Search For Autoantibodies Research Articles

Crotonaldehyde induced structural alterations in Low-Density Lipoprotein: Immunogenicity of the modified protein in experimental animals and auto-antibodies generation in various cancers

Crotonaldehyde (CA), a prominent component of cigarette smoke (CS) is a pervasive environmental pollutant that is a highly toxic, unsaturated aldehyde. Exposure to CA-rich pollutants has been linked to the emergence of many malignancies in humans. To better understand the role of CA in biomolecule modification, this study investigated the detailed structural alterations in low-density lipoprotein (LDL) modified by CA, as well as the immunogenicity of the modified protein in experimental animals and the search for autoantibodies in various cancers patients.In vitro, results indicated alterations in secondary and tertiary structures; examined using UV–visible, fluorescence, far-UV circular dichroism, and Fourier transform infrared spectroscopy techniques. Changes in the oxidation status of LDL were studied by carbonyl content assay and NBT assay. ThT binding assay, scanning, and transmission electron microscopy were used to study aggregate formation. The findings revealed significant structural damage in LDL modified by CA. The modification resulted in the unmasking of hydrophobic clusters, the loss of the protein α-helix, and the formation of β-pleated sheet structure. The amyloid aggregate formation was confirmed through ThT microscopy and electron spectroscopy. Rabbits immunized with crotonaldehyde; lead to structural changes in the LDL; that acted as extra antigenic determinants, eliciting strong antibody response. Immunoglobulin response is highly specific for modified LDL as demonstrated by the ELISA. The presence of antibodies against CA-modified LDL was confirmed by the immunoglobulin content of blood sera from human subjects with lung cancer, and competitive ELISA demonstrated the specificity of these antibodies. This study offers insights into the CA-mediated LDL modification and immunogenicity in lung cancer that will have diagnostic importance.

P8.129: Description of the Process of Inclusion and Kidney Transplantation Waiting List - Uruguay

Introduction: In Uruguay with 3,286,314 inhabitants (2011 census), renal transplantation is performed in 3 transplant centers, is regulated by the Instituto Nacional de Donación y Trasplante (INDT) and financed by the Fondo Nacional de Recursos. The allocation is made on a national algorithm and it is an INDT´s responsibity. In the last 5 years, including the Health Emergency, an average of 139 kidney transplants were performed per year. The average rate for these 5 years of renal transplantation is 42.33 pmp. Objective: Describe the renal waiting list (WL) admission process and the recipient population. Methods: The study algorithm for admission to the WL include: □ABO and Rh blood group typing. □HLA typing by PCR-SSO (Luminex) for A, B, C, DRB1, DQA1 and DQB1 locus. □HLA antibody screening (Luminex), class I and/or II. If positive, a specificity search is performed. □Search for autoantibodies by microlymphocytotoxicity technique (MLCT). □Patient’s serum is preserved (serum collection). □PRA (wall reactive antibodies) by MLCT, defining hyperimmunized PRA>80%. During the period in WL the following procedures are performed: □serum collection update every 3 months or after sensitizing events. Failure to comply with this requirement excludes recipients from the allocation. □HLA antibody screening and specificity analysis are performed annually and PRA every six months. Results: There are currently 434 patients in the WL, including one vascular emergency. Distribution - by age: 1.8% <18 years old, 85% 18-64 years old and 13.2%>65 years old; by sex: 43.8% female, 56.2% male. Blood group distribution: 54% are 0.35% A, 8% B and 2% AB. The highest immunological risk group: 18%, who aspire to be retransplanted, 1.4% hyperimmunized. There are 26.5% with positive HLA antibody screening, see table and distribution in graphs. Conclusions: A single national protocol is applied at the inclusion on the WL. In the renal WL, the adult population (18 to 65 years old), blood group 0, with a male/female ratio of 1.3 prevails. The immune risk group does not present significant changes with respect to previous evaluations. The prevalence of sensitized to both classes and hyperimmunized is maintained.

