Autoimmunity and lymphoma: tribulations of B cells

Plummer-Vinson syndrome in primary Sjögren syndrome: a case-based review

This study aimed to describe a patient with Sjögren syndrome who developed Plummer-Vinson syndrome, and to review the literature and describe shared aspects of this rare association. A systematic screening of articles was conducted in PubMed/MEDLINE, LILACS, SciELO, Scopus, Web of Science, and Cochrane, dating 1940 to 2020. All the articles included the association between Sjögren syndrome and Plummer-Vinson syndrome. No language restriction was applied. The following terms were used: "Sjögren syndrome" or "sicca syndrome" and "Plummer-Vinson syndrome" or "Paterson-Kelly syndrome." We performed our analysis by adding our present case, with a total of 4 cases. Three out of four were female (75%), age varied from 56 to 58 years old. In 2 cases, Sjögren syndrome preceded Plummer-Vinson syndrome diagnosis, and in 1 report, Plummer-Vinson syndrome appeared before Sjögren syndrome. Disease duration varied from 7 to 20 years. In two cases, autoantibodies were available, and antinuclear antibodies and anti-Ro/SS-A were positive in both, and anti-La/SS-B in one of them was associated with anti-dsDNA; however, no data regarding lupus was available in the article. Treatment involved iron supplementation in 3/3. Two out of three received parenteral iron supplementation, and in these two cases, mechanical esophageal dilatation was needless. In the other case, an additional endoscopic esophageal dilatation was necessary to receive the oral iron supplement. All 3 cases had a good outcome. This case illustrates a patient with Sjögren syndrome who developed the rare Plummer-Vinson syndrome. In Sjögren syndrome, the presence of iron-deficiency anemia, dysphagia, and weight loss should alert the physician to search for associated Plummer-Vinson syndrome.

Estrogens as regulator of hematopoietic stem cell, immune cells and bone biology

Hematopoietic stem cells provide continuous supply of all the immune cells, through proliferation and differentiation decisions. These decisions are controlled by local bone marrow environment as well as by long-range signals for example endocrine system. Sex dependent differential immunological responses have been described under homeostasis and disease conditions. Females show higher longevity than male counterpart that seems to depend on major female sex hormone, estrogen. There are four estrogens - Estrone (E1), estradiol (E2), Estriol (E3) and Estetrol (E4) that spatially and temporarily present during different female reproductive phases. In this review, we discussed recent updates describing the effects of estrogen on HSC, immune cells and in bone biology. Estradiol (E2) being a major/abundant estrogen is extensively investigated, while effects of other estrogens E1, E3 and E4 are started to unravel recently. Furthermore, clinical effect of estrogen as hormone therapy is discussed in HSC and immune cells perspectives. The data presented in this review is compiled by searches of PubMed, database of American Cancer Society (ACS). We have included article from September 1994 to March 2020 as covering all article in chronological order is not fissile so we included relevant article with substantial information in this specific area of research by using the search term (alone or in combination) estrogen, hematopoietic stem cell, immune cells, gender difference, estrone, estriol, estetrol, therapeutic application, pregnancy, effect on bone.

Excessive Pesticide Use Likely to Cause the Onset of Myasthenia Gravis in the Moroccan Agricultural Population

BACKGROUND AND OBJECTIVE

As pesticides have been and are widely used in agriculture. This work consists of highlighting one of the probable consequences of these xenobiotics. The aim of the study is possible association between the onset of autoimmune disorders and the exposure of rural populations to toxic substances will be discussed.

MATERIALS AND METHODS

To carry out this work, the data recorded in the medical records of myasthenic men and women living in the countryside were used. Of all the 117 cases withdrawn from the specialties hospital in Rabat (Morocco), 77% lived in urban areas and 23% in rural areas.

RESULTS

The result of the analysis of the files of rural inhabitants revealed a male predominance, unlike previous data on the distribution of myasthenia gravis by sex, women were in the lead in terms of quantity for this disease.

CONCLUSION

These findings may lead to highlight exposure to pesticides and their accumulation during the time spent by these agricultural workers in the fields and sometimes without appropriate personal protective equipment.

Diffuse large B-cell lymphoma involving peripheral nervous system with IgM antibodies against GM1 and GD1b: A case report

RATIONALE

The occurrence of peripheral neuropathy associated with non-Hodgkin's lymphoma (NHL) is uncommon. And autoimmunity may play an important role. We report a case of the patient with NHL, has sensorimotor demyelinating polyneuropathy.

PATIENT CONCERNS

The patient presented with a 1-month history of progressive numbness at the distal extremities and motor weakness of the lower limbs. Meanwhile, patient also endorsed a painful lump on her right cheek. And then the enlarged cervical and supra clavicular lymph nodes were observed on admission. Biopsy of the lymph nodes showed NHL. Serum IgM antibodies against GM1 and GD1b were also positive.

DIAGNOSIS

Biopsy of the lymph nodes showed NHL. Serum IgM antibodies against GM1 and GD1b were also positive. Thus, the patience was diagnosed with lymphoma and sensorimotor polyneuropathy.

INTERVENTIONS

Patient refused the further treatment.

OUTCOMES

After 11-month follow-up, the weakness of bilateral lower limbs worsens.

LESSONS

We have presented a case of NHL involving peripheral polyneuropathy with IgM antibodies against GM1 and GD1b. Patients may initially present with peripheral nerve complications or develop them during the course of lymphoma, even when in remission. This could complicate the diagnosis of peripheral polyneuropathy secondary to NHL.

Biomimetic Targeting of Nanoparticles to Immune Cell Subsets via Cognate Antigen Interactions

Within the body, cellular recognition is mediated in large part by receptor-ligand interactions that result from the surface marker expression of the participant cells. In the case of immune cells, these interactions can be highly specific, enabling them to carry out their protective functions in fighting off infection and malignancy. In this work, we demonstrate the biomimetic targeting of antigen-specific immune cell populations by using nanoparticles functionalized with natural membrane derived from cells expressing the cognate antigen. Using red blood cell (RBC)-specific B cells as a model target, it is shown that RBC membrane-coated nanoparticles exhibit enhanced affinity compared with control nanoparticles. The concept is further demonstrated using murine models of alloimmunity and autoimmunity, where B cells elicited against RBCs can be positively labeled using the biomimetic nanoparticles. This strategy for antigen-specific immune cell targeting may have utility for the detection and treatment of various autoimmune conditions, and it may additionally have implications for the prevention of immune cell malignancies.

