Call, Timothy G.

Abstract Background Factors associated with chronic immune stimulation such as transplantation, autoimmune disorders and chronic infections have been linked to the development of lymphoma, while atopic conditions have been associated with a lower risk of lymphoma. Vaccinations, in part due to their ability to induce immune responses, have been hypothesized to play a role in lymphoma etiology, but there are few studies with mixed results and limited data on lymphoma subtypes. Methods We used a clinic-based study of 2461 newly diagnosed lymphoma cases and 2253 frequency-matched controls enrolled from 2002-2015. Participants self-reported lymphoma risk factors and history of vaccinations for hepatitis A, hepatitis B, chicken pox, yellow fever and influenza. Pathology was centrally reviewed, and included 644 chronic lymphocytic leukemia, 528 follicular (FL), 414 diffuse large B-cell (DLBCL), 170 marginal zone, 127 mantle cell, 119 T-cell, 181 Hodgkin, and 278 other lymphoma subtypes. We used polytomous logistic regression to estimate odds ratio (OR) and 95% confidence intervals (CI) of vaccinations with lymphoma risk overall and for subtypes, adjusting for age, sex, socioeconomic status, body mass, alcohol use, smoking history, recreational sun exposure, and family history of hematological malignancies. Results The median age at diagnosis for lymphoma cases was 64 years (range: 18-93) and 58% were male; the median age at enrollment for controls was 62 years (range: 18-91) and 53% were male. The most common vaccinations among controls were influenza (90%) followed by hepatitis B (41%), hepatitis A (30%), chicken pox (20%), and yellow fever (11%). Vaccination for influenza was inversely associated with lymphoma risk overall (OR=0.75, CI:0.61-0.93, P=0.01), with an inverse trend for increasing number of vaccinations (P=0.0001). In subtype analyses, Influenza vaccination was inversely associated with risk of FL (OR=0.59, CI:0.43-0.80, P=0.001), DLBCL (OR=0.64, CI:0.44-0.92, P=0.02) and other lymphoma subtypes (OR=0.66, CI:0.43-1.00, P=0.05). Vaccination for hepatitis A was inversely associated with lymphoma risk (OR=0.79, CI:0.65-0.96, P=0.02), with no significant subtype-specific associations. No evidence of association with vaccination for hepatitis B (OR=0.95, CI:0.79-1.14) and chicken pox (OR=0.83, CI:0.68-1.02) for lymphoma risk overall or for any subtypes. Although no evidence of an association with vaccination for yellow fever (OR=0.81, CI:0.62-1.06) for lymphoma risk, it was inversely associated with DLBCL risk (OR=0.42, CI:0.22-0.80). Conclusion Vaccination for influenza and hepatitis A were inversely associated with overall lymphoma risk. DLBCL was associated with vaccination for influenza and yellow fever. FL was associated with vaccination for influenza. Understanding the underlying mechanisms for a putative protective effect of certain vaccines could provide new clues to the etiology and prevention of lymphoma. Citation Format: Geffen Kleinstern, Dennis P. Robinson, Carrie A. Thompson, Melissa C. Larson, Cristine Allmer, Grzegorz S. Nowakowski, Timothy G. Call, Stephen M. Ansell, Andrew L. Feldman, Neil E. Kay, Thomas M. Habermann, Susan L. Slager, James R. Cerhan. Vaccination history and risk of lymphoma and its major subtypes [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1054.

