José A. Gómez-Puerta

Therapeutic Targeting of B Cells for Rheumatic Autoimmune Diseases

Autoreactive B cells are characterized by their ability to secrete autoantibodies directed against self-peptides. During the last decade, it has become increasingly apparent that B lymphocytes not only produce autoantibodies but also exert important regulatory roles independent of their function as antibody-producing cells. This is especially relevant in the context of autoimmunity, because autoreactive B cells have been shown to possess the ability to activate pathogenic T cells, to produce pro-inflammatory cytokines, and to promote the formation of tertiary lymphoid tissue in target organs. The production of monoclonal antibodies against B-cell-surface molecules has facilitated the characterization of several distinct B lymphocyte subsets. These cell-surface molecules have not only served as useful cell differentiation markers but have also helped to unravel the important biological functions of these cells. Some of these molecules, all of which are expressed on the cell surface, have proven to be effective therapeutic targets. In both animal models and in clinical assays, the efficient elimination of B lymphocytes has been shown to be useful in the treatment of rheumatoid arthritis and other autoimmune diseases. The treatment of most rheumatic autoimmune diseases relies mainly on the use of cytotoxic immunosuppressants and corticosteroids. Although this has resulted in improved disease survival, patients may nonetheless suffer severe adverse events and, in some cases, their relapse rate remains high. The increasing need for safer and more effective drugs along with burgeoning new insights into the pathogenesis of these disorders has fueled interest in biological agents; clinical trials involving the B-cell depletion agent rituximab have been especially promising. This article reviews the current knowledge of B-cell biology and pathogenesis as well as the modern therapeutic approaches for rheumatic autoimmune diseases focusing in particular on the targeting of B-cell-specific surface molecules and on the blocking of B-cell activation and survival.

Catastrophic antiphospholipid syndrome during pregnancy and puerperium: maternal and fetal characteristics of 15 cases

Background: The catastrophic variant of the antiphospholipid syndrome (APS) is a life-threatening form of presentation of this syndrome that can be triggered by several factors. Aim: To describe the characteristics of patients who developed catastrophic APS triggered during pregnancy and puerperium. Methods: A review of the first 255 cases collected in the website-based “CAPS Registry” was undertaken. Three new and unpublished cases of catastrophic APS developed during pregnancy and puerperium were added. Results: Fifteen cases were identified. The mean (range) age was 27 (17–38) years. Most patients had a previous unsuccessful obstetric history. In 7 of 14 (50%) cases with available medical history, the catastrophic APS appeared during pregnancy, in 6 (43%) during the puerperium and in 1 (7%) after curettage for a fetal death. The main clinical and serological characteristics were similar to those patients with catastrophic APS triggered by other factors, except for a history of a higher prevalence of previous abortions (p<0.01). Several specific features were found, including the HELLP (haemolysis, elevated liver enzymes, low platelets) syndrome in 8 (53%) patients, placental infarctions in 4 (27%) patients, and pelvic vein thrombosis and myometrium thrombotic microangiopathy in 1 (7%) patient each. Mortality rate was high for the mothers (46%), and for the babies (54%). Conclusions: It is important to consider the possibility of the development of catastrophic APS in those patients with signs of HELLP syndrome and multiorgan failure during pregnancy or puerperium, especially in those patients with previous history of abortions and/or thrombosis.

The acute respiratory distress syndrome in catastrophic antiphospholipid syndrome: analysis of a series of 47 patients

Background: The acute respiratory distress syndrome (ARDS) is a non-cardiogenic form of pulmonary oedema characterised by severe hypoxaemia refractory to oxygen therapy, with diffuse pulmonary infiltrates on chest radiographs. It can be precipitated by various serious medical and surgical conditions, including systemic autoimmune diseases. The “catastrophic” variant of the antiphospholipid syndrome (APS) is an accelerated form of this systemic autoimmune condition which results in multiorgan failure because of multiple small vessel occlusions. Objective: To analyse the clinical and laboratory characteristics of patients with catastrophic APS who develop ARDS. Methods: Cases with ARDS were selected from the web site based international registry of patients with catastrophic APS (CAPS registry) (http://www.med.ub.es/MIMMUN/FORUM/CAPS.HTM) and their characteristics examined. Results: Pulmonary involvement was reported in 150 of 220 patients with catastrophic APS (68%) and 47 patients (21%) were diagnosed as having ARDS. Nineteen (40%) of these patients died. Pathological studies were undertaken in 10 patients and thrombotic microangiopathy was present in seven. There were no differences in age, sex, precipitating factors, clinical manifestations, or mortality between catastrophic APS patients with and without ARDS. Conclusions: ARDS is the dominant pulmonary manifestation of catastrophic APS. Thus the existence of ARDS in the context of an APS makes it necessary to rule out the presence of the catastrophic variant of this syndrome.

