The presence of Mott cells in the lymph nodes of rats with experimental autoimmune encephalomyelitis.

Mott cells are plasma cells that have multiple spherical Russell bodies packed in their cytoplasm. Russell bodies are dilated endoplasmic reticulum cisternae filled with aggregates of immunoglobulins that are neither secreted nor degraded. Mott cells were observed in our study by light and electron microscope in the lymph nodes of rats with experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Mott cells were detected on hematoxylin and eosin (HE)-stained lymph node sections as vacuolated cells with eccentrically positioned nuclei and large number of faint blue spherical inclusions in the cytoplasm. Electron microscopic investigation revealed the presence of Russell bodies of the "medusa" form inside Mott cells in lymph node ultra-thin sections of EAE animals. Mott cells expressed the plasma cell marker CD138 and either kappa or lambda immunoglobulin light chains, indicating their origin from polyclonally activated B cells. Finally, Mott cells were associated with active EAE, as they were not found in the lymph nodes of EAE-resistant Albino Oxford rats. The presence of Russell bodies implies an excessive production of immunoglobulins in EAE, thus further emphasizing the role of B cells, and among them Mott cells, in the pathogenesis of this animal model of multiple sclerosis.

Clinicopathological and fluorescence in situ hibridisation analysis of primary testicular diffuse large B-cell lymphoma: a single-centre case series.

Primary testicular diffuse large B-cell lymphoma (PT-DLBCL) represents a rare and aggressive extranodal non-Hodgkin's lymphoma (NHL) with some specific features that differ from other NHLs. Formalin fixed, paraffin wax embedded (FFPE) samples of 21 PT-DLBCLs and 30 comparative patients with DLBCL were analysed. All PT-DLBCL patients were treated with rituximab-containing regimens, intrathecal prophylaxis (10 patients), and irradiation of the contralateral testis (9 patients). FFPE samples were additionally analysed by immunohistochemistry (Bcl-2, c-Myc protein expression) and fluorescence in situ hybridisation (FISH) (BCL2 and MYC). The patients with PT-DLBCL (median age 48.5 years), had low frequency of B symptoms (28.6%) and were often diagnosed in I and II Ann Arbor clinical stage (66.0%). The majority of PT-DLBCL (80.9%) had a non-germinal centre B-cell-like immunophenotype. Immunohistochemical staining showed increased c-Myc protein expression in the PT-DLBCL group compared to the control group (p = 0.016). MYC rearrangement was detected in 1 of 14 (7.0%), and MYC amplification in 3 of 14 (21.0%) patients. One of the 14 cases (7.0%) in the PT DLBCL group showed BCL2 rearrangement, and four of 14 (28.05%) cases showed BCL2 amplification. Complete remission (CR) was achieved in 75.0% of PT-DLBCL patients who had superior survival compared to those who did not achieve CR (median 48 vs. 21 months, p = 0.012). Patients with PT-DLBCL express some immunohistochemical, biological, and clinical features that might differentiate them from nodal and extranodal DLBCL patients, indicating the need for a more personalised treatment approach.

BCL2 positive and BCL6 negative diffuse large B cell lymphoma patients benefit from R-CHOP therapy irrespective of germinal and non germinal center B cell like subtypes.

PURPOSE: Despite major advances in the treatment of diffuse large B cell lymphoma (DLBCL), approximately one third of the patients progress or die, suggesting the existence of additional oncogenic events. The purpose of this study was to evaluate the prognostic value of the "Hans classifier", and BCL2 and MYC protein expression and gene alterations in DLBCL patients treated with CHOP or R-CHOP chemotherapy over a 5-year period. Furthermore, we tried to correlate these parameters with the International Prognostic Index (IPI). METHODS: The immunohistochemical (IHC) expression of CD10, BCL6, MUM1 and BCL2 on paraffin-embedded formalin-fixed tumor samples from 103 centroblastic DLBCLs was analyzed. IHC expression of MYC and fluorescence in situ hybridization (FISH) for MYC and BCL2 gene alterations was performed on 67 samples using the tissue microarray (TMA) method. RESULTS: The Hans algorithm was not predictive of survival in both therapy groups. No significant difference in BCL2 and MYC alterations or MYC protein expression in relation to complete response (CR), event-free survival (EFS) and overall survival (OS) was observed in our study. High IPI correlated significantly with poor outcome and it was identified as independent prognostic factor for OS and EFS (both p=0.000). The 5-year OS was 61% in the R-CHOP compared to 38% in the CHOP group (p=0.007). Rituximab significantly improved the OS in the BCL2 positive (60 vs 29%, p=0.008), and the BCL6 negative (73 vs 25%, p=0.001) cases. CONCLUSION: IPI is an independent prognosticator for DL-BCL patients and the addition of rituximab significantly improved survival. Furthermore, patients with BCL2+ and BCL6-DLBCL benefited from R-CHOP.

Poor outcome in patients with diffuse large B-cell lymphoma is associated with high percentage of bcl-2 and Ki 67-positive tumor cells.

BACKGROUND/AIM: Newly diagnosed patients with diffuse large B-cell lymphoma (DLBCL) tretaed with immunochemotherapy have durable remission and improved overall survival. It is important to identify high risk patients who may benefit from even more effective therapies. METHODS: In a group of 50 newly diagnosed patients with DLBCL, treated with CHOP/R-CHOP (cyclophosphemide doxorubicine, vincristine, prednisone with or without rituximab) regimen, we analyzed the prognostic value of the expression of Ki67 and bcl-2 at diagnosis as well as other standard clinical parameters: International Prognostic Index (IPI), bulky disease, extranodal distribution and lactat dehydrogenase (LDH). Significance was tested according to response rate and overall survival. RESULTS: Univariate survival analysis showed that high IPI had a statistically significant negative influence on overall and event free survival time (log rank, p < 0.01). The log rank test analysis signified that patients with a high proliferative fraction (Ki-67 > 60%) had a worse overall survival rate (OS5y) of 40% compared to those with low proliferation (Ki-67 < 60%) with OS5y of 80% (p < 0.01). There was a clear difference between bcl-2 positivity (treshold 50%) and the achievement of complete remission (66% vs 86% in patients with bcl-2 high and low levels respectively, p < 0.05). In survival analysis, patients with low bcl-2 expression had significantly higher OS5y - 68% compared to those with high bcl-2+ with OS5y 37% (p < 0.05). Multivariate analysis performed by Cox model revealed that IPI > 3, high Ki-67+, bcl-2 positivity had a significant independent prognostic value concerning overall survival (p < 0.05). CONCLUSION: An initial high IPI score associated with high Ki-67+ and bcl2+ could represent possible predictive factors of poor prognosis, which would help to identify a high risk subgroup of newly diagnosed DLBCL.