Effect of the REG1 anticoagulation system versus bivalirudin on outcomes after percutaneous coronary intervention (REGULATE-PCI): a randomised clinical trial.

BACKGROUND: REG1 is a novel anticoagulation system consisting of pegnivacogin, an RNA aptamer inhibitor of coagulation factor IXa, and anivamersen, a complementary sequence reversal oligonucleotide. We tested the hypothesis that near complete inhibition of factor IXa with pegnivacogin during percutaneous coronary intervention, followed by partial reversal with anivamersen, would reduce ischaemic events compared with bivalirudin, without increasing bleeding. METHODS: We did a randomised, open-label, active-controlled, multicentre, superiority trial to compare REG1 with bivalirudin at 225 hospitals in North America and Europe. We planned to randomly allocate 13,200 patients undergoing percutaneous coronary intervention in a 1:1 ratio to either REG1 (pegnivacogin 1 mg/kg bolus [>99% factor IXa inhibition] followed by 80% reversal with anivamersen after percutaneous coronary intervention) or bivalirudin. Exclusion criteria included ST segment elevation myocardial infarction within 48 h. The primary efficacy endpoint was the composite of all-cause death, myocardial infarction, stroke, and unplanned target lesion revascularisation by day 3 after randomisation. The principal safety endpoint was major bleeding. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, identifier NCT01848106. The trial was terminated early after enrolment of 3232 patients due to severe allergic reactions. FINDINGS: 1616 patients were allocated REG1 and 1616 were assigned bivalirudin, of whom 1605 and 1601 patients, respectively, received the assigned treatment. Severe allergic reactions were reported in ten (1%) of 1605 patients receiving REG1 versus one (<1%) of 1601 patients treated with bivalirudin. The composite primary endpoint did not differ between groups, with 108 (7%) of 1616 patients assigned REG1 and 103 (6%) of 1616 allocated bivalirudin reporting a primary endpoint event (odds ratio [OR] 1·05, 95% CI 0·80-1·39; p=0·72). Major bleeding was similar between treatment groups (seven [<1%] of 1605 receiving REG1 vs two [<1%] of 1601 treated with bivalirudin; OR 3·49, 95% CI 0·73-16·82; p=0·10), but major or minor bleeding was increased with REG1 (104 [6%] vs 65 [4%]; 1·64, 1·19-2·25; p=0·002). INTERPRETATION: The reversible factor IXa inhibitor REG1, as currently formulated, is associated with severe allergic reactions. Although statistical power was limited because of early termination, there was no evidence that REG1 reduced ischaemic events or bleeding compared with bivalirudin. FUNDING: Regado Biosciences Inc.

Modeling the intrathymic pathogenesis of myasthenia gravis.

Myasthenia gravis is (MG) a prototypic autoimmune disease; the immune effector mechanisms and autoantigenic target have been delineated. However, the events that lead to the abrogation of self-tolerance to neuromuscular acetylcholine receptors (nAChRs) remain a mystery. The thymus gland has long been considered to hold the key to solving this mystery, although the nature of its involvement remains to be elucidated. The nAChR was one of the first self-proteins associated with a defined autoimmune disease that was found to be expressed on thymic stromal populations. The studies described herein represent our efforts to determine how this "promiscuous" autoantigen expression may be involved in the immunopathogenesis of MG. We review our work, characterizing the expression of the nAChR alpha subunit in the thymus, and advance a hypothesis and experimental model, which explore how intrathymic expression of this autoantigen may contribute to the immunopathogenesis of this autoimmune disease.

The B-cell superantigen Finegoldia magna protein L causes pulmonary inflammation by a mechanism dependent on MyD88 but not B cells or immunoglobulins.

