The tumor microenvironment in follicular lymphoma

Like other B-cell lymphomas, the development and progression of follicular lymphoma (FL) involves complex interactions between the neoplastic B cells and the surrounding microenvironment. Malignant B cells can manipulate the microenvironment by skewing the differentiation of immune cells, attracting regulatory T cells or suppressive monocytes, or secreting cytokines that promote an immunosuppressive environment. The importance of the microenvironment in FL has been demonstrated using methodologies such as gene expression profiling, which has shown that the nature of the tumor microenvironment predicts survival in patients with FL and may influence the response to immunotherapy and risk of transformation. Strategies that both enhance an effective antitumor response and reverse immunosuppression and dysfunction will be essential in the development of effective immunotherapeutic approaches in this disease.

Pretreatment circulating serum cytokines associated with follicular and diffuse large B-cell lymphoma: a clinic-based case-control study

BACKGROUND

Abnormal immune function is a key factor in predisposition to non-Hodgkin lymphoma (NHL). We evaluated the association of 30 cytokines individually and as a profile with diffuse large B-cell (DLBCL) and follicular (FL) lymphomas.

METHODS

We used a multiplexed assay to measure 30 cytokine concentrations in pre-treatment serum in a case-control study of 234 FL, 188 DLBCL, and 400 control participants. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for age and sex, and polytomous regression was used to evaluate heterogeneity between FL and DLBCL. Principal components analysis (PCA) was used to assess cytokine profiles associated with FL and DLBCL.

RESULTS

In single cytokine modeling, we found that 12 of the 30 circulating serum cytokines were significantly (P<0.05) associated with FL and/or DLBCL after accounting for multiple testing (q<0.05). Soluble IL-2R (sIL-2R) had the strongest association with both FL (OR=6.0 for highest versus lowest tertile, 95% CI 3.8-9.5; p-trend=1.8 × 10(-21)) and DLBCL (OR=7.6, 95% CI 4.5-13.1; p-trend=7.2 × 10(-20)). IL1RA and IL-12p40 also showed similar associations for DLBCL and FL. In contrast, HGF, MIG, and MIP-1α had a stronger association with DLBCL compared to FL, and IL-6, IL-8, IL-10, IFN-γ, IP-10, and VEGF were only statistically significantly associated with DLBCL after accounting for multiple testing. However, in PCA modeling, a cytokine profile based on sIL-2R, IL-1RA, MIG, IP-10, IL-8, and IL-12p40 explained most of the variability between controls and both FL and DLBCL.

CONCLUSIONS

We identified some cytokines unique to DLBCL, but overall cytokine associations were more similar than distinct for DLBCL and FL. While these data are limited by concerns of reverse causality, they do suggest cytokines and cytokine profiles that can be prioritized in future studies.

Germline variation in complement genes and event-free survival in follicular and diffuse large B-cell lymphoma

The complement pathway plays a central role in innate immunity, and also functions as a regulator of the overall immune response. We evaluated whether polymorphisms in complement genes are associated with event-free survival (EFS) in follicular lymphoma (FL) and diffuse large B-cell (DLBCL) lymphoma. We genotyped 167 single nucleotide polymorphisms (SNPs) from 30 complement pathway genes in a prospective cohort study of newly diagnosed FL (N = 107) and DLBCL (N = 82) patients enrolled at the Mayo Clinic from 2002 to 2005. Cox regression was used to estimate hazard ratios (HRs) for individual SNPs with EFS, adjusting for FLIPI or IPI and treatment. For gene-level analyses, we used a principal components based gene-level test. In gene-level analyses for FL EFS, CFH (P = 0.009), CD55 (P = 0.006), CFHR5 (P = 0.01), C9 (P = 0.02), CFHR1 (P = 0.03), and CD46 (P = 0.03) were significant at P < 0.05, and these genes remained noteworthy after accounting for multiple testing (q < 0.15). SNPs in CFH, CFHR1, and CFHR5 showed stronger associations among patients receiving any rituximab, while SNPs from CD55 and CD46 showed stronger associations among patients who were observed. For DLBCL, only CLU (P = 0.001) and C7 (P = 0.03) were associated with EFS, but did not remain noteworthy after accounting for multiple testing (q>0.15). Genes from the regulators of complement activation (CFH, CD55, CFHR1, CFHR5, CD46) at 1q32-q32.1, along with C9, were associated with FL EFS after adjusting for clinical variables, and if replicated, these findings add further support for the role of host innate immunity in FL prognosis.

