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Cancer research has extensively explored various factors contributing to cancer development, including chemicals, drugs, smoking, and obesity. However, the role of bacterial infections in cancer induction remains underexplored. In particular, the mechanisms underlying H. pylori -induced B-cell lymphoma, a potential consequence of bacterial infection, have received little attention. In recent years, there has been speculation about contagious agents causing persistent inflammation and encouraging B-lymphocyte transition along with lymphomagenesis. MALT lymphoma associated with chronic H. pylori infection, apart from two other central associated lymphomas - Burkitt's Lymphoma and DLBCL, is well studied. Owing to the increasing colonization of H. pylori in the host gut and its possible action in the development of B-cell lymphoma, this review aims to summarize the existing reports on different B-cell lymphomas' probable association with H. pylori infections; also emphasizing the function of the organism in lymphomagenesis; including its interaction with the host, pathogen and host-specific factors, and tumor microenvironment.

Introduction: Understanding the mechanisms underlying the pathogenesis of Sjögren's syndrome (SS) is crucially important in order to be able to discriminate the steps that lead to B cell transformation and promptly identify the patients at risk of lymphomagenesis. The aim of this narrative review is to describe the evidence concerning the role that infections or dysbiosis plays in the epigenetic control of gene expression in SS patients and their possible involvement in B cell lymphomagenesis., Materials and Methods: We searched the PubMed and Google Scholar databases and selected a total of 92 articles published during the last 25 years that describe experimental and clinical studies of the potential associations of microbiota and epigenetic aberrations with the risk of B cell lymphoma in SS patients., Results and Discussion: The genetic background of SS patients is characterized by the hyperexpression of genes that are mainly involved in regulating the innate and adaptive immune responses and oncogenesis. In addition, salivary gland epithelial cells and lymphocytes both have an altered epigenetic background that enhances the activation of proinflammatory and survival pathways. Dysbiosis or chronic latent infections may tune the immune response and modify the cell epigenetic machinery in such a way as to give B lymphocytes an activated or transformed phenotype. It is also worth noting that transposable integrated retroelements may participate in the pathogenesis of SS and B cell lymphomagenesis by inducing DNA breaks, modulating cell gene expression, or generating aberrant transcripts that chronically stimulate the immune system., Conclusions: Microorganisms may epigenetically modify target cells and induce their transcriptome to generate an activated or transformed phenotype. The occurrence of lymphoma in more than 15% of SS patients may be the end result of a combination of genetics, epigenetics, and dysbiosis or latent infections.

B-cell non-Hodgkin lymphoma (B-cell NHL) is the second commonest malignancy in the stomach. We determined the distribution of Helicobacter pylori outer membrane protein Q (HopQ) allelic type, cytotoxin-associated gene (cag)-pathogenicity activity island (cag-PAI) and vacuolation activating cytotoxin A (vacA) genes, respectively, in patients with B-cell NHL. We also compared them with their distribution in non-ulcer dyspepsia (NUD). H. pylori was cultured from gastric biopsy tissue obtained at endoscopy. Polymerase chain reaction was performed. Of 170 patients enrolled, 114 (63%) had NUD and 56 (37%) had B-cell NHL. HopQ type 1 was positive in 66 (58%) in NUD compared with 46 (82%) (P = 0·002) in B-cell NHL; HopQ type 2 was positive in 93 (82%) with NUD compared with 56 (100%) (P < 0·001) in B-cell NHL. Multiple HopQ types were present in 46 (40%) in NUD compared with 46 (82%) (P < 0·001) in B-cell NHL. CagA was positive in 48 (42%) in NUD vs. 50 (89%) (P < 0·001) in B-cell NHL; cagT was positive in 35 (31%) in NUD vs. 45 (80%) (P < 0·001) in B-cell NHL; left end of the cagA gene (LEC)1 was positive in 23 (20%) in NUD vs. 43 (77%) (P < 0·001) in B-cell NHL. VacAs1am1 positive in B-cell NHL in 48 (86%) (P < 0·001) vs. 50 (44%) in NUD, while s1am2 was positive in 20 (17%) in NUD vs. 46 (82%) (P < 0·001) in B-cell NHL. H. pylori strains with multiple HopQ allelic types, truncated cag-PAI evidenced by expression of cagA, cagT and cag LEC with virulent vacAs1 alleles are associated with B-cell NHL development.

Although patients with indolent B-cell lymphomas have a relatively good survival rate, conventional chemotherapy is not curative. Disease courses are typically characterized by multiple relapses and progressively shorter response duration with subsequent lines of therapy. There has been an explosion of innovative targeted agents in the past years. This review discusses current knowledge on the etiology of indolent B-cell lymphomas with respect to the role of micro-organisms, auto-immune diseases, and deregulated pathways caused by mutations. In particular, knowledge on the mutational landscape of indolent B-cell lymphomas has strongly increased in recent years and harbors great promise for more accurate decision making in the current wide range of therapeutic options. Despite this promise, only in chronic lymphocytic leukemia the detection of TP53 mutations and/or del17p currently have a direct effect on treatment decisions. Nevertheless, it is expected that in the near future the role of genetic testing will increase for prediction of response to targeted treatment as well as for more accurate prediction of prognosis in indolent B-cell lymphomas., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Exophiala spinifera is a dematiaceous fungus responsible for rare skin infections presenting as phaeohyphomycosis or chromoblastomycosis which has been primarily reported in tropical and subtropical areas (Asia, South and North America). We report the first case of E. spinifera phaeohyphomycosis in a European patient. The phaeohyphomycosis was limited to the skin, involving the finger of an immunocompromised patient presenting with a large B-cell lymphoma treated by R-mini-CHOP regimen. Remission was initially achieved by surgical excision; however, a local subcutaneous relapse required treatment with itraconazole. We performed a literature review of the 32 previously published cases of E. spinifera phaeohyphomycosis highlighting its clinical phenotype: disseminated infection with extracutaneous involvement and poor prognosis were reported in young patients, of whom some were recently associated with CARD9 mutations, whereas cases in older immunocompromised patients were limited to the skin and showed better prognosis. There is currently no standard treatment for E. spinifera phaeohyphomycosis; however, itraconazole, alone or in combination, allowed partial or complete response in 16 out of 20 cases., (© 2016 Blackwell Verlag GmbH.)