Diagnosis of Statin-Induced Necrotizing Myopathy: Contribution of Anti-HMGCR Antibodies

Over the last few years, several cases of statin-induced necrotizing myopathy have been described. This myopathy is characterized by the necrosis of muscle fibers and the presence of anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) antibodies. Although the diagnosis of myopathies relies on muscle biopsy, which is considered the gold-standard, the search for autoantibodies has proved to be an essential contribution to the diagnosis of immune-mediated myopathies. The detection of anti-HMGCR antibodies in the patient's serum can be performed by enzyme immunoassays, and more recently, by imunofluorescence. As for the latter, the detection of anti-HMGCR antibodies is performed on tissue sections by indirect immunofluorescence and is characterized by a typical fluorescence pattern called "HMGCR Associated Liver IFL Pattern". The authors present two case reports that show the importance of diagnosing statin-induced necrotizing myopathy as quickly as possible and the contribution of anti-HMGCR antibody detection for the diagnosis.

Autoantibodies in the diagnostic work-up of neuropathy: clinically useful or purely academic?

The search for autoantibodies in patients with acute and chronic neuropathies has become widespread in neurological practice. These tests are more routinely available and, therefore, are more commonly requested in larger hospitals with neuroscience centres. However, the clinical value of these frequently expensive tests is often unclear, and their impact on management not always obviously beneficial. This article reviews the main immunological tests used to search for specific autoantibodies in the setting of neuropathy.

Macrophages and Autoantibodies in Demyelinating Diseases.

Myelin phagocytosis by macrophages has been an essential feature of demyelinating diseases in the central and peripheral nervous systems, including Guillain–Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), and multiple sclerosis (MS). The discovery of autoantibodies, including anti-ganglioside GM1 antibodies in the axonal form of GBS, anti-neurofascin 155 and anti-contactin 1 antibodies in typical and distal forms of CIDP, and anti-aquaporin 4 antibodies in neuromyelitis optica, contributed to the understanding of the disease process in a subpopulation of patients conventionally diagnosed with demyelinating diseases. However, patients with these antibodies are now considered to have independent disease entities, including acute motor axonal neuropathy, nodopathy or paranodopathy, and neuromyelitis optica spectrum disorder, because primary lesions in these diseases are distinct from those in conventional demyelinating diseases. Therefore, the mechanisms underlying demyelination caused by macrophages remain unclear. Electron microscopy studies revealed that macrophages destroy myelin as if they are the principal players in the demyelination process. Recent studies suggest that macrophages seem to select specific sites of myelinated fibers, including the nodes of Ranvier, paranodes, and internodes, for the initiation of demyelination in individual cases, indicating that specific components localized to these sites play an important role in the behavior of macrophages that initiate myelin phagocytosis. Along with the search for autoantibodies, the ultrastructural characterization of myelin phagocytosis by macrophages is a crucial step in understanding the pathophysiology of demyelinating diseases and for the future development of targeted therapies.

Autoantibodies in the diagnostic work-up of neuropathy: clinically useful or purely academic?

The search for autoantibodies in patients with acute and chronic neuropathies has become widespread in neurological practice. These tests are more routinely available and therefore are more commonly requested in larger hospitals with neuroscience centres, although they are now also regularly requested from district general hospital settings, including by non-neurologists. However, the clinical value of these frequently expensive tests is often unclear and their impact on management not always obviously beneficial. This article reviews the main immunological tests used to search for specific autoantibodies in the setting of neuropathy and discusses their potential diagnostic importance, together with the eventual therapeutic implications of results obtained.

Ultrastructural mechanisms of macrophage-induced demyelination in CIDP.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a form of chronic neuropathy that is presumably caused by heterogeneous immune-mediated processes. Recent advances in the search for autoantibodies against components expressed at nodal regions, such as the nodes of Ranvier and paranodes, have substantially contributed to clarifying the pathogenesis of CIDP in a subpopulation of patients. In particular, immunoglobulin G4 (IgG4) antibodies to paranodal junction proteins, including neurofascin-155 and contactin-1, have attracted the attention of researchers. Paranodal dissection resulting from the attachment of IgG4 at paranodal junctions and the absence of macrophage-induced demyelination are characteristic pathologic features in patients who have these antibodies. By contrast, the mechanisms of neuropathy in cases with classical macrophage-induced demyelination remain unclear despite the long-standing recognition of this process in CIDP. In addition to complement-dependent damage provoked by autoantibodies, recent studies have shed light on antibody-dependent phagocytosis by macrophages without participation of complements. However, a direct association between specific autoantibodies and macrophage-induced demyelination has not been reported. Electron microscopic examination of longitudinal sections of sural nerve biopsy specimens suggested that macrophages recognize specific sites of myelinated fibers as the initial target of demyelination. The site that macrophages select to initiate myelin breakdown is located around the nodal regions in some patients and internode in others. Hence, it seems that the components that distinguish between the nodal regions and internode play a pivotal role in the behavior of macrophages that initiate phagocytosis of myelin. Further studies are needed to elucidate the mechanisms underlying macrophage-induced demyelination from this perspective.