Long-term follow-up of reduced-intensity allogeneic hematopoietic stem cell transplantation for refractory or relapsed follicular lymphoma

Although allogeneic hematopoietic stem cell transplantation (HSCT) is considered the only curative treatment for refractory or relapsed follicular lymphoma (FL), transplant-related mortality (TRM) greatly interferes with the success. A variety of reduced-intensity conditionings (RICs) have been used to reduce TRM, but an optimal conditioning for FL has not been fully established. We retrospectively evaluated the outcome of allogeneic HSCT for FL with RIC consisting of fludarabine and melphalan. Nineteen adult patients with relapsed or refractory FL were conditioned with fludarabine (125 mg/m2) and melphalan (140 mg/m2), and received grafts from an HLA-identical sibling (n = 6) or an unrelated donor (n = 13). For the prophylaxis of graft-versus-host disease (GVHD), cyclosporine A or tacrolimus with short-term methotrexate was given. There were no early deaths before engraftment, and all patients achieved engraftment. Three patients died of extensive-type chronic GVHD (n = 2) or bacterial infection (n = 1) without disease progression. With a median follow-up period of 75.2 months (range: 33.3–111.9 months), 16 patients were alive without disease progression. Both the 5-year overall and progression-free survival rates were 84.2% (95% CI: 67.7–100%). These results strongly suggest that allogeneic HSCT with RIC using fludarabine and melphalan could be a promising treatment choice for refractory or relapsed FL.

The composition of the microenvironment in follicular lymphoma is associated with the stage of the disease

The role of regulatory and follicular helper T-cells as prognostic markers in follicular lymphoma was evaluated within the setting of prospective, randomized trials because the previously published results were contradictory. Two hundred sixty-four diagnostic tissue specimens from patients suffering from follicular lymphoma who received therapy within prospective randomized trials of the German Low Grade Lymphoma Study Group were analyzed immunohistochemically for FoxP3 and PD-1 expression to detect regulatory and follicular helper T-cells, respectively. We did not find any correlation between the content of regulatory and follicular helper T-cells and the time to treatment failure or overall survival in patients with advanced stages of follicular lymphoma in need of treatment. However, a perifollicular pattern of regulatory T-cells was associated with a poorer prognosis. The content of regulatory T-cells was positively and the content of follicular helper T-cells inversely correlated with a higher stage of the disease at diagnosis, implying that the microenvironment changes during tumor dissemination. This finding is independent of any therapy administered and needs to be considered when possible biomarkers related to the microenvironment of follicular lymphoma are studied.

A rare fraction of drug-resistant follicular lymphoma cancer stem cells interacts with follicular dendritic cells to maintain tumourigenic potential

Follicular lymphoma (FL) comprises nearly 25% of non-Hodgkin lymphoma cases and is clinically characterized by initial sensitivity to chemotherapy followed by relapse. FL stroma contains a special type of stromal cell found in the germinal centre of lymph nodes-the follicular dendritic cell (FDC). We first isolated tumourigenic cells from the FL cell line FLK-1 by side population (SP) technique, and found that SP cells, which express ABCG2, were enriched by chemotherapy and radiation treatments. In vitro, SP cells were attracted by and adhered to FDCs through chemokine (C-X-C motif) ligand 12/chemokine (C-X-C motif) receptor 4 (CXCL12/CXCR4) signalling. In vivo, limiting dilution assays showed SP cells were highly enriched in cancer stem cells (CSC), but required FDC for tumour formation in non-obese diabetic/severe combined immunodeficiency mice. Treatment with AMD3100, a specific CXCL12/CXCR4 inhibitor, eliminated tumour growth. These findings were then verified with FL cells isolated from an FL patient's ascitic fluid (FLA-1). Finally, we detected the ABCG2 expressing lymphoma cells in FL clinical specimens. Thus, we found that the highly tumourigenic FL cells having CSC-like activities (FL-SC) interact with FDCs in a CXCL12/CXCR4 dependent manner to resist chemotherapy. Our results indicate the importance of FL-SC and niche cell signalling in maintaining tumourigenicity. These signals represent novel targets for CSC eradication.

