Over 30% of patients with splenic marginal zone lymphoma express the same immunoglobulin heavy variable gene: ontogenetic implications.

We performed an immunogenetic analysis of 345 IGHV-IGHD-IGHJ rearrangements from 337 cases with primary splenic small B-cell lymphomas of marginal-zone origin. Three immunoglobulin (IG) heavy variable (IGHV) genes accounted for 45.8% of the cases (IGHV1-2, 24.9%; IGHV4-34, 12.8%; IGHV3-23, 8.1%). Particularly for the IGHV1-2 gene, strong biases were evident regarding utilization of different alleles, with 79/86 rearrangements (92%) using allele (*)04. Among cases more stringently classified as splenic marginal-zone lymphoma (SMZL) thanks to the availability of splenic histopathological specimens, the frequency of IGHV1-2(*)04 peaked at 31%. The IGHV1-2(*)04 rearrangements carried significantly longer complementarity-determining region-3 (CDR3) than all other cases and showed biased IGHD gene usage, leading to CDR3s with common motifs. The great majority of analyzed rearrangements (299/345, 86.7%) carried IGHV genes with some impact of somatic hypermutation, from minimal to pronounced. Noticeably, 75/79 (95%) IGHV1-2(*)04 rearrangements were mutated; however, they mostly (56/75 cases; 74.6%) carried few mutations (97-99.9% germline identity) of conservative nature and restricted distribution. These distinctive features of the IG receptors indicate selection by (super)antigenic element(s) in the pathogenesis of SMZL. Furthermore, they raise the possibility that certain SMZL subtypes could derive from progenitor populations adapted to particular antigenic challenges through selection of VH domain specificities, in particular the IGHV1-2(*)04 allele.

Immunoglobulin gene repertoire in ocular adnexal lymphomas: hints on the nature of the antigenic stimulation.

Evidence from certain geographical areas links lymphomas of the ocular adnexa marginal zone B-cell lymphomas (OAMZL) with Chlamydophila psittaci (Cp) infection, suggesting that lymphoma development is dependent upon chronic stimulation by persistent infections. Notwithstanding that, the actual immunopathogenetical mechanisms have not yet been elucidated. As in other B-cell lymphomas, insight into this issue, especially with regard to potential selecting ligands, could be provided by analysis of the immunoglobulin (IG) receptors of the malignant clones. To this end, we studied the molecular features of IGs in 44 patients with OAMZL (40% Cp-positive), identifying features suggestive of a pathogenic mechanism of autoreactivity. Herein, we show that lymphoma cells express a distinctive IG repertoire, with electropositive antigen (Ag)-binding sites, reminiscent of autoantibodies (auto-Abs) recognizing DNA. Additionally, five (11%) cases of OAMZL expressed IGs homologous with autoreactive Abs or IGs of patients with chronic lymphocytic leukemia, a disease known for the expression of autoreactive IGs by neoplastic cells. In contrast, no similarity with known anti-Chlamydophila Abs was found. Taken together, these results strongly indicate that OAMZL may originate from B cells selected for their capability to bind Ags and, in particular, auto-Ags. In OAMZL associated with Cp infection, the pathogen likely acts indirectly on the malignant B cells, promoting the development of an inflammatory milieu, where auto-Ags could be exposed and presented, driving proliferation and expansion of self-reactive B cells.

PUVA plus interferon α2b in the treatment of advanced or refractory to PUVA early stage mycosis fungoides: a case series.