Myasthenia Gravis Complicated with Peripheral T-cell Lymphoma, Not Otherwise Specified (PTCL-NOS), Following Thymectomy and Longstanding Tacrolimus Therapy

Myasthenia gravis (MG), a neuromuscular junction autoimmune disease, sometimes complicates second malignancies; however, T-cell lymphoproliferative disorders have rarely been reported. A 55-year-old man, who received oral tacrolimus and prednisolone for MG for 16 years after thymectomy, presented with left abdominal pain, lymphadenopathy, and splenomegaly. A lymph node biopsy revealed peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). This is the first report of oral tacrolimus leading to a T-cell lymphoproliferative disorder in patient without a history of transplantation. Physicians should be aware of the possibility of rare T-cell lymphoproliferative disorders, such as PTCL-NOS, occurring as complications in MG patients on immunosuppressive regimens after thymectomy.

Associations of Autoimmunity, Immunodeficiency, Lymphomagenesis, and Gut Microbiota in Mice with Knockins for a Pathogenic Autoantibody

A number of mouse strains transgenic for B-cell receptors specific for nucleic acids or other autoantigens have been generated to understand how autoreactive B cells are regulated in normal and autoimmune mice. Previous studies of nonautoimmune C57BL/6 mice heterozygous for both the IgH and IgL knockins of the polyreactive autoantibody, 564, produced high levels of autoantibodies in a largely Toll-like receptor 7-dependent manner. Herein, we describe studies of mice homozygous for the knockins that also expressed high levels of autoantibodies but, unlike the heterozygotes, exhibited a high incidence of mature B-cell lymphomas and enhanced susceptibility to bacterial infections. Microarray analyses and serological studies suggested that lymphomagenesis might be related to chronic B-cell activation promoted by IL-21. Strikingly, mice treated continuously with antibiotic-supplemented water did not develop lymphomas or abscesses and exhibited less autoimmunity. This mouse model may help us understand the reasons for enhanced susceptibility to lymphoma development exhibited by humans with a variety of autoimmune diseases, such as Sjögren syndrome, systemic lupus erythematosus, and highly active rheumatoid arthritis.

Advantages of targeting B cell receptor complex to treat B-cell derived autoimmune diseases and lymphomas

Antibodies produced by B-cells provide protection from infectious agents. However, impaired cell death signaling pathways in B-cells can lead to cancer, immunodeficiency or autoimmune diseases. B-cell signaling molecules such as CD20, CD19, Btk, and BAFF-R are targeted by therapeutic drugs and used to treat B-cell derived lymphomas or autoimmune diseases. Nevertheless, B-cells could develop resistance to these therapeutic drugs or the therapeutic drugs may have off-target effects. For instance, repeated rituximab (anti-CD20 antibody) treatment may lead to the loss of its target cell surface molecule, CD20. In addition, in B-cell malignancies, loss of CD19 expression has been observed. Another target molecule, Btk is expressed not only in B-cells but also in mast cells, macrophages, and dendritic cells. Thus, targeting Btk could negatively regulate the functions of innate immunity. The expression of BAFF-R is thought to be restricted to B-cells but it is also expressed on T-cells. Targeting BAFF-R, therefore, may lead to depletion of T-cells in addition to B-cells. B cell receptor (BCR) expression and signaling, however, are critically important for development, differentiation and survival of B-cells. Moreover, BCR is exclusively expressed on B-cells, which makes it an excellent target to avoid off-target effects.

What can Sjögren's syndrome-like disease in mice contribute to human Sjögren's syndrome?

For decades, Sjögren's syndrome (SS) and Sjögren's syndrome-like (SS-like) disease in patients and mouse models, respectively, have been intensely investigated in attempts to identify the underlying etiologies, the pathophysiological changes defining disease phenotypes, the nature of the autoimmune responses, and the propensity for developing B cell lymphomas. An emerging question is whether the generation of a multitude of mouse models and the data obtained from their studies is actually important to the understanding of the human disease and potential interventional therapies. In this brief report, we comment on how and why mouse models can stimulate interest in specific lines of research that apparently parallel aspects of human SS. Focusing on two mouse models, NOD and B6·Il14α, we present the possible relevance of mouse models to human SS, highlighting a few selected disease-associated biological processes that have baffled both SS and SS-like investigations for decades.

Inflammatory myopathies and lymphoma

The inflammatory myopathies comprise a group of immune-mediated muscle diseases. Lymphoma is a term for a variety of lymphatic system malignancies. Autoimmune diseases and lymphoproliferative malignancies share a complex bidirectional relationship. A causal relationship between inflammatory mypathies and lymphoma has not been established. The diagnosis/treatment of inflammatory myopathy usually precedes the detection/diagnosis of lymphoma. Immune system dysregulation presumably underlies the evolution of lymphoma in patients with inflammatory myopathies. Inflammatory activity with chronic B-cell activation and/or antigen stimulation is deemed the major risk factor for lymphoma in patients with autoimmunity. A "paraneoplastic" phenomenon or the effects of immunosuppressive therapy may be alternative immune-based mechanisms. In chronic lymphocytic leukemia immune system disturbance rarely results in non-hematological autoimmune disease, including inflammatory myopathies.

Fc Receptor-Like Proteins in Pathophysiology of B-cell Disorder

Members of the family of Fc receptor-like (FcRL) proteins, homologous to FcγRI, have been identified by multiple research groups. Consequently, they have been described using multiple nomenclatures including Fc receptor homologs (FcRH), immunoglobulin superfamily receptor translocation-associated genes (IRTA), immunoglobulin-Fc-gp42-related genes (IFGP), Src homology 2 domain-containing phosphatase anchor proteins (SPAP), and B cell cross-linked by anti-immunoglobulin M-activating sequences (BXMAS). They are now referred to under a unified nomenclature as FCRL. Eight different human FCRL genes have been identified, all of which appear to be related to the genes of the immunoglobulin superfamily (IgSF) of cellular adhesion molecules. These type 1 transmembrane glycoproteins are composed of different combinations of 5 types of immunoglobulin-like domains, with each protein consisting of 3 to 9 domains, and no individual domain type conserved throughout all of the FCRL proteins. Ligands for the majority of the FCRLs remain unknown. In general, FCRL expression is restricted to lymphocytes and is primarily expressed in B-lymphocytes, supporting FCRL’s involvement in a variety of immune disorders. Most FCRLs functionally repress B-cell activation; however, they might have dual roles in lymphocyte functions as these proteins often possess immunoreceptor tyrosine activation (ITAM) and inhibitory (ITIM) motif elements. The biological functions of these newly recognized FCRL proteins are just beginning to emerge, and might provide the insight necessary for understanding pathophysiology of lymphocyte disorders and treating different immune diseases.

