Acquisition of antigen-presenting functions by neutrophils isolated from mice with chronic colitis.

Active episodes of the inflammatory bowel diseases are associated with the infiltration of large numbers of myeloid cells including neutrophils, monocytes, and macrophages. The objective of this study was to systematically characterize and define the different populations of myeloid cells generated in a mouse model of chronic gut inflammation. Using the T cell transfer model of chronic colitis, we found that induction of disease was associated with enhanced production of myelopoietic cytokines (IL-17 and G-CSF), increased production of neutrophils and monocytes, and infiltration of large numbers of myeloid cells into the mesenteric lymph nodes (MLNs) and colon. Detailed characterization of these myeloid cells revealed three major populations including Mac-1(+)Ly6C(high)Gr-1(low/neg) cells (monocytes), Mac-1(+)Ly6C(int)Gr-1(+) cells (neutrophils), and Mac-1(+)Ly6C(low/neg)Gr-1(low/neg) leukocytes (macrophages, dendritic cells, and eosinophils). In addition, we observed enhanced surface expression of MHC class II and CD86 on neutrophils isolated from the inflamed colon when compared with neutrophils obtained from the blood, the MLNs, and the spleen of colitic mice. Furthermore, we found that colonic neutrophils had acquired APC function that enabled these granulocytes to induce proliferation of OVA-specific CD4(+) T cells in an Ag- and MHC class II-dependent manner. Finally, we observed a synergistic increase in proinflammatory cytokine and chemokine production following coculture of T cells with neutrophils in vitro. Taken together, our data suggest that extravasated neutrophils acquire APC function within the inflamed bowel where they may perpetuate chronic gut inflammation by inducing T cell activation and proliferation as well as by enhancing production of proinflammatory mediators.

Safety profile and clinical activity of sifalimumab, a fully human anti-interferon α monoclonal antibody, in systemic lupus erythematosus: a phase I, multicentre, double-blind randomised study.

BACKGROUND: Type I interferons (IFNs) appear to play a central role in disease pathogenesis in systemic lupus erythematosus (SLE), making them potential therapeutic targets. METHODS: Safety profile, pharmacokinetics, immunogenicity, pharmacodynamics and clinical activity of sifalimumab, an anti-IFNα monoclonal antibody, were assessed in a phase I, multicentre, randomised, double-blind, dose-escalation study with an open-label extension in adults with moderately active SLE. SUBJECTS: received one intravenous dose of sifalimumab (n=33 blinded phase, 0.3, 1, 3, 10 or 30 mg/kg; n=17 open-label, 1, 3, 10 or 30 mg/kg) or placebo (n=17). Each phase lasted 84 days. RESULTS: Adverse events (AEs) were similar between groups; about 97% of AEs were grade 1 or 2. All grade 3 and 4 AEs and all serious AEs (2 placebo, 1 sifalimumab) were deemed unrelated to the study drug. No increase in viral infections or reactivation was observed. Sifalimumab caused dose-dependent inhibition of type I IFN-induced mRNAs (type I IFN signature) in whole blood and corresponding changes in related proteins in affected skin. Exploratory analyses showed consistent trends toward improvement in disease activity in sifalimumab-treated versus placebo-treated subjects. A lower proportion of sifalimumab-treated subjects required new or increased immunosuppressive treatments (12% vs 41%; p=0.03) and had fewer Systemic Lupus Erythematosus Disease Activity Index flares (3% vs 29%; p=0.014). CONCLUSIONS: Sifalimumab had a safety profile that supports further clinical development. This trial demonstrated that overexpression of type I IFN signature in SLE is at least partly driven by IFNα, and exploratory analyses suggest that IFNα inhibition may be associated with clinical benefit in SLE. Trial registration number NCT00299819.

Treatment of refractory temporal arteritis with adalimumab.

High-dose corticosteroids (CS) are the mainstay of treatment for temporal (giant cell) arteritis (TA). A usually required long-term treatment with CS, ranging from 1 to 5 years or more, frequently leads to serious side effects in about 60% of patients. There is no conclusive evidence about the role of immunosuppressive agents like methotrexate and azathioprine in the treatment of TA. There are few reports of treatment of refractory or steroid-dependent TA with tumor necrosis factor alpha (TNF-alpha) inhibitors including infliximab and etanercept. TA is characterized by infiltration of the vessel wall by macrophages, giant cells, and T lymphocytes, with production of several cytokines responsible for the acute phase response. TNF-alpha has been demonstrated in up to 60% of the cells in all areas of inflamed arteries by immunohistochemical techniques; hence, it could play a pivotal role in the pathogenesis of TA. We report the first case of resistant TA, which was treated successfully with adalimumab, a fully human recombinant IgG1, anti-TNF-alpha monoclonal antibody. The efficacy of TNF-alpha inhibitors in resistant TA should be studied in larger, controlled studies.

