysis of the entire ZAP-70 gene regulatory regions was conducted on 247 samples from patients with CLL from four independent clinical studies.
Through this comprehensive analysis, we identified a small area in the 5′ regulatory region of ZAP-70 that showed large variability in methylation in CLL samples but was universally methylated in normal B cells. High correlation with mRNA and protein expression, as well as activity in promoter reporter assays, revealed that within this differentially methylated region, a single CpG dinucleotide and neighboring nucleotides are particularly important in ZAP-70 transcriptional regulation. Furthermore, by using clustering approaches, we identified a prognostic role for this site in four independent data sets of patients with CLL using time to treatment, progression-free survival, and overall survival as clinical end points.
Comprehensive quantitative DNA methylation analysis of the ZAP-70 gene in CLL identified important regions responsible for transcriptional regulation. In addition, loss of methylation at a specific single CpG dinucleotide in the ZAP-70 5′ regulatory sequence is a highly predictive and reproducible biomarker of poor prognosis in this disease. This work demonstrates the feasibility of using quantitative specific ZAP-70 methylation analysis as a relevant clinically applicable prognostic test in CLL.
We have shown that the combination of pentostatin (P), cyclophosphamide (C) and rituximab (R) achieves an overall response (OR) rate >90% with more than 40% complete responses (CR) in patients with untreated CLL. To evaluate if the tolerability of this regimen could be enhanced without sacrificing efficacy, we conducted a phase II trial of P and R without cyclophosphamide, using a higher P dose (4 mg/m2). Among the 33 patients enrolled, 82% were male, median age was 65 (9 patients ≥70 years) and 64% were Rai stage III-IV. The OR rate was 76% with 9 CR (27%), 5 nPR, and 11 PRs. At the time of this analysis, 29/33 patients are still alive and the median follow up for patients still alive is 14 months (range: 1-34.8 months). Four (12%) patients experienced grade 3 or higher hematologic toxicity and 5 (15%) experienced grade 3 or higher non-hematologic toxicity. Comparison of this trial to our previous PCR trial showed that patients treated with PCR had a higher OR rate (91% vs. 76%) and CR rate (41% vs. 27%) compared to patients treated with PR. Median treatment-free survival for all accrued patients was notably longer in PCR treated patients compared to PR (30 vs. 16 months). These findings suggest that increasing the dose of the purine nucleoside analogue does not eliminate the need for cyclophosphamide in chemoimmunotherapy for treatment of CLL.
pentostatin; rituximab; cyclophosphamide; chemoimmunotherapy; response rates; B-CLL
While B-Chronic Lymphocytic Leukemia (CLL) is known to be a heterogeneous disease, it is only recently that the familial component of CLL has been more thoroughly investigated. This entity is seen in approximately 5–10% of all CLL patients and can be associated with earlier age of diagnosis, more female prevalence, and increased incidence of other lymphoproliferative disorders (LPD), such as non-Hodgkin Lymphoma and the more recently described monoclonal B cell lymphocytosis CLL in family members. The prognostic parameters and clinical course of familial CLL is not clearly distinguishable from that of sporadic disease. In addition, it is not clear that the treatment responses for progressive disease has any discernible difference in familial vs. sporadic CLL. The genetic etiology of CLL is unknown and early work on familial CLL has not yet uncovered any obvious gene or group of genes that can be clearly related to the pathophysiology of CLL. However, the detailed genetic study of familial CLL is likely to be critical in uncovering relevant genes. At present it is best to indicate to concerned CLL patients that their relatives are at relatively low risk of developing CLL or other LPD.
Familial CLL; Sporadic CLL; genetics; prognosis; clinical course
Patients with B-chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) have a 5–10% risk of developing autoimmune complications which primarily cause cytopenia. These autoimmune cytopenias can occur at any stage of CLL and do not have independent prognostic significance. The most common autoimmune complication is autoimmune hemolytic anemia with a lower frequency of immune thrombocytopenia and pure red blood cell aplasia and only rare patients with autoimmune granulocytopenia. Autoimmune cytopenia should always be considered in the differential diagnosis of cytopenia in patients with CLL. Patients with CLL can also have more than one form of autoimmune cytopenia which can occur together with bone marrow failure. Treatment is usually effective but rarely curative for autoimmune cytopenia complicating CLL. Optimal therapy will depend on a timely and accurate diagnosis of autoimmune cytopenia and should be individualized according to the severity of the cytopenia and the presence or absence of concomitant progressive CLL requiring therapy.