Predispositions to Lymphoma: A Practical Review for Genetic Counselors

This review provides a synopsis for genetic counselors of the major concepts of lymphoma predisposition: genomic instability, immune deficiency, inappropriate lymphoproliferation, and chronic antigen stimulation. We discuss syndromes typifying each of these mechanisms. Importantly, our review of the genetic counseling literature reveals sparse discussion of genetically-based immune-mediated lymphoma predisposition, which we address in depth here. We aim to increase awareness among genetic counselors and colleagues in oncology about familial susceptibility and facilitate critical thinking about lymphoma risk assessment. Clinical application of this knowledge is aided by recommendations for collection of personal and family history to guide risk assessment and testing. Lastly, we include a special discussion of genetic counseling issues including perceptions of the context, nature, and magnitude of lymphoma risk, as well as coping with awareness of susceptibility to lymphoma.

Lymphoma-associated dysimmune polyneuropathies

Lymphoma consists of a variety of malignancies of lymphocyte origin. A spectrum of clinical peripheral neuropathy syndromes with different disease mechanisms occurs in about 5% of lymphoma patients. There exists a complex inter-relationship between lymphoproliferative malignancies and autoimmunity. An imbalance in the regulation of the immune system presumably underlies various immune-mediated neuropathies in patients with lymphoma. This article reviews lymphoma and more-or-less well-defined dysimmune neuropathy subgroups that are caused by humoral and/or cell-mediated immune disease mechanisms directed against known or undetermined peripheral nerve antigens.

Virus-induced preferential antibody gene-usage and its importance in humoral autoimmunity

It is known that even the adaptive components of the immune system are based on genetic traits common to all individuals, and that diversity is shaped by the lifelong contacts with different non-self antigens, including those found on infectious pathogens. Besides the individual differences, some of these common traits may be more prone to react against a given antigen, and this may be exploited by the infectious pathogens. Indeed, viral infections can deregulate immune response by subverting antibody (Ab) gene usage, leading to the overexpression of specific Ab subfamilies. This overexpression often results in a protective antiviral response but, in some cases, also correlates with a higher likelihood of developing humoral autoimmune disorders. These aspects of virus-induced autoimmunity have never been thoroughly reviewed, and this is the main purpose of this review. An accurate examination of virus specific Ab subfamilies elicited during infections may help further characterize the complex interplay between viruses and the humoral immune response, and be useful in the design of future monoclonal antibody (mAb)-based anti-infective prophylactic and therapeutic strategies.

Autoantibody-Mediated Sensory Polyneuropathy Associated with Indolent B-Cell Non-Hodgkin's Lymphoma: A Report of Two Cases

Background and Purpose

Abnormalities of the peripheral nervous system occur in 5% of patients with lymphoma. Polyneuropathy has not been described in patients with mantle-cell and marginal-zone B-cell lymphomas.

Case Report

Two elderly patients with indolent non-Hodgkin's lymphoma developed a progressive sensory polyneuropathy that was associated with serum autoantibodies directed against asialosyl/sialosyl gangliosides and myelin-associated glycoprotein/sulfated glucuronyl paragloboside, respectively, which are peripheral-nerve antigens. The oligoclonal pattern of these antibodies hinted at a lymphoma-induced immune dysregulation. The neuropathy stabilized clinically during treatment with intravenous immunoglobulin G. B-cell lymphoma was managed with a "watchful waiting" approach.

Conclusions

The concept of antigen-specific, immune-mediated neuropathy associated with slow-growing lymphoma of mature B-cells may be underrecognized. The principle of treating the illness underlying neuropathy may not be always indicated or necessary if risk-benefit and cost-benefit analyses are taken into account.

Gender differences in autoimmune disease

Autoimmune diseases are a range of diseases in which the immune response to self-antigens results in damage or dysfunction of tissues. Autoimmune diseases can be systemic or can affect specific organs or body systems. For most autoimmune diseases there is a clear sex difference in prevalence, whereby females are generally more frequently affected than males. In this review, we consider gender differences in systemic and organ-specific autoimmune diseases, and we summarize human data that outlines the prevalence of common autoimmune diseases specific to adult males and females in countries commonly surveyed. We discuss possible mechanisms for sex specific differences including gender differences in immune response and organ vulnerability, reproductive capacity including pregnancy, sex hormones, genetic predisposition, parental inheritance, and epigenetics. Evidence demonstrates that gender has a significant influence on the development of autoimmune disease. Thus, considerations of gender should be at the forefront of all studies that attempt to define mechanisms that underpin autoimmune disease.

Simultaneous occurrence of early gastric carcinoma and mucosa-associated lymphoid tissue lymphoma of the omentum

The simultaneous association of gastric carcinoma with omental mucosa-associated lymphoid tissue (MALT) lymphoma is a rare event that has not been reported previously. We focused on the hypothetic pathogenetic mechanisms, diagnosis and treatment of this rare condition. A 55-year-old woman with Helicobacter pylori infection underwent distal gastrectomy in our hospital. Three independent early gastric cancers and a mass near the cecum were diagnosed preoperatively. Pathological review of the resected stomach showed three independent early signet ring cell gastric carcinomas, and the mass in the omentum near the cecum was shown to be omental MALT lymphoma. Due to the nature of the patient's disease, she was started on medical eradication of H. pylori. Synchronous gastric adenocarcinoma and omental MALT lymphoma is a rare event. Special attention given to H. pylori-associated gastric cancer patients can avoid misdiagnosis and lead to adequate treatment.