Many hyperplasias and lymphomas of marginal zone B-cells are associated with infection. We identified six children and one adolescent with cervical lymphadenopathy showing prominent polyclonal nodal marginal zone hyperplasia (pNMZH) and four adolescents with monoclonal paediatric nodal marginal zone lymphoma (pNMZL). The clonality status was assessed using BIOMED-2-IG PCR analysis. Haemophilus influenzae was identified in all six cases of pNMZH that could be tested by direct culture (N = 3) or a very sensitive PCR for the H. influenzae gyrase gene in frozen materials (N = 5). H. influenzae was not detected in three pNMZLs and 28 non-specific reactive cervical lymph nodes of age-matched controls, except for a single control node that was obtained during oropharyngeal surgery for a cleft palate showing very low copy numbers of H. influenzae. pNMZH patients were younger than pNMZL patients (median age 12 versus 21 years). pNMZH showed a prominent nodular appearance with variable fibrosis without acute inflammation. Within the nodules, the expanded germinal centres and variably sized marginal zones were colonized by activated B-cells with weak expression of IgD and lack of CD10 and/or BCL6 expression. Some areas showed skewed light chain expression in plasma cells (4/5 cases lambda). In four cases tested, this was confirmed by flow cytometry for surface Ig (3/4 cases lambda). In contrast, pNMZL showed more extensive expansion of marginal zones by centrocytoid cells and often expression of BCL2 protein. Several H. influenzae strains are known to interact with the constant part of IgD on human B-cells, leading to their polyclonal proliferation and activation. We speculate that in vivo stimulation of IgD+ marginal zone B-cells by this bacterium may be implicated in this particular lymphadenopathy that should be distinguished from monoclonal pNMZL., (Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Ataxia-telangiectasia is a genetic disorder associated with high incidence of B-cell lymphoma. Using an ataxia-telangiectasia mouse model, we compared lymphoma incidence in several isogenic mouse colonies harboring different bacterial communities, finding that intestinal microbiota are a major contributor to disease penetrance and latency, lifespan, molecular oxidative stress, and systemic leukocyte genotoxicity. High-throughput sequence analysis of rRNA genes identified mucosa-associated bacterial phylotypes that were colony-specific. Lactobacillus johnsonii, which was deficient in the more cancer-prone mouse colony, was causally tested for its capacity to confer reduced genotoxicity when restored by short-term oral transfer. This intervention decreased systemic genotoxicity, a response associated with reduced basal leukocytes and the cytokine-mediated inflammatory state, and mechanistically linked to the host cell biology of systemic genotoxicity. Our results suggest that intestinal microbiota are a potentially modifiable trait for translational intervention in individuals at risk for B-cell lymphoma, or for other diseases that are driven by genotoxicity or the molecular response to oxidative stress., (©2013 AACR.)

Aim: To assess the significance of chromosome translocation t(11;18)(q21;q21), B-cell lymphoma 10 (BCL-10) protein and Helicobacter pylori (H. pylori) infection in gastric mucosa-associated lymphoid tissue (MALT) lymphoma in Colombia., Methods: Fifty cases of gastric MALT lymphoma and their respective post-treatment follow-up biopsies were examined to assess the presence of the translocation t(11;18)(q21;q21) as identified by fluorescence in situ hybridization; to detect protein expression patterns of BCL10 using immunohistochemistry; and for evaluation of tumor histology to determine the correlation of these factors and resistance to H. pylori eradication., Results: Infection with H. pylori was confirmed in all cases of gastric MALT lymphoma in association with chronic gastritis. Bacterial eradication led to tumor regression in 66% of cases. The translocation t(11;18)(q21;q21) was not present in any of these cases, nor was there evidence of tumor transformation to diffuse large B-cell lymphoma. Thirty-four percent of the patients showed resistance to tumor regression, and within this group, 7 cases, representing 14% of all those analyzed, were considered to be t(11;18)(q21;q21)-positive gastric MALT lymphomas. Protein expression of BCL10 in the nucleus was associated with the presence of translocation and treatment resistance. Cases that were considered unresponsive to therapy were histologically characterized by the presence of homogeneous tumor cells and a lack of plasmacytic differentiation. Responder cases exhibited higher cellular heterogeneity and a greater frequency of plasma cells., Conclusion: Both t(11;18)(q21;q21)-positive MALT lymphoma cases and those with nuclear BCL10 expression are considered resistant to H. pylori eradication. It is suggested that chronic antigenic stimulation is not a dominant event in resistant cases.

Borrelia burgdorferi has been variably associated with different forms of primary cutaneous lymphoma. Differences in prevalence rates among reported studies could be a result of geographic variability or heterogeneity in the molecular approaches that have been employed. In the present study, we investigated the prevalence of Borrelia burgdorferi sensu lato DNA in diagnostic tissue samples from fresh cutaneous biopsies of 98 primary cutaneous lymphomas and 19 normal skin controls. Three different polymerase chain reaction (PCR) protocols targeting the hbb, flagellin, and Osp-A genes were used. Direct sequencing of both sense and antisense strands of purified PCR products confirmed the specificity of the amplified fragments. Sequence specificity was assessed using the Basic Local Alignment Search Tool, and MultAlin software was used to investigate the heterogeneity of target gene sequences across the different samples. Borrelia DNA was not detected in 19 controls, 23 cases of follicular lymphoma, 31 cases of extranodal marginal zone lymphoma, or 30 cases of mycosis fungoides. A single case of 14 diffuse large B-cell lymphoma cases was positive for B. burgdorferi. This study does not support a pathogenic role of B. burgdorferi in primary cutaneous B- and T-cell lymphomas from areas nonendemic for this microorganism and the consequent rationale for the adoption of antibiotic therapy in these patients.

