Autoimmunity and extranodal lymphocytic infiltrates in lymphoproliferative disorders

Metabolic Gatekeepers of Pathological B Cell Activation

Unlike other cell types, B cells undergo multiple rounds of V(D)J recombination and hypermutation to evolve high-affinity antibodies. Reflecting high frequencies of DNA double-strand breaks, adaptive immune protection by B cells comes with an increased risk of malignant transformation. In addition, the vast majority of newly generated B cells express an autoreactive B cell receptor (BCR). Thus, B cells are under intense selective pressure to remove autoreactive and premalignant clones. Despite stringent negative selection, B cells frequently give rise to autoimmune disease and B cell malignancies. In this review, we discuss mechanisms that we term metabolic gatekeepers to eliminate pathogenic B cell clones on the basis of energy depletion. Chronic activation signals from autoreactive BCRs or transforming oncogenes increase energy demands in autoreactive and premalignant B cells. Thus, metabolic gatekeepers limit energy supply to levels that are insufficient to fuel either a transforming oncogene or hyperactive signaling from an autoreactive BCR.

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.

Renal small B-cell lymphoma with plasmacytic differentiation presenting with monoclonal gammopathy and disseminated intravascular coagulation syndrome

Primary renal lymphomas are very rare. However, the kidney may be a site of metastasis, usually from a disseminated aggressive lymphoma. A 58-year-old woman was brought to the medical facility due to acute mental confusion, severe hypotension, septic shock, and signs of disseminated intravascular coagulation. Laboratory tests showed severe leukopenia, renal failure, altered liver function, and elevated serum lactate dehydrogenase levels. Protein electrophoresis revealed hypergammaglobulinemia with a monoclonal peak of IgG lambda. The clinical outcome was fulminant and the patient died less than 24 hours after admission. Autopsy revealed an indolent B-cell lymphoma with extensive plasmacytic differentiation infiltrating the right renal sinus and involving the submandibular and sublingual glands, cervical and peri-aortic lymph nodes, multiple microscopic foci in pituitary and adrenal glands, lung, breast, liver, thyroid, and bone marrow. Numerous IgG4-positive plasma cells were detected by immunohistochemistry although other histological features of IgG4-related disease were missing. There was also extensive hemorrhagic necrosis of the adrenal glands and purulent cystitis, which was probably responsible for the septic shock. The authors concluded that the kidney was most likely the primary site of the indolent lymphoma, as that was the site with the largest tumor mass. Infiltration of other organs was considered as dissemination of the disease. The differential diagnosis with mucosa-associated lymphoid tissue and lymphoplasmacytic lymphoma is discussed.

Helicobacter pylori infection and gastric cancer

Gastric cancer remains a major health burden on many societies claiming hundreds of thousands of lives every year. The discovery of Helicobacter pylori has no doubt revolutionised our understanding of this malignancy, which is now regarded as a paradigm for infection-induced chronic inflammation-mediated cancer. In this paper, we discuss the evidence for the association between H. pylori and gastric adenocarcinoma and MALT lymphoma. We also discuss the pathogenesis of these two forms of cancer and the factors that determine their outcome. There is no doubt that the knowledge accumulated over the past two decades will be translated into eventual victory over this killer cancer, largely because we now appreciate that the best way to prevent the cancer is by preventing acquisition of the infection in the first place, or by eradicating the infection in infected subjects. Defining the optimal timing of intervention is going to be the challenge facing us over the next two decades.