Deciphering the mechanism and spectrum of chronic inflammatory demyelinating polyneuropathy using morphology

AbstractChronic inflammatory demyelinating polyneuropathy (CIDP) is a form of chronic neuropathy characterized by demyelination due to immune‐mediated processes. In addition to the typical form of CIDP, several atypical forms, such as multifocal acquired demyelinating sensory and motor, distal acquired demyelinating symmetric (DADS), pure sensory, pure motor, and focal types, have also been included as subtypes of CIDP, indicating the heterogeneity of pathogenesis. The degradation of the myelin sheath by macrophages has been reported in CIDP and is considered to play an important role in the pathogenesis of this disease. By contrast, recent studies have suggested the association of autoantibodies directed against paranodal junction proteins, such as anti‐neurofascin 155 and anti‐contactin 1 antibodies, with subpopulations of CIDP patients. Although patients with these antibodies tend to manifest typical CIDP or DADS symptoms, such patients show unique clinical characteristics, such as a younger age at onset, sensory ataxia, tremor and poor response to intravenous immunoglobulin treatment. Classical macrophage‐induced demyelination is not observed in patients with these antibodies, whereas paranodal dissection resulting from attachment of immunoglobulin G4 antibodies to paranodal junctions plays a pivotal role in the mechanisms of neuropathy. Therefore, two distinct mechanisms exist that lead to nerve conduction abnormalities from a pathological viewpoint in CIDP. Advances in the search for autoantibodies in CIDP might make it necessary to reconsider the classification of this disease from the viewpoint of antibody recognition sites.

Immunological Changes in Secondary Sjogran Syndrome (Comparative Study)

Objective This study was designed to evaluate the immunological changes and its existence for early diagnosis and proper management of disease. Study Design 56 patients with RA accompanied by sSS where included in this study and compared to 60 RA patients without sSS.Schirmers test, blood tests and search for auto antibodies was done for all patients in both groups. Schirmers, blood tests and search for antinuclear antibody was done for all patients in both groups, with the measurement of salivary flow rate. Results Schirmers test was positive in all sSS and negative in all RA patients, whilst salivary flow rate was reduced in all sSS. Latex fixation test, ANA, Anti Ro and Anti La were reported significantly higher in sSS (p<0.01) Conclusions Secondary Sjogrens syndrome had a significantly positive rheumatoid factor, antinuclear antibody, anti Ro (SS-A) and anti La (SS-B) compared to rheumatoid patients without Sjogrens syndrome.

Circulating Autoantibodies and Autoimmune Comorbidities in Vitiligo Patients: A Multicenter Italian Study

Background: Autoimmune comorbidities and circulating autoantibodies have been observed in vitiligo patients, but differences in rate are present according to countries in which the studies were performed, perhaps owing to ethnic diversities or different trigger factors. Objective: To estimate the prevalence of circulating autoantibodies and overt autoimmune diseases in a fairly large sample of Italian vitiligo patients. Methods: 175 outpatients affected by vitiligo and referred to nine dermatological centers were included in the study. Patients were offered routine blood test, serological testing for thyroid function and search for autoantibodies. Results: At least one circulating autoantibody was detected in 61 (41.8%) of 146 subjects who underwent laboratory tests. Anti-thyroperoxidase (25.6%), anti-thyroglobulin (23.4%), antinuclear antibodies (16.8%) and anti-gastric parietal cell antibodies (7.8%) were the most noticed autoantibodies. 74 (41.5%) autoimmune comorbidities, mainly autoimmune thyroiditis (37%), were reported. Conclusion: The prevalence of autoimmune comorbidities and circulating autoantibodies in this study was in agreement with other surveys conducted on Caucasian patients.