Infection by cagA-positive Helicobacter pylori (H. pylori) is strongly associated with gastric carcinomas and gastric mucosa-associated lymphoid tissue (MALT) lymphomas. H. pylori translocates the bacterial protein CagA into gastric epithelial cells, and the translocated CagA deregulates intracellular signaling pathways and thereby initiates pathogenesis. This in turn raised the possibility that H. pylori is associated with the development of MALT lymphomas during persistent infection by direct interaction with B lymphocytes. In this work, we showed that CagA can be directly translocated into human B lymphoid cells by H. pylori, and the translocated CagA undergoes tyrosine phosphorylation and binds to intracellular SH-2. Meanwhile, the translocated CagA induces activation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase in human B lymphoid cells, and upregulates the expressions of Bcl-2 and Bcl-X(L), which prevents apoptosis. These results provide the first direct evidence for the role of CagA as a bacterium-derived oncoprotein that acts in human B cells, and further implies that CagA is directly delivered into B cells by H. pylori and is associated with the development of MALT lymphomas., ((c)2010 AACR.)

This review is focused on the role of infectious agents in the development of some lymphoma entities. Associations involving bacterial infections mostly regard marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT)-type. Some paradigmatic examples of these associations include the Helicobacter pylori-related gastric MALT lymphoma and the more recently reported links between Chlamydophila psittaci and ocular adnexal MALT lymphomas and Borrelia burgdorferi and cutaneous MALT lymphomas. The well-documented association between Epstein-Barr virus infection and related lymphoproliferative disorders are analysed as an example of lymphotropic virus with tumourigenic activity. Molecular, biological and clinical features as well as therapeutic implications of these associations are analysed and future perspectives in this field are discussed.

The known spectrum of skin manifestations in cutaneous Lyme disease is continuously expanding and can not be regarded as completed. Besides the classical manifestations of cutaneous borreliosis like erythema (chronicum) migrans, borrelial lymphocytoma and acrodermatitis chronica atrophicans evidence is growing that at least in part also other skin manifestations, especially morphea, lichen sclerosus and cases of cutaneous B-cell lymphoma are causally related to infections with Borrelia. Also granuloma annulare and interstitial granulomatous dermatitis might be partly caused by Borrelia burgdorferi or similar strains. There are also single reports of other skin manifestations to be associated with borrelial infections like cutaneous sarcoidosis, necrobiosis lipoidica and necrobiotic xanthogranuloma. In addition, as the modern chameleon of dermatology, cutaneous borreliosis, especially borrelial lymphocytoma, mimics other skin conditions, as has been shown for erythema annulare centrifugum or lymphocytic infiltration (Jessner Kanof) of the skin.

We reviewed the clinico-pathological features of 73 primary cutaneous B-cell lymphomas (PCBCLs), diagnosed in 10 years in Marche region in central Italy, which included 16 marginal zone lymphomas (MZL), 33 follicle centre lymphomas (FCL) and 24 diffuse large B cell lymphomas (DLBCL). We also investigated the presence of Borrelia burgdorferi in tissues by polymerase chain reaction. Differences in age, sex, location site, response to therapy, disease recurrence and 5-year disease-specific survival were observed among the 3 histological groups. Specific DNA sequences of Borrelia burgdorferi were not detected in any of the 73 cases of PCBCL. We conclude that PCBCLs in Marche region behave according to the literature data and do not seem to be associated with Borrelia burgdorferi. Additional investigations should be performed on other possible etiologies, at least in our geographical area.

Ocular adnexal lymphoma (OAL) is a mostly extranodal marginal zone lymphoma (EMZL). Recent findings have suggested an association between Chlamydia psittaci (Cp) infection and OAL. We sought to confirm this issue and to analyze the clinicopathologic characteristics of OAL in Korea. Between 1993 and 2004, 33 OAL cases were identified at the Asan Medical Center, Seoul, Korea. DNA was extracted from paraffin-embedded tissues, and touchdown enzyme time release polymerase chain reaction was performed to identify three Chlamydia species (Cp, C. tracomatis, and C. pneumoniae). The same procedures were also performed in 21 samples from patients with non-neoplastic ocular adnexal disease (NNOAD). All OAL cases were EMZL. Cp DNA was detected in 26/33 (79%) OAL samples compared with 5/21 (23%) NNOAD samples (P < 0.001). With a median follow-up of 38.5 months (range: 1-105 months), the 5-year progression-free survival (PFS) and overall survival (OS) rates of OAL patients were 72% and 93%, respectively. Clinicopathologic characteristics, recurrence rate, PFS, and OS were not associated with Cp infection. Our study demonstrates an association between OAL and Cp infection in Korea, suggesting that Cp plays a role as a causative antigen in Korean OAL patients., (2007 Wiley-Liss, Inc)

