Clonal Salivary Gland Infiltrates Associated With Myoepithelial Sialadenitis (Sjögren's Syndrome) Begin as Nonmalignant Antigen-Selected Expansions

Infectious mononucleosis complicated by transitory Epstein-Barr virus infection of T and natural killer cells

Epstein-Barr virus (EBV) typically infects B cells in infectious mononucleosis (IM), but a rare case shows EBV infection in T cells. Seven cases of lymphoproliferative disorder caused by EBV-positive cytotoxic T/natural killer (NK) cell proliferation in the lymph nodes, termed IM with transient EBV infection of T and NK cells (EBV + T/NK cells in IM), are reported here. The purpose of the study is to describe clinicopathological features of EBV + T/natural killer (NK) cells in IM of the lymph node. We retrospectively analysed seven cases of Chinese children and young people adults with EBV + T/NK cells in IM. We used morphological observation, immunohistochemical staining, EB virus in situ hybridisation detection, and analysis of T-cell receptor gene rearrangement. The patients were healthy prior to illness, experiencing sudden onset occurring in all the patients, with high fever as the first symptom, followed by lymphadenopathy and hepatosplenomegaly. Diagnosis occurred < 1.5 months of symptom onset. Most lymphocytes in lesions expressed CD3 and Granzyme B or TIA-1 and lacked CD5. CD56 was expressed in numerous cells in 5 of the 7 cases. EBV-encoded RNA (EBER) was detected in medium-to-large-sized cells (50-100 cells per cell/high-power field). T-cell receptor (TCR) gene rearrangement was seen in six cases, with monoclonal rearrangement in four cases. Treatment was conservative treatment but not chemotherapy. Four received anti-HLH therapy and others anti-inflammatory treatment. All patients survived with relapse after long-term clinical observation and follow-up. EBV + T/NK cells in IM can elicit malignant features that mimic T/NK-cell lymphoma pathologically and benign features mimicking IM clinically. These findings indicate that EBV + T/NK cells in IM could serve as valuable diagnosis. Additional clinical information, including age of onset (children and young people), nature of onset (sudden), disease course (short), symptoms (systemic), EBV infection status (acute), and lymph node involvement, is crucial for accurate diagnosis and prognostic evaluation.

Th1/17 polarization and potential treatment by an anti-interferon-γ DNA aptamer in Hunner-type interstitial cystitis

Hunner-type interstitial cystitis (HIC) is a rare, enigmatic inflammatory disease of the urinary bladder with no curative treatments. In this study, we aimed to characterize the unique cellular and immunological factors specifically involved in HIC by comparing with cystitis induced by Mycobacterium bovis bacillus Calmette-Guérin, which presents similar clinicopathological features to HIC. Here, we show that T helper 1/17 +polarized immune responses accompanied by prominent overexpression of interferon (IFN)-γ, enhanced cGAS-STING cytosolic DNA sensing pathway, and increased plasma cell infiltration are the characteristic inflammatory features in HIC bladder. Further, we developed a mouse anti-IFN-γ DNA aptamer and observed that the intravesical instillation of the aptamer significantly ameliorated bladder inflammation, pelvic pain and voiding dysfunction in a recently developed murine HIC model with little migration into the blood. Our study provides the plausible basis for the clinical translation of the anti-IFN-γ DNA aptamer in the treatment of human HIC.

Waldenström Macroglobulinemia and Non-IgM-Type Lymphoplasmacytic Lymphoma Are Genetically Similar

INTRODUCTION

Waldenström macroglobulinemia (WM) represents a subset of lymphoplasmacytic lymphoma (LPL) with the immunoglobulin (Ig)M paraprotein. MYD88 L265P and CXCR4 mutations are common mutations in WM patients, and mutations in ARID1A and KMT2D (MLL2) have also been reported. However, little information has been accumulated on genetic changes in LPL with other paraproteins like IgG.

METHODS

We therefore aimed to evaluate genetic differences between WM and LPL with non-IgM paraprotein (non-IgM-type LPL) using targeted next-generation sequencing (NGS) in 20 Japanese patients (10 with WM, 10 with non-IgM-type LPL).

RESULTS

Mutations were detected in ARID1A (10%), CXCR4 (20%), MYD88 (90%), and KMT2D (0%) for WM patients and in ARID1A (10%), CXCR4 (20%), MYD88 (70%), and KMT2D (10%) for non-IgM-type LPL patients. No significant differences were identified. No mutations were detected in NOTCH2, PRDM1, CD274 (PD-L1), PDCD1LG2 (PD-L2), RAG2, MYBBP1A, TP53, or CD79B.

DISCUSSION

Mutant allele frequency in MYD88 L265P did not differ significantly between WM and non-IgM-type LPL. Most mutations detected by NGS were subclonal following MYD88 L265P, although one non-IgM-type LPL patient harbored only CXCR4 S338X mutation. Our NGS analyses reveal genetic characteristics in LPL patients and suggest genetic similarities between these two subsets of LPL, WM and non-IgM-type.

Transformation of diffuse large B-cell lymphoma to lymphoblastic lymphoma

Transformations in diffuse large B-cell lymphoma (DLBCL) are extremely rare. Here, we are presenting a very rare case of DLBCL transforming into lymphoblastic lymphoma (LBL) diagnosed by fine-needle aspiration cytology (FNAC) and flow cytometry. A 31-year old male on antiretroviral therapy and a known case of diffuse large B-cell lymphoma diagnosed 1 year back on cervical lymphadenopathy, presented with left axillary swelling for 3 months. FNAC and Flow cytometry were performed from the left axillary swelling which confirmed the diagnosis of LBL.

Predicting lymphoma in Sjögren's syndrome and the pathogenetic role of parotid microenvironment through precise parotid swelling recording

OBJECTIVE

Parotid swelling (PSW) is a major predictor of non-Hodgkin lymphoma (NHL) in primary Sjögren's syndrome (pSS). However, since detailed information on the time of onset and duration of PSW is scarce, this was investigated to verify whether it may lead to further improved prediction. NHL localisation was concomitantly studied to evaluate the role of the parotid gland microenvironment in pSS-related lymphomagenesis.

METHODS

A multicentre study was conducted among patients with pSS who developed B cell NHL during follow-up and matched controls that did not develop NHL. The study focused on the history of salivary gland and lachrymal gland swelling, evaluated in detail at different times and for different durations, and on the localisation of NHL at onset.

RESULTS

PSW was significantly more frequent among the cases: at the time of first referred pSS symptoms before diagnosis, at diagnosis, and from pSS diagnosis to NHL. The duration of PSW was evaluated starting from pSS diagnosis, and the NHL risk increased from PSW of 2-12 months to > 12 months. NHL was prevalently localised in the parotid glands of the cases.

