Search for: rheumatoid arthritis methotrexate autoimmune disease biomarker gene expression GWAS HLA genes non-HLA genes
ID | PMID | Title | PublicationDate | abstract |
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17622741 | Induction of anti-carbonic-anhydrase-II antibody causes renal tubular acidosis in a mouse | 2007 | BACKGROUND/AIM: We recently reported that renal tubular acidosis (RTA) in Sjogren's syndrome (SjS) is associated with high titers of an autoantibody against carbonic anhydrase (CA) II, an important enzyme in renal acid-base regulation. The purpose of this study was to determine whether a CA-II antibody could cause RTA in a mouse model of SjS. METHODS: PL/J mice were immunized with human CA II to induce CA II antibody formation, whereas controls were injected with phosphate-buffered saline and adjuvant. After 6 weeks, anti-CA-II antibody titers were measured, then ammonium chloride was administered orally for 1 week to detect any acidification defect. RESULTS: CA-II-immunized mice showed higher anti-CA-II antibody titers than control mice. Pathologically, lymphocytic and plasma cell infiltration was seen in the salivary glands and kidneys of CA-II-immunized mice, but not in controls. On acid loading, blood pH and urine pH decreased in both groups of mice, but the slope of urine pH versus blood pH was less steep in the CA-II-immunized mice, suggesting that these mice had an impaired ability to reduce their urine pH in the face of metabolic acidosis. CONCLUSION: CA-II-immunized mice had a urinary acidification defect, which may be similar to that seen in patients with SjS. | |
17157576 | Functional visual acuity in Stevens-Johnson syndrome. | 2006 Dec | PURPOSE: To evaluate the correlation of functional visual acuity (FVA) measurement with ocular surface findings in patients with Stevens-Johnson syndrome (SJS). DESIGN: Prospective comparative study. METHODS: Sixty-nine eyes of 38 patients with chronic SJS assessed at the Tokyo Dental College, Tokyo Medical Center, and the Kyoto Prefectural University of Medicine, Department of Ophthalmology, Kyoto, Japan, were studied. Twenty eyes of 10 normal subjects and 40 eyes of 20 patients with Sjögren syndrome (SS) were also studied. Conventional Landolt visual acuity (VA) and FVA examinations and slit-lamp examinations were performed. FVA was measured continuously by the FVA measurement system during a 30-second blink-free period in one eye. The visual maintenance ratio (VMR) was calculated as follows: VMR = [(2.7 - FVA)/(2.7 - baseline VA)], where logarithm of minimal angle of resolution values of FVA were entered into the formula and 2.7 represented the lowest visual acuity in this series. Slit-lamp examinations, Schirmer test, and fluorescein vital stainings were also performed in all subjects. RESULTS: VMR was markedly lower in patients with SJS compared with patients with SS and controls. FVA values showed a relation with the presence of corneal opacity and vascularization. CONCLUSIONS: The FVA measurement system is not only a useful tool in the evaluation of dynamic VA changes, but also reflects the ocular surface clinical findings in SJS. | |
17998215 | Reduced sulfation of muc5b is linked to xerostomia in patients with Sjögren syndrome. | 2008 Oct | OBJECTIVES: MUC5B contains sulfated and sialylated oligosaccharides that sequester water required for moisturising the oral mucosa. Xerostomia, in patients with Sjögren syndrome, is generally associated with reduced quantities, rather than altered properties, of saliva. Here, we determined the amount of MUC5B (mRNA and protein) as well as sulfation levels in salivary glands of patients with normal or altered unstimulated salivary flow. Localisation of MUC5B and sulfated MUC5B, as well as total levels sulfated groups were determined and compared with acini basal lamina disorganisation. PATIENTS AND METHODS: In all, 18 patients with normal or altered unstimulated salivary flow and 16 controls were studied. MUC5B mRNA and protein were evaluated in salivary glands by semiquantitative RT-PCR and Western blot analysis. MUC5B sulfation was determined by Western blotting. MUC5B and sulfo-Lewis(a) antigen localisation were assessed by immunohistochemistry. The total amount of sulfated oligosaccharides was determined microdensitometrically. RESULTS: No significant differences were detected in MUC5B mRNA and protein levels between controls and patients, while