Chronic lymphocytic leukemia; small lymphocytic lymphoma; autoimmune hemolytic anemia; immune thrombocytopenia; pure red blood cell aplasia
Cytogenetic abnormalities in CLL are important prognostic indicators. Historically, only interphase cytogenetics was clinically useful in CLL because traditional mitogens are not effective mitotic stimulants. Recently, CpG-oligodeoxynucleotide (ODN) stimulation has shown effectiveness in CLL. The CLL Research Consortium (CRC) tested the effectiveness and reproducibility of CpG-ODN stimulation to detect chromosomally abnormal clones by five laboratories. More clonal abnormalities were observed after culture of CLL cells with CpG-ODN than with pokeweed mitogen (PWM)+12-O-tetradecanoyl-phorobol-13-acetate (TPA). All clonal abnormalities in PWM+TPA cultures were observed in CpG-ODN cultures, whereas CpG-ODN identified some clones not found by PWM+TPA. CpG-ODN stimulation of one normal control and 12 CLL samples showed that excepting clones of del(13q) in low frequencies and one translocation, results in all five laboratories were consistent, and all abnormalities were concordant with FISH. Thus, abnormal clones in CLL are more readily detected with CpG-ODN stimulation than with traditional B-cell mitogens. After CpG-ODN stimulation, abnormalities were reproducible among cytogenetic laboratories. CpG-ODN did not appear to induce aberrations in cell culture and enhanced detection of abnormalities and complexity in CLL. Since karyotypic complexity is prognostic and is not detectable by standard FISH analyses, stimulation with CpG-ODN is useful to identify this additional prognostic factor in CLL.
Treatment of autoimmune cytopenia complicating progressive chronic lymphocytic leukemia (CLL) is constrained by intolerance of myelosuppression and the risk of exacerbation of autoimmune cytopenia by purine analogs particularly when used as single agents. We report on 20 such patients treated with rituximab, cyclophosphamide, vincristine, and prednisone (R-CVP). Autoimmune cytopenia responded in 19 patients (14 complete remissions (CR), five partial remissions (PR)) with a median time to next treatment (TTT) for autoimmune cytopenia of 21.7 months. Progressive CLL responded in 17 patients (nine CR/complete clinical response, eight PR) with a median TTT of 27.7 months. Five patients have not required any re-treatment at 15–30 months. Grade 3–4 toxicities were infections (n = 3) and drug-induced pneumonitis (n = 1). No patient required blood cell transfusions after cycle 1 of therapy. We conclude that R-CVP is effective and tolerable therapy for autoimmune cytopenia complicating progressive CLL, but the duration of response is suboptimal.
Chronic lymphocytic leukemia; autoimmune hemolytic anemia; immune thrombocytopenia; pure red blood cell aplasia; therapy
Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) is usually an incidental diagnosis in patients with early–intermediate stage disease. However, most patients with a diagnosis of CLL will subsequently have significant morbidity and die from their disease and its complications. For these patients, CLL is not the ‘good leukemia’ with a predictably ‘benign’ outcome. Indeed, we can now identify a cohort of patients with high-risk CLL at diagnosis who will have rapid disease progression, poor response to treatment, and poor survival based on prognostic methods developed from an improved understanding of the biology of CLL. The concomitant development of improved treatments has led to risk-adjusted management approaches that could improve outcomes. We discuss the clinical and laboratory components of comprehensive risk evaluation of patients with CLL and our approach to the management of patients with a high to very high risk of disease progression and poor outcome. In addition, we review the challenges and prospects for improving prognostic precision and the development of new drugs to improve the treatment of patients with CLL with a high risk of adverse outcome.
Chronic lymphocytic leukemia; CLL; SLL; high risk; therapy; risk stratified management
CpG oligonucleotide 7909 (CpG 7909, PF-03512676), a synthetic 24mer single stranded agonist of TLR9 expressed by B cells and plasmacytoid dendritic cells, is immunomodulatory and can cause activation-induced death of chronic lymphocytic leukemia (CLL) cells. We report a phase I study of CpG 7909 in 41 patients with early relapsed CLL. A single intravenous dose of CpG 7909 was well tolerated with no clinical effects and no significant toxicity up to 1.05 mg/kg. Single dose subcutaneous CpG 7909 had a maximum tolerated dose (MTD) of 0.45 mg/kg with dose limiting toxicity of myalgia and constitutional effects. Multiple weekly subcutaneous doses at the MTD were well tolerated. CpG 7909 administration induced immunologic changes in CLL and non-malignant cells that were dose and route dependent. We conclude that multidose therapy with subcutaneous CpG 7909 (0.45 mg/kg) could be used in future phase II combination clinical trials for CLL.