We recently reported that low-grade mucosa-associated lymphoid tissue lymphoma (MALToma) and diffuse large B-cell lymphoma (DLBCL) with MALToma (DLBCL[MALT]) of stomach are equally responsive to H. pylori eradication therapy (HPET) and that H. pylori-independent status is closely associated with nuclear translocation of BCL10. However, co-existing MALToma and DLBCL components of gastric DLBCL(MALT) may respond differentially to HPET and the underlying mechanism remains unclear. Tumour tissue samples from 18 patients with microdissectable co-existing MALToma and DLBCL cells were studied. The clonality of lymphoma cells was examined by polymerase chain reaction-based amplification of the CDR3 region of the IgH gene and confirmed by DNA sequence analysis. BCL10 expression was determined by immunohistochemistry. Differential response of co-existing MALToma and DLBCL to HPET was defined as complete eradication of one component while the other component remained. Five (27.8%) of the 18 patients showed different IgH gene rearrangements in the two components and three (60%) of these five patients had differential response of MALToma and DLBCL to HPET. By contrast, 13 patients showed identical IgH gene rearrangements and only one (8%) of them had differential response of the two components to HPET (p = 0.044). Further, all four patients with differential response of MALToma and DLBCL to HPET showed nuclear expression of BCL10 in the H. pylori-independent component and cytoplasmic expression of BCL10 in the H. pylori-dependent component while the expression patterns of BCL10 were identical in both of these components in the 14 patients who had similar tumour response to HPET. We conclude that different clonality is a common reason for the differential response of co-existing MALToma and DLBCL of gastric DLBCL(MALT) to HPET and that immunohistochemical examination of BCL10 expression may help to identify the co-existence of these components., (Copyright 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Most ocular adnexal lymphomas (OAL) are extranodal marginal zone B-cell lymphomas (EMZL) of mucosa-associated lymphoid tissue (MALT)-type. Chronic antigen stimulation has been suggested to have a pathogenetic role in EMZL and Chlamydia psittaci chronic infection has been recently associated with the development of OAL in a series of patients from Italy. To assess this association, an evaluation of the presence of C. psittaci was made in a different OAL population. DNA samples were obtained from formalin-fixed, paraffin-embedded sections samples of 26 patients with OAL, 20 non-OAL and 20 benign ocular lesions, diagnosed and treated between 1998 and 2003 at National Institute of Oncology in Havana, Cuba. All samples were histologically reviewed by an expert pathologist. Fluorescence in situ hybrization (FISH) analysis of translocations involving MALT1 was performed. The presence of bacterial DNA was assessed with a multiplex touchdown enzyme time release polymerase chain reaction. DNA sequencing was performed to confirm suspicious bands. Seventy-three percent of the OAL cases were EMZL and 81% were in stage IE. FISH analysis was performed in 13 OAL cases and none of them evidenced MALT1 translocations. DNA of C. psittaci was detected in 11% of the 46 lymphomas: two orbital EMZL and three non-OAL. All 20 benign ocular lesions were negative for C. psittaci. The low prevalence of C. psittaci in OAL suggests geographical differences in the etiology of this entity. International studies are needed to clarify the role of C. psittaci in OALs.

An association between Borrelia burgdorferi with primary cutaneous B-cell lymphoma (PCBCL) has long been suspected but just recently, thanks to a polymerase chain reaction technique, it had been possible to demonstrate B. burgdorferi-specific DNA in skin lesions of patients with different PCBCL subtypes. Locating cases of PCBCL that are related to B. burgdorferi infection could be really important for therapeutic implications; in fact, there are several reports of PCBCL responding to antibiotic therapy against B. burgdorferi. We report a case of B. burgdorferi-associated primary cutaneous marginal-zone B-cell lymphoma that, after specific antimicrobial therapy, did not show any clinical regression. We can conclude that additional studies are necessary in order to establish the use of antimicrobial therapy in B. burgdorferi-associated PCBCL., (Copyright 2007 S. Karger AG, Basel.)

Extra-nodal marginal zone B cell lymphomas (MZBCLs) of the mucosa-associated lymphoid tissues (MALT) arise at sites of chronic antigenic stimulation due to organ-specific autoimmunity or infections, like Helicobacter pylori-associated chronic gastritis and Borrelia burgdorferi dermatitis. Recently, conflicting data have been published regarding a possible association between Chlamydia psittaci and ocular adnexal MZBCL. In the present study, we analyzed a cohort of ocular adnexal MZBLs from the Netherlands for the presence of C. psittaci DNA. We found no evidence for the presence of C. psittaci DNA in any of the tumor samples studied. Our data do not support a role for C. psittaci in the pathogenesis of ocular adnexal lymphomas in patients from the Netherlands.

Primary gastric lymphoma is a rare gastrointestinal cancer in children. Adult cases of primary gastric lymphoma are often associated with Helicobacter pylori infection and in the past were treated mainly by surgery with additional chemotherapy and/or radiotherapy. We experienced a case recently of a primary gastric lymphoma in a girl. She presented at our hospital with epigastric abdominal pain and upper gastrointestinal bleeding. Chemotherapy alone sufficiently controlled the disease and no additional therapeutic modalities were needed.

Objective: To assess the expression of specific virulence-associated Helicobacter pylori (Hp) genotypes. (cag A, vac A, and ice A status) in primary gastrointestinal B cell lymphoma., Methods: Forty-nine paraffin wax embedded tissues were analyzed by immunohistochemical staining and polymerase chain reaction., Results: There were 14 cases of mucosa associated lymphoid tissue lymphoma (MALT-L) (8 in stomach, and 6 in intestine) and 35 cases of diffuse large B cell lymphoma (DLBCL) (21 in stomach, and 14 in intestine) in all. The positive rates of vac A s1, vac A s2, vac A m2, ice A 1 and cag A were 50.0%, 42.9%, 50.0%, 14.3% and 85.7% in MALT-L; 57.1%, 40.0%, 25.7%, 5.7% and 91.4% in DLBCL, respectively., Conclusion: High toxicity cag A+Hp strains seem to play a role in the pathogenesis of gastrointestinal B cell lymphoma, whereas vac A m2 may be more associated with MALT-L. Clinical stage was not associated with virulence-associated Hp genotypes.