sulfo-Lewis(a) antigen levels were lower in patients. The number of sulfo-Lewis(a) positive mucous acini was reduced in patients but no correlation was observed between lower levels of sulfation and unstimulated salivary flow. Microdensitometric data confirmed the presence of reduced sulfated oligosaccharides levels in mucous acini from patients with highly disorganised basal lamina. CONCLUSION: Disorganisation of the basal lamina observed in patients with Sjögren syndrome may lead to dedifferentiation of acinar mucous cells and, as a consequence, alter sulfation of MUC5B. These changes are suggested to represent a novel mechanism that may explain xerostomia in these patients. | |
17954109 | Primary lymphoma of the subglottic airway in a patient with Sjogren's syndrome mimicking h | 2007 Nov | Primary B cell lymphoma of the central airways is a rare tumor. This report describes a case of primary B cell lymphoma of the subglottic airway in a patient with Sjogren's syndrome, which resembled a benign, cicatricial subglottic stenosis. Successful management was achieved using surgical resection with laryngotracheal reconstruction. | |
16385526 | Production of a novel class of polyreactive pathogenic autoantibodies in BXD2 mice causes | 2006 Jan | OBJECTIVE: The BXD2 mouse strain spontaneously develops glomerulonephritis and erosive arthritis. The goal of this study was to identify the antigenic target proteins and epitopes and to unravel the mechanisms by which the related conditions arise in BXD2 mice. METHODS: Individual hybridomas isolated from the spleen of a 10-month-old BXD2 mouse were injected intraperitoneally into nonautoimmune mice for evaluation of pathogenicity of each autoantibody. Autoantigens were immunoprecipitated with the pathogenic autoantibody L3A4. Autoantigens were identified using enzyme-linked immunosorbent assay, Western blotting, 2-dimensional gel electrophoresis, and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MS) and tandem MS. Antigenic epitopes were determined using a high-throughput epitope mapping method. RESULTS: The production of autoantibodies in BXD2 mice occurred in an orderly progression, with peak levels of autoantibodies to nitrotyrosine (NT)-modified enolase, Ro, alpha-actin, and heat-shock proteins (HSPs) preceding peak levels of antihistone, anti-DNA, and rheumatoid factor. Two monoclonal autoantibodies, L3A4 and T56G10, were identified that could induce immune complexes, renal disease, and/or arthritis. Both L3A4 and T56G10 were polyreactive, and each reacted with separate sets of autoantigens. The antigenic targets of L3A4 consisted of NT-modified enolase, ATP5b, alpha-actin, and Hsp70 family proteins including Hspa5 and Hsp74. The antigenic epitopes of NT-modified enolase and Hspa5 exhibited sequence homology and cross-reactivity, suggesting that epitope spreading may occur through a molecular mimicry mechanism. CONCLUSION: The polyreactivity of autoantibodies that target a novel class of autoantigens may enable these autoantibodies to induce erosive arthritis or glomerulonephritis either by direct pathogenic mechanisms or indirectly via Fc or immune complex deposition. | |
17023256 | Open-label study of clarithromycin in patients with undifferentiated connective tissue dis | 2006 Oct | OBJECTIVE: The macrolide family of antibiotics (erythromycin, clarithromycin, and others), have both antimicrobial and immunomodulatory effects. This study explored the effect of clarithromycin on the clinical course of patients with undifferentiated connective tissue disease (UCTD) in a 12-week open-label study. METHODS: The diagnosis of UCTD was based on symptoms/signs of connective tissue disease, and the presence of 1 or more positive autoimmune disease tests, but with insufficient criteria to make a definitive diagnosis. Screening and monthly follow-up visits over 12 weeks included the following: history and physical examination; concurrent medications; the 68/66 tender/swollen joint count; visual analog scores 0 to 100 mm for patient and physician global assessment of disease activity, and patient pain; antinuclear antibody panel, rheumatoid factor, erythrocyte sedimentation rate, C-reactive protein, and blood chemistry. RESULTS: Seven patients with rheumatic disease were treated with clarithromycin; 6 of 7 had symptomatic relief. Two subjects treated empirically before the decision to perform an open-label study responded favorably. Four of 5 patients who completed the prospective open-label study had mean maximal improvements from baseline of 78, 75, and 79% in patient pain, patient global, and investigator global assessments, respectively. Pain relief occurred as early as 1 week. Drug withdrawal with rechallenge in 2 patients resulted in flare followed by recapture of symptomatic relief. CONCLUSIONS: Clarithromycin, a macrolide antibiotic, led to clinical improvement in patients with UCTD. Efficacy and safety data support further investigation of macrolide antibiotic use as a primary or adjunctive treatment in various connective tissue diseases. | |