CONCLUSION

A more precise clinical recording of PSW can improve lymphoma prediction in pSS. PSW as a very early symptom is a predictor, and a longer duration of PSW is associated with a higher risk of NHL. Since lymphoma usually localises in the parotid glands, and not in the other salivary or lachrymal glands, the parotid microenvironment appears to be involved in the whole history of pSS and related lymphomagenesis.

Aberrant expression of CD54 detected by flow cytometry is a characteristic of B-lymphoma cells in bone marrow specimens

Background

Flow cytometry (FC) is a popular method to detect bone marrow (BM) involvement in patients with B-cell non-Hodgkin lymphoma (B-NHL). The majority of screen panels of FC still rely on finding monoclonal B-cells, e.g., B-cells with immunoglobin (Ig) light-chain restriction, which has many limitations. Therefore, exploring new markers is warranted.

Methods

A total of 52 cases of B-NHL with BM involvement were collected. The median age was 60 years. Out of these 52 cases, 34 were male, and 18 were female. A 10-color FC panel was used to detect the expression of CD54 on lymphoma cells. The expression of CD54 was calculated as the mean fluorescence index ratio (MFIR) and was described as the mean ± standard error of the mean (SEM).

Results

Up to 18/52 (34.62%) of BM specimens abnormally expressed an increased level of CD54, including 1/10 cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), 9/13 cases of mantle cell lymphoma (MCL), 2/14 cases of follicular lymphoma (FL), 5/9 cases of marginal zone lymphoma (MZL), and 1/3 cases of high-grade B-NHL (HG B-NHL). The expression level of CD54 was significantly increased in MCL cases (53.41 ± 11.04) compared with CLL/SLL cases (11.66 ± 2.79) and FL cases (13.49 ± 2.81). The lowest percentage of CD54-positive B-cells attained 0.13%. In 5/9 cases of MZL and 1/3 cases of HG B-NHL, increased expression of CD54 was the only abnormal immunophenotype detected besides Ig light-chain restriction. No aberrant CD54 expression was identified by FC in lymphoplasmacytic lymphoma (LPL) (0/2) and Burkitt lymphoma (BL) (0/1) cases. Aberrant expression of CD54 was not related to plasma cell differentiation.

Conclusion

Lymphoma cells, especially in MCL and MZL cases, frequently show increased expression of CD54. Such aberrant expression is not related to plasma cell differentiation. We highly recommend adding CD54 to the FC screening panel to detect BM involvement in patients with B-NHL.

[Interstitial cystitis: the latest findings on its aetiopathogenesis]

New findings provide progress in the understanding of the complicated aetiopathogenesis of interstitial cystitis/bladder pain syndrome (IC/BPS), whose causalities have only been deciphered in fragments so far. An increasingly complex network of pathomechanisms is emerging, in which the frequently mentioned mast cells and urothelial changes seem to be only a fragment of the pathological changes. The latest findings regarding a possible genetic and epigenetic predisposition are based on pedigree analyses, detection of single nucleotide polymorphisms and significant changes in differentially expressed genes. Multiple alterations can be detected at the molecular level. Platelet-activating factor, VEGF, corticotropin-releasing hormone and the inflammasome are important players in understanding the disease, but the pathomechanism underlying the "activation" of IC remains unclear. New starting points could be the detection of viruses (Epstein-Barr virus, BK polyomaviruses) or bacterial inflammation by pathogens that cannot be detected in standard cultures.

Biomarkers in the Light of the Etiopathology of IC/BPS

In this review, we focused on putatively interesting biomarkers of interstitial cystitis/bladder pain syndrome (IC/BPS) in relation to the etiopathology of this disease. Since its etiopathology is still under discussion, the development of novel biomarkers is critical for the correct classification of the patients in order to open personalized treatment options, on the one hand, and to separate true IC/BPS from the numerous confusable diseases with comparable symptom spectra on the other hand. There is growing evidence supporting the notion that the classical or Hunner-type IC (HIC) and the non-Hunner-type IC (NHIC) are different diseases with different etiopathologies and different pathophysiology at the full-blown state. While genetic alterations indicate close relationship to allergic and autoimmune diseases, at present, the genetic origin of IC/BPS could be identified. Disturbed angiogenesis and impairment of the microvessels could be linked to altered humoral signaling cascades leading to enhanced VEGF levels which in turn could enhance leucocyte and mast cell invasion. Recurrent or chronic urinary tract infection has been speculated to promote IC/BPS. New findings show that occult virus infections occurred in most IC/BPS patients and that the urinary microbiome was altered, supporting the hypothesis of infections as major players in IC/BPS. Environmental and nutritional factors may also influence IC/BPS, at least at a late state (e.g., cigarette smoking can enhance IC/BPS symptoms). The damage of the urothelial barrier could possibly be the result of many different causality chains and mark the final state of IC/BPS, the causes of this development having been introduced years ago. We conclude that the etiopathology of IC/BPS is complex, involving regulatory mechanisms at various levels. However, using novel molecular biologic techniques promise more sophisticated analysis of this pathophysiological network, resulting in a constantly improvement of our understanding of IC/BPS and related diseases.

Light Chain-Restricted Plasmacytoid Cells in Hyperplastic Germinal CentersA Clinicopathologic Investigation

OBJECTIVES

Follicular hyperplasias (FHs) with light chain-restricted (LCR) plasmacytoid/plasma cells (PCs) within germinal centers (GCs) based on immunohistochemistry (IHC)/in situ hybridization (ISH) can potentially lead to diagnostic error. This study aims to better characterize such cases, including their clinical implications.

METHODS

LC expression by IHC/ISH was quantitatively assessed in GCs of 17 FHs with LCRGCs. BCL2, CD10, BCL6, BCL2, immunoglobulin (Ig) heavy chains, IgG4, and Epstein-Barr encoding region stains were performed. In total, 8 cases had polymerase chain reaction (PCR)-based clonality studies.

RESULTS

All cases showed FH, including 4 with progressively transformed GCs (PTGCs); 0.8% to 52% (median, 21%) of the GCs were LCR; 13 of 17 had both κ- and λ-LCRGCs, and 4 of 17 had only κ-LCRGCs; 7 of 16 had prominent intrafollicular IgG4-positive cells. One case demonstrated BCL2-positive cells in focal LCRGCs but lacked BCL2 rearrangement. B-cell monoclonality was demonstrated in 3 of 8 cases (only after microdissection). Seven patients had autoimmune disorders, and 1 had had a transplant. Three patients had a history of lymphoma, 1 developed lymphoma, and 1 developed lymphomatoid granulomatosis subsequently.