Defective stromal remodeling and neutrophil extracellular traps in lymphoid tissues favor the transition from autoimmunity to lymphoma

Altered expression of matricellular proteins can become pathogenic in the presence of persistent perturbations in tissue homeostasis. Here, we show that autoimmunity associated with Fas mutation was exacerbated and transitioned to lymphomagenesis in the absence of SPARC (secreted protein acidic rich in cysteine). The absence of SPARC resulted in defective collagen assembly, with uneven compartmentalization of lymphoid and myeloid populations within secondary lymphoid organs (SLO), and faulty delivery of inhibitory signals from the extracellular matrix. These conditions promoted aberrant interactions between neutrophil extracellular traps and CD5(+) B cells, which underwent malignant transformation due to defective apoptosis under the pressure of neutrophil-derived trophic factors and NF-κB activation. Furthermore, this model of defective stromal remodeling during lymphomagenesis correlates with human lymphomas arising in a SPARC-defective environment, which is prototypical of CD5(+) B-cell chronic lymphocytic leukemia (CLL).

Possible Mechanisms of Lymphoma Development in Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a systemic as well as an organ-specific autoimmune disease characterized by lymphocytic infiltration of the glandular epithelial tissue. SS patients have been reported to be at highest risk of developing lymphoproliferative neoplasms, when compared with patients with other rheumatoid diseases. Factors such as cytokine stimulation, environmental factors, viral infection and genetic events as well as vitamin deficiency may contribute to the development of lymphoma. Over the past few decades, numerous efforts have been made to assess the relationship between lymphoma and SS. These include epidemiological surveys, molecular biologic assessments of clonality and well-linked register cohort studies evaluating the predictive value of clinical, laboratory and histological findings. Nevertheless, the mechanisms and factors predictive of lymphoma development in pSS patients remain to be defined. This review summarizes updated knowledge on the incidence of and risk factors for lymphoma development in pSS patients, as well as discussing the most recent findings on the development and treatment of lymphoma in pSS patients and the possible mechanism of lymphoma development.

Low levels of vitamin-D are associated with neuropathy and lymphoma among patients with Sjögren's syndrome

BACKGROUND/PURPOSE

Primary Sjögren's syndrome (SS) is a chronic autoimmune disease primarily involving the exocrine glands. The clinical picture of SS ranges from exocrinopathy to systemic disease affecting the lung, kidney, liver, skin, musculockeletal and nervous systems. The morbidity of SS is mainly determined by extraglandular disease and increased prevalence of lymphoma. Environmental and hormonal factors, such as vitamin-D may play a role in the pathogenic process and disease expression. Thus, we aimed to evaluate levels of vitamin-D and their association with manifestations of SS.

METHODS

Vitamin-D levels were determined in 176 primary SS patients and 163 matched healthy volunteers utilizing the LIAISON chemiluminescent immunoassays (DiaSorin-Italy). A correlation between vitamin-D levels and clinical and serological manifestations of SS was performed.

RESULTS

Mean vitamin-D levels were comparable between SS patients and control 21.2 ± 9.4 ng/ml and 22.4 ± 10 ng/ml, respectively. Peripheral neuropathy was diagnosed in 23% of SS patients and associated with lower vitamin-D levels (18.6 ± 5.5 ng/ml vs. 22.6±8 ng/ml (p = 0.04)). Lymphoma was diagnosed in 4.3% of SS patients, who had lower levels of vitamin-D (13.2 ± 6.25 ng/ml), compared to SS patients without lymphoma (22 ± 8 ng/ml), (p = 0.03). Other clinical and serological manifestations did not correlate with vitamin-D status.

CONCLUSIONS

In this study, low levels of vitamin-D correlated with the presence of peripheral neuropathy and lymphoma among SS patients. The link between vitamin-D and neuropathy or lymphoma was reported in other conditions, and may support a role for vitamin-D in the pathogenesis of these processes. Plausible beneficial effect for vitamin-D supplementation may thus be suggested.

The age-risk relationship of haematologic malignancies in female patients with systemic lupus erythematosus: a nationwide retrospective cohort study

BACKGROUND

The risks of haematologic malignancies in female patients with systemic lupus erythematosus (SLE) have been observed to be higher in young age groups than in old age groups. However, the age-risk relationship between haematologic malignancies and SLE is poorly defined.

DESIGN AND METHODS

A retrospective cohort study was conducted nationwide with newly diagnosed SLE female patients during the period of 1997 to 2001 using the database acquired from the Taiwan National Health Research Institute. Each patient in the study was randomly frequency matched with five SLE-free people based on age. The subsequent developments of haematologic malignancies were observed until the date haematologic cancer was diagnosed or December 2008. The age-adjusted standardized incidence ratios (SIRs), the incidence per 1000 person-years, the follow-up duration to the diagnosis of haematologic malignancies and the cumulative hazard rates of haematologic malignancies between SLE and controls were analysed.

RESULTS

A total of 35 lymphoid and 14 myeloid malignancies were observed among 9349 female SLE patients. Further, significantly higher incidences of both lymphoid and myeloid malignancies were found in SLE patients (SIR: 3.30, 95% confidence interval (CI) = 2.20-4.93 and SIR: 2.86, 95% CI = 1.49-5.09). Also, two peaks of risk ratios for lymphoid malignancies were found in patients aged 21-30 years and 41-50 years. It was observed that the follow-up duration for haematologic malignancies was significantly shorter in SLE patients than in controls (73.21 vs. 105.25 months, respectively). In addition, higher cumulative hazard rates in both lymphoid and myeloid malignancies were found in SLE patients (p < 0.0001).

CONCLUSION

Female SLE patients have a higher incidence of haematologic malignancy in different age groups, and with shorter incubating time than SLE-free people.

Malignant lymphomas and autoimmunity-a single center experience from Hungary

Autoimmune diseases and malignant lymphomas have numerous similarities in their etiology and pathogenesis. Patients with autoimmune disorders have increased risk to develop non-Hodgkin's lymphomas, yet little is known about the occurrence of autoimmune features within lymphoma patients. Our aim was to examine the prevalence of autoimmune diseases among patients with non-Hodgkin's (NHL) and Hodgkin's lymphoma (HL). We reviewed 352 patients' charts with malignant lymphomas to assess the rate of associated autoimmune diseases. Of 231 NHL patients, 30 (12.9%) had autoimmune disorders, while there were 11 patients who suffered from more than one disease entity. It was Sjögren's syndrome that occurred in the largest number (eight cases), other frequent entities were undifferentiated connective tissue disease (seven), thyroiditis (six), rheumatoid arthritis (four), and systemic vasculitis (four). The female/male ratio was significantly different between patients with or without autoimmune diseases, while no other clinical features differed significantly between the two groups. Ten patients (33.3%) were initially diagnosed with lymphoma, 13 (43.3%) of them had already been diagnosed with autoimmune disease at the time of lymphoma occurrence. Six patients (20%) with previously diagnosed immunological disorder developed new autoimmune condition after the treatment of lymphoma. Lymphoma and autoimmune disease occurred simultaneously in one patient. Among the 121 HL patients, 14 (11.5%) had associated autoimmune disease. Ten patients developed thyroiditis after the lymphoma treatment, two had immune thrombocytopenia, and one had autoimmune hemolytic anemia. One female patient was diagnosed with systemic sclerosis 10 years before the onset of HL. Our results highlight that an increased risk for the development of autoimmune diseases should be considered in patients both with NHL and HL.