IgM-enriched human intravenous immunoglobulin suppresses T lymphocyte functions in vitro and delays the activation of T lymphocytes in hu-SCID mice

Previous studies of an experimental human immunoglobulin preparation for intravenous use, containing normal pooled IgM (IVIgM), have shown its beneficial therapeutic effect in experimental autoimmune diseases. The mechanisms of its immunomodulatory activity remain however, poorly understood. In the experiments reported here, IVIgM inhibited the proliferation of various autonomously growing human lymphoid cell lines in vitro, as well as of MLR- and of PHA-stimulated human T-lymphocytes. These effects of IVIgM were observed at non-apoptotic concentrations and were stronger on a molar basis than those of normal pooled IgG for intravenous use (IVIg). Both preparations, when administered to SCID mice, repopulated with human peripheral blood mononuclear cells, delayed the expression of the early activation marker CD69 on both human CD4+ and CD8+ T-lymphocytes, activated by the mouse antigenic environment. The data obtained show that normal pooled human IgM exerts a powerful antiproliferative effect on T-cells that is qualitatively similar but quantitatively superior to that of therapeutic IVIg. Our results suggest that infusions with IVIgM might have a significant beneficial immunomodulating activity in patients with selected autoimmune diseases.

Influence of antigen on the development of MALT lymphoma

Mucosa-associated lymphoid tissue (MALT) B-cell lymphomas develop in the context of autoimmune or chronic inflammations like Helicobacter pylori-induced gastritis. Remission of most gastric MALT lymphomas after eradication of H pylori links tumor cell proliferation to antigen-induced inflammation and the need for antigenic contact. Furthermore, the tumor cells correspond to antigen-activated memory B cells. To investigate the reactivity of the tumor immunoglobulins we employed in vitro-generated antibodies identical to those produced by MALT lymphoma cells. The immunoglobulin rearrangements of 7 MALT lymphomas were amplified, cloned, and expressed as single-chain fragment variable (scFv) antibodies. Antigen specificity of these 7 scFvs was analyzed by immunohistochemical staining of various normal, reactive, and malignant human tissues. Also, an expression library comprising approximately 30,000 proteins from human fetal brains (protein filter) and a peptide library were screened. One scFv stained a subpopulation of tonsillar plasma cells in immunohistochemical studies. On protein filters this scFv recognized the plasma cell-related protein Ufc1. Peptide library screening identified 9 peptides as binding partners of an additional scFv. The majority of MALT lymphoma immunoglobulins studied, however, showed no reactivity against antigens, indicating that the tumor immunoglobulins do not play a significant role in stimulation and proliferation of the MALT lymphoma tumor cells.

[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.

The epidemiology of non-Hodgkin's lymphoma

The incidence of non-Hodgkin's lymphoma (NHL) has doubled over the past two decades in the US and most other westernized countries. While improved cancer reporting, changes in lymphoma classification, and increases in AIDS-associated lymphomas have contributed to the startling escalation of disease incidence, these factors are estimated to account for only about 50% of the increase in observed incidence. The elucidation of etiologic factors and their mechanistic role in the pathogenesis of this malignancy are critical to advancements in disease prevention and treatment. Current evidence suggests that factors/conditions that precipitate either chronic antigenic stimulation or immunosuppression may provide a preferential milieu for development of NHL. High rates of lymphoma have been observed among individuals with autoimmune disease, organ transplants, and primary or acquired immunodeficiencies. Ultraviolet radiation, previously demonstrated to have an immunosuppressive effect, has also been suggested as a possible risk factor for NHL. Several pathogens have been linked to the risk of lymphoma, including Epstein-Barr virus, human immunodeficiency virus, human T-cell lymphotropic virus-1, Helicobacter pylori, hepatitis C, and simian virus 40. Whether these microbes are responsible for specific genetic mutations that initiate tumor growth, antigenic stimulation leading to B-cell proliferation, and increased potential of random cell replication errors, or immunosuppression, which thereby promotes tumor growth, has not been clearly delineated. Other exogenous factors which have been implicated in lymphomagenesis are chemicals and agricultural exposures, hair dyes, and blood transfusions. We must build on our current knowledge regarding the etiology of NHL in order that prevention, treatment, and ultimately, cure of this malignancy becomes a reality.