CONCLUSIONS

FHs with LCRGC by IHC/ISH are typically not associated with the development of lymphoma, even though they can express BCL2 and show monoclonality by PCR. They may be associated with increased intrafollicular IgG4-positive cells, PTGC, and autoimmunity.

Autoimmune B Cell Repertoire in a Mouse Model of Sjögren's Syndrome

In genetically prone individuals, chronic immune activation may lead to expansion of autoreactive lymphocyte clones that can induce organ damage developing autoimmune disorders. Sjögren’s Syndrome (SjS) is a systemic chronic autoimmune disease that primarily affects exocrine glands. Despite the accumulated evidences of profound B-cell alterations of humoral immunity, the repertoire and development of B-cell autoreactivity in SjS remains to be determined. We hypothesize that SjS mice will have an increased frequency of self-reactive B cells with a progressive evolution to antigen-driven oligoclonality. Here, we study the B cell repertoire of NOD.H-2^h4 mice, a mouse model of spontaneous autoimmunity mimicking SjS without developing diabetes. A library of 168 hybridomas from NOD.H-2^h4 mice and 186 C57BL/6J splenocytes at different ages was created. The presence of mono or polyreactive autoantibodies to several antigens was evaluated by ELISA, and their staining patterns and cellular reactivity were tested by IFA and FACS. We observed a higher frequency of autoreactivity among B-cell clones from NOD.H-2^h4 mice as compared to wild-type mice. The presence of polyreactive and autoreactive IgG clones increased with mice age. Strikingly, all anti-Ro52 autoantibodies were polyreactive. No loss of polyreactivity was observed upon antibody class switching to IgG. There was a progression to oligoclonality in IgG B cells with mice aging. Our results indicate that in the NOD.H-2^h4 mouse model of SjS, IgG+ B cells are mainly polyreactive and might expand following an unknown antigen-driven positive selection process.

[Clonality analysis in practice]

Malignant lymphomas are derived from a common progenitor cell with a unique rearrangement of immunoglobulin or T‑cell receptor genes. Polymerase chain reaction (PCR)-based analyses allow detection of the clone and are an important adjunct for the diagnosis of difficult lymphoproliferations, e.g. for the discrimination of reactive versus malignant lesions. Further applications are detection of disease dissemination and evaluation of the clonal relationship of two lymphomas. However, clonality analysis is not a stand-alone test and must always be considered in context with clinical, histological and immunophenotypic data. For the correct use of clonality analysis, comprehensive knowledge of the biological basis, technical requirements and interpretation are needed in order to avoid incorrect conclusions.

Pathogenetic Mechanisms Implicated in Sjögren's Syndrome Lymphomagenesis: A Review of the Literature

Sjögren's Syndrome (SS) is a chronic autoimmune disorder characterized by focal mononuclear cell infiltrates that surround the ducts of the exocrine glands, impairing the function of their secretory units. Compared to other autoimmune disorders, SS is associated with a notably high incidence of non-Hodgkin lymphoma (NHL) and more frequently mucosa associated lymphoid tissue (MALT) lymphoma, leading to increased morbidity and mortality rates. High risk features of lymphoma development include systemic extraepithelial manifestations, low serum levels of complement component C4 and mixed type II cryoglobulinemia. The discrimination between reactive and neoplastic lymphoepithelial lesion (LEL) is challenging, probably reflecting a continuum in the evolution from purely inflammatory lymphoid infiltration to the clonal neoplastic evolution. Early lesions display a predominance of activated T cells, while B cells prevail in severe histologic lesions. This strong B cell infiltration is not only a morphologic phenomenon, but it is also progressively associated with the presence of ectopic germinal centers (GCs). Ectopic formation of GCs in SS represents a complex process regulated by an array of cytokines, adhesion molecules and chemokines. Chronic antigenic stimulation is the major driver of specific B cell proliferation and increases the frequency of their transformation in the ectopic GCs and marginal zone (MZ) equivalents. B cells expressing cell surface rheumatoid factor (RF) are frequently detected in the salivary glands, suggesting that clonal expansion might arise from antigen selection of RF-expressing B cells. Abnormal stimulation and incomplete control mechanisms within ectopic lymphoid structures predispose RF MZ like cells to lymphoma development. Immunoglobulin recombination, somatic mutation and isotype switching during B cell development are events that may increase the translocation of oncogenes to immunoglobulin loci or tumor suppressor gene inactivation, leading to monoclonal B cell proliferation and lymphoma development. Concerning chronic antigenic stimulation, conclusive data is so far lacking. However immune complexes containing DNA or RNA are the most likely candidates. Whether additional molecular oncogenic events contribute to the malignant overgrowth remains to be proved.

Salivary Gland Mucosa-Associated Lymphoid Tissue-Type Lymphoma From Sjögren's Syndrome Patients in the Majority Express Rheumatoid Factors Affinity-Selected for IgG

Objective

Patients with Sjӧgren's syndrome (SS) have an increased risk of developing malignant B cell lymphomas, particularly mucosa‐associated lymphoid tissue (MALT)–type lymphomas. We have previously shown that a predominant proportion of patients with SS‐associated salivary gland MALT lymphoma express somatically hypermutated IgM with strong amino acid sequence homology with stereotypic rheumatoid factors (RFs). The present study was undertaken in a larger cohort of patients with SS‐associated MALT lymphoma to more firmly assess the frequency of RF reactivity and the significance of somatic IGV‐region mutations for RF reactivity.

Methods

B cell antigen receptors (BCRs) of 16 patients with SS‐associated salivary gland MALT lymphoma were analyzed. Soluble recombinant IgM was produced of 12 MALT lymphoma samples, including 1 MALT lymphoma sample that expressed an IgM antibody fitting in a novel IGHV3‐30–encoded stereotypic IGHV subset. For 4 of the 12 IgM antibodies from MALT lymphoma samples, the somatically mutated IGHV and IGKV gene sequences were reverted to germline configurations. Their RF activity and binding affinity were determined by enzyme‐linked immunosorbent assay and surface plasmon resonance, respectively.

Results

Nine (75%) of the 12 IgM antibodies identified in patients with SS‐associated salivary gland MALT lymphoma displayed strong monoreactive RF activity. Reversion of the IGHV and IGKV mutations to germline configuration resulted in RF affinities for IgG that were significantly lower for 3 of the 4 somatically mutated IgM antibodies. In stereotypic IGHV3‐7/IGKV3‐15–encoded RFs, a recurrent replacement mutation in the IGKV3‐15–third complementarity‐determining region was found to play a pivotal role in the affinity for IgG‐Fc.