19061941 | Cloning, characterisation, and comparative quantitative expression analyses of receptor fo | 2009 Apr 1 | RAGE is a member of the immunoglobulin superfamily of cell surface molecules playing key roles in pathophysiological processes, e.g. immune/inflammatory disorders, Alzheimer's disease, diabetic arteriosclerosis and tumourigenesis. In humans 19 naturally occurring RAGE splicing variants resulting in either N-terminally or C-terminally truncated proteins were identified and are lately discussed as mechanisms for receptor regulation. Accordingly, deregulation of sRAGE levels has been associated with several diseases e.g. Alzheimer's disease, Type 1 diabetes, and rheumatoid arthritis. Administration of recombinant sRAGE to animal models of cancer blocked tumour growth successfully. In spite of its obvious relationship to cancer and metastasis data focusing sRAGE deregulation and tumours is rare. In this study we screened a set of tumours, healthy tissues and various cancer cell lines for RAGE splicing variants and analysed their structure. Additionally, we analysed the ratio of the mainly found transcript variants using quantitative Real-Time PCR. In total we characterised 24 previously not described canine and 4 human RAGE splicing variants, analysed their structure, classified their characteristics, and derived their respective protein forms. Interestingly, the healthy and the neoplastic tissue samples showed in majority RAGE transcripts coding for the complete receptor and transcripts showing insertions of intron 1. | |
18952137 | In vivo evaluation of the safety of triptolide-loaded hydrogel-thickened microemulsion. | 2008 Dec | Triptolide (TP) is a major active component of Tripterygium wilfordii Hook F (TWHF), which is used to treat rheumatoid arthritis (RA). TP has a narrow therapeutic window. To increase the therapeutic index of TP, a novel TP-loaded transdermal delivery system, named TP-loaded hydrogel-thickened microemulsion (TP-MTH), has been developed to treat RA. Our previous studies have demonstrated the good efficacy of TP-MTH in animals. This paper evaluated the safety of TP-MTH with several animals. Results demonstrated no obvious toxicities in a series of toxicity tests: acute toxicity study of TP-MTH (1.2mg/kg) in rabbits, 6-month long-term toxicity study of TP-MTH (0.06, 0.18, 0.54mg/kg) in rabbits, safety pharmacology study of TP-MTH (0.03, 0.09, 0.27mg/kg, for 5 d) in mice and beagle dogs, skin irritation study in rabbits, and skin allergic reaction test in guinea pigs. Only mild reversible skin irritation signs were observed on the skin of animals. These studies suggest that topical TP-MTH is a promising drug formulation for the treatment of RA. | |
18829735 | Early-onset pancytopenia and skin ulcer following low-dose methotrexate therapy. | 2008 Jul | Pancytopenia is a rare but serious adverse effect of low-dose methotrexate (MTX) sodium therapy, and this case report describes a very early-onset of pancytopenia and cutaneous lesions after three days of ingestion. A 64-year-old man was presented to Emergency Department with weakness, fever, poor appetite, nausea, and vomiting after he had had accidentally ingested MTX tablets (2.5 mg) twice a day for the last three days. On initial examination, several painful lesions in his oral mucosa and a cutaneous ulceration on his right foot were also observed. He had severe pancytopenia, poor kidney functions, and abnormal coagulation parameters. The blood level of MTX was found to be within therapeutic range. He was treated with leucovorine, intravenous antibiotics, and appropriate blood transfusions; he was discharged from hospital without any sequela. Pancytopenia associated with low-dose (cumulative dose of 15 mg in 3 days) MTX therapy had not been reported previously. The Naranjo probability scale showed pancytopenia and skin ulcer associated with low-dose MTX therapy as probable adverse reactions. Risk factors for pancytopenia such as renal insufficiency, hypoalbuminemia, low folate levels, concomitant infections, concomitant use of drugs, and folate supplementation were not identified in our patient. Although pancytopenia associated with low-dose MTX therapy is not expected as early as 3 days after initiation of the therapy, physicians should also be aware of this life threatening adverse effect during the very first days of MTX therapy for rheumatoid arthritis patients. | |