Pulmonary hypertension in a patient with adult-onset Stills disease.

Pulmonary manifestations of adult-onset Still's disease (AOSD) include aseptic pneumonitis, pleural effusions, rarely acute respiratory distress syndrome, and restrictive lung disease. Pulmonary arterial hypertension (PAH) occurs with several rheumatologic diseases, however, has only been reported once in AOSD. We describe a 29-year-old woman with a 9-year history of AOSD, who developed PAH without any other obvious cause. Therefore, we conclude that this is likely a result of pulmonary vascular changes related to AOSD.

Prevalence of active hepatitis C virus infection in patients with systemic lupus erythematosus.

OBJECTIVE: Hepatitis C virus (HCV) infection is associated with various autoimmune disorders and can mimic systemic lupus erythematosus (SLE) clinically and serologically. There are few reports of prevalence of HCV infection in patients with SLE. The aim of this study was to determine the prevalence of HCV viremia by polymerase chain reaction (PCR) in patients with SLE. METHODS: We tested sera from 40 consecutive patients with SLE collected from 1993 to 2000. All of the patients had HCV viral load measured by PCR. The results were compared with the prevalence of HCV viremia in a control group of blood donors in our geographic area as well as in United States general population. RESULTS: HCV was detected in 4 of 40 patients (10%). The prevalence of HCV in our area blood donors is 130 cases per 100,000 persons (0.13%; P<0.0001). The prevalence of HCV infection in the United States general population, screened by PCR, is 1330 cases per 100,000 people (1.33%; P=0.002). The prevalence of HCV infection was significantly higher in our SLE patients than in our area blood donors. The frequency of HCV infection was also higher than that of the United States general population. CONCLUSION: Our observations support those of other investigators who have reported an increased prevalence of HCV infection in SLE patients. Further detailed investigation of this association may help in understanding the pathogenesis of SLE. HCV infection should be tested when the diagnosis of SLE is considered.

Clinical aspects of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease of unknown etiology affecting both articular tissues and extraarticular organs. The disease is often progressive and results in pain, stiffness, and swelling of joints culminating in significant morbidity and increased mortality. This chapter discusses the epidemiology, possible etiology, clinical manifestations, diagnostic approach and treatment options of RA.

Intercellular adhesion molecule 1 is important for the development of severe experimental malaria but is not required for leukocyte adhesion in the brain.

Plasmodium berghei-infected mice, a well-recognized model of experimental cerebral malaria (ECM), exhibit a systemic inflammatory response. Most investigators hypothesize that leukocytes bind to endothelial cells via intercellular adhesion molecule 1 (ICAM-1), which causes endothelial damage, increased microvascular permeability, and, ultimately, death. ICAM-1-deficient mice on an ECM-susceptible C57BL/6 background were significantly (p = .04) protected from P. berghei mortality compared with ICAM-1 intact controls. ICAM-1 expression assessed by the dual radiolabeled monoclonal antibody technique was increased in the brain and lung in C57BL/6 mice on day 6 of P. berghei infection compared with uninfected controls (5.3-fold, p = .0003 for brain and 1.8-fold, p = .04 for lung). The increase in ICAM-1 expression coincided with significant (p < .05) increases in microvascular permeability in the brain and lung. In contrast to the hypothesized role for ICAM-1, in vivo analysis by intravital microscopy of leukocyte rolling and adhesion in brain microvasculature of mice revealed markedly increased levels of leukocyte rolling and adhesion in ICAM-1-deficient mice on day 6 of P. berghei infection compared with uninfected controls. In addition, ICAM-1 expression and microvascular permeability were increased in infected ECM-resistant BALB/c mice compared with uninfected BALB/c controls. These results collectively indicate that although ICAM-1 contributes to the mortality of experimental malaria, it is not sufficient for the development of severe experimental malaria. In addition, ICAM-1 expressed on the endothelium or on leukocytes is not required for leukocyte rolling or adhesion to the brain microvasculature of mice during P. berghei malaria. Leukocyte rolling and adhesion in the brain vasculature during P. berghei malaria use different ligands than observed during inflammation in other vascular beds.

Pathology case of the month. 39-year-old woman with abdominal pain and weight loss. Takayasu's arteritis (TA).