Conclusion

A majority of patients with SS‐associated salivary gland MALT lymphoma express somatically mutated BCRs that are selected for monoreactive, high‐affinity binding of IgG‐Fc. These data underscore the notion that soluble IgG, most likely in immune complexes in inflamed tissues, is the principal autoantigen in the pathogenesis of a variety of B cell lymphomas, particularly SS‐associated MALT lymphomas.

Predicting lymphoma development in patients with Sjögren's syndrome

Introduction: The issue of predicting lymphoma in primary Sjögren's syndrome (pSS) starts from its clinical and biologic essence, i.e., an autoimmune exocrinopathy with sicca syndrome, inflammation and lymphoproliferation of MALT (mucosa-associated lymphoid tissue) in exocrine glands. Areas covered: The two major predictors to be firstly focused are persistent salivary gland (SG) swelling and cryoglobulinemic vasculitis with related features as purpura and low C4, or the sole serum cryoglobulinemia repeatedly detected. They are pathogenetically linked and reflect a heavier MALT involvement by histopathology, with the expansion of peculiar rheumatoid factor (RF)-positive clones/idiotypes. Other predictors include lymphadenopathy, splenomegaly, neutropenia, lymphopenia, serum beta2-microglobulin, monoclonal immunoglobulins, light chains, and RF. Composite indexes/scores may also predict lymphoma. Expert opinion: Prediction at baseline needs amelioration, and must be repeated in the follow-up. Careful clinical characterization, with harmonization and stratification of large cohorts, is a relevant preliminary step. Validated and new biomarkers are needed in biologic fluids and tissues. SG echography with automatic scoring could represent a future imaging biomarker, still lacking. Scoring MALT involvement in pSS, as an additional tool to evaluate disease activity and possibly to predict lymphoma, is welcomed. All these efforts are now ongoing within the HarmonicSS project and in other research initiatives in pSS.

Lymphoepithelial Sialadenitis Involving HIV-Infected and Sjogren Syndrome Patients: A Cytologic Study

Lymphoepithelial salivary gland cysts are rarely seen in autoimmune diseases particularly Sjogren syndrome as well as in HIV for which medical management is advocated. To study the morphology of these cysts, correlate with the disease process and assess the final outcome. Case series. Fine needle aspiration clinic. HIV-infected and autoimmune disease patients with lymphoepithelial cysts. Antiretroviral therapy for HIV-patients and anti-inflammatory drugs for Sjogren syndrome. Three HIV-infected patients (two children and one adult) and three middle aged female patients presented with parotid and submandibular cysts, two of which were bilateral along with submandibular (one each in the HIV and the autoimmune group). In the adult HIV-patient, the cyst was found at the inception of the disease while the other pediatric HIV-patients just crossed a decade. Of the other three cases of Sjogren syndrome, two were primary and one, secondary to rheumatoid arthritis. All the cysts regressed completely with treatment of the respective diseases which was confirmed by ultrasonograms. Lymphoepithelial cysts are produced by release of serous secretion by the acinar and ductal cells within the epithelial islands in the process of their destruction. Possibly, antibody mediated increased secretion in the initial stages also plays a role. Lymphoepithelial cysts of HIV patients may occur in the course of treatment, not necessarily in the beginning, though it resolves spontaneously. Lymphoepithelial cysts of primary or secondary Sjogren syndrome may be repressed sufficiently by anti-inflammatory/immunosuppressant treatment.

MALT lymphoma: A paradigm of NF-κB dysregulation

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) invariably arises from a background of chronic microbial infection and/or autoimmune disorder at diverse mucosal sites. The prolonged chronic infection and/or autoimmunity generate active immune and inflammatory responses that provide a setting for evolution and development of autoreactive B-cells, their expansion and eventual malignant transformation following acquisition of genetic changes. The immune responses also play a critical role in sustaining the growth and survival of the transformed cells as shown by complete regression of a high proportion of MALT lymphoma of the stomach, ocular adnexa and skin following anti-microbial treatment. B-cell receptor engagement by auto-antigen as well as T-cell help including both cognate interaction and bystander help via soluble ligands such as CD40L and BAFF are thought to underpin the immunological drive in the lymphoma development through activation of the canonical and non-canonical NF-κB pathway respectively. Similarly, the three MALT lymphoma associated chromosome translocations, namely t(1;14)(p22;q32)/BCL10-IGH, t(14;18)(q32;q21)/IGH-MALT1,and t(11;18)(q21;q21)/BIRC3 (API2)-MALT1, are also capable of activating both canonical and non-canonical NF-κB pathways. Furthermore, TNFAIP3 (A20) inactivation by deletion and/or mutation abolishes the auto-negative feedback to several signalling including BCR and TLR, which connect to the canonical NF-κB activation pathway. Thus, there is a considerable overlap in the molecular pathways dysregulated by immunological drive and somatic genetic changes, strongly arguing for their oncogenic cooperation in the development of MALT lymphoma.

Next-generation IgVH sequencing CLL-like monoclonal B-cell lymphocytosis reveals frequent oligoclonality and ongoing hypermutation

Chronic lymphocytic leukemia (CLL) develops from CLL-like monoclonal B-cell lymphocytosis (MBL) which represents a low-level asymptomatic expansion of cells that phenotypically resemble CLL. Although antigen selection plays a key role during CLL development, it is not known whether this occurs in early MBL or only during progression to CLL. Recent studies suggested that MBL sometimes displays oligoclonality, but these used techniques with limited sensitivity and specificity and were not conclusive. In this study, we combine cell sorting and next-generation sequencing of rearranged immunoglobulin heavy chain variable (IgVH) genes to thoroughly assess the VH repertoire and oligoclonality of purified MBL cells. Clonal functional rearrangements or clonotypes were identified in 29 of 30 sequenced cases, with 7 or 24% having two clonotypes with unrelated CDR3 sequences. In four of the seven cases with unrelated clonotypes, VH segments from the same family were used. In addition, 6 of 29 cases showed clear evidence of ongoing VH gene hypermutation with three of these being among the seven with unrelated clonotypes. This study conclusively shows that MBL cases often contain multiple B-cell clones, the first to report ongoing VH gene mutation in MBL, and that antigen selection appears to occur in early MBL.