Prevalence and pattern of antinuclear autoantibodies in 347 patients with non-Hodgkin's lymphoma

The presence of antinuclear autoantibodies (ANA) was investigated in a large cohort of patients with non-Hodgkin's lymphoma (NHL) in order to assess their frequency, specificity and prognostic relevance. ANA were analysed in 347 patients with different histological subgroups of NHL and in 213 controls using an indirect immunofluorescence technique on HEp2 cells. As the appearance of autoantibodies may be found after treatment of NHL, samples were collected at the time of diagnosis of NHL before any therapy. Sixty-six (19%) NHL patients and 12 (5.6%) patients from the control group displayed ANA. The prevalence between the two groups was found to be significantly higher in NHL patients (P < 0.0001) with a marked increased prevalence in follicular and mantle cell lymphoma subgroups. Autoantibodies directed against mitotic proteins or mitotic-associated proteins were found in 6.9% of NHL patients versus 0.5% in the control group (P < 0.001), with a significantly increased incidence in follicular and mantle cell lymphoma subgroups (P < 0.0001). Some 28% of the patients with positive ANA displayed clinical symptoms that could correspond to classical autoimmune manifestations, this frequency appearing to be higher in the marginal zone/mucosa-associated lymphoid tissue lymphoma subgroup. These data demonstrate a significant incidence of ANA before any treatment in NHL occurrence, which seems to be higher in some histological subgroups with particular ANA, such as ANA directed against mitotic proteins or mitotic-associated proteins.

Nongastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue

A retrospective survey of patients with pathologically reviewed extragastric mucosa-associated lymphoma tissue (MALT) lymphomas from 20 institutions was performed. A total of 180 patients with histologically confirmed diagnosis of extragastric MALT lymphomas were studied. Their median age was 59 years (range, 21-92 years). Ann Arbor stage I disease was present in 115 patients (64%) and stage II disease in 16 (9%). Most cases were in the low or low-intermediate risk groups according to the International Prognostic Index (IPI). Forty-one (23%) patients had involvement of more than one extranodal site at diagnosis and in 24 cases (13%) the lymphoma presented at multiple mucosal sites (9 of them with only mucosal involvement, without bone marrow or nodal disease). Lymph node involvement was present in 21%. Patients were treated with a variety of therapeutic strategies, including chemotherapy in 78 cases. The median overall survival (OS) was not reached; the 5-year OS rate was 90% (95% CI, 82%-94%), the 5-year cause-specific survival (CSS) was 94% (95% CI, 87%-97%), and the 5-year progression-free survival (PFS) was 60% (95% CI, 50%-70%). Multivariate analysis showed that Ann Arbor stage was significantly associated with longer OS, nodal involvement with longer CSS, and favorable IPI score with better PFS. At a median follow-up of 3.4 years, 48 patients (27%; 95% CI, 20%-34%) had a relapse, 6 (3%; 95% CI, 1%-7%) showed histologic transformation, and 18 (10%; 95% CI, 6%-15%) experienced the development of a second tumor. Our data confirm the indolent nature of nongastric MALT lymphomas and the high rate of patients presenting with disseminated disease, which, when limited to mucosal sites, was not associated with a poorer outcome.

Acquired inhibitors to coagulation factors in patients with gastrointestinal diseases

OBJECTIVES

To study the frequency and specificity of acquired coagulation inhibitors in inflammatory and malignant gastrointestinal diseases.

METHODS

In a 10-year period, 511 patients from the island of Crete in Greece were studied, 302 with ulcerative colitis, 112 with Crohn's disease, 82 with gastrointestinal carcinoma and 15 with gastrointestinal lymphoma. Prothrombin time and activated partial thromboplastin time were measured by routine methods. When prothrombin time and/or activated partial thromboplastin time were found to be prolonged, mixture experiments with 25%, 50% and 75% pooled normal human plasma were performed. If clotting times were inadequately corrected, the presence of an acquired inhibitor against a coagulation factor was suggested. Specific coagulation factor assays were then performed with deficient plasmas.

RESULTS

Fifteen patients acquired inhibitors to the following coagulation factors within the 10-year observation period: factor IX (four patients); factor X (three patients); factor XII (three patients); factor VIII (two patients); factor XI (two patients); and factor V (one patient). The activity of the above factors varied from < 1% to 10%. Five patients with ulcerative colitis, six with Crohn's disease, two with gastrointestinal lymphoma and two with gastrointestinal carcinoma developed an inhibitor. Only one patient with factor VIII inhibitor presented with severe bleeding and was treated with recombinant human activated factor VII, while the others had no complications. Remission was obtained in all patients after immunosuppressive therapy, chemotherapy or tumour resection.