17517083 | Audit of pneumocystis pneumonia in patients seen by the Christchurch Hospital rheumatology | 2007 Oct | AIM: The aim of the study was to review all cases of Pneumocystis carinii pneumonia (PCP) in patients seen by the Christchurch Hospital Rheumatology service over a 5-year period and to determine the annual incidence of PCP. METHODS: The Canterbury Health Laboratory database was searched for rheumatology patients testing positive for PCP from 31 December 2000 to 31 December 2005. The rheumatology database was then searched to identify patients receiving the same immunosuppressant medication as those who developed PCP to determine the annual incidence of PCP in this group. RESULTS: Four rheumatology patients were diagnosed with PCP during the 5-year period. Two were receiving oral methotrexate (MTX) for rheumatoid arthritis and two were receiving cyclophosphamide (CYC), one each for Wegener's granulomatosis and dermatomyositis. None of the four cases was receiving PCP chemoprophylaxis. Five hundred and forty-seven patients commenced MTX over the same 5-year period and 47 commenced CYC. Only 14 of 47 (29.7%) CYC-treated patients received PCP prophylaxis. The annual incidence of PCP was 0.17% (95% confidence interval (CI) 0.02-0.63) and 5.33% (95%CI 0.65-19.24) in patients prescribed MTX and CYC, respectively. For the 33 patients receiving CYC without concomitant PCP prophylaxis the annual incidence was 9.50% (95%CI 1.15-34.33). CONCLUSION: In our study the annual incidence of PCP in patients taking MTX was low and would not support the use of routine PCP chemoprophylaxis. In patients receiving CYC without concomitant PCP chemoprophylaxis the annual incidence of PCP was higher although the number of cases was small. Given the high morbidity and mortality in this group, PCP chemoprophylaxis should be considered. | |
17502871 | Pharmacodynamic effects of the murine p75-Fc fusion protein in mice. | 2007 May | Overproduction of inflammatory mediators, such as tumor necrosis factor (TNF), is key to the development and maintenance of inflammatory processes. Etanercept is a soluble TNF receptor fusion protein used in the treatment of various chronic inflammatory diseases, including rheumatoid arthritis and psoriasis. This study investigated the effects of murine p75-Fc, a soluble TNF receptor protein, on TNF-induced IL-6 production in mice. Six groups of mice received either murine p75-Fc (0.15, 0.50, 1.5, 5, and 15 mg/kg) or phosphate-buffered saline. Three days later, mice were injected intravenously with 10 microg of murine TNF and blood samples were taken after 3 hours. Serum IL-6 and TNF were measured by ELISA. Mice treated with 5 and 15 mg/kg murine p75-Fc demonstrated complete inhibition of TNF-induced IL-6 production. Murine p75-Fc (1.5 mg/kg) resulted in a partial but significant reduction of TNF-induced IL-6 production. No TNF was detected in 5 and 15 mg/kg murine p75-Fc-treated mice, except one in the 5 mg/kg dose group. In conclusion, murine p75-Fc completely inhibits TNF-induced IL-6 production in mice. | |
17496730 | Tumor necrosis factor-alpha inhibitor associated ulcerative colitis. | 2007 Mar | BACKGROUND: Flares or onset of inflammatory bowel disease in association with immunosuppression has been reported in the literature. METHODS: We studied 4 cases of patients with rheumatic disease who developed or had a flare of ulcerative colitis either after initiation of or while taking a tumor necrosis factor-alpha inhibitor. RESULTS: We identified 4 patients, three male and one female. Two of the male patients had a seronegative spondyloarthropathy and one had rheumatoid arthritis. The female patient had amyopathic dermatomyositis. Two of the 4 patients had ulcerative colitis prior to tumor necrosis factor-alpha treatment. Both of these patients had quiescent ulcerative colitis that flared after they began taking etanercept. Two patients developed de novo ulcerative colitis while taking a tumor necrosis factor-alpha inhibitor. CONCLUSIONS: The data presented in these 4 cases supports a temporal relationship between initiating a tumor necrosis factor-alpha inhibitor and onset or flare of ulcerative colitis. These observations raise the possibility that tumor necrosis factor-alpha inhibitor therapy, which has been used as treatment for inflammatory bowel disease, may rarely be a factor in the development of disease. | |