Ectopic B-cell clusters that infiltrate transplanted human kidneys are clonal

B cells and their immunoglobulin products participate in allograft rejection of transplanted human kidneys in which an interesting feature is the presence of a germinal center like B-cell clusters in the allograft. We report here that the immunoglobulin repertoires of these infiltrating B cells are highly restricted and the B cells within a cluster are clonal. Antibody libraries made from the infiltrating B cells of individual patients unexpectedly revealed that each patient utilizes a particular set of dominant germ line genes as well as dominant complementarity determining region 3. Comparison of kidney and peripheral blood from the same patient showed that the immunoglobulin genes from both compartments had dominant clones, but they differed. The lymphocytes that infiltrate the kidneys express the immunoglobulin gene somatic recombination machinery usually restricted to highly activated lymphocytes in germinal centers and lymphomas. An analogy can be made between the inescapable antigenic drive in chronic infection versus that in an allograft, both of which may lead to emergence of dominant B-cell clones and even lymphoid malignancy.

Rare antibodies from combinatorial libraries suggests an S.O.S. component of the human immunological repertoire

Convergence of observations from different sources is the norm in science. However, when convergence occurs in man for antibodies it is remarkable because the repertoire of possible immunoglobulin products is very large and diverse. Thus, one would not expect to see the same antibody twice from divergent populations unless there is special significance as to why the immune response is constrained. Now, broadly neutralizing antibodies isolated from combinatorial libraries from three separate populations have been shown to all use the same (V(H) 1-69) germ line gene and interact with the influenza virus in very similar ways. Here we discuss the reasons for this convergence in terms of how the immunological repertoire responds to emergency situations where time is short as occurs, for example, in potentially lethal infections. It is suggested that there is a first responder or S.O.S. component of the antibody repertoire that evolved to initiate rapid defense against infectious agents. The discovery of the homologies between these commonly produced antibodies may have significance for the design of novel vaccines. Finally, these convergent results may give much insight into why antibodies encoded by the V(H) 1-69 germ line gene are highly over represented in B-cell lymphomas.

A role for lymphotoxin in primary Sjogren's disease

The etiology of salivary gland injury in primary Sjögren's disease is not well understood. We have previously described a mouse model of Sjögren's disease, IL-14α transgenic (IL14αTG) mice, which reproduces many of the features of the human disease. We now demonstrate a critical role for lymphotoxin α (LTA) in the pathogenesis of Sjögren's disease in IL14αTG mice. IL14αTG mice express LTA mRNA in their salivary glands and spleen and produce soluble LTA protein in their salivary secretions. When IL14αTG mice were crossed with LTA(-/-) mice, the IL14αTG.LTA(-/-) mice retained normal salivary gland secretions and did not develop either lymphocytic infiltration of their salivary glands or secondary lymphomas. However, both IL14αTG and IL14αTG.LTA(-/-) mice produced similar amounts of IFN-α and had similar deposition of autoantibodies in their salivary glands. Both IL14α and IL14α/LTA(-/-) mice had similar B cell responses to T-dependent and T-independent Ags, L-selectin expression, and expression of RelA, RelB, and NF-κB2 in their spleens. These studies suggest that LTA plays a critical role in the local rather than systemic inflammatory process of Sjögren's disease. Furthermore, local production of soluble LTA in the salivary glands of IL14αTG mice is necessary for the development of overt Sjögren's disease. Autoantibody deposition alone is not sufficient to produce salivary gland dysfunction. We also demonstrate that LTA is increased in the salivary gland secretions and sera of patients with Sjögren's disease, further strengthening the biological relevance of the IL14αTG model to understanding the pathogenesis of human disease.

Sjögren syndrome: advances in the pathogenesis from animal models

Sjögren syndrome is an autoimmune disease characterized by hyposecretion of the lacrimal and salivary glands, resulting in dryness of the eyes and mouth. Individuals may experience primary Sjögren syndrome or a secondary form accompanying another rheumatic autoimmune disease, such as rheumatoid arthritis or systemic lupus erythematosus. The pathogenic mechanisms of Sjögren syndrome remain largely unknown, in part a consequence of the heterogeneity of the disease. Animal models have shed light on the connections between specific pathways and symptoms, but an ideal system is wanting. Improved disease models will enable a better understanding of Sjögren syndrome, including how immune tolerance is lost and potential therapeutic interventions. Most importantly, an optimal model will enable detection of disease biomarkers, since injury to the salivary glands may precede lymphocytic infiltration. This review aims to characterize available mice models of Sjögren syndrome, including advantages and disadvantages, from the researcher's perspective.

Genetic and immune-related factors in the pathogenesis of lymphoproliferative and plasma cell malignancies

There are data to support a role for genetic and immune-related factors in the pathogenesis of lymphomas and plasma cell diseases. In this paper, we review our published large population-based studies and other relevant studies in Hodgkin's and non-Hodgkin's lymphomas, multiple myeloma, and the precursor condition monoclonal gammopathy of undetermined significance. We discuss the overlap in risk factors between related malignancies and explore the underlying mechanisms. Based on these studies, we provide clinical implications and discuss the relevance of these data for patient counseling and clinical follow-up. Finally, we suggest future directions for new studies designed to increase our current knowledge and to define underlying biological mechanisms of our findings.

Autoimmunity and lymphomagenesis

For more than 50 years, links between autoimmunity and lymphomas have been described based on human and animal studies. Over the last 3 decades, many studies have addressed specific hypotheses about these associations using population level data. This has been accomplished by assessing previous autoimmune history in case-control studies of patients with lymphoma (mainly non-Hodgkin lymphoma) and myeloma, and by following cohorts of patients with various autoimmune diseases for subsequent development of lymphoma and multiple myeloma. In this article, we review our recently published series of association studies based on data from Scandinavia and from US Veterans and other relevant findings. We also discuss what these associations have revealed about the mechanisms and pathways underlying both autoimmunity and lymphoma. Finally, we discuss the future directions involving a combination of population and molecular studies that are needed to better define underlying biological mechanisms.