A 39-year-old white woman presented with a history of aortoiliac occlusive disease diagnosed in 1992 attributed to oral contraceptive use. Shortly thereafter, aortoiliac replacement was performed. Mild hyperlipidemia was diagnosed in 2001. At the current clinic visit, she presented to her primary care physician with a 3-month history of postprandial midepigastric abdominal pain relieved by vomiting and a 30-pound weight loss. Her evaluation included an esophagogastroduodenoscopy, a colonoscopy, and an abdominal ultrasound, all of which were within normal limits. Because of her medical history, the patient underwent an arteriogram, which revealed brachiocephalic stenosis (Figure 1), occlusion of the left subclavian artery (Figures 2a and 2b), and narrowing of the superior and inferior mesenteric arteries (not shown). Since she had discontinued her oral contraceptives in 1992 and her hyperlipidemia was mild, the rheumatology service was consulted to evaluate this patient. On physical examination, she had decreased left brachial and radial pulses and a right carotid bruit. Laboratory evaluation revealed a normal complete blood count, comprehensive metabolic panel, erythrocyte sedimentation rate, and C - reactive protein. Subsequent testing included a prothrombin time, activated partial thromboplastin time, protein S, protein C, reptilase time, antithrombin III, anticardiolipin antibody, antiphospholipid antibody, lupus anticoagulant, homocysteine, RPR, and a lipid profile. All test results were within normal limits. Due to the severity of her abdominal pain, the patient underwent superior mesenteric artery (SMA) bypass surgery. Sections from the aorta resected in 1992 are shown in Figures 3 and 4.

Immunosuppressive monocytes: possible homeostatic mechanism to restrain chronic intestinal inflammation.

Chronic colitis is accompanied by extensive myelopoiesis and accumulation of CD11b+Gr-1+ cells in spleens and secondary lymphoid tissues. Although cells with similar phenotype have been described in cancer, chronic infection, or autoimmunity, where they were associated with suppression of T cell responses, little is known regarding how these cells affect CD4 T cell responses in the context of chronic intestinal inflammation. Therefore, we undertook this study to characterize the interplay between colitis-induced myeloid cells and CD4 T cell. Within the CD11b+Gr-1+ population, only monocytes (Ly6G(neg)Ly6C(high)) but not other myeloid cell subsets suppressed proliferation and production of cytokines by CD4 T cells. Suppression was mediated by cell-contact, NO and partially by IFN-γ and PGs. Interestingly, Ly6C(high) MDCs, isolated from colitic colons, showed up-regulation of iNOS and arginase-1 and were more potent suppressors than those isolated from spleen. On a single-cell level, MDCs inhibited Th1 responses but enhanced generation of foxp3+ T cells. MDCs, cocultured with activated/Teffs, isolated from inflamed colons under hypoxic (1% O2) conditions typical for the inflamed intestine, suppressed proliferation but not their production of proinflammatory cytokines and chemokines. Taken together, expansion of monocytes and MDCs and activation of their suppressive properties may represent a homeostatic mechanism aimed at restraining excessive T cell activation during chronic inflammatory settings. The contribution of immunosuppressive monocytes/MDCs to chronic colitis and their role in shaping T cell responses in vivo require further investigation.

Roles of T cell-associated L-selectin and ß7 integrins during induction and regulation of chronic colitis.

BACKGROUND: L-selectin (CD62L) and ß(7) integrins are important for trafficking of naive T cells under steady-state conditions. The objectives of this study were to dissect the requirements for T cell-associated CD62L and ß(7) integrins during initiation, progression, and regulation of chronic colitis. METHODS: Using the T-cell transfer model, we compared colitogenic potential between T cells lacking one or both of these molecules with wild-type T cells. To assess trafficking of cells to the secondary lymphoid tissue and the gut, we performed co-homing experiments. RESULTS: Adoptive transfer of wild-type, CD62L(-/-) or ß(7)(-/-) single-deficient T cells induced moderate to severe disease with slightly different kinetics. However, transfer of CD62L(-/-) ß(7)(-/-) double-deficient (DKO) T cells produced significantly attenuated gut inflammation, which correlated with fewer T cells and reduced levels of proinflammatory cytokines in the colon lamina propria. Our subsequent experiments established that lack of colitogenic potential of these cells was due to inability of DKO T cells to home to the secondary lymphoid tissue. Furthermore, homing of in vitro-generated effector DKO T cells to the inflamed intestine was significantly impaired. Lastly, DKO regulatory T cells were ineffective at suppressing colitis induced by wild-type T cells. CONCLUSIONS: We established that T cells can use either CD62L(-/-) or ß(7)(-/-) integrins to induce chronic colitis, but lack of both abrogates their colitogenic potential. Effector T cells critically rely on ß(7) integrin during their recruitment to the inflamed intestinal mucosa. Finally, regulation of intestinal inflammation by regulatory T cells requires one or both of these adhesion molecules.