To look for a needle in a haystack: the search for autoantibodies in multiple sclerosis

The search for autoantibodies in multiple sclerosis (MS) has been challenging for the last 3 decades. With the development of new proteomic methods and advances in expression and assay technologies, progress in the identification of MS autoantibodies has been made. A number of MS-specific autoantibodies have been proposed, most of them targeting proteins expressed in oligodendrocytes and along the myelin sheath. In this review, we summarize the status of antibody research in MS and then discuss recent developments and future strategies in defining and characterizing the potential antigenic targets of autoantibodies in MS.

Autoantibodies and decreased expression of the transcription factor ELF‐3 together with increased chemokine pathways support an autoimmune phenotype and altered differentiation in lichen planus located in oral mucosa

The pathogenesis of oral lichen planus (OLP), a chronic inflammatory disease, is not fully understood. It is known that OLP has autoimmune features, and it is suggested to be an autoimmune disease. ELF-3 is involved in differentiation of keratinocytes and deregulated in different tumours and inflammatory diseases. CXCR-3 and its ligands CXCL-10 and CXCL-11 are increased in autoimmune diseases and linked to Th-1 immune response. To analyse and compare expression of ELF-3, CXCR-3, CXCL-10 and CXCL-11 in OLP lesions and controls in whole and microdissected epithelium. Tissue biopsies from 20 patients clinically and histologically diagnosed with OLP and 20 healthy controls were studied using whole tissues or microdissected epithelium. By the use of qRT-PCR, mRNA levels of ELF-3, CXCR-3, CXCL-10 and CXCL-11 were studied. Western blot was used for analysis of ELF-3 protein expression. Sera from 19 OLP patients and 20 controls were analysed with ELISA in search for autoantibodies. Results The upregulation of CXCR-3, CXCL-10 and CXCL-11 found in OLP is similar to previous findings showing an autoimmune phenotype in lichen planus (LP) and lichen sclerosus. Decreased expression of the differentiation-related transcription factor ELF-3 was also seen in OLP lesions, and we further demonstrate presence of circulating autoantibodies against the ELF-3 protein in sera from 3 of 19 (16%) LP patients tested. On the basis of these findings, we confirm that OLP shows features of an autoimmune disease and suggest deregulated differentiation of keratinocytes to be one of the causes of the disease phenotype.

The search for autoantibodies against elastin, collagen and decorin in COPD

To the Editors: Several studies indicate that an autoimmune response may underlie the pathogenesis of chronic obstructive pulmonary disease (COPD). A high prevalence of anti-Hep-2 epithelial cell autoantibodies has been shown in patients with COPD 1, 2, as well as autoantibodies against airway epithelial cells 1, endothelial cells 3, lung elastin 4, several immunogenic peptides 5 and cytokeratin 18 6. The most convincing evidence for an autoimmune response in COPD was provided by Lee et al. 4. They showed a specific autoantibody and a specific T-cell response against elastin in COPD patients, as well as increased numbers of anti-elastin antibody-producing cells in the lungs of COPD patients. Recent studies 7, 8, however, could not confirm such an anti-elastin autoantibody response. Cottin et al. 7 found no evidence for an anti-elastin autoantibody response in patients with combined pulmonary fibrosis and emphysema. Additionally, Greene et al. 8 investigated the presence of autoantibodies against elastin- and collagen-derived proline–glycine–proline in patients with COPD and α1-antitrypsin deficiency, and also did not observe increased autoantibody levels. We assessed the presence of autoantibodies against elastin, collagen and decorin in serum of COPD patients and healthy controls. In addition, and as an extension of previous studies, we included equal numbers of current, ex- and never-smokers, in order to investigate the effect of the smoking status on autoantibody levels. We chose to asses autoantibodies against elastin and collagen to confirm the previous results of Lee et al. 4 in two different patient groups. As we previously demonstrated a decreased presence of the extracellular …

Recurrent Autoimmune Pancreatitis in a 10‐Year‐Old Boy

Recurrent Autoimmune Pancreatitis in a 10‐Year‐Old Boy

Association of Complement with Microvascular Endothelial Cell Injury in Thrombotic Microangiopathy In Vivo and in In Vitro Model Systems.