Oxidative stress in Fanconi anemia hematopoiesis and disease progression

Patients with the genomic instability syndrome Fanconi anemia (FA) commonly develop progressive bone marrow failure and have a high risk of cancer. The prominent role of the FA protein family involves DNA damage response and/or repair. Oxidative stress, defined as an imbalance between the production of reactive oxygen species and antioxidant defense, is considered to be an important pathogenic factor in leukemia-prone bone marrow diseases such as FA. Cellular responses inducing resistance to oxidative stress are important for cellular survival, organism lifespan, and cancer prevention, but until recently, mammalian factors regulating resistance to oxidative stress have not been well characterized. Significant evidence supports excessive apoptosis of hematopoietic stem/progenitor cells, induced by stresses, most significantly oxidative stress, as a critical factor in the pathogenesis of bone marrow failure and leukemia progression in FA. In this brief review, we discuss the functional link between FA proteins and oxidative DNA damage response/repair, with emphasis on the implication of oxidative stress in the pathophysiology and abnormal hematopoiesis in FA.

Hepatitis C virus infection, mixed cryoglobulinemia and BLyS upregulation: targeting the infectious trigger, the autoimmune response, or both?

Mixed cryoglobulinemia syndrome (MCsn) is a systemic vasculitis prevalently mediated by immune complexes, i.e., mixed cryoglobulins, and characterized by non-neoplastic B-cell lymphoproliferation favouring the progression into frank B-cell non-Hodgkin lymphoma (NHL) in 5-10% of patients. The hepatitis C virus (HCV) infection is the etiologic agent in the large majority of MCsn cases and chronic antigenic stimulation by HCV is considered a key mechanism sustaining the proliferation of the RF-secreting B-cell clones. Besides chronic antigenic stimulation, cytokines and growth factors may also play a key role in sustaining B-cell overactivation. B-lymphocyte stimulator (BlyS) was recently described as a critical survival factor for B cells, promoting their activation and maturation. Abnormal production of BLyS alters immune tolerance by allowing the survival of autoreactive B cells, thus triggering autoimmune disorders. BLyS inhibits B-cell apoptosis, and B-cell apoptosis is implicated in the pathogenesis of MCsn, as well as of other autoimmune diseases. Both antiviral therapy and B- cell depletive therapy in MCsn may influence BlyS expression. Antiviral therapy, monotherapy against biologic targets downstream viral infection, or the combination of the two, should be optimized in the single patient and stage of the disease, based on disease pathobiology, efficacy and safety issues.

Update on Sjögren's syndrome autoimmune epithelitis: from classification to increased neoplasias

Sjögren's syndrome is a chronic inflammatory process that primarily involves the exocrine glands. Its clinical manifestations range from autoimmune exocrinopathy to extraglandular (systemic) involvement affecting the lungs, kidneys, blood vessels, and muscles; it can occur alone (primary Sjögren's syndrome) or in association with other autoimmune diseases (secondary Sjögren's syndrome). In recent years, clinical and laboratory observations have highlighted the central role of the epithelial cell and it has been suggested that the etiological name of the disease should be 'autoimmune epithelitis'. The extraglandular manifestations of the disease are divided in two groups: (1) lung, kidney (interstitial nephritis), and liver involvement as a result of lymphocytic invasion in epithelial tissues; and (2) skin vasculitis, peripheral neuropathy, and glomerulonephritis, with low C4 levels, which is the result of immune complex disease, are associated with increased morbidity and high risk for lymphoma. The diagnosis of the disease is based on the classification criteria, raised by the American-European Study Group and which have been built on the European preliminary classification criteria, developed in 1992. The association of Sjögren's syndrome with lymphoma is well documented as in approximately 5% of patients the benign autoimmune process is transformed into a lymphoid malignancy. The salivary extranodal marginal zone B-cell lymphomas of the mucosa-associated lymphoid tissue type are the most common lymphoma in Sjögren's syndrome. These tumors are antigen-stimulated B-cell lymphomas and are characterized by localized stage, indolent clinical course, and recurrence in other extranodal sites. Among the clinical and serological parameters that have been associated with lymphoma development in patients with Sjögren's syndrome, the presence of palpable purpura, low C4 and mixed monoclonal cryoglobulinemia constitute the main predictive markers; patients displaying these risk factors should be monitored closely. The purpose of this review is to discuss the clinical picture, the diagnostic procedure, and the malignant lymphoproliferation in the disease.

Targeting TRAFs for Therapeutic Intervention

TNF-receptor associated factors (TRAFs) are the molecules that upon engagement of the TNF-receptor (TNFR) by a TNF-family ligand come first in contact with the activated TNFR, initially acting as docking molecules for kinases and other effector proteins that are recruited to the activated receptor. TRAFs later regulate the subcellular relocalization of the receptor-ligand complex and finally they modulate the extent of the response by controlling the degradation of key proteins in the pathway. In this chapter, we review the involvement of different TRAF family members in the etiology of a variety of pathologies and address the question of whether the use of TNFR-mimic-peptides or small molecule modulators targeting TRAFs might be suitable for therapeutic intervention, discussing the advantages and disadvantages of this strategy.

B-cell lymphoproliferation in chronic inflammatory rheumatic diseases

Patients with chronic inflammatory rheumatic diseases, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and especially primary Sjögren's syndrome (SS), are at higher risk than the general population of developing B-cell non-Hodgkin lymphoma (NHL). Analyses of the association between various lymphoma subtypes and specific disease entities suggest that this association might be mediated by disease-specific mechanisms, as well as by mechanisms unique to lymphoma subtype. These specific associations can provide important information about abnormal B-cell stimulation in these conditions. Patients with primary SS, SLE and RA are at high risk of developing diffuse large B-cell lymphomas, a group of high-grade NHLs with remarkable heterogeneity. Patients with primary SS are at particularly high risk of developing marginal-zone B-cell lymphomas. The risk factors of lymphoma development in primary SS seem to be closely related to the underlying mechanisms of abnormal stimulation and/or impaired censoring mechanisms of B cells. In patients with RA and SLE, more intense disease activity and/or long-lasting disease might be indications of a higher risk of lymphoma development. This Review will focus on the risk of lymphoma, common and disease-specific mechanisms of B-cell lymphoma development, and on the clinical consequences of lymphoma in patients with inflammatory rheumatic diseases.