Pharmacokinetics and tolerability of human mouse chimeric anti-CD22 monoclonal antibody in Chinese patients with CD22-positive non-Hodgkin lymphoma

The safety and pharmacokinetics assessment of antibodies targeting CD22 (e.g., epratuzumab) have been established in western Caucasian populations, but there are no reports of the effects in Chinese populations. This dose-escalation study examines the safety, pharmacokinetics and biologic effects of multiple doses of anti-CD22 human-murine chimeric monoclonal antibody SM03 in 21 Chinese patients with CD22-positive non-Hodgkin lymphoma. Most of drug-related adverse events (AEs) were mild and reversible. Two patients experienced serious AEs (hemorrhage); one patient had grade 4 neutropenia; one patient had asymptomatic grade III prolongation of activated partial thromboplastin time (APTT). Major AEs included fever (71%), prolongation of APTT (42.8%), leukocytopenia (44.4%), alanine transaminase elevation (28.6%), elevated serum creatinine (23.8%) and injection site skin redness (14.3%). Circulating B cells transiently decreased without significant effects on T cells or immunoglobulin levels. Pharmacokinetic data revealed that mean maximum observed SM03 concentration and mean AUC from time zero to infinity increased in a dose-dependent manner up to 360 mg/m (2) SM03. Mean clearance was similar at doses ≤ 360 mg/m (2) and decreased significantly at dose 480 mg/m (2), supporting saturation of B-cell binding at 360 mg/m (2). Across all dose levels and histologies, one patient achieved partial response at 480 mg/m (2) dose; 14 patients had stable disease as best response and four patients progressed. Overall, SM03 was tolerated at doses ranging from 60-480 mg/m (2) and had potential efficacy in Chinese patients with follicular lymphoma.

A case of follicular lymphoma associated with paraneoplastic cerebellar degeneration

Paraneoplastic neurological disorders (PND) are neurological effects of malignancy that are recognized as immune-mediated disorders caused by aberrant expression of a tumor antigen that is normally expressed in the nervous system. We report a case of cerebellar ataxia which turned out to be paraneoplastic cerebellar degeneration, a subtype of PND that develops cerebellar symptoms, that was caused by follicular lymphoma. After chemotherapy, the patient attained sufficient improvement of cerebellar symptoms along with complete remission of lymphoma. Paraneoplastic cerebellar degeneration should be recognized as a rare complication of lymphoma as it is important to start proper treatment before the neurological symptoms become irreversible.

Follicular lymphoma tumor-infiltrating T-helper (T(H)) cells have the same polyfunctional potential as normal nodal T(H) cells despite skewed differentiation

The follicular lymphoma (FL) T-cell microenvironment plays a critical role in the biology of this disease. We therefore determined the lineage, differentiation state, and functional potential of FL-infiltrating CD4(+) T-helper cells (T(H)) compared with reactive and normal lymph node (NLN) T(H) cells. Relative to NLNs, FL cells have decreased proportions of naive and central memory but increased proportions of effector memory T(H) cells. We further show differences in the distribution and anatomical localization of CXCR5(+) T(H) populations that, on the basis of transcription factor analysis, include both regulatory and follicular helper T cells. On Staphylococcus enterotoxin-B stimulation, which stimulates T cells through the T-cell receptor, requires no processing by APCs, and can overcome regulator T cell-mediated suppression, the proportion of uncommitted primed precursor cells, as well as T(H)2 and T(H)17 cells is higher in FL cells than in reactive lymph nodes or NLNs. However, the proportion of T(H)1 and polyfunctional T(H) cells (producing multiple cytokines simultaneously) is similar in FL cells and NLNs. These data suggest that, although T(H)-cell differentiation in FL is skewed compared with NLNs, FL T(H) cells should have the same intrinsic ability to elicit antitumor effector responses as NLN T(H) cells when tumor suppressive mechanisms are attenuated.