BACKGROUND: The combination of PUVA with variable doses of systemically administered interferon α2b (IFN-α2b) reduces the number of PUVA treatments and the dose of IFN-α2b required to produce remission in all mycosis fungoides (MF) stages. OBJECTIVES: To evaluate the efficacy of the combination of PUVA and IFN-α2b in patients with late stage or refractory to treatment early stage MF. METHODS: The combination of PUVA three times weekly and IFN-α2b 2-5 MU three times weekly was retrospectively reviewed in 22 patients. Kaplan-Meyer method and log-rank test was used for statistical analysis. RESULTS: Twenty-two patients were analysed, seven with refractory to PUVA early stage MF, seven with tumour stage, five with erythrodermic MF and three with Sézary syndrome (SS). The overall response rate (complete or partial response) was 68%, including 10 complete responses (CR) (45%) and five partial responses (PR) (23%). Significantly, more patients of the early stage group achieved CR compared with the advanced stage group (86% vs. 27%, P=0.03). Within the advanced stage group, CR rates were 14% vs. 37% in stage IIB and III/SS patients respectively, but the difference was not statistically significant. Patients with early stage disease had a 2-year PFS of 100% vs. 27% for the advanced stage group (P<0.001). Sustained remissions (>2 years) were achieved in five out of six complete responders in the early stage group of patients. CONCLUSION: This combination of IFN-α2b and PUVA is an effective and safe treatment for refractory to treatment early stage MF patients as well as treatment-naïve advanced stage patients. Its efficacy is more pronounced in the former patient group.

Splenic marginal zone lymphoma proposals for a revision of diagnostic, staging and therapeutic criteria.

Since the initial description of splenic marginal zone lymphoma (SMZL) in 1992, an increasing number of publications have dealt with multiple aspects of SMZL diagnosis, molecular pathogenesis and treatment. This process has identified multiple inconsistencies in the diagnostic criteria and lack of clear guidelines for the staging and treatment. The authors of this review have held several meetings and exchanged series of cases with the objective of agreeing on the main diagnostic, staging and therapeutic guidelines for patients with this condition. Specific working groups were created for diagnostic criteria, immunophenotype, staging and treatment. As results of this work, guidelines are proposed for diagnosis, differential diagnosis, staging, prognostic factors, treatment and response criteria. The guidelines proposed here are intended to contribute to the standardization of the diagnosis and treatment of these patients, and should facilitate the future development of clinical trials that could define more precisely predictive markers for histological progression or lack of response, and evaluate new drugs or treatments.

Activated T-lymphocytes with myelosuppressive properties in patients with chronic idiopathic neutropenia.

To characterize the cellular components responsible for the impaired granulopoiesis in chronic idiopathic neutropenia (CIN), we investigated the origin of the proapoptotic cytokine producing cells in the bone marrow (BM) microenvironment of CIN patients. We found that the interferon gamma (IFN gamma) and/or Fas-ligand expressing cells in patient BM mononuclear cells and long-term BM culture stroma cells were the CD3(+) T-lymphocytes but not the CD14(+) monocytes/macrophages. The percentage of activated T-lymphocytes was increased in patients' BM as indicated by the proportions of human leucocyte antigen (HLA)-DR(+), CD25(+), CD38(+), CD69(+) and Fas(+) cells within the CD3(+) fraction. Intracellular IFN gamma expression was higher in the BM than peripheral blood of the patients and was associated with increased BM T-lymphocyte numbers. In crossover experiments, patient CD3(+) T-lymphocytes conferred autologous and allogeneic haemopoietic progenitor cell colony inhibition. Patients' T-cell receptor repertoire and polymerase chain reaction analysis did not reveal any clonal T-lymphocyte expansion, suggesting the absence of a direct, antigen-driven recognition of CD34(+) myeloid progenitor cells by patient T-lymphocytes. We conclude that CIN patients have increased number of activated T-lymphocytes in the BM, probably in the setting of a localized polyclonal immune reaction and that these cells confer an inhibitory effect on myelopoiesis through myelosuppressive cytokines including Fas-ligand and IFN gamma.

A unique case of splenic marginal zone-cell lymphoma with synchronous clonal T-cell large granular lymphocyte proliferation: an immunologic, immunohistochemical and genotypic study.

We describe a case of synchronous splenic marginal zone-cell lymphoma (SMZL) and T-cell large granular lymphocyte leukemia involving the spleen, liver, bone marrow and peripheral blood. The synchronous occurrence of these two processes was documented by morphological, immunophenotypical and molecular (PCR) analyses of all affected tissues. The pathogenetic mechanisms which may be responsible for the concomitant appearance of these two rather infrequent entities in the same anatomic sites are discussed.