The normal counterpart to the chronic lymphocytic leukemia B cell

Chronic lymphocytic leukemia (CLL) is characterized by the monoclonal expansion of small mature-looking B cells that accumulate in the blood, marrow, and lymphoid organs, and have a remarkable phenotypic homogeneity. By definition, CLL cells co-express CD5 and CD23 with faint to undetectable amounts of monoclonal surface immunoglobulins (sIg). The concept of phenotypic homogeneity has been reinforced by gene expression profiling data, which suggest that the pathogenesis of CLL has to be associated with a fairly common mechanism of transformation. In recent years the biology of CLL has been enriched by an unprecedented flurry of new observations that are leading to a better understanding of the natural history of the disease. Still CLL cells have so far defied any attempt to satisfactorily answer the simple time-honored question of what their cell of origin is. It is the purpose of this review to discuss the features a cell must possess to be considered with reasonable approximation the normal counterpart of a CLL B cell.

Familial inflammatory dilated cardiomyopathy

BACKGROUND

Systematic family screening has recently identified dilated cardiomyopathy as an inherited disorder in up to 30% of cases. Mutations in genes encoding proteins responsible for myocardial architecture have been identified, but additional pathophysiological mechanisms including inflammatory reactions have been proposed.

AIMS

Identification and characterization of familial DCM, where at least one affected family member fulfils the criteria for inflammatory DCM may lead to a better understanding of the aetiology and pathogenesis of (inflammatory) DCM.

METHODS AND RESULTS

Ten families were examined. In six families, clinical characteristics and mode of inheritance were compatible with pure fDCM, fDCM with conduction defect and autosomal recessive fDCM. In four families, (auto-)immune features were diagnosed in affected and non-affected family members.

CONCLUSIONS

Familial DCM with an inflammatory component was identified as a specific subgroup of familial DCM. In most cases, the inflammatory process seems to modify, i.e. aggravate, the "classic, cytoskeletopathic" familial DCM, but in some, especially when taking clinical and genetic aspects into account, inflammatory (auto-)immune features can be addressed as the leading pathogenetic principle. Further elucidation of these families may provide a better insight into pathophysiologic processes and may aid in the development of specific therapeutic strategies.

Itch genetically interacts with Notch1 in a mouse autoimmune disease model

Homozygous itchy mice develop a fatal, late-onset autoimmune-like disease due to a loss of function mutation in an ubiquitin protein ligase. Phylogenetic and in vitro analyses suggest that Itch is a negative regulator of Notch signaling. Since Notch proteins have many important functions in the immune system, we determined whether Itch regulates Notch signaling in vivo. This was accomplished by breeding homozygous itch mice to mice carrying an activated Notch1 transgene that was specifically overexpressed in developing thymocytes. Interestingly, all itch mice carrying this transgene were smaller than their littermates and died by 12 weeks of age. These mice had a similar autoimmune disease to that seen in itch animals. However, the lesions were more severe with a much earlier age of onset, supporting the assertion that these mutations genetically interact. In addition, the combination of these mutations produced novel phenotypes including a perturbation in T cell development, with a reduction in the number of double-positive (DP) and an increase in the number of double-negative and single-positive T cells. TUNEL staining showed reduced apoptosis in the thymus of itch animals that carry the Notch1 transgene. Antibody staining displayed increased levels of full-length Notch1 and phospho-AKT specifically in DP thymocytes but no change in other signaling pathways including MAPK, p38 and JNK. These results provide the first direct demonstration that increased AKT-mediated Notch1 signaling results in autoimmunity and may provide insight into the treatment of a group of diseases that affect a significant proportion of the population.

Malignant lymphomas in autoimmunity and inflammation: a review of risks, risk factors, and lymphoma characteristics

Certain autoimmune and chronic inflammatory conditions, such as Sjögren's syndrome and rheumatoid arthritis (RA), have consistently been associated with an increased risk of malignant lymphomas, but it is unclear whether elevated lymphoma risk is a phenomenon that accompanies inflammatory conditions in general. Likewise, it is debated whether the increased risk identified in association with some disorders pertains equally to all individuals or whether it varies among groups of patients with different phenotypic or treatment-related characteristics. It is similarly unclear to what extent the increased lymphoma occurrence is mediated through specific lymphoma subtypes. This update reviews the many findings on risks, risk levels, and lymphoma characteristics that have been presented recently in relation to a broad range of chronic inflammatory, including autoimmune, conditions. Recent results clearly indicate an association between severity of chronic inflammation and lymphoma risk in RA and Sjögren's syndrome. Thus, the average risk of lymphoma in RA may be composed of a markedly increased risk in those with most severe disease and little or no increase in those with mild or moderate disease. The roles of immunosuppressive therapy and EBV infection seem to be limited. Furthermore, RA, Sjögren's syndrome, systemic lupus erythematosus, and possibly celiac disease may share an association with risk of diffuse large B-cell lymphoma, in addition to well-established links of Sjögren's syndrome with risk of mucosa-associated lymphoid tissue lymphoma and of celiac disease with risk of small intestinal lymphoma. However, there is also obvious heterogeneity in risk and risk mediators among different inflammatory diseases.

Development of Autoimmunity in IL-14α-Transgenic Mice

Multiple genetic loci contribute to the development of systemic lupus erythematosus (SLE). In murine models for SLE, various genes on chromosome four have been implicated. IL-14 is a cytokine originally identified as a B cell growth factor. The il14 gene is located on chromosome 4. IL-14alpha is a cytokine encoded by the plus strand of the IL-14 gene using exons 3-10. The expression of IL-14alpha is increased in (NZB x NZW)F1 mice. In this study, we produced IL-14alpha-transgenic mice to study the role of IL-14alpha in the development of autoimmunity. At age 3-9 mo, IL-14alpha-transgenic mice demonstrate increased numbers of B1 cells in the peritoneum, increased serum IgM, IgG, and IgG 2a and show enhanced responses to T-dependent and T-independent Ags compared with littermate controls. At age 9-17 mo, IL-14alpha-transgenic mice develop autoantibodies, sialadenitis, as in Sjögren's syndrome, and immune complex-mediated nephritis, as in World Health Organization class II SLE nephritis. Between the ages 14-18 mo, 95% of IL-14alpha-transgenic mice developed CD5+ B cell lymphomas, consistent with the lymphomas seen in elderly patients with Sjögren's syndrome and SLE. These data support a role for IL-14alpha in the development of both autoimmunity and lymphomagenesis. These studies may provide a genetic link between these often related disorders.