8026 Background: CLL progression and CLL-related complications (infections and second malignancies) were the leading cause of death (COD) in a prospective cohort of CLL patients (Strati, BJH 2017). The CLL-IPI integrates major clinical and molecular prognostic factors and stratifies patients into 4 risk groups with distinct prognosis. It is unknown if COD differs according to CLL-IPI risk group in patients with newly diagnosed CLL. Methods: Patients diagnosed with CLL between 1/2000-12/2019 and seen within 1 year of diagnosis were identified from the Mayo Clinic CLL database. Cumulative incidences of cause-specific death were analyzed using Gray’s test, with deaths from different causes treated as competing events and deaths from unknown causes excluded. Results: 1276 patients were included in this study. The median age at diagnosis was 63 years (range 24-92), and 880 (69%) were male. Based on CLL-IPI score, 449 (35%) had low risk disease, 443 (35%) had intermediate risk disease, and 384 (30%) had high/very high risk disease. Median follow-up time for the study was 6 years; 286 deaths occurred. The COD was CLL progression in 99 (35%), infection in 16 (6%), second malignancy in 47 (16%), CLL-unrelated in 59 (21%), and unknown in 65 (23%) patients. The rates of death due to CLL progression were higher (17.3% at 5 years; 30.3% at 10 years) than the rates due to CLL-related complications (5.7% at 5 years; 12.9% at 10 years) or due to CLL-unrelated causes (8.6% at 5 years; 16.9% at 10 years) in the CLL-IPI high/very high risk group, but not the CLL-IPI low or intermediate risk group (Table). A higher CLL-IPI risk group was associated with a higher rate of death due to CLL progression ( P < 0.001), as well as a higher rate of death due to CLL-related complications ( P = 0.013), and CLL-unrelated causes ( P < 0.001). Conclusions: Causes of death in newly diagnosed CLL patients differ according to their CLL-IPI risk group. In patients with high/very high risk CLL, improving CLL disease control with novel agents seems justified. In patients with low/intermediate risk CLL, there should be increased efforts to reverse immune dysfunction to reduce infections and second malignancies. [Table: see text]

Abstract Background: We had previously piloted thalidomide treatment in MMM and showed an approximately 20% response in terms of both anemia and splenomegaly (Elliott et al. BJH2002;117:288). Encouraged by this experience, we undertook the current phase II study to explore the therapeutic activity of the more potent as well as less neurotoxic immunomodulatory drug, lenalidomide (CC-5013). Methods: The study group comprised a consecutive series of patients with MMM that fulfilled protocol entry criteria that included hemoglobin level ≤ 10 g/dL, platelet count ≥ 100 x 109/L, and neutrophil count ≥ 1 x 109/L. The treatment program consisted of daily oral lenalidomide (10 mg/day) for 3 consecutive 28-day cycles with a plan to continue with additional 3 cycles in case of response. Results: i. Pretreatment patient information Twenty-seven patients (median age, 66 years; range, 40–78) were accrued between March 5, 2004 and June 15, 2005. Median duration of disease prior to protocol treatment was 30 months (range, 1–245). Previous therapy was documented in all but 2 patients. Twenty patients were RBC transfusion-dependent. Baseline median (range) values for palpable spleen size, leukocyte count, platelet count, CD34 cell count, and serum lactate dehydrogenase (LDH) were 16 cm (0–31), 8.4 x 109/L (1.8–84.4), 299 x 109/L (124–831), 166.1 x 106/L (2.8–5176.4), and 778 U/L (267–1725), respectively. Cytogenetic abnormalities were detected in 13 patients (48%). JAK2 V617F mutation analysis was performed in 21 patients and revealed homozygous, heterozygous, and wild-type alleles in 3, 8, and 10 patients, respectively. ii. Adverse events Adverse events (any/grade 3 or 4) with definite, probable, or possible attributions to the drug included fatigue (52%/12%), neutropenia (40%/24%), pruritus (36%/0%), thrombocytopenia (28%/8%), anemia (16%/8%), rash (12%/8%), and respiratory distress with hypoxia (8%/8%). To date, 7 deaths have been reported, all occuring after discontinuation of protocol therapy, and none were directly linked to the drug. iii. Response The median post-treatment follow up is now 16 months (range 1–17 months). During this period, 6 patients (22%) have experienced either a major (3 patients normalized their hemoglobin level), minor (2 patients became transfusion-independent), or marginal response in anemia. The median time to response and response duration were 2 and 7 months, respectively. Two of the 3 major responders had a baseline der(1;18)(q10;q10) or del(5)(q13q33) cytogenetic abnormality, the latter one of which displayed a major cytogenetic remission. In the patient with der(1;18)(q10;q10), the hemoglobin level increased to a level of 19.1 g/dL from being transfusion-dependent at the start of lenalidomide therapy. Interestingly, the particular patient was homozygous for the JAK2 V617F mutation. Responses were also recorded for palpable splenomegaly (26%), constitutional symptoms (67%), and serum LDH level (70%). Seven patients normalized their LDH. Conclusion: Lenalidomide therapy improved anemia in at least 20% of patients with MMM. Some of the responses were spectacular and appeared to be associated with specific cytogenetic abnormalities. The documentation of a positive drug effect on LDH, constitutional symptoms, and splenomegaly in patients not showing early response in anemia suggests the possibility of an even higher response rate with a longer treatment schedule.