Risk of development of lung cancer is increased in patients with rheumatoid arthritis: a large case control study in US veterans.

OBJECTIVE: To investigate the occurrence of lung cancer in patients with rheumatoid arthritis (RA) in the US veteran population. Patients with rheumatic diseases appear to have an increased risk for the development of lymphoproliferative and some solid organ malignancies. METHODS: We conducted a retrospective case control study using prospectively collected data from the Veterans Integrated Service Networks (VISN) 16 Veteran Affairs (VA) database from 1998 to 2004. We studied the association of RA and lung cancer and analyzed data on 483,721 VA patients. Patients were identified by searching for the diagnoses of RA and lung cancer based on the International Classification of Diseases (ICD) codes. We identified 8768 (1.81%) patients with a diagnosis of RA (ICD code 714.0), 7280 (1.5%) patients with lung cancer (ICD code 162.0), 247 patients with lung cancer and RA, and 7033 patients with lung cancer but no RA. Logistic regression analysis was performed to adjust for age, gender, race, and tobacco and asbestos exposure. Statistical tests were conducted at a 5% level of significance. RESULTS: The diagnosis of RA was determined to have a significant association with lung cancer in this veteran population. Patients with RA are 43% (odds ratio 1.43) more likely to develop lung cancer than patients without RA, when adjusted for covariates. CONCLUSION: Our study shows a significant positive association between RA and the development of lung cancer in the veteran population. Veterans with RA have an increased incidence of lung cancer when compared to the non-RA population.

Wegener granulomatosis: a case report and update.

Wegener granulomatosis (WG) is a systemic disease of unknown etiology characterized by necrotizing granulomatous inflammation, tissue necrosis, and variable degrees of vasculitis in small and medium-sized blood vessels. The classic clinical pattern is a triad involving the upper airways, lungs and kidneys. Ninety percent of patients present with symptoms involving the upper and/or lower airways, and 80% will eventually develop renal disease. WG should be suspected in any patient with progressive or unresponsive sinus disease, glomerulonephritis, pulmonary hemorrhage, mononeuritis multiplex or unexplained multisystem disease. Before the routine use of glucocorticoids and cyclophosphamide, the one year mortality was 82%. However in 1973, Fauci and Wolf discovered that daily prednisone and cyclophosphamide induced complete remission in 75% of patients. The continued use of prednisone and cyclophosphamide for 1 year past remission leads to marked improvement in more than 90% of patients; however, is also associated with serious toxicities. Depending on the disease severity, current treatments employ induction with short-term cyclophosphamide followed by less toxic agents such as methotrexate to maintain disease remission. Although it is a rare disorder, it is pertinent to internists because it is a multisystem disease that presents in a variety of ways. We describe a 63-year-old white male with WG who presented with progressively worsening headaches, bilateral eye redness, epistaxis, hemoptysis and an unintentional 20 pound weight loss, and review the current treatment recommendations.

Impact of treatment with infliximab on anticyclic citrullinated peptide antibody and rheumatoid factor in patients with rheumatoid arthritis.

OBJECTIVE: To investigate the impact of infliximab treatment on anticyclic citrullinated peptide (anti-CCP) antibody and rheumatoid factor (RF) levels in patients with rheumatoid arthritis (RA). METHODS: Sera from 33 RA patients receiving infliximab and disease modifying antirheumatic drugs were tested for anti-CCP antibody, IgA-, IgG- and IgM-RF using a commercially available semiquantitative ELISA at baseline, 30 and 54 weeks after treatment. RESULTS: The serum levels of anti-CCP antibody and IgA-RF decreased significantly after 30 weeks (P = 0.002 and 0.024); however, the decrease was not significant at week 54 (P = 0.147 and 0.207). The decrease in IgG-RF level was not significant at 30 and 54 weeks (P = 0.059 and 0.097). IgM-RF levels, however decreased significantly at 30 and 54 weeks (P = 0.002 and 0.004). A strong correlation between anti-CCP and IgA-, IgG- and IgM-RF was observed at baseline (r(s) = 0.48, 0.43, 0.65, P = < 0.05) and after infliximab treatment at 30 (r(s) = 0.45, 0.46, 0.62, P = < 0.05) and 54 (r(s) = 0.49, 0.45, 0.60, P = < 0.05) weeks. CONCLUSION: Treatment with infliximab results in decreased anti-CCP antibody and IgA-RF early in the course of therapy that is not sustained. IgM-RF declines and remains decreased for at least 54 weeks. Investigations in larger cohorts of RA patients (especially early RA) with longer follow-up are needed to assess the impact of specific therapeutic interventions on anti-CCP antibody and RF levels and the relationship of their levels to disease activity.