Systemic rituximab in multifocal primary cutaneous follicle centre lymphoma

The aim of this retrospective study was to assess the efficacy and tolerance of intravenous rituximab in multifocal primary cutaneous follicle centre lymphomas (PCFCL). Eleven patients with a multifocal PCFCL were treated with rituximab (MabThera(®)) administrated intravenously. After four infusions, an objective response was observed in 90% of patients, and one month after all the infusions (median of 6 infusions) all the patients had an objective response and complete remission was obtained in 7 of 11 patients (64%). Follow-up ranged from 9 to 65 months (median: 30 months). Local disease recurrence was observed in five patients. The median progression-free survival time after the end of treatment was 23.6 months. This study is the largest series of patients with multifocal primary PCFCL treated with intravenous rituximab. This therapy is a safe and effective treatment and could represent an excellent alternative treatment to radiotherapy.

Allogeneic stem cell transplantation in follicular lymphoma

Myeloablative allogeneic transplantation in follicular lymphoma has been found to be particularly effective in patients with relapsed disease and an inadequate bone marrow reserve or massive bone marrow involvement. Allogeneic transplantation carries the promise of long-term disease control by graft-versus-lymphoma immunity but is associated with a 30%-40% risk of transplant-related mortality. Nonmyeloablative stem cell transplantation exploits the graft-versus-lymphoma effect without the attendant toxicity of myeloablative conditioning. The results of several recent reports suggest that it has a high likelihood of resulting in long-term disease-free survival in patients up to 70 years of age with a good performance status, chemotherapy-sensitive disease, and HLA-matched sibling donors. At The University of Texas MD Anderson Cancer Center, the standard NST conditioning regimen for patients with follicular lymphoma is fludarabine, cyclophosphamide, and rituximab. This regimen results in a transplantation-related mortality rate of 10%, and 85% of patients are alive without disease at 8 years. In this article, we discuss the current issues in NST for follicular lymphoma, including chemosensitivity, conditioning intensity, graft-versus-host disease, donor lymphocyte infusion's role, and ongoing strategies to treat refractory disease.

Novel antibodies against follicular non-Hodgkin's lymphoma

The anti-CD20 monoclonal antibody rituximab has revolutionized the treatment of patients with follicular B-cell lymphoma. With the combination of chemotherapy and rituximab the overall survival rate has increased with approximately 30%. Unfortunately, there is resistance to rituximab with relapse of the disease in about 60% of the patients during the first five years of treatment and eventually in all patients. To this end, there is a need to develop improved anti-CD20 monoclonal antibodies and antibodies that target other attractive molecules expressed on the follicular lymphoma cell. This review describes the development and clinical achievements so far of next generation anti-CD20 and other antibodies in the treatment of follicular B-cell lymphoma.

CD5-positive follicular lymphoma: a case report and literature review

A 59-year-old man exhibited an enlarged right inguinal lymph node in February 2009. A pathological diagnosis of follicular lymphoma (FL), grade 3A, was made based on a biopsy specimen from the right inguinal lymph node. The immunophenotypes of the lymphoma cells were CD3-, CD5+, CD7-, CD10+, CD19+, CD20+, CD23+, IgM+, Igκ-, and Igλ+. Fluorescence-activated cell sorting (FACS) dual staining indicated that the cells were double-positive for both CD5 and CD20. Mantle cell lymphoma (MCL), small lymphocytic lymphoma (SLL) and CD5-positive diffuse large B-cell lymphoma (DLBCL) were ruled out by the presence of cyclin D1-, CD10+, and the pathological findings. Based on these findings, the patient was diagnosed as having CD5-positive FL. Eight cycles of rituximab plus six cycles of CHOP were performed, and complete remission was achieved. To our knowledge, this is a rare case of CD5-positive FL. A literature review suggested a relatively higher incidence in younger and male patients. Remarkably, patients with grade 3 tend to undergo a transformation from CD5-positive FL to DLBCL.