Abstract Background: Results of conventional cytogenetic studies on specimens processed without B-cell mitogens are usually normal in B-CLL: this observation is often attributed to lack of mitotic B-CLL cells. Using metaphase FISH with D13S319, we now have evidence that these apparently normal mitotic B-CLL cells often exhibit submicroscopic interstitial deletions in 13q14. This observation indicates B-CLL cells do divide in unstimulated cultures, but the abnormal metaphases are not detected because the abnormalities are submicroscopic and represent a low percentage of proliferating cells. Methods: We studied 12 patients with B-CLL who had normal metaphases by conventional cytogenetics, but abnormal interphase nuclei by FISH with D13S319. This cohort consisted of 7 females and 5 males who ranged in age from 50 to 87 years. Clinical information was available for 11 patients: Rai stages were 0, I, II, III, or IV for 6, 1, 1, 2, and 1 patients, respectively; 8 patients received treatment and 3 have died. Conventional cytogenetic studies and metaphase FISH were done on bone marrow specimens that were processed by standard 24 and 48-hour unstimulated cultures with Chang Medium BMC. Interphase FISH studies were done on blood or bone marrow (collected within 3 days of specimens for conventional cytogenetic studies) using probes to detect anomalies of chromosomes 6, 11, 12, 13, 14 and 17. For each patient, metaphase FISH was done with commercial probes from Vysis Inc., Downers Grove, IL for D13S319/13q34 using leftover fixed cells from conventional cytogenetics studies. Results: Metaphase FISH results were normal for 3 bone marrow specimens: the remaining 9 specimens had 1.9 to 13.8% metaphases with interstitial deletions of 13q14. One patient had a cytogenetically visible chromosome 13 deletion in 2.2% of metaphases. In the remaining 8 specimens, the size of the abnormal 13 was similar to the normal 13 homolog and other acrocentric chromosomes. By comparison, interphase FISH revealed 13 to 93% nuclei with 13q-x1 or 13q-x2. Seven patients had additonal anomalies in their interphase nuclei; 3 had 11q-, 2 had 17p-, 1 had +12 and 1 had +IGH. Conclusions: This investigation indicates that metaphase FISH detects submicroscopic deletions in chromosome 13 as well as infrequent mitotic B-CLL cells in patients who have normal conventional cytogenetic results. Therefore, metaphase FISH is a novel and useful technique to detect abnormal mitotic cells in B-CLL in cultures without special B-cell mitogens. The prognostic significance of abnormal metaphase FISH results is still under investigation. We speculate that this method will allow for identification of more aggressive proliferating disease even in so-called “favorable” prognostic groups based on interphase FISH results.

Abstract Background: Non-Hodgkin lymphoma (NHL) is a malignancy of lymphocytes, and may develop in the setting of inflammation and immune dysfunction. Small scale evaluations have suggested that common genetic variation in candidate genes related to immune function may predispose to the development of NHL. Here we report a comprehensive analysis of variants within genes associated with immunity and inflammation and risk of NHL. Methods: We used ParAllele’s Immune and Inflammation panel of 9,412 single nucleotide polymorphisms (SNPs) from 1,450 immune/inflammation genes as a discovery tool in a clinic-based study of 458 NHL cases and 484 frequency matched controls seen at the Mayo Clinic from 2002–2005. The panel included 537 coding non-synonymous SNPs (nsSNPs), with the remainder of the SNPs selected as tags from HapMap (tagSNPs) to provide coverage of the candidate genes (r2 = 0.8 and minor allele frequency &gt;0.05). To assess the association of individual SNPs with risk of NHL, we calculated Odds Ratios (ORs) and 95% confidence intervals, adjusted for age and gender. The most prevalent homozygous genotype was used as the reference group, and each polymorphism was modeled individually as having a log-additive effect in the regression model. Associations between haplotypes from each gene and the risk of NHL were calculated using a score test implemented in HAPLO.SCORE. We also modeled the main effects for all independent (r2 &lt;0.25) SNPs from a gene in a multivariate logistic regression model. Results: The mean age at diagnosis was 60 years for cases and 58% were male; in controls the mean age at enrollment was 61.6 years and 55% were male. In the gene analyses, the strongest findings (p≤0.001 from multiple SNP logistic regression or haplotype analysis) were for cAMP responsive element binding protein 1 (CREB1; p=0.0004), fibrinogen alpha chain (FGA; p=0.0006), TNF receptor-associated factor 1 (TRAF1; p=0.001), dual specificity phosphatase 2 (DUSP2; p=0.001), and fibrinogen gamma chain (FGG; p=0.001). In the nsSNP analyses, the strongest findings (p≤0.01) were for integrin β3 (ITGB3) L59P (OR=0.64, 0.50–0.83), Beta-1,3-N-acetylglucosaminyltransferase 3 (B3GNT3) H328R (OR=0.72, 0.57–0.91), transporter 2, ATP-binding cassette (TAP2) T665A (OR=1.32, 1.07–1.63), HLA-B associated transcript 2 (BAT2) V1895L (OR=0.60, 0.42–0.85), and complement component 7 (C7) T587P (OR=1.39, 1.07–1.80). Conclusions. Our results suggest that genetic variability in genes associated with antigen processing (CREB1 and TAP2), lymphocyte trafficking (B3GNT3), immune activation (TRAF1, BAT2), complement and coagulation pathways (FGA, FGG, ITGB3, C7), and MAPK signaling (DUSP2) may be important in the etiology of NHL, and should be pursued in replication studies.