Hunner-Type (Classic) Interstitial Cystitis: A Distinct Inflammatory Disorder Characterized by Pancystitis, with Frequent Expansion of Clonal B-Cells and Epithelial Denudation

Interstitial cystitis (IC) is a chronic bladder disease with urinary frequency, bladder discomfort or bladder pain of unknown etiology. Based on cystoscopic findings, patients with IC are classified as either Hunner-type/classic IC (HIC), presenting with a specific Hunner lesion, or non-Hunner-type IC (NHIC), presenting with no Hunner lesion, but post-hydrodistension mucosal bleeding. Inflammatory cell infiltration, composed predominantly of lymphocytes, plasma cells and epithelial denudation, has in the past been documented as a major pathological IC finding. However, the significance of the pathological evaluation of IC, especially with regard to the difference between HIC and NHIC, has been downplayed in recent years. In this study, we performed immunohistochemical quantification of infiltrating T-lymphocytes, B-lymphocytes and plasma cells, and measured the amount of residual epithelium in urinary bladder biopsy specimens taken from patients with HIC and NHIC, and those with no IC, using image analysis software. In addition, in situ hybridization of the light chains was performed to examine clonal B-cell expansion. Lymphoplasmacytic infiltration was significantly more severe in HIC specimens than in NHIC specimens (P <0.0001). Substantial lymphoplasmacytic inflammation (≥200 cells/mm²) was observed in 93% of HIC specimens, whereas only 8% of NHIC specimens were inflamed. Plasmacytic infiltration was more prominent in HIC specimens compared with NHIC and non-IC cystitis specimens (P <0.005). Furthermore, expansion of light-chain-restricted B-cells was observed in 31% of cases of HIC. The amount of residual epithelium was decreased in HIC specimens compared with NHIC specimens and non-IC cystitis specimens (P <0.0001). These results suggest that NHIC and HIC are distinct pathological entities, with the latter characterized by pancystitis, frequent clonal B-cell expansion and epithelial denudation. An abnormality in the B-cell population may be involved in the pathogenesis of HIC.

Evaluation of Germinal Center-like Structures and B Cell Clonality in Patients with Primary Sjögren Syndrome with and without Lymphoma

Objective.

Germinal center (GC)-like structures have previously been observed in minor salivary glands (MSG) of patients with primary Sjögren syndrome (pSS). The aim of our study was to explore the prevalence and features of GC-like structures and B cell clonality in patients with pSS with and without lymphoma.

Methods.

Based on a nationwide survey in Norway, we included 21 patients with pSS and with a concomitant lymphoma from whom MSG and/or lymphoma biopsies were available. Tonsil biopsies and MSG from 28 patients with pSS without lymphoma were used as controls. The presence of GC-like structures was investigated with H&E staining and double staining for CD21/IgD and CD38/IgD. B cell clonality in MSG and tumors were investigated with analysis of immunoglobulin gene rearrangements.

Results.

H&E labeling of MSG revealed GC-like structures in 17/40 (43%) of the patients: 4/12 (33%) with and 13/28 (46%) without lymphoma. Staining for CD21/CD38/IgD demonstrated CD21+ networks in 27/40 (68%) of the patients. CD21+/CD38– infiltrates were seen in 25/40 (63%) of the patients, and 16 of these were IgD+ within the infiltrate. Five percent (2/40) of the patients presented with CD21+/CD38+ infiltrates resembling tonsillar GC. Monoclonal B cell infiltration in MSG was present in 5/12 patients (42%) with and 5/28 patients (18%) without lymphoma (p = 0.12). In 2/10 (20%) of cases where both MSG and lymphoma biopsies were available, identical clonal rearrangements were detected.

Conclusion.

GC-like structures seen in H&E-stained MSG may represent various subtypes of CD21+ infiltrates. We were unable to detect a clear association between cellular infiltrates, B cell clonality, and lymphoma development.

Immunoglobulin gene repertoire diversification and selection in the stomach - from gastritis to gastric lymphomas

Chronic gastritis is characterized by gastric mucosal inflammation due to autoimmune responses or infection, frequently with Helicobacter pylori. Gastritis with H. pylori background can cause gastric mucosa-associated lymphoid tissue lymphoma (MALT-L), which sometimes further transforms into diffuse large B-cell lymphoma (DLBCL). However, gastric DLBCL can also be initiated de novo. The mechanisms underlying transformation into DLBCL are not completely understood. We analyzed immunoglobulin repertoires and clonal trees to investigate whether and how immunoglobulin gene repertoires, clonal diversification, and selection in gastritis, gastric MALT-L, and DLBCL differ from each other and from normal responses. The two gastritis types (positive or negative for H. pylori) had similarly diverse repertoires. MALT-L dominant clones (defined as the largest clones in each sample) presented higher diversification and longer mutational histories compared with all other conditions. DLBCL dominant clones displayed lower clonal diversification, suggesting the transforming events are triggered by similar responses in different patients. These results are surprising, as we expected to find similarities between the dominant clones of gastritis and MALT-L and between those of MALT-L and DLBCL.

Lymphoma development in patients with autoimmune and inflammatory disorders--what are the driving forces?

For decades, it has been known that patients with certain autoimmune and inflammatory disorders, such as rheumatoid arthritis (RA) and primary Sjögren's syndrome (pSS), have an increased risk of developing malignant lymphoma. Although the clinico-biological reasons for this association remain largely unknown, our knowledge has improved and new insights have been obtained. First, the direct link between autoimmunity and lymphomagenesis has been strengthened by large epidemiological studies showing a consistent risk increase of lymphoma associated with certain autoimmune/inflammatory conditions in independent cohorts from different countries. Second, a number of local and systemic disease-related risk factors in these diseases have been repeatedly linked to lymphoma development, with the prime examples being disease severity and the degree of inflammatory activity. Considering the key role of B- and T-cell activation in the pathogenesis of both autoimmunity and lymphoma, it is perhaps not surprising that longstanding chronic inflammation and/or antigen stimulation have emerged as major predisposing factors of lymphoma in patients with active autoimmune disease. Finally, increasing evidence suggests that lymphomas associated with autoimmunity constitute a different spectrum of entities compared to lymphomas arising in patients without any known autoimmune or inflammatory conditions, pointing to a different pathobiology. In this review, we summarize the recent literature that supports a direct or indirect link between immune-mediated disease and lymphoma and describe the characteristics of lymphomas developing in the different diseases. We also discuss molecular, genetic and microenvironmental factors that may come into play in the pathobiology of these disorders.

The role of viruses in autoreactive B cell activation within tertiary lymphoid structures in autoimmune diseases

TLS, characterized by the formation of ectopic B/T cell follicles with FDCs supporting an ectopic GC response, have been described in the target organs of several autoimmune diseases, including MS, RA, SS, and autoimmune thyroiditis. These structures represent functional niches, whereby autoreactive B cells undergo in situ affinity maturation and differentiation to autoantibody-producing cells, thus contributing to the progression and persistence of autoimmunity. Increasing evidence demonstrates that TLS can also develop in the context of cancer, as well as chronic infections. In this review, we collect recent evidences that highlights the relationship between persistent viral infection and the development of ectopic lymphoid structures in animal models and patients. Furthermore, we shall discuss the concept that whereas in physiological conditions, inducible TLS are critical for viral clearance and the establishment of protective immunity, but in the context of susceptible individuals, persistent viral infections may contribute, directly or indirectly, to the development of breach of tolerance against self-antigens and the development of autoimmunity through the formation of TLS.