17453722 | Multiple specificities of autoantibodies against hnRNP A/B proteins in systemic rheumatic | 2007 May | Spliceosomal small nuclear ribonucleoproteins (U-snRNPs) are frequent and specific targets of autoantibodies in systemic rheumatic diseases. The abundant, functionally related heterogeneous nuclear ribonucleoprotein complexes (hnRNPs) have later defined as a new target of autoantibodies, of which their immunochemical/immunogenic and pathogenic properties are still under investigation. Among hnRNP proteins, those belonging to the A/B type are considered as the major autoantigens targeted by antibodies in sera of patients suffering with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). By performing an extensive screening using rat liver 40S hnRNP antigenic material, we document here the existence of multiple specificities of anti-hnRNP A/B autoantibodies in sera of Greek patients suffering with a spectrum of systemic rheumatic diseases. This included patients with SLE, Sjogren's syndrome (SS), Scleroderma (SSc) and a specific group of patients mostly with undifferentiated disease (UD patients). In total, four distinct types of anti-hnRNP A/B autoantibodies have been recognized. The first two referred to the known anti-hnRNPA2(RA33) and anti-hnRNP A1; the latter appearing very rarely. The third was of the new type selectively reacting with hnRNP B2 and an hnRNP A3 variant, while the fourth was a rare case of anti-hnRNP B2 alone. In addition, a novel specificity of autoantibodies against hnRNP L protein was identified in association with anti-hnRNP A/B antibodies. The co-existence within a serum of autoantibodies having variable specificity for hnRNP A/B and L autoantigens was shown. Specific immunochemical features of the identified autoantibodies are presented and a possible mechanism of autoepitope spreading within protein components of hnRNP complexes is discussed. | |
16603581 | Preliminary evidence for cachexia in patients with well-established ankylosing spondylitis | 2006 Nov | OBJECTIVES: Cachexia, defined as an accelerated loss of skeletal muscle in the context of a chronic inflammatory response, is common in rheumatoid arthritis but it has not been demonstrated in patients with ankylosing spondylitis (AS). The aim of this study was to determine muscle wasting and its functional consequences in a group of patients with well-established AS. METHODS: Nineteen male patients (mean age 53 yrs) with long-standing AS (mean disease duration 19 yrs) and radiological changes (84% had one or more syndesmophytes) were compared with 19 age-matched healthy males with similar levels of habitual physical activity. Body composition was assessed by dual energy X-ray absorptiometry. Muscle strength was measured by isokinetic knee extension and hand grip dynamometry, and by 30 s arm curl and chair sit-to-stand tests. RESULTS: AS patients showed a statistically and clinically significant 12% reduction in arms and legs lean mass, a proxy measure of total body skeletal muscle mass, compared with healthy controls (P < 0.05). This muscle loss was significantly associated with reduced upper and lower body strength (correlation coefficients ranging between 0.37 and 0.79, P < 0.05). CONCLUSION: These results provide preliminary evidence that cachexia is a functionally relevant systemic complication of AS, particularly in patients with long-standing disease and radiological changes. Progressive resistance training and other interventions aimed at stimulating skeletal muscle growth might be beneficial in this population, and further studies on the pathophysiology of cachexia in AS patients are needed. | |