Automated pattern-guided principal component analysis vs expert-based immunophenotypic classification of B-cell chronic lymphoproliferative disorders: a step forward in the standardization of clinical immunophenotyping

Immunophenotypic characterization of B-cell chronic lymphoproliferative disorders (B-CLPD) is becoming increasingly complex due to usage of progressively larger panels of reagents and a high number of World Health Organization (WHO) entities. Typically, data analysis is performed separately for each stained aliquot of a sample; subsequently, an expert interprets the overall immunophenotypic profile (IP) of neoplastic B-cells and assigns it to specific diagnostic categories. We constructed a principal component analysis (PCA)-based tool to guide immunophenotypic classification of B-CLPD. Three reference groups of immunophenotypic data files-B-cell chronic lymphocytic leukemias (B-CLL; n = 10), mantle cell (MCL; n = 10) and follicular lymphomas (FL; n = 10)--were built. Subsequently, each of the 175 cases studied was evaluated and assigned to either one of the three reference groups or to none of them (other B-CLPD). Most cases (89%) were correctly assigned to their corresponding WHO diagnostic group with overall positive and negative predictive values of 89 and 96%, respectively. The efficiency of the PCA-based approach was particularly high among typical B-CLL, MCL and FL vs other B-CLPD cases. In summary, PCA-guided immunophenotypic classification of B-CLPD is a promising tool for standardized interpretation of tumor IP, their classification into well-defined entities and comprehensive evaluation of antibody panels.

Current immunochemotherapy strategies in follicular lymphoma

Nowadays, there is no consensus about the best treatment for patients with follicular lymphoma (FL) in differing situations. In frontline treatment, a watchful waiting policy remains a good option if the patient has no risk criteria; the role of rituximab is under investigation in this setting. In patients needing therapy, immunotherapy or immunochemotherapy are the best options; although it has not been established which chemotherapy, including cyclophosphamide, vincristine, and prednisone (CVP); cyclophosphamide, adriamycin, vincristine, and prednisone (CHOP); fludarabine, or bendamustine combinations, is the best partner for rituximab. Following frontline treatment, recent and still unpublished data strongly suggest a role for maintenance with rituximab, instead of observation only. At relapse, immunochemotherapy is the standard induction approach. The role of maintenance after induction is well established, although comparative studies with autologous stem-cell transplantation (ASCT) or other combinations are warranted. The role of ASCT in this setting is a matter of discussion. Other monoclonal antibodies, as well as vaccines and other immunotherapies, are currently under investigation. Finally, allogeneic transplantation should be reserved for a very select group of young high-risk patients in the setting of clinical trials.

CD4 (+)CD25 (+)Foxp3 (+) regulatory T cells and hematologic malignancies

Regulatory T cells (Tregs) are an immunosuppressive T cell subset that functions to prevent autoimmunity and to regulate physiologic immune reactions. Tregs are also present in the tumor microenvironment and appear to play an important role in the pathophysiology of malignant processes. Available data suggests that this role is context-dependent, as a higher density of tumor infiltrating Tregs at diagnosis may be associated with either a positive or a negative clinical outcome. Negative prognostic associations are found primarily in solid tumors such as ovarian carcinoma, while positive associations have been reported in various lymphomas, most prominently in those of germinal center (GC) B cell derivation. Most of these observations are correlative, however, as mechanistic studies have lagged behind descriptive observations because of a lack of informative animal models. Nonetheless, the available data are intriguing and provide compelling support for the hypothesis that Tregs are pathobiologically relevant. This review focuses on studies of the role of CD4 (+)CD25 (+)FOXP3 (+) Tregs in hematopoietic malignancies and clonal myeloid neoplasms.