Anti-CD20-based therapy of B cell lymphoma: state of the art.

Over the last 5 years, studies applying the chimeric anti-CD20 MAb have renewed enthusiasm and triggered world-wide application of anti-CD20 MAb-based therapies in B cell non-Hodgkin's lymphoma (NHL). Native chimeric anti-CD20 and isotope-labeled murine anti-CD20 MAbs are currently employed with encouraging results as monotherapy or in combination with conventional chemotherapy and in consolidation of remission after treatments with curative intent (ie after/ in combination with high-dose chemotherapy and hematopoietic stem cell rescue). On the available experience, anti-CD20 MAb-based therapeutic strategies will be increasingly integrated in the treatment of B cell NHL and related malignancies.

Evidence for T-large granular lymphocyte-mediated neutropenia in Rituximab-treated lymphoma patients: report of two cases.

We report two cases with B cell malignancies (case #1: refractory mantle cell lymphoma; case #2: lymphocyte predominant Hodgkin's disease (LPHD)) who developed neutropenia post-Rituximab therapy in a setting of significant infiltration of the peripheral blood (PB) and bone marrow (BM) by T cells with an immunophenotype of large granular lymphocytes. Possible pathogenetic mechanisms are discussed.

Somatic hypermutation targeting to intrinsic hotspots of immunoglobulin genes in follicular lymphoma and multiple myeloma.

In this study, we analyzed the targeting of the somatic hypermutation (SHM) mechanism at specific hotspot sequence motifs in the V(H) and Vkappa genes of 10 follicular lymphoma (FL) cases and the Vkappa and Vlambda genes of 11 kappa- and six lamda-light chain expressing multiple myeloma (MM) cases. These sequences were analyzed for targeting of specific motifs, ie certain highly mutable trinucleotides (3-NTPs), the tetranucleotide (4-NTP) RGYW and its complementary, WRCY (where R = purine, Y = pyrimidine and W = A or T). Comparisons were carried out between mutation frequencies in RGYW vs WRCY and the incidence of mutations in complementarity determining region (CDR)-1 vs CDR2 vs CDR3. Statistically significant differences were obtained when comparing: (1) the ratio of mutations in 4-NTPs (RGYW, WRCY, RGYW+WRCY)/mutations in the whole V sequence in MM-Vkappa vs MM-Vlamda; (2) the total number of mutated 4-NTPs in MM-Vkappa vs FL-Vkappa; (3) the number of mutated RGYW 4-NTPs in MM-Vkappa vs FL-Vkappa and FL-V(H) vs FL-Vkappa; (4) the number of mutated WRCY 4-NTPs in MM-Vkappa vs FL-Vkappa (P= 0.006) and FL-V(H) vs FL-Vkappa; (5) the targeting of RGYW vs WRCY in the CDRs of FL-V(H) genes. Similar results (regarding statistical significance) were obtained when undertaking intergroup comparisons for 3-NTPs. These findings conform well with relevant data derived from normal peripheral B cells. The differences observed in favor of 4-NTP (RGYW and WRCY) targeting in FL-V(H) vs FL-Vkappa and MM-Vkappa vs FL-Vkappa may implicate differences in the evolution of SHM coupled with selection in different stages of B cell ontogeny. Several explanations can be offered for the fact that hotspot sequences were not always targeted by SHM in FL and MM: (1) other unrecognized motifs may be targets of SHM; (2) 'inappropriately' introduced mutations were fixed and propagated by the neoplastic process; (3) certain FL and MM cases might have lost their ability to correct mutations introduced in classic hotspots due to deficient mismatch-repair (MMR) mechanisms; conversely, in other cases with intact MMR function, the hotspot to non-hotspot targeting of somatic hypermutation is balanced.

Gingival overgrowth as the initial paraneoplastic manifestation of Hodgkin's lymphoma in a child. A case report.