CONCLUSION

An increased incidence of coagulation factor inhibitors was found in patients with gastrointestinal inflammatory and malignant diseases compared to the healthy population. In addition, an increased incidence of these inhibitors was also found in the common population of Crete compared to that found in other areas.

A role for sex steroids in autoimmune diseases: a working hypothesis and supporting data

In recent years there has been a continuingly increasing interest in novel research subjects, as yet poorly explored, either because they relate to aspects previously thought to be marginal with respect to classical fields of investigation, or because they require both specialized competence and intense cross-talk by researchers from disparate areas. The potential interaction between immunity and cancer has generated a remarkable number of studies, including those related to the newly explored immune-neuro-endocrine system. In this paper, we review a few autoimmune diseases as examples of a mutual relationship between immune diseases and malignancies. We also review our previous studies on patients with rheumatoid arthritis (RA). In particular, aiming to define the hormone-responsive or -sensitive status of synovial tissues and cells, we have inspected different endocrine end-points, including (1) high- and low-affinity sites of androgen and estrogen binding; (2) the activity of key enzymes of steroid metabolism; and (3) the hormonal profile of synovial fluids as an indication of local endocrine milieu. Overall, our data provide convincing evidence for synovial macrophage-like cells and a subset of T lymphocytes to be considered as target cells for gonadal steroids. This provides a basis for developing new strategies for alternative treatments of RA and possibly unveils novel perspectives in both research and the clinic for other autoimmune diseases as well. In addition, the association of autoimmunity and cancer may disclose promising new avenues of research linking steroid hormones, the immune system, and malignant transformation.

Lymphomas of mucosal-associated lymphoid tissue in common variable immunodeficiency

Common variable immunodeficiency (CVID) is a primary immunodeficiency disease characterized by low serum immunoglobulins IgG, IgA, and usually IgM. The central immune deficiency is impaired secretion of immunoglobulins and lack of antibody production; however, T cell dysfunction and a variety of inflammatory complications suggest global immune dysregulation. A number of reports have documented the association of primary immunodeficiency diseases with the development of non-Hodgkin's lymphoma (NHL). In CVID, the risk has been estimated to lie between 1.4% and 7%. As for NHL arising in other immunodeficiency states, the lymphomas in CVID are extranodal and are usually B cell in type. Of 22 B cell lymphomas that have appeared over a period of 25 years in a cohort of subjects with CVID, five lymphomas, appearing in more recently studied subjects, that arose in mucosal sites would be classified as mucosa-associated lymphoid tissue (MALT) lymphomas. MALT lymphomas are low-grade B cell lymphomas that result from a proliferation of neoplastic marginal-zone related cells of lymphoid tissue and tend to occur in organs that have acquired lymphoid tissue due to long-term infectious or autoimmune stimulation. Lymphomas of this kind have not been described in patients with congenital immunodeficiency, although chronic mucosal antigen stimulation is an integral part of these immune deficiency states.

Prevalence and clinical significance of anticardiolipin and anti-beta2-glycoprotein-I antibodies in patients with non-Hodgkin's lymphoma

The association of antiphospholipid antibodies (APA) has been reported in several cases of patients with non-Hodgkin's lymphoma (NHL) with or without thromboembolic complications. The purpose of this study was to analyse systematically the prevalence of APA and its clinical significance in lymphoma patients. Sera of 90 consecutive unselected patients with NHL were tested for the presence of anticardiolipin (aCL) antibodies and anti-beta2-glycoprotein-I (anti-beta2-GPI) antibodies. The patients were followed up over a median period of 14 months to note the occurrence of thromboembolism. We found APA in 24 out of 90 NHL patients (26.6%). Elevated APA were more often detected in women and in the elderly. The presence of elevated APA was not correlated with the histology and the stage of the lymphoma. None of the 24 patients with elevated APA developed a thromboembolic event in the follow-up period. Thromboembolic events were observed in 12 patients (13.3%), all with negative APA. High APA titres and the combination of positive aCL- and anti-beta2-GPI antibodies, features which are known to be more strongly correlated with thrombosis among patients with antiphospholipid syndrome and systemic lupus erythematous (SLE), were very uncommon in our cohort of NHL patients (3.3%). Vessel compression by lymphoma but not elevated APA remains the main cause of thrombosis in NHL patients.