Antitransgene rejection responses contribute to attenuated persistence of adoptively transferred CD20/CD19-specific chimeric antigen receptor redirected T cells in humans

Immunotherapeutic ablation of lymphoma is a conceptually attractive treatment strategy that is the subject of intense translational research. Cytotoxic T lymphocytes (CTLs) that are genetically modified to express CD19- or CD20-specific, single-chain antibody-derived chimeric antigen receptors (CARs) display HLA-independent antigen-specific recognition/killing of lymphoma targets. Here, we describe our initial experience in applying CAR-redirected autologous CTL adoptive therapy to patients with recurrent lymphoma. Using plasmid vector electrotransfer/drug selection systems, cloned and polyclonal CAR(+) CTLs were generated from autologous peripheral blood mononuclear cells and expanded in vitro to cell numbers sufficient for clinical use. In 2 FDA-authorized trials, patients with recurrent diffuse large cell lymphoma were treated with cloned CD8(+) CTLs expressing a CD20-specific CAR (along with NeoR) after autologous hematopoietic stem cell transplantation, and patients with refractory follicular lymphoma were treated with polyclonal T cell preparations expressing a CD19-specific CAR (along with HyTK, a fusion of hygromycin resistance and HSV-1 thymidine kinase suicide genes) and low-dose s.c. recombinant human interleukin-2. A total of 15 infusions were administered (5 at 10(8)cells/m(2), 7 at 10(9)cells/m(2), and 3 at 2 x 10(9)cells/m(2)) to 4 patients. Overt toxicities attributable to CTL administration were not observed; however, detection of transferred CTLs in the circulation, as measured by quantitative polymerase chain reaction, was short (24 hours to 7 days), and cellular antitransgene immune rejection responses were noted in 2 patients. These studies reveal the primary barrier to therapeutic efficacy is limited persistence, and provide the rationale to prospectively define T cell populations intrinsically programmed for survival after adoptive transfer and to modulate the immune status of recipients to prevent/delay antitransgene rejection responses.

Mediastinal follicular lymphoma diagnosed with multidirectional analysis using tissue samples obtained by EBUS-TBNA

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been developed as a useful tool for the diagnosis of diseases adjacent to the airway to be used in place of open surgery or mediastinoscopy. In this report, we present a 46-year-old man with a solid tumor in the mediastinum. Since no other pathological sites were identified, EBUS-TBNA was employed for tumor sampling. Sufficient tissue specimens were collected and the diagnosis of follicular lymphoma was established based on the combination of immunohistochemistry, flow cytometry and FISH analysis. This report demonstrates the advantage of EBUS-TBNA even for the diagnosis of hematological disease.

Dendritic cell distribution in lymphomas

Dendritic cells (DC) are specialized antigen presenting cells (APC) that have important roles in host defenses and in generating anti-tumour immune response. Altered frequency and maturation of DC have been reported in malignant tumours. We studied the distribution and maturation status of DC by immunohistochemistry, on the formalin-fixed, paraffin-embedded lymph node tissues of 32 histologically diagnosed lymphomas and 40 inflammatory conditions that were retrieved from the Department of Pathology, UKM Medical Centre, Kuala Lumpur. Our study showed a significant reduction in the total DC counts in the lymphoma tissues compared to the inflammatory conditions. The mature and immature DC counts were both significantly reduced (p = 0.008 and 0.001 respectively), although a greater reduction was observed in mature DC numbers. We also observed compartmentalization of DC where the immature DC were seen within the tumour tissues and the mature DC were more in peri-tumoural areas. Our findings were similar to other reports, suggesting that reduced numbers of DC appears to be a factor contributing to lack of tumour surveillance in these cases.

Current advances, problems and prospects for vaccine-based immunotherapy in follicular non-Hodgkin's lymphoma

Despite advances in chemotherapy, radiotherapy and combined modality treatment, a significant proportion of non-Hodgkin's lymphomas remain incurable. The disease usually responds well to chemotherapy or radiation, but relapses are observed within months to a few years, with frequent failure of subsequent therapies. High-dose chemotherapy with or without radiation and autologous or allogeneic hematopoietic stem cell transplantation provide higher cure rates and longer remissions in certain patients with aggressive lymphomas. However, the higher treatment-related morbidity and mortality of high-dose chemotherapy has driven a search for new and more tumor-specific treatment modalities, such as immunotherapy. Tumor antigens expressed by B-cell lymphomas, such as the "idiotype antigen", are seen as unique and specific target molecules for direct lymphoma immunotherapy. This review will delineate advances, problems and prospects for approaches to anti-B cell lymphoma immunotherapy where pre-clinical studies and proof of principle have been directly translated to patient care.