Malignant lymphoma in primary Sjögren's syndrome: an update on the pathogenesis and treatment

OBJECTIVES

Sjögren's syndrome (SS), a chronic autoimmune disorder, particularly compromises the function of exocrine glands. Its association with lymphoma is well documented. Our aim was to systematically review the molecular, clinical, histopathologic, and therapeutic aspects of these SS-related malignant lymphoproliferations.

METHODS

The literature was searched for original articles published between 1968 and 2012 focusing on the risk factors for lymphoma development in Sjögren's syndrome using MEDLINE and PubMed. The search terms we used were "Sjögren's syndrome," "lymphoma," and "risk factors." All papers identified were English-language, full-text papers.

RESULTS

A low-grade marginal-zone lymphoma related to mucosa-associated lymphoid tissue is the commonest lymphoid neoplasia in SS. The majority of SS-associated lymphomas are characterized by localized stage, indolent clinical course, and recurrence in other extranodal sites. Although the transition from a chronic inflammatory condition to malignant lymphoma is a multistep process that is yet poorly understood, there is increasing evidence that chronic antigenic stimulation by an exoantigen or autoantigens plays an essential role in the development of SS-associated lymphoproliferation.

CONCLUSIONS

This review discusses the pathogenetic aspects of lymphomagenesis in SS. Recent advances in the treatment of lymphoma in SS are also stated.

Risk, predictors, and clinical characteristics of lymphoma development in primary Sjögren's syndrome

OBJECTIVE

To assess the risk and predictors of lymphoma development in a large cohort of patients with primary Sjögren's syndrome (pSS).

METHODS

Cox-regression analyses were used to study the predictive value of clinical and laboratory findings at pSS diagnosis, and Kaplan-Meier survival curves to compare survival probability between patients who developed lymphoma and the total cohort. Expected risk for lymphoma was calculated by comparison with the background population.

RESULTS

Eleven (4.5%) from 244 patients developed a non-Hodgkin lymphoma (NHL). Diffuse large B-cell and mucosa-associated lymphoid tissue lymphomas occurred at a similar frequency. Three (27.3%) patients died: 2 due to transformation from mucosa-associated lymphoid tissue to diffuse large B-cell. Purpura (HR 8.04, 95% confidence interval [CI] 2.33-27.67), parotidomegaly (HR 6.75, 95%CI 1.89-23.99), anemia (HR 3.43, 95%CI 1.04-11.35), leukopenia (HR 8.70, 95%CI 2.38-31.82), lymphocytopenia (HR 16.47, 95%CI 3.45-78.67), hypergammaglobulinemia (HR 4.06, 95%CI 1.06-15.58), low C3 (HR 36.65, 95%CI 10.65-126.18), and low C4 (HR 39.70, 95%CI 8.85-126.18) levels at pSS diagnosis were significant predictors of NHL development, but only hypocomplementemia and lymphocytopenia were independent risk factors. Hypocomplementemia was related to earlier development of NHL and higher mortality. The cumulative risk of developing lymphoma ranged from 3.4% in the first 5 years to 9.8% at 15 years. Standardized incidence ratio (95%CI) for NHL development was 15.6 (95%CI 8.7-28.2).

CONCLUSIONS

Patients with pSS have a 16-fold increased risk of developing lymphoma. This risk increases with time. Hypocomplementemia and lymphocytopenia at pSS diagnosis are the strongest predictors. Survival is clearly reduced in patients with hypocomplementemia. Indolent lymphomas tend to evolve over time toward a more aggressive histologic type.

XCR1 expression and biased VH gene usage are distinct features of diffuse large B-cell lymphoma initially manifesting in the bone marrow

A total of 29 cases of diffuse large B-cell lymphoma initially manifesting in the bone marrow (BM-DLBCL) were analyzed for V(H) gene sequence, and expression microarray of chemokines and chemokine receptors and immunohistochemical analysis were done. Seminested polymerase chain reaction (PCR) and sequencing analyses of 18 cases revealed that the V(H) gene usage in 6 cases was restricted to V(H)3-7, in 3 cases to V(H)4-34, and in 2 cases to V(H)4-39, which were all previously reported to be autoreactive. In total, 14 of 18 V(H) genes were those associated with autoimmune diseases, including V(H)3-21, V(H)3-23, and V(H)3-48. Furthermore, cDNA microarray analysis specific for chemokine and chemokine receptors revealed that chemokine receptor XCR1 expression was significantly elevated in the BM-DLBCL cases (P < .05), which was confirmed by quantitative reverse transcriptase-PCR and immunohistochemical analysis. Expression of the chemokine receptor XCR1 and frequent usage of autoreactive V(H) genes seem to be distinct characteristics of BM-DLBCL.

Selected topics on lymphoid lesions in the head and neck regions

Lymphoid tissue located in the head and neck region include multiple regional lymph node chains as well as mucosa associated lymphoid tissue of the conjunctiva, buccal and nasopharyngeal cavities (Waldeyer's ring), and thyroid and salivary glands. This region is a rich source of antigenic stimuli including infectious agents coming from the outside environment. Many reactive conditions that affect lymphoid tissue in this region may mimic neoplasia. In fact, distinguishing between benign and malignant lymphoid proliferations in the head and neck region is a relatively frequent diagnostic challenge and in many instances, this distinction is not straightforward. It therefore behooves the practicing pathologist to be able to recognize the benign lymphoproliferative disorders that affect this region so as to effectively guide the appropriate clinical management of such patients. Kimura disease, Epstein Barr lymphadenitis, HIV associated salivary gland disease and chronic sialadenitis are benign conditions that not infrequently affect lymphoid tissue in the head and neck region and that share certain overlapping features with malignant lymphoma. In this brief review, we discuss these conditions and highlight clinicopathological features that may help distinguish them from neoplastic lymphoproliferations that may share similar features.