OBJECTIVE AND DESIGN: To determine whether Finegoldia magna protein L (PL) causes lung inflammation and, if so, whether the response is dependent on its immunoglobulin (Ig)-binding B-cell superantigenic property. MATERIAL: Pulmonary inflammatory reactions were analyzed at various time points after intratracheal administration of PL to various strains of mice. RESULTS: PL caused peribronchial and perivascular inflammation that peaked at 18-24 h. Polymorphonuclear cells (PMNs) began to accumulate in bronchoalveolar lavage fluid (BALF) of PL-challenged mice by 4 h and accounted for >90% of leukocytes by 18-24 h. Inflammation was marked by the appearance of MIP-2, KC, TNF-α, and IL-6 in the BALF with peak levels attained 4 h after PL administration. PL-induced pulmonary inflammation was associated with increased airway hyper-reactivity following inhalation of methacholine. The inflammatory reaction was unabated in mice lacking B cells and immunoglobulins. In contrast, PL-induced inflammation was abrogated in MyD88-deficient mice. PL-induced responses required alveolar macrophages. CONCLUSIONS: These results strongly suggest that PL-induced lung inflammation is dependent on an innate MyD88-dependent pathway rather than the Ig-binding properties of this microbial B cell superantigen. We propose that this pulmonary inflammatory reaction is caused by the interaction of PL with a Toll-like receptor expressed on alveolar macrophages.

The relationship between hypogammaglobulinemia, monoclonal gammopathy of undetermined significance and humoral immunodeficiency: a case series.

Hypogammaglobulinemia of the non-monoclonal immunoglobulin heavy chain classes has been reported in monoclonal gammopathy of undetermined significance (MGUS) patients. Whether low polyclonal immunoglobulin levels are associated with impaired specific antibody production and whether they represent a risk factor for the development of recurrent bacterial infections have not been established in this population. We determined the frequency of MGUS in patients referred to a tertiary care clinical immunology ambulatory care practice for evaluation of hypogammaglobulinemia, who were assessed for deficits in specific antibody production and the presence of recurrent infections. Of the 133 patients evaluated for hypogammaglobulinemia, 68 were screened for monoclonal gammopathy and 5 were found to have MGUS. Three had MGUS associated hypogammaglobulinemia in the absence of a defining primary immunodeficiency, one possibly had common variable immunodeficiency, and one had an uncertain diagnosis. Thus, MGUS may be uncovered in patients presenting with hypogammaglobulinemia even in those who lack an elevated serum level of IgG, IgM, or IgA.

Granulomatous-lymphocytic interstitial lung disease (GLILD) in common variable immunodeficiency (CVID).

Infectious complications of the lung occur quite frequently in patients with common variable immunodeficiency (CVID), a clinical syndrome that represents a primary immunodeficiency. However, there appears to be noninfectious pulmonary complications in association with CVID as well, and recently the term granulomatous-lymphocytic interstitial lung disease (GLILD) has been created to describe these noninfectious, diffuse lung disease complications that develop in CVID patients. They exhibit both granulomatous and lymphoproliferative histologic patterns, consisting of lymphocytic interstitial pneumonia (LIP), follicular bronchiolitis, and lymphoid hyperplasia. There are many unanswered questions surrounding this relatively unstudied entity. In an attempt to answer some of these questions, this review discusses in detail pathologic and clinical features of GLILD and its proposed pathogenesis with a particular attention to potential role of human herpesvirus 8 (HHV-8). Lastly, therapeutic approach is discussed to generate novel treatment strategy to better care for a subgroup of CVID patients afflicted with this entity.

Toll-like receptor 7-induced naive human B-cell differentiation and immunoglobulin production.

BACKGROUND: Toll-like receptors contribute to the establishment of adaptive immune responses. OBJECTIVE: The reported studies were conducted to examine the effects of the Toll-like receptor (TLR)-7 ligand, resiquimod, on human naive B-cell differentiation. METHODS: Naive human B cells were cultured with resiquimod in the presence or absence of IL-2 and IL-10. Secreted IgM and IgG were measured by ELISA, and IL-6, IL-10, and IFN-alpha were measured by a multiplex protein array. Cell proliferation was assessed by measuring [(3)H]thymidine uptake. mRNA for activation-induced cytidine deaminase and I(gamma 1)-C(mu) circle transcripts was measured by means of RT-PCR. RESULTS: Resiquimod induced the production of IgM and, to a lesser extent, IgG by naive human B cells in association with the secretion of IL-6 and IL-10, and a weak proliferative response. IL-2 and IL-10 synergized with resiquimod in markedly augmenting resiquimod-induced IgM and IgG production and proliferation. Resiquimod also stimulated production of IgG by B cells isolated from the blood of a patient with the X-linked hyper-IgM syndrome, with a greater response when these cells were costimulated with IL-2 and IL-10. The stimulated naive B cells from healthy volunteers displayed molecular evidence of immunoglobulin class-switch recombination-namely the appearance of activation-induced cytidine deaminase and I(gamma 1)-C(mu) circle transcripts. CONCLUSION: Perturbation of TLR-7 on naive human B cells can lead to the induction of immunoglobulin class switch and IgG production in the absence of B-cell receptor cross-linking and CD40-CD40L interaction. The results are relevant to vaccine development and mechanisms by which microbial infection may lead to autoimmunity.