Prolymphocytoid transformation of follicular lymphoma with coexpression of CD5 and CD10

Histologic transformation of follicular lymphoma is usually to a diffuse large B-cell lymphoma. We present a rare example of a histologic transformation of follicular lymphoma manifested by prolymphocytoid morphology and an unusual immunophenotype characterized by coexpression of CD5 and CD10. The transformed prolymphocytoid lymphoma was positive for CD5 and CD10 antigens by both flow cytometry and immunohistochemistry. The case also expressed bcl-2 and bcl-6 proteins, and exhibited t(14;18), consistent with derivation from a pre-existing follicular lymphoma. Polymerase chain reaction analysis of the immunoglobulin kappa light chain genes derived from the follicular lymphoma and prolymphocytoid lymphoma showed identical rearranged bands, suggesting clonal identity of the two neoplasms. The basis for coexpression of CD5 and CD10 remains unclear. Because the preceding low-grade follicular lymphoma was positive only for CD10 and did not express CD5, CD5 expression appears to be an acquired phenomenon accompanying the process of histologic transformation in this particular case. Prolymphocytoid transformation, similar to other histologic forms of transformation of follicular lymphoma, appears to accompany clinical progression of disease.

BiovaxID, a personalized therapeutic vaccine against B-cell lymphomas

Biovest International Inc (a subsidiary of Accentia BioPharmaceuticals Inc), under license from Stanford University, is developing BiovaxID, a personalized therapeutic vaccine against B-cell lymphomas that, in combination with GM-CSF, exclusively targets cancerous B-cells by raising an immune response to tumor-specific immunoglobulin proteins called idiotypes, for the potential treatment of follicular non-Hodgkin's lymphoma (NHL). Phase I and II clinical trials demonstrated the immunogenicity, safety and therapeutic efficacy of BiovaxID. Phase III clinical trials in NHL were ongoing at the time of publication.

Diffuse large B-cell lymphoma after transformation from low-grade follicular lymphoma: morphological, immunohistochemical, and FISH analyses

Follicular lymphoma (FL) is one of the most common subtypes of non-Hodgkin lymphoma and frequently transforms to diffuse large B-cell lymphoma (DLBCL). To clarify some aspects of the natural history of FL, we retrospectively examined 43 consecutive patients who had DLBCL with pre- or coexisting FL grade 1 or 2. The patients comprised 22 men and 21 women with a median age of 53 years. Most of the patients (34/43) showed advanced-stage (III or IV) disease initially. We examined both FL and DLBCL components morphologically, immunohistochemically, and by interface fluorescence in situ hybridization (FISH: IGH/BCL2 fusion, BCL6 translocation) analysis. Most of the DLBCLs were classified as the centroblastic subtype, with two exceptions of the anaplastic subtype. Immunohistochemical analysis of both the FL and DLBCL components revealed the following respective positivity rates: CD20 100%/100%, CD10 86%/66%, Bcl-2 96%/91%, Bcl-6 84%/88%, MUM1 16%/34%, CD30 0%/20%, CD138 0%/0%, and CD5 0%/3%. Loss of CD10 (6/36, 17%) and gain of MUM1 (7/28, 25%) and CD30 (5/21, 24%) through transformation were not infrequent. High positivity rates for Bcl-2 and Bcl-6 were maintained throughout transformation. Among the DLBCLs, 84% were classified as the germinal center B-cell phenotype (GCB) and 16% as non-GCB in accordance with the criteria of Hans et al. IGH/BCL2 fusion was detected by FISH in 89% of FLs and 82% of DLBCLs. BCL6 translocation was detected in 1/6 (17%) DLBCLs without IGH/BCL2 fusion. Thus, although the morphological features and FISH results for DLBCL were consistent with transformed FL, the immunophenotype showed wide heterogeneity.