Secondary tumours in Sjögren's syndrome

The frequent association of Sjögren's syndrome (SS) with non-Hodgkin's B cell lymphoma (NHL) provides an example of the interplay of systemic autoimmunity and lymphoproliferative diseases, and an opportunity to study the pathogenetic steps of lymphomagenesis. NHL develops in approximately 5% of SS patients. Parotidomegaly, lymphadenopathy, inflammatory neuropathy and vasculitis have been found to be predictive of the development of lymphoma. A subsequent NHL is also heralded by the appearance of cryoglobulinaemia and serum or urinary monoclonal proteins. The typical histological type of NHL in SS is a low-grade extranodal marginal zone B cell lymphoma. The authors discuss the proposed key immunopathologic steps of lymphomagenesis in SS in detail. Recent results indicating the pathogenetic role of ectopic germinal centre formation in the involved exocrine glands, the potential importance of an antigen-driven clonal proliferation of autoreactive B-lymphocytes, the proposed role of the B-lymphocyte activating factor (BAFF) and of further cytokines and, finally, the changes of the chemokine milieu at the site of lymphoma development are highlighted.

Use of similar immunoglobulin VH gene segments by MALT lymphomas of the ocular adnexa

Extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue type (MALT lymphomas) develop from acquired reactive infiltrates directed against external or autoantigens. Although some European cases of ocular adnexal MALT lymphoma have been associated with Chlamydia psittaci infections, C. psittaci has not been detected in large studies of US-based cases. To evaluate whether the growth of US-based ocular adnexal MALT lymphomas may be promoted by a similar antigen, we identified and analyzed the expressed immunoglobulin VH genes in 10 cases. Interestingly, the VH genes in two cases used the same VH1 family V1-2 gene segment, and three cases used the same VH4 family V4-34 gene segment. The other five cases all used different gene segments V4-31, V5-51, V3-23, V3-30, and V3-7. All of the VH genes were mutated from germ line, with percent homologies ranging between 96.9 and 89.0%. The distribution of replacement and silent mutations within the VH genes was nonrandom consistent with the maintenance of immunoglobulin function and also strongly suggestive of antigen selection in the six VH genes with highest mutation loads. The CDR3 sequences in two of three VH-34 cases were the same size (15 amino acids) and had similar sizes in the two VH1-2 cases (18 and 16 amino acids). In conclusion, US-based MALT lymphomas of the ocular adnexa preferentially express a limited set of VH gene segments not frequently used by other MALT lymphomas and consistent with some recognizing similar antigens. Analysis of somatic mutations present within the VH genes is also consistent with antigen binding stimulating the growth of these lymphomas.

Fatal non-transplant-related epstein-barr virus-associated atypical lymphoid proliferations in infants and children: a clinicopathologic study

Most Epstein-Barr virus (EBV)-related infections in infants and children are asymptomatic or self-limited mild viral illnesses, but rare cases of a rapidly fatal disorder have been described. Failure of the cellular response to control EBV-related lymphoid proliferation leads to severe disease with multiple complications, including a fatal outcome or development of an EBV-driven, clonal lymphoid neoplasm. In this report we characterize 3 cases of fatal, nontransplant, or immunodeficiency-related EBV infection in very young children with immunophenotypic and molecular evidence of B/natural killer (NK)-T cell clonal expansion. An immunohistochemical staining panel included testing for B-cell antigen (CD20), and T/NK cell antigens including CD2, CD3, CD4, CD8, CD56, CD57, and TIA-1. T-cell and B-cell PCR clonality testing was performed on paraffin tissue specimens to identify clonal populations. The ages of these 3 patients ranged from 22 months to 4 years. Initial clinical presentations included pneumonia, abnormal liver function tests and fever, and lymphadenopathy. The 3 patients died within 17 to 72 days of presentation, and autopsy was performed on 1 patient. All cases demonstrated prominent atypical lymphoid or lymphohistiocytic infiltrates, and necrosis was present in 2 of the 3 cases. The atypical lymphocytes were positive for CD3 (cytoplasmic), CD2, CD8, TIA-1, and CD57 and negative for CD4. We molecularly identified B-cell clones in the 2 tested patients, who also showed evidence of hemophagocytosis. Fatal EBV infection is characterized by a morphologic spectrum with atypical lymphoid infiltrates and variable necrosis. Our molecular studies of these patients suggest a clonally-derived expansive process, most likely driven by EBV infection. Our results also suggest that development of clonality is associated with an aggressive clinical course and may be useful in predicting greater risk for fatal outcome. A high index of suspicion, coupled with appropriate serologic and molecular testing, aids in early recognition and diagnosis of these lymphoproliferative processes.

CXCL13, CCL21, and CXCL12 expression in salivary glands of patients with Sjogren's syndrome and MALT lymphoma: association with reactive and malignant areas of lymphoid organization

The chemokines (CKs) CXCL13, CCL21, and CXCL12 are known to play differential roles in the organization of the lymphoid tissues and the development of lymphoid malignancies. We investigated the expression of these CKs and their receptors in the salivary glands of Sjogren's syndrome patients with lymphoepithelial lesions (lymphoepithelial sialadenitis or LESA) and in MALT lymphoma to understand their involvement in salivary gland lymphomagenesis. We demonstrate that within salivary glands with LESA and MALT lymphoma the lymphoid CKs CXCL13 and CCL21 are selectively associated with areas of reactive lymphoid proliferation, whereas no significant expression of these molecules was detected in the malignant lymphoid aggregate. Conversely, CXCL12 was observed predominantly in infiltrated ducts and malignant B cells. Accordingly, CXCL13 and CCL21 transcript levels were significantly increased in LESA samples while CXCL12 levels were increased in MALT lymphoma and isolated tumor cells. Low levels of CK receptors were detected on lymphoma-extracted lymphocytes, suggesting down-regulation in the abundance of ligands. Our findings suggest that in salivary gland MALT lymphoma the lymphoid CKs CXCL13 and CCL21 are directly implicated in the organization of ectopic reactive lymphoid tissue, whereas CXCL12 is associated with the infiltrated epithelium and malignant B cell component and is possibly involved in the regulation of malignant B cell survival.

Clonal relationship between infiltrating immunoglobulin G4 (IgG4)-positive plasma cells in lacrimal glands and circulating IgG4-positive lymphocytes in Mikulicz's disease

Mikulicz's disease (MD) is gaining acceptance as an immunoglobulin G4 (IgG4)-related disease characterized by bilateral lacrimal and salivary gland swelling. The aetiology of MD and other IgG4-related diseases is still unclear. The present work was performed to study the clonality of infiltrating IgG4-positive plasma cells in lacrimal glands and circulating peripheral blood cells in patients with MD, and compare the clonal relationship between infiltrating and circulating IgG4 positive cells. Total cellular RNA was extracted from the lacrimal glands and peripheral blood in five MD patients. Reverse transcription polymerase chain reaction was performed with primers specific for activation-induced cytidine deaminase (AID) and for Ig VH and IgG4. Sequences of Ig VH were compared with the structure of Ig VH of the lacrimal glands and the peripheral blood cells. AID was expressed to varying degrees in lacrimal glands of all MD patients. Most IgG4-positive cells infiltrating lacrimal glands and in peripheral blood were polyclonal, although several clonally related pairs were detected. In one patient, two of the circulating IgG4 VH4-59 clones shared identical CDR3 sequences with the clones within the lacrimal glands. In conclusion, while most tissue-infiltrating and circulating IgG4-positive cells in MD are polyclonal, some clonally related IgG4 positive cells exist between lacrimal gland and peripheral blood, accounting for the clinical features of MD as an IgG4-related disease involving multiple organs.

