Hepatitis C virus in MALT-lymphoma of the ocular adnexa.

OBJECTIVE: Hepatitis C virus (HCV) has been proposed as a possible etiologic factor in ocular adnexal marginal zone lymphoma (OAML). We aimed to assess the prevalence of HCV infection in patients with OAML through a systematic review and meta-analysis. METHODS: Electronic databases were searched from their inception to August 2019 for studies assessing HCV seroprevalence in patients with OAML. Pooled prevalence of HCV infection was calculated with 95 % confidence interval (CI). Statistical heterogeneity among studies was quantified via the inconsistency index (I2). Funnel plot symmetry was used to assess the risk of bias across studies. RESULTS: Nine studies with 360 patients were included. Overall pooled prevalence of HCV in OAML was 12.7 %, with low statistical heterogeneity (I2 = 17.4 %) and with asymmetrical funnel plot. The studies clustered into two groups: 5 studies (3 from Italy and 2 multicenter with a major Italian contribution) showed a higher HCV prevalence in OAML (15.6 %), while the other 4 (from countries other than Italy) showed a lower prevalence (4.7 %); in both subgroups, statistical heterogeneity was null (I2 = 0%) and funnel plot was symmetrical. CONCLUSION: HCV might be a significant etiologic factor of OAML in Italy.

Composite Epstein-Barr virus-positive mucosa-associated lymphoid tissue lymphoma and Epstein-Barr virus-negative diffuse large B-cell lymphoma in the parotid salivary gland of a patient with Sjögren's syndrome and rheumatoid arthritis: a case report.

BACKGROUND: Epstein-Barr virus is associated with many human hematopoietic neoplasms; however, Epstein-Barr virus-positive mucosa-associated lymphoid tissue lymphoma is extremely rare. In routine clinical practice, detection of mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma in a tissue sample presumes a clonal relation between these neoplasms and that diffuse large B-cell lymphoma developed by transformation of the mucosa-associated lymphoid tissue lymphoma. However, evidence to support this presumption is sparse and controversial. Assessment of the clonal relationship of the lymphoid components of a composite lymphoma is important for understanding its pathogenesis and correct diagnosis. CASE PRESENTATION: We present an unusual case of composite lymphoma (Epstein-Barr virus-positive mucosa-associated lymphoid tissue lymphoma/Epstein-Barr virus-negative diffuse large B-cell lymphoma) in the parotid salivary gland of a 62-year-old Caucasian woman with Sjögren's syndrome and rheumatoid arthritis. Simultaneous occurrence of mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma in the parotid salivary gland led us to initially assume a clonal relationship between diffuse large B-cell lymphoma and mucosa-associated lymphoid tissue lymphoma. Epstein-Barr virus was detected by in situ hybridization and polymerase chain reaction in the mucosa-associated lymphoid tissue lymphoma, but not in diffuse large B-cell lymphoma, suggesting that these lymphomas were not clonally related. Fragment analysis of frame region 3 polymerase chain reaction products from microdissected mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma components revealed different clonal pattern rearrangements of the immunoglobulin heavy chain gene. CONCLUSIONS: Our patient's case highlights the importance of assessing the clonal relationships of the lymphoid components of a composite lymphoma and Epstein-Barr virus screening in mucosa-associated lymphoid tissue lymphoma in patients with autoimmune disease.

High-throughput sequencing reveals no viral pathogens in eight cases of ocular adnexal extranodal marginal zone B-cell lymphoma.

The purpose of the present study was to perform a next-generation sequencing (NGS) based analysis of viruses in ocular adnexal extranodal marginal zone B-cell lymphoma (EMZL). Eight patients with extraocular EMZL were identified in the archives of Department of Ophthalmology, Copenhagen University Hospital. All cases were validated according to the World Health Organization classification. We subjected samples to enrichment of virion-associated (encapsidated) nucleic acids which included sample homogenization, filtration, and nuclease treatment. Both DNA and RNA were sequenced, and we analyzed the sequencing data for the presence of viral sequences. We detected no pathogenic viruses likely to be associated to development of EMZL. In one case, we detected human polyomavirus 7 and traces of Epstein-Barr virus (EBV) (human herpesvirus 4 (HHV4)) and a human papillomavirus. In conclusion, no viral pathogens were consistently detected in the extraocular EMZL samples when applying NGS-based methods.