We investigated the relationship of gastric mucosa-associated lymphoid tissue (MALT) lymphoma tumorigenesis to Helicobacter pylori infection, the t (11;18) translocation, and alterations in cell cycle regulators. We sought to assess the implications of altered expression of p27(Kip1), a cyclin-dependent kinase inhibitor, on high-grade transformation and responsiveness to eradication therapy. We used immunohistochemistry to examine p27(Kip1), p53, and Ki-67 expression in 23 MALT lymphomas, five diffuse large B-cell lymphomas (DLBCLs), and four DLBCLs with associated MALT lymphoma. All of the MALT lymphomas were positive for p27(Kip1) expression and negative for p53 with a low Ki-67 index, regardless of the sensitivity of these cells to eradication. All DLBCLs were negative for p27(Kip1) and positive for p53, exhibiting a high Ki-67 index. In DLBCLs with MALT lymphoma, p27(Kip1) expression was absent from both the MALT and large cells components. In all of these lymphomas, the MALT components were negative for p53 and displayed a low Ki-67 index, while the large cell components were positive for p53 with a high Ki-67 index. The expression patterns of the DLBCLs differed significantly from those of the MALT lymphomas. p27(Kip1) was not detected in either component of DLBCL with MALT lymphoma, suggesting that decreased expression of p27(Kip1) in the MALT component may be related to high-grade transformation. Thus, p27(Kip1) expression in morphological MALT lymphomas could be useful tool to predict high-grade transformation to DLBCL.

Non-Hodgkin lymphomas are among the most common primary tumors occurring in the ocular adnexa. Herein, we present a 14-year single-institution experience in 62 patients with primary ocular adnexal lymphomas (OALs). Association with Chlamydia psittaci infection is examined in 57 tumor specimens. Extranodal marginal zone lymphoma (EMZL) was the most frequent histologic subtype (89%). The majority of patients with EMZL (84%) presented with stage E-extranodal (IE), however only 16% had an advanced stage. All stage IE patients were treated with local radiotherapy, whereas patients with disseminated disease received systemic therapy with or without local irradiation. All but 1 patient with EMZL achieved complete remission (CR). During a median follow-up of 52 months (range, 3-153 months), the estimated 5-year overall survival (OS) and freedom from progression (FFP) were 96% and 79%, respectively. During the follow-up, 22% of patients relapsed, mainly in extranodal sites, and 4% transformed to diffuse large B-cell lymphoma. None of the patients exhibited local orbital failure in the radiation field. None of the OAL specimens harbored C psittaci DNA. Our study demonstrates that EMZLs, accounting for the majority of primary OALs, are characterized by an indolent natural history with frequent, continuous extranodal relapses. In South Florida, OALs are not associated with C psittaci infections.

Human cell lines are often infected by mycoplama strains. We have demonstrated that when infected by Mycoplasma fermentans, human B lymphoma cell proliferation increased strongly. These infected B cells expressed a p45 kDa protein which interacted with the intracellular domain of CD21, the EBV/C3d receptor. p45 analysis demonstrated that this is a new gene which encodes an elongation factor originating from Mycoplasma fermentans. p45 interaction with CD21 was specific, there being no interaction with CD19. This is the first demonstration that Mycoplasma fermentans, in infecting human B cells, generates a p45 Mycoplasma component that interacts with CD21, which is involved in B cell proliferation.

Purpose: Some infectious agents contributing to lymphomagenesis have been considered targets for new therapeutic strategies. Chlamydia psittaci DNA has been detected in 80% of ocular adnexal lymphomas. The present pilot study was carried out to assess whether C psittaci-eradicating antibiotic therapy is associated with tumor regression in ocular adnexal lymphomas., Patients and Methods: Nine patients with C psittaci-positive marginal-zone B-cell lymphoma of the ocular adnexa at diagnosis or relapse were treated with doxycycline 100 mg, bid orally, for 3 weeks. The presence of C psittaci DNA in peripheral-blood mononuclear cells (PBMCs) was also assessed before and after treatment in seven patients. Objective lymphoma regression was assessed 1, 3, and 6 months after therapy conclusion and every 6 months during follow-up., Results: All patients completed antibiotic therapy with excellent tolerability. At 1 month from doxycycline assumption, chlamydial DNA was no longer detectable in PBMCs of all four positive patients. Objective response was complete in two patients, partial response (> 50%) was observed in two patients, and minimal response (< 50%) was observed in three patients. Duration of response in the seven responders was 12+, 29+, 31+, 8+, 7+, 2+, and 1+ months, respectively., Conclusion: C psittaci-eradicating antibiotic therapy with doxycycline is followed by objective response in patients with ocular adnexal lymphoma, even after multiple relapses of the disease. A confirmatory, large, phase II trial is warranted to confirm whether this fast, cheap, and well-tolerated therapy could replace other more aggressive strategies as first-line treatment against ocular adnexal lymphomas.

We describe a 67-year-old woman with bronchiectasis and Mycobacterium avium complex infection who underwent wedge resection of her pulmonary infiltrates because they were progressing despite antibiotic therapy. In addition to the expected granulomatous changes, she was found to have a B-cell lymphoma of bronchus associated lymphoid tissue (BALT). Despite normal bone marrow morphology, marrow involvement was demonstrated by flow cytometry. Her lymphoma remains suppressed with antimycobacterial therapy 6 months after resection of bulk disease., (Copyright 2004 Wiley-Liss, Inc.)

Unlabelled: Helicobacter pylori has been associated with gastric adenocarcinoma and gastric lymphoma. We report on the systematic evaluation of serologic detection of H. pylori in a lymphoma case-control study., Methods: Cases (N = 536) were consecutive patients newly diagnosed with a lymphoid malignancy between 1998 and 2002 in four centers in Spain. Lymphomas were diagnosed and classified using the WHO Classification. Controls (N = 603) were hospitalized patients frequency-matched to the cases by 5-year age group, sex, and study center. Severe immunocompromised patients were excluded as controls. Patients underwent a personal interview and blood sampling. H. pylori infection was evaluated by the presence of IgG antibodies using the Premier enzyme immunoassay kit (Meridian Diagnostics Inc., Cincinnati, OH). Logistic regression analysis was used to estimate the odds ratios and 95% confidence intervals (OR, 95% CI) for lymphoma categories., Results: Anti-H. pylori antibodies were detected in 68.5% of the cases and 71.3% of the controls (P = 0.29) H. pylori was associated with a 3-fold excess risk of splenic marginal B-cell lymphoma (OR = 3.97, 95% CI = 0.92-17.16). H. pylori was not associated with an overall increased risk of extranodal lymphomas (OR = 0.73, 95% CI = 0.44-1.22) but when specific sites were explored, the four mucosa-associated lymphoid tissue and the six diffuse large B-cell lymphomas primary localized in the stomach were all H. pylori seropositive., Conclusion: Persistent infection with H. pylori may be implicated in the development of lymphomas of the gastric mucosa and of the spleen. These results could have clinical implications in the management of splenic marginal zone lymphomas.