Lymphoma and other malignancies in primary Sjögren's syndrome

Low peripheral CD4+ counts or low CD4+/CD8+ ratios may be important risk factors for lymphoma in SS

[Auto-immune manifestations in Non-Hodgkin's lymphoma]

PURPOSE

A wide spectrum of auto-immune manifestations is frequently reported in non-Hodgkin's lymphoma (NHL). The purpose of the review is to describe the immune manifestations observed in NHL, according to their histological subtype and to discuss the current physiopathological hypothesis with their therapeutic relevance.

CURRENT KNOWLEDGE AND KEY POINTS

Most of the organs can be targeted by an immune process due to the lymphoproliferative disease: they include skin diseases (paraneoplastic pemphigus, vasculitis, urticaria, acrosyndromes), peripheral and central nervous system involvement (polyneuropathy, multifocal neuropathy), haematological manifestations (immune cytopenia, acquired bleeding disorders), rheumatologic diseases (arthritis, systemic vasculitis, myositis) and renal lesion (cryoglobulinemia, glomerulopathies). A higher prevalence of autoantibodies, such as antinuclear antibodies, Antiphospholipid antibodies, or endomysium antibodies, is observed in NHL but usually without clinical manifestations. In B-cell NHL, clinical and biological immune manifestations are more frequently observed in indolent lymphoma than in aggressive NHL. In T-cell NHL, immune manifestations are frequent and polymorphous, preceding usually the diagnosis of lymphoma. The prognosis value of the immune manifestations in NHL is unclear. Immune manifestations can be also be related to the treatment procedure, including fludarabine, Interferon, autograft or Rituximab. The physiopathology of the immune manifestations may involve auto-antibodies production by natural CD5+ autoreactive B-cell from which is issue the proliferation, a lost of immune tolerance, an abnormality in the Fas/Fas Ligand pathway or a chronic antigenic stimulation.

FUTURE PROSPECTS AND PROJECTS

As observed in T-cell lymphoma cases, immunosuppressive treatment can control both immune manifestations and lymphoproliferation, suggesting that lymphoma and auto-immunity may be the two aspects of the same process. The monoclonal antibody anti-CD20 (rituximab), able to suppress the tumoral cells and change the B-cell repertoire is the most promising treatment to cure immune disorders related to NHL. So far, rituximab has been successfully used in mixed cryoglobulinemia and cold agglutinins secondary to NHL.

Clonality analysis of alveolar B lymphocytes contributes to the diagnostic strategy in clinical suspicion of pulmonary lymphoma

The diagnostic procedure of chronic pulmonary opacities may envisage the search for non-Hodgkin lymphoma (NHL). Previous retrospective studies have shown that clonality analysis of bronchoalveolar B lymphocytes could reflect the clonality of pulmonary lymphocytes. Our objective was to define the diagnostic usefulness of bronchoalveolar lavage (BAL) B-lymphocyte clonality analysis in the setting of a clinical suspicion of both primary and secondary pulmonary lymphoma. A prospective BAL fluid B-cell clonality analysis was performed by polymerase chain reaction (PCR) in 106 consecutive patients presenting with a clinical suspicion of pulmonary NHL. Diagnosis was pulmonary B-cell lymphoma for 22 patients (13 primary and 9 secondary). When compared, pulmonary biopsy and BAL fluid have clonal identity. The detection of a strong B-cell clonal population in BAL fluid was associated with the diagnosis of pulmonary NHL (P <.0001), with a 97% specificity and a 95% negative predictive value. Thus, the absence of a dominant B-cell clone detection in BAL fluid could help to dismiss invasive investigations of pulmonary lesions. The detection of a dominant B-cell clone would lead to the performance of a pulmonary biopsy to get histologic diagnosis in primary pulmonary lymphoma and, by contrast, would avoid the need for biopsy in the setting of a secondary pulmonary lymphoma.

Deficiencies of GM-CSF and interferon gamma link inflammation and cancer

Chronic inflammation contributes to carcinogenesis, but the underlying mechanisms are poorly understood. We report that aged granulocyte-macrophage colony stimulating factor (GM-CSF)-deficient mice develop a systemic lupus erythematosis (SLE)-like disorder associated with the impaired phagocytosis of apoptotic cells. Concurrent deficiency of interferon (IFN)-gamma attenuates the SLE, but promotes the formation of diverse hematologic and solid neoplasms within a background of persistent infection and inflammation. Whereas activated B cells show a resistance to fas-induced apoptosis, antimicrobial therapy prevents lymphomagenesis and solid tumor development. These findings demonstrate that the interplay of infectious agents with cytokine-mediated regulation of immune homeostasis is a critical determinant of cancer susceptibility.

API2-MALT1 fusion defines a distinctive clinicopathologic subtype in pulmonary extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue

t(11;18)(q21;q21) is associated with mucosa-associated lymphoid tissue (MALT)-type lymphoma and results in API2-MALT1 fusion. However, its clinicopathologic significance remains unclarified. API2-MALT1 fusion is detected most frequently in MALT lymphomas primarily involving the lung. We therefore screened 51 cases of pulmonary MALT lymphoma for API2-MALT1 fusion, and studied its relationship with clinicopathologic factors including the immunohistochemical expression of BCL10, another MALT lymphoma-associated molecule. The API2-MALT1 fusion transcript was detected in 21 of 51 (41%) cases, and was correlated with the absence of any underlying autoimmune disease, and with a normal serum lactate dehydrogenase, a "typical" histology without marked plasmacytic differentiation or an increased number of large cells, and aberrant nuclear BCL10 expression. However, its prognostic impact was not identified in the limited follow-up (6 to 187 months, median 27). These data suggest that the API2-MALT1 fusion may be a causative gene abnormality unrelated to autoimmune disease. In addition, this alteration may define a homogeneous MALT lymphoma subtype that is clinically more indolent and histologically more "typical." Aberrant nuclear BCL10 expression may have a possible role as a tool to screen for this API2-MALT1 fusion. A large-scale study with a long follow-up is necessary to establish the prognostic significance of API2-MALT1 fusion.