Chronic lymphocytic leukemia; CLL; CpG oligonucleotide 7909; PF-03512676; CpG 2006; TLR9
cytogenetics; CLL; CpG
To better understand the implications of genomic instability and outcome in B-cell CLL, we sought to address genomic complexity as a predictor of chemosensitivity and ultimately clinical outcome in this disease. We employed array-based comparative genomic hybridization (aCGH), using a one-million probe array and identified gains and losses of genetic material in 48 patients treated on a chemoimmunotherapy (CIT) clinical trial. We identified chromosomal gain or loss in ≥6% of the patients on chromosomes 3, 8, 9, 10, 11, 12, 13, 14 and 17. Higher genomic complexity, as a mechanism favoring clonal selection, was associated with shorter progression-free survival and predicted a poor response to treatment. Of interest, CLL cases with loss of p53 surveillance showed more complex genomic features and were found both in patients with a 17p13.1 deletion and in the more favorable genetic subtype characterized by the presence of 13q14.1 deletion. This aCGH study adds information on the association between inferior trial response and increasing genetic complexity as CLL progresses.
CLL; aCGH; genotype; prognosis
The t(14;18)(q32;q21) is the most commonly observed chromosomal translocation in non-Hodgkin lymphoma (NHL), resulting in constitutive Bcl-2 expression and apoptosis inhibition. In addition, germline variation in both BCL2L11 (BIM) and CASP9, known regulators of apoptosis, have recently been linked to NHL risk. We conducted a comprehensive evaluation of 36 apoptosis pathway genes with risk of NHL.
We genotyped 226 single nucleotide polymorphisms (SNPs) from 36 candidate genes in a clinic-based study of 441 newly diagnosed NHL cases and 475 frequency matched controls. We used principal components analysis to assess gene-level associations, and logistic regression to assess SNP-level associations. MACH was used for imputation of SNPs in BCL2L11 and CASP9.
In gene level analyses, BCL2L11 (p=0.0019), BCLAF1 (p=0.0097), BAG5 (p=0.026) and CASP9 (p=0.0022) were associated with NHL risk after accounting for multiple testing (tail strength 0.38; 95% CI 0.05, 0.70). Two of the 5 BCL2L11 tagSNPs (rs6746608 and rs12613243), both genotyped BCLAF1 tagSNPs (rs797558 and rs703193), the single genotyped BAG5 tagSNP (rs7693), and 3 of the 7 genotyped CASP9 tagSNPs (rs6685648, rs2020902, rs2042370) were significant at p<0.05. We successfully imputed BCL2L11 and CASP9 SNPs previously linked to NHL, and replicated all 4 BCL2L11 and 2 of 3 CASP9 SNPs.
We replicated the association of BCL2L11 and CASP9 with NHL risk at the gene and SNP-level, and identified novel associations with BCLAF1 and BAG5.
Closer evaluation of germline variation of genes in the apoptosis pathway with risk of NHL and its subtypes is warranted.
Bcl-2 pathways; caspases; molecular epidemiology; non-Hodgkin lymphoma
We present the design features and implementation of a clinic-based case-control study on the molecular epidemiology of lymphoma conducted at the Mayo Clinic (Rochester, Minnesota, USA), and then assess the internal and external validity of the study. Cases were newly diagnosed lymphoma patients from Minnesota, Iowa and Wisconsin seen at Mayo and controls were patients from the same region without lymphoma who had a pre-scheduled general medical examination, frequency matched on age, sex and residence. Overall response rates were 67% for cases and 70% for controls; response rates were lower for cases and controls over age 70 years, cases with more aggressive disease, and controls from the local area, although absolute differences were modest. Cases and controls were well-balanced on age, sex, and residence characteristics. Demographic and disease characteristics of NHL cases were similar to population-based cancer registry data. Control distributions were similar to population-based data on lifestyle factors and minor allele frequencies of over 500 SNPs, although smoking rates were slightly lower. Associations with NHL in the Mayo study for smoking, alcohol use, family history of lymphoma, autoimmune disease, asthma, eczema, body mass index, and single nucleotide polymorphisms in TNF (rs1800629), LTA (rs909253), and IL10 (rs1800896) were at a magnitude consistent with estimates from pooled studies in InterLymph, with history of any allergy the only directly discordant result in the Mayo study. These data suggest that this study should have strong internal and external validity. This framework may be useful to others who are designing a similar study.