Epstein-Barr Virus-Associated Nodal Marginal Zone Lymphoma: Part of the Spectrum of Posttransplant Lymphoproliferative Disorder?

A 56-year-old man, who received deceased kidney transplant 20 years ago, presented with an enlarged submandibular lymph node. Histologic examination revealed nodal marginal zone lymphoma in which the neoplastic lymphoid cells showed diffuse positivity for Epstein-Barr virus early RNA by in situ hybridization. Systemic lymphoma workup showed stage I disease. The tumor was managed as a posttransplant lymphoproliferative disorder and the immunosuppression was modified. There was no evidence of lymphoma at follow-up 6 years after excision alone. This case supports the inclusion of Epstein-Barr virus-positive nodal marginal zone lymphoma as a form of monomorphic B-cell lymphoproliferative disorder, in line with the status of its extranodal mucosa-associated lymphoid tissue lymphoma counterpart.

Lymphomagenic properties of a HIV p17 variant derived from a splenic marginal zone lymphoma occurred in a HIV-infected patient.

Despite antiretroviral therapy, HIV+ individuals still have increased risk to develop lymphomas, including marginal zone lymphomas, suggesting that factors other than HIV-related immunosuppression are probably acting as lymphomagenic factors in the HIV setting. The possible pathogenic involvement of HIV p17 protein variants was investigated in a particularly informative case of HIV-related splenic marginal zone lymphoma, which was negative for oncogenic virus infections, thus allowing us to assess the possible direct contribution of these HIV-encoded proteins to lymphomagenesis. The presence of p17 protein was analyzed by immunohistochemistry in lymphoma tissue. Recombinant p17 protein derived from the dominant sequence detected in plasma and lymphoma biopsy was characterized for B-cell proliferation, clonogenicity in soft agar, in vitro tube formation and wound healing. Intracellular signaling was investigated by immunoblotting. HIV p17 protein was detected in reactive lymphoid follicles but not within lymphoma cells. An identical dominant variant p17 sequence, p17-Lyrm, carrying a 117 to 118 Ala-Ala insertion was detected in both plasma and lymphoma tissue. Recombinant p17-Lyrm enhanced B-cell proliferation and clonogenicity promoted the formation of capillary-like structures and enhanced endothelial cell migration. Unlike reference p17, the p17-Lyrm variant enhanced the activation of Akt and ERK, critical kinases in lymphomagenesis. p17-Lyrm clonogenic activity was dependent on the activation of Akt but not of ERK1/2. These results indicated that HIV p17 variants with distinct molecular signatures and functional properties may accumulate in lymphoid tissues of HIV-infected individuals where they may act as a local stimulus promoting the development of lymphomas.

Expanding the Spectrum of EBV-positive Marginal Zone Lymphomas: A Lesion Associated With Diverse Immunodeficiency Settings.

Traditionally low-grade B-cell lymphomas have been excluded from the category of monomorphic posttransplant lymphoproliferative disorders. However, recent reports identified Epstein-Barr virus-positive (EBV) extranodal marginal zone lymphomas (MZL), almost exclusively seen in the posttransplant setting. Some reported cases responded to reduced immunosuppression, suggesting that they should be considered as a form of posttransplant lymphoproliferative disorders. We identified 10 cases of EBV MZL, 9 in extranodal sites and 1 presenting in lymph node. Two cases arose following solid organ transplantation, but other settings included iatrogenic immunosuppression for rheumatoid arthritis (2); prior chemotherapy (2); congenital immune deficiency (1); and increased age (3), as the only potential cause of immune dysfunction. There were 4 males and 6 females; age range 18 to 86. The atypical plasmacytoid and/or monocytoid B cells were positive for EBV in all cases, with either latency I or II in all cases tested. Monotypic light chain expression was shown in all with 6 cases positive for IgG, and 2 for IgM, undetermined in 2. Clonal immunoglobulin gene rearrangement was positive in all cases with successful amplification. MYD88 L265P was wild type in the 6 cases tested. We show that EBV MZLs can arise in a variety of clinical settings, and are most often extranodal. Treatment varied, but most patients had clinically indolent disease with response to reduction of immune suppression, or immunochemotherapy.

Epstein-Barr Virus-Positive Extranodal Marginal Zone Lymphoma of Bronchial-Associated Lymphoid Tissue in the Posttransplant Setting: An Immunodeficiency-Related (Posttransplant) Lymphoproliferative Disorder?