Abstract Background: Loss of p53 is detected by fluorescence in situ hybridization (FISH) in interphase nuclei in 8–10% of patients with B-CLL and has been associated with aggressive disease and poor response to therapy. Results of chromosome studies suggest loss of p53 is often due to structural anomalies of chromosome 17 rather than monosomy 17. To characterize chromosome 17 anomalies in B-CLL, we used interphase and metaphase FISH to study a series of patients with this disorder. Methods: We studied 16 patients with B-CLL who had chromosome 17 anomalies detected by conventional chromosome studies or interphase FISH. The study cohort consisted of 8 females and 8 males (age 54 – 73 years). Clinical data was available for 15 patients: Rai stages were I, II, III and IV for 1, 2, 6 and 6 patients, respectively; 14 patients received treatment and 10 have died. Metaphase and interphase FISH studies were performed using left-over fixed bone marrow or peripheral blood cell pellets from conventional cytogenetic studies. To identify recurrent chromosome 17 breakpoint cluster regions, patients were first studied with p53(17p13.1) and D17Z1(centromere17), and then with FISH probes for SMS(17p11.2) and RARA(17q21). For patients retaining the SMS probe site, we did FISH for HNPP(17p11.2–12) and D17Z1(centromere17). A total of 200 interphase nuclei and up to 20 metaphases were analyzed by each probe set. Results: The karyotype was normal for 3 patients and complex involving various abnormalities of chromosome 17 for the remaining 13. All patients showed loss of one p53 probe site with retention of both chromosome 17 centromeres. The SMS locus was absent in 13 patients indicating a breakpoint cluster region between the centromere and SMS probe site. In the remaining 3 patients, HNPP was absent, but the SMS probe site was retained indicating chromosome breakage between the SMS and HNPP probe sites. Metaphase FISH results indicate loss of p53 was due to an isochromosome 17p11.2 in 4 patients and an unbalanced translocation involving 17p11.2 in 12 patients. Conclusions: This study shows that loss of p53 in B-CLL cells is due to isochromosome formation or unbalanced translocations that involve a ~6,400 kb breakpoint cluster region adjacent to the centromere on the short arm of chromosome 17. Importantly, our findings indicate that loss of p53 is not due to loss of chromosome 17, simple deletions of p53, or chromosome breakage near the p53 locus. The region between the centromere and HNPP on chromosome 17 is known to be rich in low copy repeats and homologous DNA sequences are dispersed throughout the genome. In somatic cells, these repeats can result in pairing of the same or different chromosomes; crossing over within these homologous regions can result in translocations or isochromosomes. Undoubtedly, this genetic mechanism plays an important role in the origin of structural anomalies of chromosome 17 in B-CLL.