Granulomatous-lymphocytic interstitial lung disease associated with common variable immunodeficiency: CT findings.

PURPOSE: To evaluate computed tomography (CT) scans of individuals with granulomatous-lymphocytic interstitial lung disease and common variable immunodeficiency (CVID) to determine if there are imaging features that distinguish this manifestation of CVID from the more usual imaging findings. MATERIALS AND METHODS: A review of the CVID population at our institution identified a series of 5 patients with CVID who had documented granulomatous disease on biopsy specimens. The initial and follow-up CT examinations were reviewed by 2 radiologists, and imaging findings in the chest and abdomen were tabulated by consensus. In addition, a pathologist reviewed histopathologic specimens and clinical presentations and therapeutic interventions were obtained from patient charts. RESULTS: In all, 5/5 patients (100%) had widespread pulmonary micronodules with a lower lung zone predominance, 4/5 (80%) had smooth interlobular septal thickening with mid to lower lung zone predominance, 1/5 (20%) had mild bronchiectasis, 4/5 (80%) had multifocal pulmonary consolidation, 5/5 (100%) had thoracic or abdominal lymphadenopathy, 2/5 (40%) had hepatomegaly, 5/5 (100%) had splenomegaly, 1/5 (20%) had nonspecific hypoattenuating splenic lesions, and 2/5 (40%) had nonspecific hypoattenuating renal lesions. The pulmonary nodules and lymphadenopathy commonly tended to wax and wane in severity over time, and more marked disease was often associated with areas of focal consolidation. CONCLUSION: Granulomatous-lymphocytic interstitial lung disease, which can occur in patients with CVID, presents with CT findings distinct from the usual airway abnormalities most commonly associated with CVID.

Progressive multifocal leukoencephalopathy in a patient with common variable immunodeficiency and abnormal CD8+ T-cell subset distribution.

BACKGROUND: Patients with primary hypogammaglobulinemia have been reported to have encephalopathy, but progressive multifocal leukoencephalopathy (PML) due to JC virus reactivation is a rare cause. OBJECTIVE: To provide the clinical details and case discussion of a patient diagnosed as having common variable immunodeficiency (CVID) who has progressive neurodegenerative symptoms and was found to have PML and an abnormal CD8+ T-cell subset distribution. METHODS: A detailed case report providing the patient's immunodeficiency history, diagnostic evaluation, and medical management and a review of related literature. RESULTS: Before his neurodegenerative illness, the patient was found to have hypogammaglobulinemia, poor specific antibody responses, low circulating B-cell levels, and abnormal delayed-type hypersensitivity responses; there was no Bruton tyrosine kinase (BTK) mutation. The PML was diagnosed using brain biopsy and was confirmed using a DNA probe specific for JC virus. Peripheral blood flow cytometry at the time of PML diagnosis revealed an accumulation of naive CD8+ T cells (CD3+CD8+CD45RA+) and a deficiency of memory CD8+ T-cell subsets (CD3+CD8+CD45RA- or CD3+CD8+CD45RO+). Despite aggressive treatment with interleukin 2, interferon-gamma, and intravenous cidofovir, the patient died. CONCLUSIONS: JC virus infection should be considered in the differential diagnosis of the patient with CVID and signs and symptoms of encephalopathy. The role of this patient's abnormal CD8' T-cell subset distribution in the development or control of this rare infection is worthy of consideration and has encouraged us to enumerate naive and memory CD4+ and CD8+ T-cell subsets in patients diagnosed as having CVID, even in the absence of neurodegenerative symptoms.

Response to pneumococcal vaccine in patients with early rheumatoid arthritis receiving infliximab plus methotrexate or methotrexate alone.