The WHO separates marginal zone B-cell lymphomas (MZBL) of nodal and extranodal type. Both arise from memory B cells of the marginal zone. Extranodal MZBL of the mucosa-associated lymphatic tissue (MALT) have characteristic features such as homing in epithelial tissue, lymphoepithelial destruction, and a very indolent clinical course. They arise in epithelial tissues normally devoid of lymphatic cells, where the lymphatic tissue was acquired after, for instance, a chronic infection. The best example here is infection of the stomach with Helicobacter pylori ( Hp). Besides the classical association with gastric MALT lymphomas, there have been reports in which an association between Hp and diffuse large B-cell lymphoma (DLBCL) has been observed as well. Consequently, cure of Hp infection resulted in remission induction not only in gastric MALT lymphomas, but also in some patients with very limited stages of DLBCL of the stomach. In addition to the association with Hp, progress has been made with regard to MALT lymphoma biology. Translocation t(1;14) involving the Bcl-10 gene, and translocation t(11;18) involving a novel gene called MLT1, both result in activation of the crucial transcription factor NF-kappaB. These genetic events seem specific in that they have been observed only in MALT lymphomas. Once present, at least the more frequently observed translocation t(11;18) renders cells resistant to cure of Hp infection. Another clinically important question is that in many patients in complete remission after cure of Hp infection, detection of minimal residual disease is positive. Whether these cells are normal memory B cells (with the identical B-cell rearrangement as the original lymphoma clone), or dormant lymphoma cells, is unclear at present. In patients not responding to cure of Hp infection, several treatment options are discussed. MALT lymphomas have opened up a new discussion of lymphoma biology and have thus been called a model disease.

Primary non-Hodgkin's lymphomas of the stomach are associated with Helicobacter pylori infection. We analyzed gastric lymphoma onset data with respect to prior H. pylori infections based on the multistage theory of carcinogenesis. This theory provides a link between epidemiological data and biological processes. The study involved 133 patients, aged 29-75 years, diagnosed with marginal zone B-cell lymphoma (MZBL) and diffuse large cell B-cell lymphoma (DLBL). A 2-parametric Weibull model was applied to MZBL and DLBL onset data. Median age of diagnosis of MZBL (DLBL) was 59 years (55 years) in males and 65.5 years (64 years) in females. Infection with H. pylori was found in 81.3% (59.5%) of the patients diagnosed with MZBL (DLBL). Lymphoma latency data were fitted to Weibull distributions with a shape parameter of 5.7 for MZBL cases and 4.2 for DLBL. The shape parameter that indicates the number of steps in carcinogenesis was approximately independent of the status of infection with H. pylori in DLBL in contrast to MZBL. It was shown that gastric lymphoma onset data can be described by Weibull distribution functions. The findings support the hypothesis that MZBL and DLBL have different lines of development. There is indication of stronger antigen dependency in the carcinogenesis of MZBL in comparison to DLBL., (Copyright 2003 Wiley-Liss, Inc.)

Long term follow up data are not available for cases of diffuse large B cell gastric lymphoma treated by eradicating Helicobacter pylori alone. We present the case of an 82 year old man with diffuse large B cell lymphoma localised to the stomach which responded to H pylori eradication and which has not recurred after more than five years of close follow up. Our patient was not a candidate for other modalities of treatment. This case demonstrates that the option of treating H pylori infection as the initial trial of treatment for localised diffuse large B cell lymphoma is appropriate for consideration. If medical therapy using eradication of H pylori is used, it is essential that the patient undergoes close observation and repeated surveillance endoscopies.

Background: The aetiology of Hodgkin's disease is still unknown more than 160 years after its original description. In recent years a viral aetiology was the preferred hypothesis. Epidemiological, clinical, laboratory, and histological findings, however, point rather to a bacterial aetiology., Methods: In the histological work-up of tissues from patients suffering from malignant lymphoma periodic acid-Schiff (PAS) stains are routinely done. In several bacterial infections intracellular PAS-positive material can be observed. We examined PAS-stained slides at magnifications of 1000x of six Hodgkin and twelve Non-Hodgkin patients., Results: We found PAS-positive diastase resistant intracellular rods and spheres in all Hodgkin patients and in all of the six patients suffering from sclerosing mediastinal B-cell lymphomas, but not the other Non-Hodgkin lymphomas., Conclusions: The diastase resistant PAS-positive structures are compatible with intracellular bacteria. After gastric MALT-lymphoma and gastric non-cardia adenocarcinoma it appears that Hodgkin's disease and sclerosing mediastinal B-cell lymphomas may also be human tumors related bacteria.

The paper presents start-of-art knowledge of primary gastric B-cell lymphomas. Despite the progress of the investigations, a lot of questions remain still unanswered and many doubts wait for explanation.