Case-control study; etiology; lymphoma; molecular epidemiology; validity
The treatment of chronic lymphocytic leukemia (CLL) has evolved over the past decade. Our better understanding of disease biology and risk stratification has allowed delivering more effective therapies. In fact, front-line chemoimmunotherapy has demonstrated improvement in overall survival when compared to chemotherapy in randomized studies. Yet, treatment of relapsed CLL remains challenging and few agents are effective in that setting. Ofatumumab (Ofa) is a humanized monoclonal antibody targeted against CD20 with demonstrable activity in rituximab-resistant CLL cell lines. This agent was recently approved for the treatment of relapsed/refractory CLL patients who have failed fludarabine and alemtuzumab. In this review, we provide a historical perspective on approaches to CLL as front-line and in the relapsed setting. We further summarize novel anti-CD20 antibodies with specific emphasis on ofa. We review studies that led to ofatumumab’s approval including pre-clinical data, trials using ofa in combination therapies, and adverse events/toxicities reported with this agent.
CLL; Ofatumumab; anti-CD20; targeted therapy; monoclonal antibodies
Deletion 13q14 on fluorescence in situ hybridization (FISH) analysis is the most common cytogenetic abnormality in chronic lymphocytic leukemia (CLL), and is a favorable prognostic biomarker when detected as a sole abnormality. We intensively interrogated clinical outcome in 323 consecutive, untreated CLL patients with isolated 13q- identified within two years of diagnosis. We also analyzed outcome in 217 additional patients with deletion 11q22.3 or 17p13.1, or trisomy 12 based on whether these occurred in isolation or in conjunction with 13q-. Patients with a heterozygous 13q- and those with a homozygous deletion had similar time to first treatment (TFT) and overall survival (OS). In contrast, a higher percentage of 13q- nuclei was associated with significantly shorter TFT (p<0.001). The 5-year untreated rate was 79% for patients with isolated 13q- in ≤65.5% of nuclei compared to 38% among those with 13q- in >65.5% of nuclei (p<0.001). The percentage of nuclei exhibiting 13q- remained an independent predictor of TFT after controlling for ZAP-70, IgVH, or CD38 (all p<0.001). Among patients with 13q- plus one other FISH abnormality, concomitant 13q- appeared to attenuate the shorter survival associated with 17p- (p=0.019). The clinical implications of 13q- in CLL appear more complex than originally appreciated.
Chronic lymphocytic leukemia; 13q deletion; 17p deletion
The pathology and clinical course of patients with CD5+ chronic B-cell lymphoproliferative disorders, excluding those that present with typical chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) or mantle cell lymphoma, (i.e. CD5+B-CLPD) are poorly defined.
We studied patients with CD5+B-CLPD to 1) more completely define the clinical features and pathology of CD5+B-CLPD, 2) compare these features to patients presenting with typical CLL, and 3) test the hypothesis that a subset of patients with CD5+B-CLPD could have a unique B-cell malignancy.
We identified 229 patients with CD5+B-CLPD. A definitive pathological diagnosis was made in all 61 (27%) CD5+B-CLPD patients with non-bone marrow (BM) biopsy specimens considered adequate for a comprehensive pathological examination. The most common diagnosis among these 61 patients was CLL (44%) followed by the leukemic phase of marginal zone lymphoma (34%), lymphoplasmacytic lymphoma (11%), diffuse large B cell lymphoma (8%), and high grade B cell lymphoma not otherwise specified (2%). In contrast, among 168 patients without a non-BM tissue biopsy specimen, a specific diagnosis could be made on review of all available data in only 24 (14%) with 144 (86%) remaining “unclassified”.
In patients with CD5+B-CLPD, a definitive diagnosis can be made on an adequate non-BM tissue biopsy suggesting that this entity does not include a novel disease. We recommend that all patients with CD5+B-CLPD should have a non-BM tissue biopsy to make a definitive diagnosis prior to initiation of treatment.
CD5; chronic lymphoproliferative disorders; CLL; SLL; lymphoma
It was hypothesized that contact between chronic lymphocytic leukemia (CLL) B-cells and marrow stromal cells impact both cell types. To test this hypothesis, we utilized a long-term primary culture system from bone biopsies that reliably generates a mesenchymal stem cell (MSC). Co-culture of MSC with CLL B-cells protected the latter from both spontaneous apoptosis and drug-induced apoptosis. The CD38 expression in previously CD38 positive CLL B-cells was up-regulated with MSC co-culture. Up-regulation of CD71, CD25, CD69 and CD70 in CLL B-cells was found in the co-culture. CD71 up-regulation was more significantly associated with high-risk CLL, implicating CD71 regulation in the microenvironment predicting disease progression. In MSC, rapid ERK and AKT phosphorylation (within 30 min) were detected when CLL B-cells and MSC were separated by transwell; indicating that activation of MSC was mediated by soluble factors. These findings support a bi-directional activation between bone marrow stromal cells and CLL B-cells.
B-cells; cell signalling; chronic lymphocytic leukaemia; mesenchymal cells; stromal cell