18710403 | Alteration of N-glycosylation in the kidney in a mouse model of systemic lupus erythematos | 2009 Mar | Changes in the glycan structures of some glycoproteins have been observed in autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis. A deficiency of alpha-mannosidase II, which is associated with branching in N-glycans, has been found to induce SLE-like glomerular nephritis in a mouse model. These findings suggest that the alteration of the glycosylation has some link with the development of SLE. An analysis of glycan alteration in the disordered tissues in SLE may lead to the development of improved diagnostic methods and may help to clarify the carbohydrate-related pathogenic mechanism of inflammation in SLE. In this study, a comprehensive and differential analysis of N-glycans in kidneys from SLE-model mice and control mice was performed by using the quantitative glycan profiling method that we have developed previously. In this method, a mixture of deuterium-labelled N-glycans from the kidneys of SLE-model mice and non-labelled N-glycans from kidneys of control mice was analysed by liquid chromatography/mass spectrometry. It was revealed that the low-molecular-mass glycans with simple structures, including agalactobiantennary and paucimannose-type oligosaccharides, markedly increased in the SLE-model mouse. On the other hand, fucosylated and galactosylated complex type glycans with high branching were decreased in the SLE-model mouse. These results suggest that the changes occurring in the N-glycan synthesis pathway may cause the aberrant glycosylations on not only specific glycoproteins but also on most of the glycoproteins in the SLE-model mouse. The changes in glycosylation might be involved in autoimmune pathogenesis in the model mouse kidney. | |
18535937 | Ofatumumab, a human monoclonal antibody for lymphoid malignancies and autoimmune disorders | 2008 Jun | Genmab A/S and licensee GlaxoSmithKline plc are developing ofatumumab, an anti-CD20 human mAb, for the potential intravenous treatment of non-Hodgkin's lymphoma and autoimmune diseases, such as rheumatoid arthritis (RA) and multiple sclerosis (MS). Phase I and II clinical trials have been completed in patients with chronic lymphocytic leukemia (CLL), rituximab-refractory follicular lymphoma (FL) and RA. At the time of publication ofatumumab was undergoing a phase II clinical trial in patients with diffuse large B-cell lymphoma and phase III clinical trials in patients with B-cell CLL (B-CLL) in which fludarabine and alemtuzumab treatments have failed and in patients with rituximab-refractory FL. Ofatumumab was also undergoing phase II clinical trials as a combination therapy for previously untreated patients with FL in combination with cyclophosphamide, adriamycin, vincristine, and prednisone and in combination with fludarabine and cyclophosphamide for the treatment of B-CLL. In addition, two phase III clinical trials to assess patients who have an inadequate response to methotrexate and TNFalpha therapy were ongoing for patients with RA, and a phase II clinical trial to investigate the effects of repeated doses of ofatumumab was recruiting patients with RA from a previous trial on ofatumumab. A phase I/II clinical trial of ofatumumab in relapsing-remitting MS was expected to commence in 2008. | |
18417424 | TIRAP (MAL) S180L polymorphism is a common protective factor against developing tuberculos | 2008 Sep | BACKGROUND AND AIM: The involvement of Toll-like receptor (TLR)-mediated pathways in infectious and autoimmunity has been suggested. The MyD88 adaptor-like (Mal) protein, also known as the TIR domain-containing adaptor protein (TIRAP), is implicated in the TLR2- and TLR4-mediated MyD88-dependent signaling pathway. The aim of this study was to investigate the influence of the functional TIRAP (MAL) S180L polymorphism on tuberculosis (TB) and four autoimmune diseases namely: rheumatoid arthritis (RA), primary Sjögren's syndrome (pSS), systemic lupus erythematosus (SLE) and type 1 diabetes mellitus (T1D). METHODS: This was a case-control and family based association study in which 1325 individuals from a well-defined Colombian population were involved. TIRAP (MAL) S180L genotyping was done by using a polymerase chain reaction-restriction fragment length polymorphism technique and by direct sequencing. RESULTS: Leu180 allele was found to be a protective factor against developing TB (odd ratio (OR): 0.53, 95% confidence interval (CI): 0.29-0.97) and SLE (OR: 0.29, 95% CI: 0.14-0.61) while no significant influence on RA, pSS and T1D was observed. CONCLUSION: These results support the influence of TIRAP (MAL) S180L polymorphism on TB and indicate that TB and SLE might share a common immunogenetic pathway in the innate immune response. | |