Background: We investigated numerical chromosomal abnormalities, using the fluorescence in situ hybridization (FISH) method, in gastric mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma (DLBL). We also compared the histopathological findings, including the presence or absence of Helicobacter pylori infection, with the analytical results., Methods: Sixteen patients who underwent operation for malignant gastric lymphoma in our department were divided into three groups: patients with low-grade gastric MALT lymphoma (l-MALT; n = 5), those with high-grade gastric MALT lymphoma (h-MALT; n = 8), and those with DLBL (n = 3). Numerical abnormalities of chromosomes 8, 9, 12, and 17 were investigated by the FISH method, and the presence or absence of H. pylori infection was microscopically examined., Results: Numerical abnormality was observed in chromosome 12 in 11 patients (68.8%), in chromosome 8 in 10 (62.5%), and in chromosome 17 in 5 (31.3%), showing a high frequency. H. pylori infection was detected in 80% and 50% of patients with l-MALT and h-MALT, respectively, but no H. pylori infection was observed in patients with DLBL., Conclusions: A new biological characteristic of gastric MALT lymphoma was obtained, i.e., a high frequency of numerical abnormalities of chromosomes 12, 8, and 17. There was no correlation between the numerical chromosomal abnormalities and the clinicopathological findings.

Background: An association between Borrelia burgdorferi and cutaneous B-cell lymphoma (CBCL) has been made in several European countries. The evidence in favor of such an association has recently been based on more definitive tests for the pathogenetic role of B. burgdorferi in CBCL, including positive cultures or polymerase chain reaction (PCR) amplification of borrelial DNA from lesional skin. However, there is only one report of B. burgdorferi in four North American cases of B-cell lymphoma., Methods: We retrieved 38 cases of primary and secondary CBCL from different geographic regions of the United States. Two separate techniques were used to detect borrelial DNA by PCR, a nested PCR method to amplify a B. burgdorferi-specific gene as well as a borrelial chromosomal Ly-1 clone amplification method. Southern blot hybridization was used for confirmation of the PCR results., Results: No B. burgdorferi-specific DNA was detected in any of the 38 CBCL cases, whereas detectable PCR products were obtained with our positive controls., Conclusions: Our findings, in light of previous studies, suggest that B. burgdorferi plays a minimal role in the development or pathogenesis of CBCL in the United States. The findings also suggest that the geographic variations in the clinical manifestations of B. burgdorferi are indeed real and may be secondary to the genetic and phenotypic differences between B. burgdorferi strains present in Europe and North America.

The primary gastric lymphomas are extranodal non-Hodgkin's lymphomas that likely originate from the mucosa-associated lymphoid tissue (MALT). Data suggest that chronic infection with Helicobacter pylori (H pylori) is significantly associated with the pathogenesis of low-grade gastric MALT lymphomas. This is in keeping with the observation that many patients with early low-grade MALT lymphomas have complete remissions after H pylori eradication therapy. However, the stability of these remissions remains unclear and relapses have been reported. It can be difficult to distinguish between early malignant and benign disorders of the gastric mucosa. A polymerase chain reaction (PCR) assay can detect rearrangements of the variable region of immunoglobulin heavy chains. This assay can be used to distinguish the clonality of B lymphocytes and has been investigated as a test for differential diagnosis of MALT lymphomas. Monoclonality is observed in the majority of MALT-lymphoma samples at diagnosis but has been found in gastritis samples as well. Whether the presence of monoclonal B cells is associated with the risk of lymphoma progression remains unclear. As many as 50% of patients who have complete histologic remissions of MALT lymphoma after H pylori eradication therapy have persisting monoclonal bands in follow-up PCR monitoring. Although it is unclear as to whether monoclonality indicates the presence of minimal residual disease, patients who have persistent monoclonal bands during follow-up should be considered at risk for relapse. The PCR assay for rearrangements of the variable region of the immunoglobulin heavy-chain gene appears to be of low value in the diagnosis of B-cell malignancies but could provide a useful tool in the follow-up of patients who achieve remissions after H pylori eradication.

Objective: Gastric lymphoma of mucosa-associated lymphoid tissue (MALT) type is closely related to Helicobacter pylori (H. pylori) infection. In vitro studies have demonstrated H. pylori-induced B cell proliferation to be strain dependent. High prevalences of CagA protein and FldA protein have been reported in strains obtained from patients with gastric lymphoma of MALT type. The aims of the present study were to evaluate the prevalence of H. pylori infection and to search for antigenic particularities in 53 patients with primary gastric lymphoma in comparison with a group of infected patients with benign disease., Methods: Of the 53 patients, 37 presented with low-grade lymphoma of MALT type (LGLM) and 16 with diffuse large B-cell lymphoma (DLBCL). They were compared to a group of 162 H. pylori-infected subjects comprising the control group: 111 had gastric or duodenal ulcer (GDU) and 51 nonulcer dyspepsia (NUD). Diagnosis of gastric lymphoma was established on histological examination of endoscopic specimens. Anti-H. pylori antibodies were assayed by third-generation ELISA. Western blot assay was used to detect antibodies against nine antigens (including CagA protein), which were recognized on the basis of their molecular weight., Results: Of the 53 patients with gastric lymphoma, 45 were H. pylori-positive (85%): of these, 25 (56.5%) had anti-CagA antibodies. The prevalence of H. pylori seropositivity was 78% (29/37) in LGLM and 100% (16/16) in DLBCL. The prevalence of CagA seropositivity in H. pylori-positive patients was 44.8% (13/29) and 75% (12/16), respectively (p < 0.05). In comparison, the seroprevalence of CagA was 77.4% (86/111) in GDU patients and 43.1% (22/53) in NUD patients. The prevalence of antibodies to other antigenic proteins detected with Helicoblot 2.0 (19.5kd, 30kd, 35kd, VacA, HSPb, Urease A, and Urease B) did not differ among the groups except for 35kd protein, which was significantly higher (p < 0.01) in GDU than in NUD and in LGLM (76.6% vs 49% and 46.7%)., Conclusion: These findings suggest that in patients who develop gastric lymphomas in response to H. pylori, virulent strains expressing CagA protein are preferentially associated with DLBCL.