BACKGROUND: The purpose of this paper is to present the first case of gingival overgrowth, premature root resorption, and alveolar bone loss, which preceded the diagnosis of a stage IVB Hodgkin's lymphoma (HL) in a 9-year-old boy. METHODS: The child presented complaining of gingival pain which first appeared 3 months prior. Clinical examination revealed inflamed, hyperplastic gingivae, while x-ray showed premature root resorption and alveolar bone loss. Medical work-up was significant for cervical lymphadenopathy. Gingival biopsy, followed by lymph node resection, was performed twice. RESULTS: Histological examination of both gingival biopsies disclosed a mixed inflammatory infiltrate, while classical Hodgkin's lymphoma of the nodular sclerosis type was diagnosed from the second lymph node biopsy. Chemotherapy was instituted with mustard-vincristine-procarbazine-prednizone and adriamycine-bleomycine-vinblastine-dacarbazine. Remission of the lymphoma was observed with concomitant regression of the gingival overgrowth. CONCLUSIONS: The inflammatory gingival overgrowth, premature root resorption of deciduous teeth, and alveolar bone loss in this case, in conjunction with the regression of gingival overgrowth which followed the completion of chemotherapy, are strongly indicative of a paraneoplastic manifestation of HL. The postulated mechanism for the development of the manifestation is the constitutive activation of the transcription factor NF-kB. The gingival inflammatory reaction was probably further aggravated by the bacterial-stimulated cytokine secretion released by monocytes.

Simultaneous appearance of mycosis fungoides and chronic lymphocytic leukemia in the same patient.

A patient is presented having simultaneously chronic lymphocytic leukemia with a monoclonal B-lymphocyte population and mycosis fungoides with atypical T-cell population in the skin lesion and in the enlarged lymphoid nodes confirmed by detailed phenotyping.

Molecular insights into the immunopathogenesis of follicular lymphoma.

Follicular lymphoma is caused by the transformation of a germinal-center-derived B cell with a t(14;18) chromosomal translocation. The distribution of somatic mutations within immunoglobulin genes indicates that follicular-lymphoma cells can interact with antigen. In addition, nonimmunoglobulin genes such as BCL6 seem to undergo somatic hypermutation. Here, Kostas Stamatopoulos and colleagues relate the molecular data about immunoglobulin genes and the protooncogenes BCL2 and BCL6 to the pathogenesis and evolution of follicular lymphoma.

Molecular analysis of bcl-1/IgH junctional sequences in mantle cell lymphoma: potential mechanism of the t(11;14) chromosomal translocation.

Mantle cell lymphoma (MCL) is characterized by the t(11;14) translocation that juxtaposes the bcl-1 locus to immunoglobulin (Ig) gene sequences and leads to deregulation of cyclin D1 gene. t(11;14) is thought to result from an error of the recombinase during D-JH Ig gene assembly; however, data on the underlying mechanism and candidate recombination-targeting motifs in the major translocation cluster (MTC) of the bcl-1 gene are lacking. bcl-1/IgH junctional sequences from seven MCL patients were amplified by PCR using primers targeting MTC and JH sequences on chromosomes 11q13 and 14q32, respectively. PCR products were directly sequenced and junctional sequences were searched for homology to known germline D genes. bcl-t MTC breakpoints were searched for the presence of possible recombination target motifs; heptamers, nonamers, binding sequence of the bp45 nuclease, x-like sequences and D gene segments. bcl-1/JH junctions were found to bear homology to D gene segments (DLR3, DM and DIR5) in 3/7 MCL samples. A computer-based search in previously published and/or submitted to GenBank bcl-1/JH junctional sequences identified homology to D genes in 1/4 MCL tumour samples and 1/4 MCl cell lines; DXP4 or D23/7 and DHQ52 or D22/21 or DXP5, respectively. The MTC locus contained motifs with homology to bp45 nuclease binding sequence, x-like sequences, heptamers/nonamers, D-like DIR genes and non-homologous recombination short (6 bp) DNA sequences. The above data indicate that the t(11;14) translocation in MCL may also occur at a more mature stage of B-cell ontogeny than previously thought, i.e. during VH-to-DJH rearrangement. Various known recombination motifs within MTC may contribute to an illegitimate recombination event between bcl-1 and DJH.