The dual association between lymphoma and autoimmunity

Autoimmune rheumatic diseases and lymphocytic malignancies are related and this association is bidirectional. Lymphomas occur more frequently in the course of autoimmune disease and autoimmune rheumatic manifestations occur in the course of lymphocytic malignancies. An increased incidence of malignant lymphocytic diseases is present in patients with rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, and autoimmune thyroid disease. Descriptions of lymphocytic malignancies among other autoimmune rheumatic disease have been published. In some patients, the malignant disease is diagnosed months or years before the appearance of the rheumatic disease.

Cancer and autoimmunity: autoimmune and rheumatic features in patients with malignancies

OBJECTIVES

To review the autoimmune and rheumatic manifestations of patients with malignancy.

METHODS

A Medline search of all published papers using keywords related to malignancies, autoimmunity, rheumatic diseases, and paraneoplastic syndromes.

RESULTS

Patients with malignant diseases may develop autoimmune phenomena and rheumatic diseases as a result of (a) generation of autoantibodies against various autoantigens, including oncoproteins (P185, 1-myc, c-myc, c-myb), tumour suppression genes (P53), proliferation associated antigens (cyclin A, B1, D1, E; CENP-F; CDK, U3-RNP), onconeural antigens (Hu, Yo, Ri, Tr), cancer/testis antigens (MAGE, GAGE, BAGE, SSX, ESO, SCP, CT7), and rheumatic disease associated antigens (RNP, Sm). The clinical significance of the various autoantibodies is not clear. Anti-oncoprotein and anti-tumour suppression gene antigens are detected before the diagnosis of the cancer or in the early stages of the malignant disease, suggesting a potential diagnostic or prognostic role. Anti-onconeural antibodies are pathogenic and are associated with specific clinical neurological syndromes (anti-Hu syndrome and others). (b) Paraneoplastic syndromes, a wide range of clinical syndromes, including classic autoimmune rheumatic diseases that develop among patients with cancer. (c) Rheumatism after chemotherapy, a clinical entity characterised by the development of musculoskeletal symptoms after combination chemotherapy for malignancy.

CONCLUSION

Autoimmune and rheumatic features are not rare among patients with malignancies. They are the result of various diverse mechanisms and occasionally they may be associated with serious clinical entities.

MALT Lymphomas

This review addresses the biology and the treatment of lymphomas arising from mucosa-associated lymphoid tissue (MALT). This entity, first described in 1983, represents about 8% of all non-Hodgkin's lymphomas and was recently re-classified as "extranodal marginal zone lymphomas of MALT-type." The term marginal zone lymphoma (MZL) encompasses the three closely related lymphoma subtypes of nodal, primary splenic and extranodal lymphomas of MALT type: the latter represent the vast majority of MZL. These lymphomas arise at different anatomic sites, are composed of mature B-cells lacking expression of CD5 and CD10, often present with overlapping morphologic features, but typically quite distinct clinical behaviors. Only very recently cytogenetic/molecular genetic observations have underlined the distinctiveness of these three lymphoid neoplasms, which in both the R.E.A.L. and WHO-classifications are included in the general term of MZL. MALT lymphomas arise in numerous extranodal sites, but gastric MALT lymphoma is the most common and best studied and is, therefore, the paradigm for the group as a whole. Dr. Isaacson describes the principal histological features of these lymphomas, including criteria to distinguish this entity from other small B-cell lymphomas. Several lines of evidence suggest that gastric lymphoma arises from MALT acquired as the result of aH. pyloriinfection. However, at least 1/3 of cases do not respond to eradication ofH. pylori. Very recent data suggest that both t(11;18) (q21;q21) and bcl10 nuclear expression are associated with failure to respond to this treatment. Dr. Gascoyne discusses the biologic function of proteins deregulated through the different translocations, which play a role in pathogenesis of MALT lymphomas, emphasizing particularly their influence in disrupting the apoptotic pathway. Dr. Zucca reviews findings suggesting that MALT lymphoma is an antigen driven neoplasm. He also presents specific guidelines for treatment of gastric lymphomas trying to shed some light on the amazingly inconsistent and confusing data in the literature. Taking advantage on the more than 300 non-gastric MALT lymphomas collected by the International Extranodal Lymphoma Study Group (ILESG), Dr. Cavalli compares gastric lymphomas with those arising in many other sites. Overall, the data presented in this session will underline the fact, that MALT lymphomas are characterized by some unique biological properties.