We have previously shown that plasma from patients with idiopathic as well as HIV and thienopyridine-linked TTP induces apoptosis of microvascular endothelial cells (MVEC) in vitro, with specific sparing of large vessel and pulmonary MVEC, consistent with the clinical syndrome. This correlates with in vivo measures of apoptosis in splenic tissue of TTP patients. We found that osteoprotegrin (OPG), an inhibitor of multiple inducers of MVEC apoptosis, could block TTP plasma-mediated MVEC injury. Utilizing OPG affinity-binding columns and MS-TOFI analysis of column eluates, we subsequently identified complement (C) components and C-regulatory factors as potentially involved in TTP plasma-mediated EC injury. Building on the observation that familial TTP syndromes have been linked to genetic deficiencies of the C-regulatory factors Factor H and MCP, and three cases of sporadic HUS in children have been accompanied by autoantibodies to factor H, we hypothesized that the C-system plays an important role in TTP-induced MVEC injury, facilitated by autoantibody-mediated suppression of C-regulatory proteins. To evaluate the role of the complement system we looked at:IFA staining of splenic tissue from TTP patients versus controls for C-components in conjunction with CD34+ indentification of MVEC.ELISA-based assays of complement activation/deposition on MVEC exposed to TTP vs. control plasma.Ability of anti-C agents to block TTP plasma-mediated MVEC apoptosis.DNA microarray analysis of TTP plasma MVEC exposed to TTP vs. control plasma.ELISA-based search for autoantibodies against C-regulatory proteins in TTP plasma.IFA staining demonstrated increased deposition of C-components on MVEC in vivo on splenic tissue of TTP vs. control patients (4/5 TTP, 0/3 control). Increased C-activation was demonstrated on MVEC exposed to plasmas of TTP patients in vitro as evidenced by decreased C3b (p=0.002) and C4d (p=0.0002) deposition. Microarray data revealed increased expression of C-regulatory factors in resistant vs. susceptible MVEC exposed to TTP plasma. C-inhibtion resulted in prevention of TTP-plasma induced MVEC apoptosis by annexin-V staining (P<0.02). The search for autoantibodies against five C-regulatory components: CD46 (MCP), CD55 (DAF), CD59, Factor H, and Factor I by ELISA assay is currently ongoing. In conclusion, the clinical expression of thrombotic microangiopathy likely requires a double-hit of endothelial cell injury and autoantibodies against proteins vital to hemostasis and/or MVEC survival. In some patients this may involve autoantibodies to ADAMTS13; in others, C-system activation and inhibition of C-regulation by C-regulatory protein autoantibodies may be involved. Inhibition of the C-system may be a feasible clinical approach in some patients with thrombotic microangiopathies.

Sarcoid relapse with isolated kidney involvement

A 70-year-old Caucasian male presented with history of systemic symptoms lasting since several weeks including malaise, anorexia, weight loss, and low-grade fever. He had no other significant symptoms or clinical findings, physical examination was unrevealing, and vital parameters were normal. When the patient was 45 yeas old, a diagnosis of pulmonary sarcoid was made upon results of radiologic imaging tests, gallium-67 scanning, and the histological demonstration of non-caseating granulomas at a transbronchial lung biopsy. At that time, all other known causes of granulomatous lung inflammation were ruled out and complete recovery was achieved after 6 months of steroid treatment at tapering doses. Afterwards, he had several episodes of recurrent right flank pain, which were managed conservatively; 10 months before admission lithotripsy was performed and calcium oxalate urinary stones recovered. At that time, serum creatinine was 2.1 mg/dl (normal range 0.5-1.2 mg/dl), urea was 72 mg/dl (normal range 10-50 mg/dl), and calcium was 12.4 mg/dl (normal range 8.1-10.4 mg/dl). Follow-up laboratory results until 1 month before presentation revealed persistent mild hypercalcaemia, with calcium blood levels ranging from 10.6 to 11.2 mg/dl, and stable serum creatinine and urea levels; the other variables remained within normal ranges on each occasion. There was no personal and family history of hypertension or any other cardiovascular, metabolic or systemic disorders, and the patient denied alcohol use, toxic habits, or taking any other medications, including over-the-counter medications, or herbal remedies. On admission, laboratory analyses showed renal impairment with a glomerular filtration rate of 14 ml/min; serum creatinine was 4.1 mg/dl, urea was 106 mg/dl, and calcium was 14.4 mg/dl. Electrolytes, a complete blood count, uric acid, cholesterol, triglycerides, protein, amylase and lipase, liver function tests, intact parathyroid hormone, and the coagulation profile were all normal; the erythrocyte sedimentation rate was 50 mm/h. Urinalysis showed a pH of 6.5, a specific gravity of 1012, and the urine tested positive for occult blood; there were between 5 and 10 red cells and calcium oxalate crystals per high-power field with no white cells, casts, or bacteria. Cultures grew no pathogens and the 24h urinary protein excretion was < 500 mg. Complement was normal and search for autoantibodies, including antinuclear, antiphospholipid, and antineutrophil cytoplasmic antibodies, rheumatoid factor, cryoglobulins, and lupus anticoagulant was also negative; blood levels of angiotensin-converting enzyme (ACE) were not measured at this time. An electrocardiogram did not show any abnormalities and a chest