Anti-neutrophil cytoplasmic antibody pathogenesis in small-vessel vasculitis: an update.

Vasculitides associated with serum positivity for anti-neutrophil cytoplasmic antibodies (ANCAs) that affect small- to medium-sized vessels are commonly known as ANCA-associated vasculitis (AAV) and include Wegeners granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome. Evidence derived from both in vitro studies and recent animal models points to a pathogenic role of ANCAs in AAV. In 2002, the first in vivo breakthrough in the pathogenesis of ANCAs showed that mouse ANCAs against myeloperoxidase (MPO) led to intrinsic pauci-immune renal vasculitis in mice. In 2004, a report using both in vitro and in vivo studies proposed that proteinase 3 (PR3)-directed autoimmunity involved the complementary peptide of PR3 (cPR3), which is encoded by the antisense strand of the PR3 gene. The last breakthrough came in October 2008 with a previously undescribed molecular explanation for the origin and development of injury in pauci-immune renal vasculitis, with potential clinical implications. This report showed that infection by fimbriated bacteria may trigger cross-reactive autoimmunity to a previously characterized ANCA antigen, lysosomal membrane protein-2, which is contained in the same vesicles that harbor MPO and PR3. Infection by fimbriated bacteria resulted in the production of autoantibodies, which activated neutrophils and killed human microvascular endothelium in vitro and caused renal vasculitis in rats. Although the evidence for a pathogenic role of ANCAs, mainly MPO-ANCAs, is striking, various questions remain unanswered. Understanding the key pathogenic mechanisms of AAV may provide a safer, more rational therapeutic approach than the traditional (ie, corticosteroids and immunosuppressants) treatment strategy.

Anti-chromatin (anti-nucleosome) antibodies: diagnostic and clinical value.

Anti-chromatin (nucleosome) autoantibodies were one of the first autoantibodies ever detected since they make up the majority of antibodies causing LE Cell formation. The prevalence of anti-chromatin antibodies in systemic lupus erythematosus (SLE) varies from 50% to 100%, being similar to that of the classical positive LE cell. The presence of these antibodies can be used, in conjunction with clinical findings and other laboratory tests, to help in the diagnosis of SLE and drug-induced lupus. Anti-chromatin antibodies have also been found in a lesser percentage of other autoimmune disorders such as primary Sjögrens syndrome and primary antiphospholipid syndrome. The presence of anti-chromatin antibodies has also been linked to glomerulonephritis and disease activity in SLE patients. Recent studies demonstrated the induction of anti-chromatin (anti-nucleosome) antibodies after an anti-tumour necrosis factor (TNF)-alpha agent treatment.

Antineutrophil Cytoplasmic Antibody-Associated Vasculitides and Respiratory Disease

Vasculitides associated with serum positivity for antineutrophil cytoplasmic antibodies (ANCAs) are a well-established subgroup affecting small- to medium-sized vessels that are commonly recognized as ANCA-associated vasculitis, which includes necrotizing granulomatous vasculitis (NGV) [formerly Wegener granulomatosis], microscopic polyangiitis (MPA), and Churg-Strauss syndrome. NGV usually starts as a granulomatous disease of the respiratory tract and progresses to systemic disease with proteinase 3 (PR3)-ANCA-associated vasculitis, suggesting an aberrant cell-mediated immune response to exogenous or endogenous antigens in the respiratory tract and resulting in granuloma formation. In NGV, granulomata may represent lymphoid structures ultimately responsible for PR3-ANCA production. In both NGV and MPA, necrotizing glomerulonephritis and necrotizing pulmonary capillaritis may well result from an injury orchestrated by ANCA. Untreated NGV and MPA normally are rapidly progressive and fatal. Pulmonary capillaritis with alveolar hemorrhage is a severe complication in patients with MPA and NGV. Because plasma exchange removes circulating ANCAs and other proteins from the blood, its use has been advocated in critical situations of severe renal and pulmonary involvement. However, no studies of plasma exchange in ANCA-associated vasculitis focused on pulmonary involvement have been reported. Dissecting the mechanisms of inflammation may identify molecular targets for future therapies in ANCA-associated vasculitis. Thus, biological agents are emerging as potential therapies in refractory cases. Notably, rituximab and infliximab have been trialed with apparent initial clinical success.

Therapeutic plasma exchange for the management of refractory systemic autoimmune diseases: report of 31 cases and review of the literature.