Cutaneous vasculitis.

Vasculitis is defined as inflammation of blood vessels and can affect multiple organs. Several classification systems exist to categorize vasculitis such as vessel size, presence of anti-neutrophil cytoplasmic antibody, pathogenesis of the inflammation, and type of inflammatory cell infiltrate. Cutaneous vasculitis occurs as a manifestation of many diseases including rheumatologic diseases, hypersensitivity syndromes, infections, and malignancies. The diagnosis of the cutaneous vasculitis and the underlying cause requires a complete history and physical exam and usually a biopsy or angiogram. The treatment depends on the etiology of the inflammation and includes immunosuppression, withdrawal of the offending agent, antibacterial/antiviral agents, and chemotherapies. A clear understanding and approach to this condition will improve the physician's ability to provide optimal patient care.

Inhibition of platelet adherence to brain microvasculature protects against severe Plasmodium berghei malaria.

Some patients with Plasmodium falciparum infections develop cerebral malaria, acute respiratory distress, and shock and ultimately die even though drug therapy has eliminated the parasite from the blood, suggesting that a systemic inflammatory response contributes to malarial pathogenesis. Plasmodium berghei-infected mice are a well-recognized model of severe malaria (experimental severe malaria [ESM]), and infected mice exhibit a systemic inflammatory response. Because platelets are proposed to contribute to ESM and other systemic inflammatory responses, we determined whether platelet adherence contributes to experimental malarial pathogenesis. Indeed, a significant (P < 0.005) increase in the number of rolling and adherent platelets was observed by intravital microscopy in brain venules of P. berghei-infected mice compared with the number in uninfected controls. P-selectin- or ICAM-1-deficient mice exhibit increased survival after P. berghei infection. We observed a significant (P < 0.0001) reduction in the morbidity of mice injected with anti-CD41 (alpha(IIb) or gpIIb) monoclonal antibody on day 1 of P. berghei infection compared with the morbidity of infected controls injected with rat immunoglobulin G. Additionally, platelet rolling and adhesion in brain venules were reduced in P. berghei mice lacking either P-selectin or ICAM-1 or when the platelets were coated with anti-CD41 monoclonal antibody. Unlike other inflammatory conditions, we did not detect platelet-leukocyte interactions during P. berghei malaria. Because (i). leukocyte adhesion is not markedly altered in the absence of P-selectin or ICAM-1 and (ii). CD41 is not an adhesion molecule for parasitized erythrocytes, these findings support the hypothesis that inhibition of platelet adhesion to the brain microvasculature protects against development of malarial pathogenesis.

P-selectin contributes to severe experimental malaria but is not required for leukocyte adhesion to brain microvasculature.

Plasmodium berghei-infected mice, a well-recognized model of experimental cerebral malaria (ECM), exhibit many of the hallmarks of a systemic inflammatory response, with organ damage in brain, lung, and kidneys. Identification of the molecules mediating pathogenesis of the inflammatory response, such as leukocyte adhesion, may lead to new therapies. Indeed, mice lacking the cell adhesion molecule P-selectin were significantly (P = 0.005) protected from death due to P. berghei malaria compared with C57BL/6 controls despite similar parasitemia (P = 0.6) being found in both groups of mice. P-selectin levels assessed by the quantitative dual radiolabeled monoclonal antibody technique increased significantly (P < 0.05) in several organs in C57BL/6 mice infected with P. berghei, supporting the concept of a systemic inflammatory response mediating malarial pathogenesis. Intravital microscopic analysis of the brain microvasculature demonstrated significant (P < 0.001) leukocyte rolling and adhesion in brain venules of P. berghei-infected mice compared with those found in uninfected controls. The maximum leukocyte adhesion occurred on day 6 of P. berghei infection, when the mice become moribund and exhibit marked vascular leakage into the brain, lung, and heart. However, P-selectin levels were significantly (P < 0.005) increased in brain, lung, and kidneys during P. berghei malaria in ECM-resistant BALB/c mice compared with those found in uninfected BALB/c controls, indicating that increased P-selectin alone is not sufficient to mediate malarial pathogenesis. Leukocyte adhesion to brain microvessels of P-selectin-deficient mice with P. berghei malaria was similar to that observed in control mice. Collectively, these results indicate that P-selectin is important for the development of malarial pathogenesis but is not required for leukocyte adhesion in brain.