OBJECTIVES: Posttransplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of hematolymphoid proliferations arising in the context of chronic immunosuppression. The common and indolent B-cell lymphomas, including extranodal marginal zone lymphomas (ENMZLs) of mucosa-associated lymphoid tissue (MALT), are excluded from the category of PTLD in the current World Health Organization classification. METHODS: We report a case of Epstein-Barr virus (EBV)-positive bronchial-associated lymphoid tissue (BALT) lymphoma involving the lungs of a transplant patient. RESULTS: Aside from history of cardiac transplant, young patient age, and EBV positivity, the histopathologic findings were indistinguishable from usual BALT lymphoma. CONCLUSIONS: We review the literature of ENMZL occurring in immunocompromised patients and present this case for consideration that this specific entity is a PTLD. We believe that additional studies might lend strength to the hypothesis that this particular group of EBV-positive, posttransplant ENMZLs merits classification and management as PTLDs.

Regression of uterine cervical diffuse large B-cell lymphoma transformed from mucosa-associated lymphoid tissue lymphoma subsequent to Chlamydia trachomatis eradication.

A 37-year-old-woman was referred to our center after her uterine cervix health screening presented abnormal findings. We performed a biopsy of the uterine cervix to examine for cervical dysplasia, and diagnosed a diffuse large B-cell lymphoma transformed from mucosa-associated lymphoid tissue (MALT) lymphoma of the cervix. The patient presented with concurrent chlamydial cervicitis and received eradication therapy for Chlamydia trachomatis. Four months later, the CD20 positive abnormal lymphocyte disappeared and complete remission was achieved. MALT lymphoma is considered to correlate with infection and inflammation. Particularly, the relationship between gastric MALT lymphoma and Helicobacter pylori is well known. MALT lymphoma of the uterine cervix is rare, and its relationship with C.trachomatis infection is unknown. Further studies are warranted to investigate this association.

Hepatitis C virus - Associated marginal zone lymphoma.

The link between hepatitis C virus (HCV) infection and the development of B-cell non-Hodgkin lymphoma is now well established and based on a number of epidemiological studies. It is further supported by the observation of lymphoma regression after HCV eradication by antiviral treatment. The far most frequent entities are marginal zone lymphoma (MZL) and diffuse large B-cell lymphoma (DLBCL). MZL usually emerge on a background of mixed cryoglobulinemia, a low-grade lymphoproliferation, and often transform into DLBCL, thereby following a multistep oncogenesis process. The role of HCV in lymphomagenesis is not yet fully understood but several mechanisms have been proposed including (i) chronic external stimulation through the B-cell receptor and other surface receptors, and (ii) direct transformation by intracellular viral proteins, the former being probably predominant in MZL. Regression of HCV-associated MZL can be achieved with antiviral therapy and the novel generation of direct-acting antiviral agents appears highly effective and safe for the treatment of these lymphoma.

A Gain-Of-Function Mutation in the Plcg2 Gene Protects Mice from Helicobacter felis-Induced Gastric MALT Lymphoma.

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas develop from a chronic Helicobacter infection. Phospholipase C gamma 2 (PLCG2) is important for B-cell survival and proliferation. We used BALB/c mice with a gain-of-function mutation in the Plcg2 gene (Ali5) to analyze its role in the development of gastric MALT lymphoma. Heterozygous BALB/c Plcg2Ali5/+ and wildtype (WT) mice were infected with Helicobacter felis (H. felis) and observed up to 16 months for development of gastric MALT lymphomas. In contrast to our initial hypothesis, Plcg2Ali5/+ mice developed MALT lymphomas less frequently than their WT littermates after long-term infection of 16 months. Infected Plcg2Ali5/+ mice showed downregulation of proinflammatory cytokines and decreased H. felis-specific IgG1 and IgG2a antibody responses. These results suggested a blunted immune response of Plcg2Ali5/+ mice towards H. felis infection. Intriguingly, Plcg2Ali5/+ mice harboured higher numbers of CD73 expressing regulatory T cells (Tregs), possibly responsible for impaired immune response towards Helicobacter infection. We suggest that Plcg2Ali5/+ mice may be protected from developing gastric MALT lymphomas as a result of elevated Treg numbers, reduced response to H. felis and decrease of proinflammatory cytokines.