Pneumopathies infiltrantes diffuses : les auto-anticorps en pratique clinique

The clinical, computed tomography, cytological, and histological aspects of interstitial lung disease complicating an autoimmune disease lack specificity. Search for autoantibodies in the serum is thus warranted once the essentially clinical diagnosis has been established. An exhaustive history taking should aim at identifying extrathoracic elements of a possible systemic autoimmune disease. The battery of the biological tests which can be useful are discussed here in light of the diagnostic, prognostic, therapeutic, and even conceptual aspects of the disease. For the clinician, a simplified analysis of the main methods and the interpretation of immunological tests is discussed together with new tools currently under development.

Troubles psychiatriques itératifs révélateurs d’un lupus érythémateux disséminé

There is a wide range of non-specific symptoms that can reveal neurolupus, sometimes making diagnosis difficult. A 29-year-old man presented, from 1996 to 2002, three episodes of mood disorders with hetero-aggression, preceded by seizures, which resolved completely. Repeated investigations were negative except for lymphopenia, an inflammatory cerebrospinal fluid and some rare non-specific areas of high intensity signals in the white matter on the brain MRI. After a six-year course, the patient was considered to have a severe mood disorder related to a schizoid personality. A new dot-blot search for antinuclear antibodies detected anti-Sm antibodies was positive, leading to the diagnosis of neuropsychiatric lupus since the patient's symptoms fulfilling four of the American Rheumatism Association criteria (neuropsychiatric events, lymphopenia, antinuclear and anti-Sm antibodies). The patient was given monthly pulses of cyclophosphamide and remained symptom free one year after the last flare up. Lupus can rarely be revealed by long-standing isolated psychiatric disorders. Search for auto-antibodies, using highly specialized techniques (western blot, dot blot) should be a routine practice since antibody titres fluctuate during the course of the disease; elevated titres may correlate with exacerbations. Considering the prominence and severity of these behavior disorders, systemic diseases may often be misdiagnosed.

Search for autoantibodies against the HNK-1 carbohydrate epitope in the human eye in intermediate uveitis.

Molecules bearing the immunogenic HNK-1 epitope are present in the inner connective tissue layer and epithelia of the ciliary body. We investigated whether autoantibodies to these molecules can be detected in patients with intermediate uveitis, which affects the ciliary body. Serum was collected from 9 patients with intermediate uveitis, and from 6 controls with idiopathic iritis and 3 controls with sarcoid uveitis, representing nongranulomatous and granulomatous uveitis, respectively. The sera were used as polyclonal antibodies to immunostain 3 formalin-fixed, paraffin-embedded normal human donor eyes by the avidin-biotinylated peroxidase complex method. No immunostaining in the ciliary body could be detected using the sera from patients with intermediate uveitis or from the controls. Serum within blood vessels was nonspecifically immunolabelled with the secondary anti-human anti-serum. No autoantibodies against the HNK-1 epitope or other antigens of the ciliary body could be demonstrated in patients with intermediate uveitis. It is unlikely that such autoantibodies against the HNK-1 epitope have a role in intermediate uveitis.

A Search for Autoantibodies to Thrombomodulin in Patients with Documented Thrombosis

A Search for Autoantibodies to Thrombomodulin in Patients with Documented Thrombosis