Abstract Background: Chronic lymphocytic leukemia (CLL) can have a profound effect on the quality of life (QOL) of patients living with the illness. To our knowledge, no studies to date have evaluated the influence of the doctor-patient relationship on patient’s emotional distress or QOL. Methods: We conducted an international, web-based survey of patients with CLL using standardized instruments to evaluate QOL. Additional questions on the survey explored how often patients thought about their disease and evaluated their satisfaction with specific aspects of their relationship with the physician caring for them. Patients were also asked to indicate what phrases their physicians had used to describe/characterize CLL. Results: Between June and October 2006, 1482 patients responded to the survey. The diagnosis of CLL was validated in a randomly selected subset of patients. Over half (55.9%; n=822) of patients reported they thought about their CLL diagnosis daily. Although the proportion of patients who thought about CLL daily decreased with time, two or more years after diagnosis over 50% of patients still thought about their disease every day. When asked to indicate their satisfaction with various aspects of the physician caring for their CLL, more than 90% (n=1340) of patients felt their doctor had a good understanding of how their disease was progressing (i.e., the stage, blood counts, lymph nodes) but only 69% (n=1024) felt their physician had a good understanding of how CLL affected their QOL (anxiety, worry, fatigue, etc.). Similarly, while 90% (n=1324) of patients felt comfortable talking to their doctor about treatment and management of CLL, only 77% (n=1134) felt comfortable talking to their doctor about how CLL affected QOL. Reported satisfaction with their physician in these areas strongly related to patients’ measured emotional and overall QOL on standardized instruments (all p&lt;0.001). This effect on QOL remained (p&lt;0.002) after adjustment for age, extent of co-morbid health conditions, measured fatigue, and treatment status in a regression analysis. Finally, patients were asked to indicate whether the physician caring for them had used specific phrases to describe CLL. Thirty-three percent of patients had been told “CLL is the ‘good’ leukemia,” 24% had been told “don’t worry about your CLL,” and 35% had been told “if you could pick what cancer to have, this is what you would choose.” Overall, 52% of patients had received one or more of these characterizations of CLL by their physician. The emotional and overall QOL were worse among patients who reported their physician had used these phrases to describe CLL (all p≤0.001). This effect on QOL remained after regression analysis (p&lt;0.002). Patients whose physician had used one of these phrases to describe CLL were also less likely to feel their physician understood how CLL was effecting their QOL and to feel comfortable discussing the effects of CLL on their QOL with their physician (all p&lt;0.001). Conclusions: Physicians play an important role helping patients adjust to the physical, intellectual, and emotional challenges of CLL. The effectiveness with which physicians accomplish these tasks appears to impact the QOL of patients with CLL. Additional studies exploring how physicians can best support patients with CLL are needed.

Abstract BACKGROUND: Green tea has long been touted as a health promoting substance. The active chemical compounds in green tea are called polyphenols or catechins. Epigallocatechin gallate(EGCG) is the major catechin in green tea. We previously reported the in vitro ability of EGCG to induce apoptotic cell death in chronic lymphocytic leukemia(CLL) B-cells in vitro (Blood 104:788). After publication of our findings, clinical activity in individuals using over the counter green tea extracts were reported (Leuk Res 30:707). Based on this information, we opened a phase I/II trial of green tea extracts for patients with asymptomatic, early stage CLL in fall of 2005. METHODS: The purpose of the phase I portion of this trial was to determine the optimal dose of EGCG in the Polyphenon E preparation for chronic daily administration and define tolerability in CLL patients. Previously untreated patients with asymptomatic, Rai stage 0–II CLL not currently meeting National Cancer Institute(NCI) Working Group(WG) Criteria for treatment were eligible for participation. Polyphenon E with a standardized dose of EGCG was obtained from NCI. The phase I portion of the trial was designed with 8 dose levels(range 400–2000 mg orally BID) using the standard 3 patient per dose level design. Patients remained on study up to 6 months. Grade 2 adverse events attributed to study treatment that did not respond to supportive care were considered dose limiting toxicity. The trial was designed to administer Polyphenon E in the fasting state. After accrual to dose levels 1 and 2, the U.S. FDA mandated all U.S. trials of Polyphenon E administer drug in the fed state. Accordingly, drug was administered in the fed state for dose levels 3–8. Trough plasma EGCG levels were measured 1 month after initiation of therapy. Response was classified using the NCI WG Criteria. RESULTS: As of August 2007, 33 patients have been accrued to dose levels 1–8. The maximum tolerated dose(MTD) has not been reached. Side effects have generally been mild. The most common