Helicobacter pylori CagA Translocation Is Closely Associated With the Expression of CagA-signaling Molecules in Low-grade Gastric Mucosa-associated Lymphoid Tissue Lymphoma.

We previously reported that the direct contact of Helicobacter pylori (HP) and B cells results in CagA translocation into the latter and that the translocated CagA regulates intracellular signaling pathways. Similarly, we recently found that CagA does exist in the malignant B cells of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and that its presence is closely associated with HP dependence. In this study, we further evaluated whether CagA expression regulates signal transduction molecules in the tumor cells and further contributes to the lymphomagenesis of HP-dependent growth of gastric MALT lymphoma. Forty-seven patients with stage IE HP-positive gastric MALT lymphoma who received HP eradication as their frontline therapy were included. The expression of CagA and signaling pathway-related proteins, such as phospho-SHP-2 (p-SHP-2), p-ERK, p-p38 MAPK, Bcl-2, and Bcl-xL, in tumor cells was evaluated by immunohistochemistry. There were 25 HP-dependent and 22 HP-independent cases. We observed that the CagA expression rate was significantly higher in HP-dependent than in HP-independent tumors (72% [18/25] vs. 18.2% [4/22]; P<0.001). The expression of CagA was closely associated with p-SHP-2 (P=0.012), p-ERK (P=0.002), p-p38 MAPK (P=0.006), Bcl-2 (P=0.020), and Bcl-xL (P=0.006) expression. Spearman correlation coefficient analysis showed a strong correlation between CagA and signaling molecule expression. Combined CagA expression, p-SHP-2 expression, and p-ERK expression showed an increased positive predictive value (93.3% [14/15] vs. 81.8% [18/22]) and an increased specificity (95.5% [21/22] vs. 81.8% [18/22]) for HP dependence compared with CagA expression alone. Our results indicate that CagA protein expression is biologically relevant and is associated with the activation of its downstream signals in HP-dependent gastric MALT lymphoma.

Management of the marginal zone lymphomas.

Marginal zone lymphomas (MZL) represent around 8 % of all non-Hodgkin lymphomas. During the last decades a number of studies have addressed the mechanisms underlying the disease development. Extranodal MZL lymphoma usually arises in mucosal sites where lymphocytes are not normally present from a background of either autoimmune processes, such as Hashimoto thyroiditis or Sjögren syndrome or chronic infectious conditions. In the context of a persistent antigenic stimulation, successive genetic abnormalities can progressively hit a B-cell clone among the reactive B-cells of the chronic inflammatory tissue and give rise to a MALT lymphoma. The best evidence of an etiopathogenetic link is available for the association between Helicobacter pylori-positive gastritis and gastric MALT lymphoma. Indeed, a successful eradication of this micro-organism with antibiotics can be followed by gastric MALT lymphoma regression in more than 2/3 of cases. Other microbial agents have been implicated in the pathogenesis of MZL arising in the skin (Borrelia burgdorferi), in the ocular adnexa (Chlamydophila psittaci), and in the small intestine (Campylobacter jejuni). The prevalence of hepatitis C virus (HCV) has also been reported higher in MZL patients (particularly of the splenic type) than in the control population, suggesting a possible causative role of the virus. In non-gastric MALT lymphoma and in splenic MZL the role of the antimicrobial therapy is, however, less clear. This review summarizes the recent advances in Marginal Zone Lymphomas, addressing the critical points in their diagnosis, staging and clinical management.

Emerging role of infectious etiologies in the pathogenesis of marginal zone B-cell lymphomas.

Extranodal marginal zone B-cell lymphomas of the mucosa-associated lymphoid tissue (MALT) arise from lymphoid populations that are induced by chronic inflammation in extranodal sites. The most frequently affected organ is the stomach, where MALT lymphoma is incontrovertibly associated with a chronic gastritis induced by a microbial pathogen, Helicobacter pylori. Gastric MALT lymphoma therefore represents a paradigm for evaluating inflammation-associated lymphomagenesis, which may lead to a deeper understanding of a possible etiologic association between other microorganisms and nongastric marginal zone lymphomas. Besides infectious etiology, chronic inflammation caused by autoimmune diseases, such as Sjögren syndrome or Hashimoto thyroiditis, can also carry a significant risk factor for the development of marginal zone lymphoma. In addition to the continuous antigenic drive, additional oncogenic events play a relevant role in lymphoma growth and progression to the point at which the lymphoproliferative process may eventually become independent of antigenic stimulation. Recent studies on MALT lymphomas have in fact demonstrated genetic alterations affecting the NF-κB) pathway, a major signaling pathway involved in many cancers. This review aims to present marginal zone lymphoma as an example of the close pathogenetic link between chronic inflammation and tumor development, with particular attention to the role of infectious agents and the integration of these observations into everyday clinical practice. See all articles in this CCR Focus section, "Paradigm Shifts in Lymphoma."