INTRODUCTION Therapeutic plasma exchange (TPE) represents a treatment option in patients with systemic autoimmune diseases because most of their clinical manifestations are related to the presence of antibodies or immune complex deposition. OBJECTIVE To describe the main demographic and clinical characteristics as well as the outcome of patients with systemic autoimmune diseases treated with TPE at a tertiary care center. METHODS We included all patients with systemic autoimmune diseases in whom the indication for treatment with TPE was a flare of the disease between 1999 and 2010. The indications for treatment, complications and outcomes were obtained from review of medical records. RESULTS A total of 31 patients (18 (58%) females and 13 (42%) males) were treated with a total of 196 TPE sessions with an average of 6.3 sessions per patient. Mean age at the time of TPE was 52.9 years (range, 26.0-82.0 years). Ten (32.3%) patients had ANCA-associated vasculitides, 6 (19.4%) mixed cryoglobulinemia secondary to hepatitis C virus (HCV) infection, 5 (16.1%) essential mixed cryoglobulinemia, 4 (12.9%) catastrophic antiphospholipid syndrome, 3 (9.7%) systemic lupus erythematosus, 2(6.5%) dermatomyositis and 1 (3.1%) polyarteritis nodosa. All patients except one were receiving corticosteroids at varying doses and all received a concomitant immunosuppressive drug. Ten (32.3%) and 9 (29.0%) patients received rituximab and intravenous immunoglobulins prior to TPE, respectively. Six patients experienced catheter-related infections, 5 urinary infections and 3 patients developed hospital acquired pneumonia. Eleven patients died in spite of the TPE. CONCLUSIONS TPE is an effective therapeutic option for treating serious manifestations of systemic autoimmune diseases and a valid option for those patients with refractory disease to conventional treatments.

Distinct synovial immunopathology in Behçet disease and psoriatic arthritis.

IntroductionThe aim of the study was to investigate synovial immunopathology differences between early Behçet disease (BD) and psoriatic arthritis (PsA).MethodsNeedle arthroscopy of an inflamed knee joint was performed in patients with early untreated BD (n = 8) and PsA (n = 9). Synovial fluid (SF) was collected for cytokines, perforin, and granzyme analysis. Eight synovial biopsies per patient were obtained for immunohistochemical analysis of the cellular infiltrate (T cells, natural killer cells, macrophages, B cells, plasma cells, mast cells, and neutrophils), blood vessels as well as expression of perforin and granzyme. The stained slides were evaluated by digital image analysis.ResultsThe global degree of synovial inflammation was similar in the two types of arthritis. In the analysis of the innate immune cell infiltration, there was a striking neutrophilic inflammation in BD synovitis whereas PsA displayed significantly higher numbers of cells positive for c-kit, a marker of mast cells. As for lymphocytes, CD3+ T cells, but neither CD20+ B cells nor CD138+ plasma cells, were significantly increased in BD versus PsA. Further analysis of the T-lymphocyte population showed no clear shift in CD4/CD8 ratio or Th1/Th2/Th17 profile. The SF levels of perforin, an effector molecule of cytotoxic cells, displayed a significant four- to fivefold increase in BD.ConclusionsThis systematic comparative analysis of early untreated synovitis identifies neutrophils and T lymphocytes as important infiltrating cell populations in BD. Increased levels of perforin in BD suggest the relevance of cytotoxicity in this disease.

The Multiple Autoimmune Syndromes. A Clue for the Autoimmune Tautology

The multiple autoimmune syndromes (MAS) consist on the presence of three or more well-defined autoimmune diseases (ADs) in a single patient. The aim of this study was to analyze the clinical and genetic characteristics of a large series of patients with MAS. A cluster analysis and familial aggregation analysis of ADs was performed in 84 patients. A genome-wide microsatellite screen was performed in MAS families, and associated loci were investigated through the pedigree disequilibrium test. Systemic lupus erythematosus (SLE), autoimmune thyroid disease (AITD), and Sjögren’s syndrome together were the most frequent ADs encountered. Three main clusters were established. Aggregation for type 1 diabetes, AITD, SLE, and all ADs as a trait was found. Eight loci associated with MAS were observed harboring autoimmunity genes. The MAS represent the best example of polyautoimmunity as well as the effect of a single genotype on diverse phenotypes. Its study provides important clues to elucidate the common mechanisms of ADs (i.e., autoimmune tautology).

Lung sarcoidosis induced by TNF antagonists in rheumatoid arthritis: a case presentation and a literature review.

Abstract We report the case of a 72 year-old woman with established rheumatoid arthritis diagnosed with pulmonary granulomatosis compatible with sarcoidosis after 49 months of treatment with etanercept. The symptoms and radiology remitted after the suspension of treatment against tumor necrosis factor (TNF) and with a course of steroids. To date, 27 cases of histologically-proven pulmonary sarcoidosis have been reported in relation to anti-TNF therapy, with etanercept being more frequent in comparison with the anti-TNF monoclonal antibodies infliximab and adalimumab. Probable pathogenic mechanisms of the paradoxical effect of anti-TNF treatment are discussed. It is important for clinicians to be aware of this potential and uncommon complication of biological therapy with TNF antagonists.