toxicities were nausea(grade 1: 42%; grade 2: 3%), elevation in SGOT (42%; all grade 1), and abdominal pain (36%; all grade 1). To date, no patient has had a sustained 50% reduction in both absolute lymphocyte count (ALC) and lymphadenopathy that would meet the NCI WG criteria for partial response. A majority of patients have had a reduction in ALC(Table). Among the 10 patients who had palpable adenopathy at study enrollment, 7 patients experienced at least a 50% reduction in the sum of the products of all nodal areas at some point during treatment. Trough plasma EGCG levels after 1 month of treatment ranged from 2.93974 ng/mL(median 40.5 ng/mL). Plasma levels did not clearly relate to the degree of reduction in ALC suggesting sensitivity to Polyphenon E may relate more to characteristics of the leukemic clone than plasma EGCG levels. CONCLUSION: Daily oral EGCG in the Polyphenon E preparation was well tolerated by CLL patients in this phase I trial. The MTD has not been reached. As classified by the NCI WG criteria, no partial or complete remissions have been observed to date, however declines in ALC and lymphadenopathy have been observed in the majority of patients. The phase II portion of this trial will open at Mayo Clinic Fall 2007. Best reduction in ALC n % of patients At least 10% decline 25 76% At least 20% decline 14 42% At least 30% decline 8 24% At least 40% decline 4 12% At least 50% decline 2 6%

Abstract Background and Significance : Chronic lymphocytic leukemia (CLL) is the most heritable hematologic malignancy; however, no common CLL predisposition genes are known. Monoclonal B lymphocytosis (MBL) is a hematologic syndrome characterized by small accumulations of B lymphocytes in the peripheral blood. MBL has a CLL-like immunophenotype, may progress to overt CLL, and is over represented in CLL families. Therefore, MBL observed in the context of familial CLL may be a marker of inherited risk for development of CLL. Detailed characterization of family-associated MBL may also provide mechanistic insights into the pathogenesis of familial CLL. Our strategy was to detail the biologic characteristics of CLL in family-associated MBL. Methods : Persons with MBL were identified by flow cytometric screening of peripheral blood from unaffected members of CLL kindreds ascertained by Genetic Epidemiology of CLL Consortium (GEC) sites. Flow cytometry was used to determine the surface immunophenotype including CD38 and intracellular ZAP-70. We defined MBL as populations of CD19+, CD5+, CD20lo, CD23+ B cells that comprised at least 2% of the CD19+ peripheral B cell compartment and did not exceed 5.0 × 109 MBL cells/L. RNA and genomic DNA from single MBL cells isolated by flow cytometric sorting were analyzed using PCR to determine immunoglobulin heavy and light chain sequences. MBL cells were sorted in bulk for FISH for loci associated with clinical CLL. Results : Twenty-two out of 190 (12%) unaffected family members were found to have MBL. We observed significant variability in the size of the MBL clone as a percentage of the CD19+ B cell compartment (mean 32%; range 2%–97%). Nonetheless, the absolute size of the MBL clone was small, 15 of 17 individuals had &lt; 200 × 106 MBL cells/L. CD38 expression (defined as CD38 surface expression in ≥30% of MBL cells) was observed in 8 of 18 subjects tested. ZAP-70 (defined as intracellular expression in ≥ 20% of MBL cells) was expressed in 4 of 12 participants. Among 12 subjects tested, 5 MBL expressed both surface IgD and IgM, 3 expressed IgD only, 2 expressed IgM only, and 2 did not express IgD or IgM. Analysis of immunoglobulin heavy and light chains has been completed in 8 individuals. Both immunoglobulin heavy chain variable (IgVH) region mutated (n = 12) and unmutated (n = 4) sequences were observed. Four of 8 individuals had 2 or more unrelated MBL clones (range 2–5), including one individual with both unmutated and mutated clones. Among the 16 MBL clones identified in these 8 subjects, VH3 or VH4 rearrangements were observed in all MBL clones. The most commonly rearranged IgVH genes were 3–07 (3 MBL clones), 3–15 (3), and 4–34 (3). No VH1 family gene rearrangements were observed. In one individual, a VH3–07 MBL clone showed intraclonal diversification suggestive of antigen driven immunoglobulin sequence changes. Twenty productive light chain rearrangements were identified among the 16 MBL clones, with 11 Vλ and 9 Vκ genes used. We observed 6 productive rearrangements of Vλ1–51. MBL cells were bulk sorted for FISH from 9 subjects. Mono or biallelic deletion of 13q14.3 was observed in 5 subjects, the other 4 were normal. Conclusions : Our findings confirm that MBL is commonly observed among the unaffected family members from CLL kindreds. We found that some MBL clones express ZAP-70, CD38 or have unmutated IgVH genes and thus are similar to clinical CLL. The clinical outcome of these MBL clones in relation to our baseline prognostic characterization will be of interest. Small MBL clones are commonly oligoclonal. Importantly, although the immunoglobulin heavy and light chain genes rearranged in these MBL clones are all commonly used in CLL, the absence of VH1 and abundance of Vλ1–51 rearrangements do suggests differences in BCR usage between CLL and MBL. Further investigation of family associated MBL may clarify the genetics and immunobiology of familial CLL.