[Clinicopathological and survival features of primary hepatic lymphoma: an analysis of 35 cases].

OBJECTIVE: To evaluate the clinicopathological features and prognosis of primary hepatic lymphoma (PHL). METHODS: Thirty-five patients with PHL who underwent surgical resection and were confirmed by pathology in our hospital from 1982 to 2012 were re-evaluated for clinicopathological data, including their symptoms, radiological features, recurrence interval, histopathological properties and prognosis. RESULTS: Of the 35 patients, 25 were men (71.4%) and 10 were women (28.6%), with an average age of 52.6 years old (range, 17-79 years). Presented symptoms were epigastric phymatosis, abdominal pain and low-grade fever. In the present study, 21 (60.0%) patients were positive for HBsAg, 1(2.9%) patient was positive for anti-HCV, 3 patients were positive for AFP, 12 patients and 2 patients were complicated by cirrhosis and hepatocellular carcinoma, respectively. Pathologically, 35 PHL were classified into 19 DLBCL (54.3%), 13 T cell-lymphoma (37.1%), and 3 MALT lymphoma (8.6%). Patients with DCBCL showed better postoperative survival than patients with T cell-lymphoma (31.7 ± 3.2) months vs. (22.9 ± 2.2) months (P < 0.05). CONCLUSIONS: Hepatitis B virus (HBV) infection may contribute to the pathogenesis of Chinese patients with PHL. Surgical resection followed by comprehensive therapy is the first-line option for PHL. The prognosis of patients with PHL is associated with PHL subtypes.

Relationships between lymphomas linked to hepatitis C virus infection and their microenvironment.

The relationships between lymphomas and their microenvironment appear to follow 3 major patterns: (1) an independent pattern; (2) a dependent pattern on deregulated interactions; and (3) a dependent pattern on regulated coexistence. Typical examples of the third pattern are hepatitis C virus (HCV)-associated marginal zone lymphomas (MZLs) and mucosa-associated lymphoid tissue lymphomas. In these lymphomas, a regulated coexistence of the malignant cells and the microenvironmental factors usually occurs. At least initially, however, tumor development and cell growth largely depend on external signals from the microenvironment, such as viral antigens, cytokines, and cell-cell interactions. The association between HCV infection and B-cell lymphomas is not completely defined, although this association has been demonstrated by epidemiological studies. MZL and diffuse large B-cell lymphoma are the histotypes most frequently associated with HCV infection. Many mechanisms have been proposed for explaining HCV-induced lymphomagenesis; antigenic stimulation by HCV seems to be fundamental in establishing B-cell expansion as observed in mixed cryoglobulinemia and in B-cell lymphomas. Recently, antiviral treatment has been proved to be effective in the treatment of HCV-associated indolent lymphomas. Importantly, clinically responses were linked to the eradication of the HCV-RNA, providing a strong argument in favor of a causative link between HCV and lymphoproliferation.

Marginal zone lymphomas and infectious agents.

A link with infectious agents, bacteria and viruses in particular, has been reported for many lymphoma entities. Marginal zone lymphomas (extranodal, nodal and splenic forms) are frequently associated with chronic infections, with important clinical, molecular, biological, and therapeutic implications. The well-known correlation between Helicobacter pylori and gastric MALT-lymphoma, the recently reported links between Chlamydophila psittaci and ocular adnexal MALT-lymphoma and Borrelia burgdorferi and cutaneous MALT lymphoma constitute the best studied examples of lymphomagenic activity of bacteria, while the hepatitis C virus represents the most extensively investigated virus associated with marginal zone lymphomas. Biological and clinical features, therapeutic implications and future perspectives of these lymphoma-microbial associations are discussed in this review.