Clinical, immunologic, and molecular factors predicting lymphoma development in Sjogren's syndrome patients

Among autoimmune diseases, Sjogren's syndrome (SS) displays the highest incidence of non-Hodgkin lymphoma (NHL) development with the salivary extranodal marginal zone B cell lymphomas being the most common type. The majority of SS-associated NHLs are characterized by localized stage, indolent clinical course, and recurrence in other extranodal sites. Although the transition from a chronic inflammatory condition to malignant lymphoma is a multistep process yet poorly understood, there is increasing evidence that chronic antigenic stimulation by an exoantigen or autoantigens plays an essential role in the development of SS associated lymphoproliferation. Additional molecular oncogenic events such as microsatellite instability, loss of the B cell cycle control, and the forced overproduction of specific B cell biologic stimulators seem to contribute to the emergence and progression of the malignant overgrowth. Among the clinical and serological parameters that have been associated with lymphoma development in SS patients, the presence of palpable purpura, low C4, and mixed monoclonal cryoglobulinemia constitute the main predictive markers, and patients displaying these risk factors should be monitored closely.

Activation-induced cytidine deaminase expression in follicular dendritic cell networks and interfollicular large B cells supports functionality of ectopic lymphoid neogenesis in autoimmune sialoadenitis and MALT lymphoma in Sjögren's syndrome

Demonstration of ectopic germinal center-like structures (GC-LSs) in chronically inflamed tissues in patients with autoimmune disorders is a relatively common finding. However, to what extent ectopic lymphoid structures behave as true GC and are able to support class switch recombination (CSR) and somatic hypermutation (SHM) of the Ig genes is still debated. In addition, no information is available on whether CSR and SHM can take place in the absence of GCs at extrafollicular sites in an ectopic lymphoid tissue. In this study, we show that in salivary glands (SGs) of Sjögren's syndrome (SS) activation-induced cytidine deaminase (AID), the enzyme responsible for CSR and SHM is invariably expressed within follicular dendritic cell (FDC) networks but is not detectable in SGs in the absence of ectopic GC-LSs, suggesting that FDC networks play an essential role in sustaining the Ag-driven B cell proliferation within SS-SGs. We also show that the recently described population of interfollicular large B cells selectively expresses AID outside ectopic GC in the T cell-rich areas of periductal aggregates. Finally, we report that AID retains its exclusive association with numerous, residual GCs in parotid SS-MALT lymphomas, whereas neoplastic marginal zone-like B cells are consistently AID negative. These results strongly support the notion that ectopic lymphoid structures in SS-SGs express the molecular machinery to support local autoantibody production and B cell expansion and may play a crucial role toward lymphomagenesis.

Clonality analysis of lymphoproliferative disorders in patients with Sjögren's syndrome

The aim of this study was to clarify the nature of the clonal lymphocyte infiltration in Sjögren's syndrome (SS) patients associated with lymphoproliferative disorders. We examined B cell clonality in lymphoproliferative tissues from six primary SS patients associated with lymphoproliferative disorders or lymphoma by cloning and sequencing of the gene rearrangement of the immunoglobulin heavy chain complementarity determining region 3 (IgVH-CDR3). Three patients with sequential observation showed progressional clonal expansion with the presence of the same subclone in different tissues during the course of disease. Among them, one patient developed mucosa-associated lymphoid tissue (MALT) lymphoma in glandular parotid. The other three SS patients concomitant with malignant B cells lymphomas showed different clonal expansion of B cells between nodal sites and salivary glands. The cloanality analysis indicated that monoclonal B cell population could spread from one glandular site to another site during the course of SS, suggesting that the malignant clone may arise from the general abnormal microenvironment, not restricted to the glandular tissue, in some SS patients.

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.

High incidence of autoimmune disease in Japanese patients with ocular adnexal reactive lymphoid hyperplasia

PURPOSE

To determine the incidence of autoimmune disease in Japanese patients with ocular adnexal lymphoid proliferations.

DESIGN

Case series study.

METHODS

The authors investigated the incidence of autoimmune disease in 88 patients with primary ocular adnexal lymphoid proliferations. Southern blot analysis was used to determine the presence of B-cell clonality in reactive lymphoid hyperplasia (RLH) associated with autoimmune disease.

RESULTS

Histopathologic analysis indicated that 15 (17%) patients had RLH, 62 (70%) patients had mucosa-associated lymphoid tissue lymphoma (MALToma), and 11 (13%) patients had primary lymphomas. The incidence of autoimmune disease was seven (47%) of 15 patients with RLH, two (3%) of 62 patients with MALToma, and zero (0%) of 11 patients with primary lymphoma. B-cell clonality was detected in one (14%) of seven RLH patients with autoimmune disease.

CONCLUSIONS

Ocular adnexal RLH with or without B-cell clonality is highly associated with autoimmune disease.

B cells in autoimmune diseases: insights from analyses of immunoglobulin variable (Ig V) gene usage

The role of B cells in autoimmune diseases has not been fully elucidated. It is also unclear whether breaking of B cell tolerance in patients with autoimmune diseases is due to underlying defects in the molecular mechanisms involved in the arrangement of antibody genes or deficiencies in the subsequent selective influences that shape the antibody repertoire. Analysis of immunoglobulin (Ig) variable (V) gene usage is beginning to provide answers to some of these questions. Such analyses have identified some differences in the basic Ig V gene repertoire of patients with autoimmune diseases compared to healthy controls, even though none of these differences can be considered major. Defects in positive and negative selection, mutational targeting and, in some cases, receptor editing have also been detected. In addition, analysis of Ig V gene usage in target organs and tissues of patients with autoimmune diseases has clearly demonstrated that there is a highly compartmentalized clonal expansion of B cells driven by a limited number of antigens in these tissues. Great progress has been made in the structural and functional characterization of disease-associated antibodies, largely because of the development of the combinatorial library technique. Use of antibodies generated by this technique offers great promise in identifying B cell epitopes on known target antigens and in gaining greater insights into the pathogenic role of B cells in both B and T cell mediated autoimmune diseases.