18406636 | Mast cell transcriptional networks. | 2008 Jul | Unregulated activation of mast cells can contribute to the pathogenesis of inflammatory and allergic diseases, including asthma, rheumatoid arthritis, inflammatory bowel disease, and multiple sclerosis. Absence of mast cells in animal models can lead to impairment in the innate immune response to parasites and bacterial infections. Aberrant clonal accumulation and proliferation of mast cells can result in a variety of diseases ranging from benign cutaneous mastocytosis to systemic mastocytosis or mast cell leukemia. Understanding mast cell differentiation provides important insights into mechanisms of lineage selection during hematopoiesis and can provide targets for new drug development to treat mast cell disorders. In this review, we discuss controversies related to development, sites of origin, and the transcriptional program of mast cells. | |
18393827 | Cellular and molecular mechanisms involved in the action of vitamin D analogs targeting vi | 2008 Apr | The active metabolite of vitamin D3 - 1,25-(OH)2D3 - exerts most of its physiological and pharmacological actions through its nuclear receptor (VDR), regulating the transcriptional machinery of a variety of cell types. Basic research motivated by the detection of VDR in numerous target cells, has indicated potential therapeutic applications of VDR ligands in osteoporosis, cancer, secondary hyperparathyroidism and autoimmune diseases such as psoriasis, systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes and multiple sclerosis. In recent years vitamin D analogs, particularly calcipotriol and tacalcitol, have been used as topical therapeutic agents in vitiligo, an autoimmune pigmentary disorder characterized by aberrant loss of functional melanocytes from involved epidermis. The presence of cytotoxic T cells targeting melanocyte antigens and imbalance of the cytokine network were described as characteristics of the disease, eventually leading to melanocyte damage and death. Vitamin D ligands are designed to target the local immune response in vitiligo, acting on specific T cell activation, mainly by inhibiting the transition of T cells from early to late G1 phase and by inhibiting the expression of several pro-inflammatory cytokines genes, such as those encoding tumor necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma). Vitamin D(3) compounds are known to influence melanocyte maturation and differentiation and also to up-regulate melanogenesis through pathways activated by specific ligand receptors, such as endothelin receptor and c-kit. In this review we summarize the complex pathogenetic rationale of vitamin D analogs in vitiligo depigmentation. Understanding the cellular and molecular mechanisms through which vitamin D targets the epidermal melanin unit is of great interest for identification of new effective therapeutic combination(s) that might induce repigmentation in vitiligo. | |
18337174 | Rituximab-induced B cell depletion in autoimmune diseases: potential effects on T cells. | 2008 Jun | Peripheral B cell depletion strategies have been employed recently in the treatment of systemic autoimmune diseases and the initial clinical results have been encouraging. Although the major target of rituximab-based treatments was to reduce the levels of circulating autoantibodies, additional mechanisms of action may operate. Recent studies have addressed the question of potential effects of transient B cell depletion on other, non-B cell populations. The data, albeit uncontrolled, suggest that anti-CD20 monoclonal antibody treatment is associated with significant effects in the T cell pool, whereas individual clinical responses do not always correlate with changes in autoantibody titers. More specifically, it has been reported that rituximab administration may decrease the activated phenotype of peripheral and tissue-resident T cells by abolishing antigen presentation by B cells, and may enhance the numbers and function of regulatory T cells. In this review we analyze and discuss available data emerging from B cell depletion studies in patients with systemic lupus erythematosus, rheumatoid arthritis and other autoimmune conditions. Further controlled studies are needed to confirm the role of B cell depletion in modifying T cell function in vivo. |