Emerging concepts in the management of the malignant haematological disorders

A comprehensive review of novel cytoreductive agents is presented. Such novel agents may be found among chemical compounds directed against specific molecular targets (cytostatics) or within the biological substances selectively aimed at the malignant clone (immunotherapy). It is stated that the purposes of immunotherapy in general are to generate a T-lymphocytic response against the tumour cells, e.g., graft versus leukaemia (GvL) effect, natural killer T-cell cytolysis, antibody-dependent cytolysis etc.; or to reprogramme the immune system of the tumour-bearing host by DNA and/or RNA manipulation with subsequent interference with the signalling pathway in the tumour cells. Some immunotherapeutic modalities are shortly described: donor T-lymphocyte infusion and GvL effect, polyclonal antibodies, monoclonal antibodies, vaccines, gene replacement therapy, suicide gene therapy, antisense oligonucleotides, alterations of DNA-RNA transcript factors and malignant antigenic drive etc. Most likely, a sequence of different treatment modalities will be used in the future comprising an initial debulking by means of standard chemotherapy and/or irradiation followed by target unspecific immunotherapy (polyclonal immunoglobulins, GvL effect etc.) and finally target specific elimination of residual tumour, probably with repeated use of the minimum effective pharmacologic dose (MEPD) of the agents used. In contrast, the current use of high-dose myeloablative chemotherapy with the use of maximum tolerable dose (MTD) and associated severe organ toxicity, and high rates of secondary malignancies will probably be substituted in the future. An effective supportive treatment will be highly necessary, especially related to prevention and treatment of infections.

Current issues in the diagnosis and treatment of Sjögren's syndrome

Modification of the European Cooperative Group (EEC) criteria for Sjögren's Syndrome (SS) should lead to less confusion in diagnosis and therapeutic trials. The proposed EEC modification will require either a positive minor salivary gland biopsy or a positive autoantibody against Sjögren's-associated A (Ro) or B (La) antigen. This modification will decrease the proportion of women fulfilling EEC criteria from 3-5% to about 0.5%, which is similar to San Diego and San Francisco criteria. Genetic studies have shown increased frequency of alleles for peptide transporter genes TAP1 (0101) and TAP2 (0101) genes as well as tumor necrosis factor microsatellite a2 alleles. Although these markers confer markedly increased risk, they are found in only a small proportion of patients. An increased frequency of drug (antibiotic) allergy and other allergic manifestations appears present in patients with SS and may be linked to HLA-DR3. Hepatitis C as a cause of sicca symptoms, positive anti-nuclear autoantibodies, and mixed cryoglobulinemia is increasingly reported in different parts of the world. Antibodies against muscarinic M3 receptor and expression of costimulatory molecules (CD80 and CD86) by ductal epithelial cells may play a role in pathogenesis. Treatment with pilocarpine is effective in double-blind trials and low dose oral alpha interferon looks promising in initial open studies. In pregnant patients who exhibit evidence of neonatal heart block, treatment with dexamethasone is preferred over prednisone, since the placenta is unable to metabolically activate the latter compound.