OBJECTIVE: We assessed whether the addition of anti-tumor necrosis factor (TNF) agent to methotrexate (MTX) therapy might alter the response of patients with rheumatoid arthritis (RA) to pneumococcal vaccination. METHODS: Seventy patients with early RA (n = 20, 36, and 14 in the infliximab 3 mg/kg plus MTX, infliximab 6 mg/kg plus MTX, and placebo plus MTX groups, respectively) were included in an analysis of patients enrolled in an ASPIRE substudy. Patients received 0.5 ml pneumococcal vaccine (Pneumovax) 34 weeks after initiation of study treatment; patient sera were collected 4 weeks later (week 38). Antibody responses were tested using enzyme immunoassay methods for reactivity to a panel of 12 serotypes of the pneumococcal vaccine. RESULTS: No significant difference in response to Pneumovax was observed between the infliximab plus MTX and placebo plus MTX groups. Roughly 80%-85% of patients responded to at least one serotype; however, only 20%-25% of patients in the different treatment groups responded to at least 6 different serotypes. Comparable proportions of patients in the 3 treatment groups responded to an increasing number (> or = 1 to > or = 6) of different serotypes. Patients < 45 years of age and those receiving oral corticosteroids generally appeared to respond better than those age 45 to 65 years and those not receiving oral corticosteroids. CONCLUSION: All treatment groups in this study had lower responses to vaccine than would be expected in the normal population. However, the addition of the anti-TNF agent infliximab to MTX therapy did not appear to affect the response of patients with RA to pneumococcal vaccination.

Pathogenesis of B-cell superantigen-induced immune complex-mediated inflammation.

Staphylococcal protein A (SpA) is representative of a new class of antigens, the B-cell superantigens (SAgs). These antigens bind to the Fab regions of immunoglobulin molecules outside their complementarity-determining regions. SpA, the best-studied B-cell SAg, reacts with the Fabs of most VH3+ immunoglobulins, which are expressed on 30 to 60% of human peripheral B cells. Therefore, B-cell SAgs like SpA have great potential to elicit inflammatory responses in vivo. We previously reported that the interaction of SpA with VH3+ immunoglobulin molecules leads to activation of the complement cascade and produces a histologic pattern of inflammation in the skin of a rabbit indicative of immune complex injury. To elucidate the cellular and molecular events contributing to this type of unconventional immune complex-mediated inflammation, we established a mouse peritoneal Arthus reaction model. Mice treated intravenously with human polyclonal immunoglobulin G (IgG), followed by intraperitoneal injection of SpA, showed neutrophil influx into the peritoneal cavity with peak numbers appearing at 8 h. This inflammatory reaction was dependent on the interaction of SpA with VH3+ IgG. Mast cells, FcgammaRIII, complement components, and tumor necrosis factor alpha play obligatory roles, and the reaction is associated with the local release of the CXC chemokines macrophage inflammatory protein 2 and KC. The data provide further compelling evidence for the induction of immune complex-mediated injury by a B-cell SAg and highlight important factors contributing to the pathogenesis of this novel type of inflammatory reaction.

The intrathymic pathogenesis of myasthenia gravis.

The thymus is considered to play an important role in the pathogenesis of Myasthenia gravis, an autoimmune disease characterized by antibody-mediated skeletal muscle weakness. However, its role is yet to be defined. The studies described herein summarize our efforts to determine how intrathymic expression of the neuromuscular type of acetylcholine (ACh) receptors is involved in the immunopathogenesis of this autoimmune disease. We review the work characterizing the expression of neuromuscular ACh receptors in the thymus and advance a new hypothesis that examines the intrathymic expression of this autoantigen in disease pathogenesis.

A 55-year-old man with hypogammaglobulinemia, lymphopenia, and unrelenting cutaneous warts.