Purpose: Treatment of low-grade gastric mucosa-associated lymphoid tissue lymphoma by eradication of Helicobacter pylori is reported to result in complete lymphoma remission in approximately 75% of cases. The effect that cure of the infection has on the course of a primary high-grade gastric lymphoma is largely uncertain. The aim of this study was to report the effect of cure of H pylori infection exerted in patients with high-grade B-cell gastric lymphoma., Patients and Methods: Eight patients (4 males and 4 females; age range, 26 to 85 years) with H pylori infection and high-grade lymphoma received eradication therapy before planned treatment. The effect of H pylori eradication on the course of high-grade lymphoma was assessed by analysis of surgical specimens (n = 2) or endoscopic biopsies (n = 6)., Results: H pylori eradication was successful in all patients and led to complete remission of the lymphoma in seven patients. One patient has experienced partial remission. Two patients were referred to surgery, one of whom (stage II(1E)) had lymph node involvement, and the histologic work-up of the resected stomach revealed residual infiltrates of a low-grade lymphoma, which prompted consolidation chemotherapy. In one patient (initially stage I(1E)), abdominal lymphoma developed 6 months after eradication therapy, which regressed completely after chemotherapy. In four patients, no further treatment was given. Six patients continue in complete remission (range, 6 to 66 months)., Conclusion: Primary high-grade B-cell gastric lymphoma in stages I(E) through II(E1) associated with H pylori may regress completely after successful cure of the infection. Prospective trials are needed to investigate this treatment in larger numbers of patients.

Aims: A relationship between Borrelia burgdorferi and primary cutaneous B-cell lymphoma (PCBCL) has recently been confirmed following demonstration of the organism in lesional skin of patients with PCBCL. We report herein two cases of B. burgdorferi-associated PCBCL which strengthen this association by demonstrating the organism in cutaneous B-cell infiltrates present at sites in which PCBCL subsequently developed., Methods and Results: All studies were performed on formalin-fixed paraffin-embedded tissues. These were examined by routine light microscopy and immunohistochemically by a standard streptavidin-biotin-complex technique. Genotypic studies were also undertaken using semi-nested polymerase chain reaction (PCR) for immunoglobulin heavy chain gene rearrangement, and nested PCR for B. burgdorferi flagellin gene. Both patients presented with erythematous skin lesions, biopsy of which showed dense perivascular infiltrates comprising small T-lymphocytes and collections of B-blasts. Primary cutaneous marginal zone lymphoma (MZL) developed subsequently in both cases at the same site. PCR for B. burgdorferi flagellin gene was positive in the perivascular lymphocytic infiltrates and the succeeding lymphomas in both patients., Conclusions: These results show that, at least in some instances, PCBCL arises from chronically stimulated lymphoid tissue acquired in the skin in response to B. burgdorferi infection. This may have significant therapeutic implications and warrant further studies on the extent of this association.

Background & Aims: Appropriate management of primary gastric lymphoma is controversial. This prospective, multicenter study aimed to evaluate the accuracy of endoscopic biopsy diagnosis and clinical staging procedures and assess a treatment strategy based on Helicobacter pylori status and tumor stage and grade., Methods: Of 266 patients with primary gastric B-cell lymphoma, 236 with stages EI (n = 151) or EII (n = 85) were included in an intention-to-treat analysis. Patients with H. pylori-positive stage EI low-grade lymphoma underwent eradication therapy. Nonresponders and patients with stage EII low-grade lymphoma underwent gastric surgery. Depending on the residual tumor status and predefined risk factors, patients received either radiotherapy or no further treatment. Patients with high-grade lymphoma underwent surgery and chemotherapy at stages EI/EII, complemented by radiation in case of incomplete resection., Results: Endoscopic-bioptic typing and grading and clinical staging were accurate to 73% and 70%, respectively, based on the histopathology of resected specimens. The overall 2-year survival rates for low-grade lymphoma did not differ in the risk-adjusted treatment groups, ranging from 89% to 96%. In high-grade lymphoma, patients with complete resection or microscopic tumor residuals had significantly better survival rates (88% for EI and 83% for EII) than those with macroscopic tumor residues (53%; P < 0.001)., Conclusions: There is a considerable need for improvement in clinical diagnostic and staging procedures, especially with a view toward nonsurgical treatment. With the exception of eradication therapy in H. pylori-positive low-grade lymphoma of stage EI and the subgroup of locally advanced high-grade lymphoma, resection remains the treatment of choice. However, because there is an increasing trend toward stomach-conserving therapy, a randomized trial comparing cure of disease and quality of life with surgical and conservative treatment is needed.

Although a link between primary cutaneous B-cell lymphoma (PCBCL) and Borrelia burgdorferi infection has long been suspected, previous studies have not demonstrated a significant association. The authors looked for evidence of B. burgdorferi in 20 cases of PCBCL from the Scottish Highlands, an area with endemic Lyme disease, and compared their findings with those in 40 control patients (20 undergoing wide reexcision at sites of malignant melanoma and 20 biopsies of inflammatory dermatoses). All studies were performed on formalin-fixed, paraffin-embedded tissues. The cases of PCBCL were classified according to criteria described by the European Organization for Research and Treatment of Cancer Cutaneous Lymphoma Project Group using a combination of morphology, immunohistochemistry, and seminested polymerase chain reaction (PCR) for immunoglobulin heavy chain gene rearrangement. A nested PCR was performed on deoxyribonucleic acid (DNA) extracts from the lymphoma and control cases using primers to a unique conserved region of the B. burgdorferi flagellin gene. B. burgdorferi-specific DNA was detected in seven of 20 lymphoma cases (five of 12 marginal zone lymphomas, one of five primary cutaneous follicle center cell lymphomas, one of three diffuse, large B-cell lymphomas of the leg) and in one melanoma reexcision patient of 40 control subjects. The relationship between B. burgdorferi and PCBCL was significant when compared with the control groups separately (p <0.05) or in combination (p <0.01). These results provide strong evidence to support the concept of B. burgdorferi-driven lymphomagenesis in the skin.