A 55-year-old white man with a history of hypertension, fibromyalgia, and colonic polyps presented with unrelenting plantar warts on his hands and feet for the past 4 years. He was otherwise healthy and without a history of recurrent infections. Physical examination was unremarkable except for extensive warts on his hands and feet. Pertinent laboratory findings included hypoalbuminemia, hypogammaglobulinemia, and lymphopenia most severely affecting CD4(+) T cells. Testing for HIV infection was negative. This clinical and laboratory presentation suggested a combined humoral and cellular immunodeficiency syndrome that could be best explained by loss of lymphocytes, immunoglobulins, and other serum proteins. Additional immunologic testing revealed a marked reduction in peripheral blood naive (CD4(+)CD45RA(+)) T cells. A 24-hour stool collection showed a markedly elevated alpha(1)-antitrypsin level. These findings were most consistent with the diagnosis of intestinal lymphangiectasia, a type of protein-losing enteropathy associated with hypoalbuminemia, hypogammaglobulinemia, and lymphopenia, characterized by a preferential loss of naive CD4(+) T cells into the gastrointestinal tract. This case illustrates the importance of considering intestinal loss of immunoglobulins and lymphocytes in the differential diagnosis of the adult patient who presents with laboratory evidence of a combined humoral and cellular immunodeficiency. It also underscores the diagnostic utility of the clinical immunology laboratory and how flow cytometry, in particular, can contribute to an understanding of pathogenic mechanisms.

Coexistent yellow nail syndrome and selective antibody deficiency.

BACKGROUND: Yellow nail syndrome (YNS) is a rare, often underdiagnosed condition of unknown origin. The clinical features of the syndrome include yellow nails, chronic sinusitis, bronchiectasis, pleural effusion, and lymphoedema. Despite the frequent occurrence of upper and lower respiratory tract infections in patients with YNS, comprehensive analysis of their humoral immunity has not been previously reported. OBJECTIVE: To present the case of a patient with YNS whose recurrent upper and lower respiratory tract infections may have been caused by an underlying selective antibody deficiency that manifests as impaired IgG antibody response to polysaccharide antigens. METHODS: The patient underwent cultures of purulent sputum for Streptococcus pneumoniae and Haemophilus influenzae, bronchial washings for H. influenzae, and nail scrapings for fungi. Her serum levels of IgG, IgA, IgM, IgG subclasses, and serum titers of IgG antitetanus toxoid, anti-H. influenzae, and anti-S. pneumoniae antibodies were measured. RESULTS: Cultures of purulent sputum were positive on multiple occasions for S. pneumoniae and H. influenzae and bronchial washings were positive for H. influenzae. Nail scrapings were consistently negative for fungi. She had no reductions in serum levels of IgG, IgA, IgM, or IgG subclasses and had normal serum titers of IgG antitetanus toxoid antibodies. However, she demonstrated impaired IgG antibody responses following immunization with Pneumovax and an H. influenza B vaccine. CONCLUSIONS: This case report describes the first comprehensive analysis of humoral immune function in a patient with YNS. The finding of a selective antibody deficiency in our patient provides a potential explanation for the occurrence of respiratory infections in YNS. Accordingly, we recommend that functional antibody determinations and quantitative serum immunoglobulins be evaluated in patients diagnosed as having this unusual, enigmatic syndrome.

A new model linking intrathymic acetylcholine receptor expression and the pathogenesis of myasthenia gravis.

The thymus is thought to play an important role in the pathogenesis of myasthenia gravis (MG), an autoimmune disease characterized by skeletal muscle weakness. However, its role remains a mystery. The studies described represent our efforts to determine how intrathymic expression of the neuromuscular type of acetylcholine receptors (nAChRs) is involved in the immunopathogenesis of MG. We review our work characterizing the expression of the alpha subunit of nAChR (nAChRalpha) in the thymus and advance a new hypothesis that examines the intrathymic expression of this autoantigen in disease pathogenesis.

Intrathymic expression of neuromuscular acetylcholine receptors and the immunpathogenesis of myasthenia gravis.

The thymus has been considered to play an important role in the pathogenesis of myasthenia gravis (MG), an autoimmune disease characterized by skeletal muscle weakness. However, the pathogenic role of the thymus still remains a mystery. The neuromuscular type of acetylcholine receptor (AChR) was the first self-protein associated with a defined autoimmune disease that was found to be expressed by thymic stromal populations. The studies described herein represent our efforts to determine how this "promiscuous" autoantigen expression may be involved in the immunopathogenesis of MG. We review our work, characterizating the expression of the alpha subunit of AChR (AChRalpha) in the thymus, and advance a new hypothesis that examines the intrathymic expression of this autoantigen in disease pathogenesis.