Advances in physiopathology of rheumatoid arthritis: Time for a new theory? [Avances sobre la fisiopatogenia de la artritis reumatoide, ¿Tiempo para una nueva teoría?]

[No abstract available

POTENCOR: A program to calculate power and correlation spectra of EEG signals

The use of biomarkers as tools to evaluate genotoxicity is increasing recently. Methods that have been used previously to evaluate genomic instability are frequently expensive, complicated, and invasive. The micronuclei (MN) and nuclear abnormalities (NA) technique in buccal cells offers a great opportunity to evaluate in a clear and precise way the appearance of genetic damage whether it is present as a consequence of occupational or environmental risk. This technique is reliable, fast, relatively simple, cheap, and minimally invasive and causes no pain. So, it is well accepted by patients; it can also be used to assess the genotoxic effect derived from drug use or as a result of having a chronic disease. Furthermore the beneficial effects derived from changes in life style or taking additional supplements can also be evaluated. In the present paper, we aim to focus on the explanation of MN test and its usefulness as a biomarker; we further give details about procedures to perform and interpret the results of the test and review some factors that could have an influence on the results of the technique. " 2014 Olivia Torres-Bugarín et al.",,,,,,"10.1155/2014/956835",,,"http://hdl.handle.net/20.500.12104/43773","http://www.scopus.com/inward/record.url?eid=2-s2.0-84896944641&partnerID=40&md5=db9d0fb5d5eb58b072bf2b6c405ae84

The clinical significance of posttranslational modification of autoantigens

Posttranslational modifications (PTMs) are defined as covalent modifications occurring in a specific protein amino acid in a time- and signal-dependent manner. Under physiological conditions, proteins are posttranslationally modified to carry out a large number of cellular events from cell signaling to DNA replication. However, an absence, deficiency, or excess in PTMs of a given protein can evolve into a target to trigger autoimmunity, since PTMs arise in the periphery and may not occur in the thymus; hence, proteins with PTMs never tolerize developing thymocytes. Consequently, when PTMs arise during cellular responses, such as inflammation, these modified self-antigens can be taken up and processed by the antigen-presenting cells (APCs). Autoreactive T cells, which recognize peptides presented by APCs, can then infiltrate into host tissue where the modified antigen serves to amplify the autoimmune response, eventually leading to autoimmune pathology. Furthermore, a PTM occurring in an amino acid residue can induce changes in the net charge of the protein, leading to conformational modifications in the tertiary and quaternary structure of the protein, especially interaction with human leukocyte antigen (HLA) molecules. Molecular mimicry (MM) was until now the prevailing hypothesis explaining generation of autoimmunity; nevertheless, experimental animal models need inflammation via infection or other immunogens to ensure autoimmunity; MM alone is not sufficient to develop autoimmunity. PTMs could arise as an additive factor to MM, which is required to start an autoimmune response. PTMs have been found to be present in different pathologic conditions such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), antiphospholipid syndrome, and primary biliary cirrhosis. The aim of the present review is to expose protein posttranslational modifications and the evidence suggesting their role in the generation of autoimmunity. � 2014 Springer Science+Business Media

Serum IgG activity against cyclic citrullinated peptide in patients evaluated for rheumatoid factor correlates with the IgM isotype

The purpose of this study was to evaluate the frequency of seric antibodies against cyclic citrullinated peptide (a-CCP) in patients tested for rheumatoid factor (RF) reactivity, and to analyze the correlation between their titers. We obtained serum from 112 consecutive patients (85 female), aged 47.2 � 13.4 years and from 46 clinically healthy subjects (CHS). Patients where stratified into four subgroups: rheumatoid arthritis (RA), probable RA (PRA), spondylarthropathies and other diagnosis. The a-CCP antibodies were determined by enzyme linked immunoassay (ELISA), RF by nephelometric test (IgM) and ELISA (IgG and IgM). Analysis of variance (ANOVA) showed statistically that a-CCP antibodies differs among RA versus CHS and other diagnosis; PRA versus CHS and other diagnosis. A significant Rho value of 0.84 (P < 0.05, Spearman's correlation) was identified between a-CCP antibodies and RF in PRA subgroup. When a correlation of a-CCP antibodies with RF (both isotypes) was done, the higher correlation was observed against IgM RF. The data suggests different pathways and times for each antibody generation. � 2008 Springer-Verlag

Anti-cyclic citrullinated peptide antibodies and rheumatoid factor sera titers in leprosy patients from Mexico

Leprosy offers a broad spectrum of altered immunological sceneries, ranging from strong cell-mediated immune responses seen in tuberculoid leprosy (TT), through borderline leprosy (BB), to the virtual absence of T cell responses characteristic in lepromatous leprosy (LL). The exact mechanism of autoantibodies production remains unknown in leprosy and other chronic inflammatory diseases and also the contribution of these antibodies to the pathogenesis of the disease. The aim of this study is to evaluate the frequency and profiles of serum anti-cyclic citrullinated peptide antibodies (a-CCP), rheumatoid factor (RF) and its relationship with leprosy spectrum. Serum samples from 67 leprosy patients (54 LL, 5 TT and 8 BB) and 46 clinically healthy subjects (CHS) from the same endemic region were investigated. The clinical chart and questionnaire were used to obtain clinical information. Anti-cyclic citrullinated peptide antibodies (a-CCP) were measured by enzyme-linked immunosorbent assay, whereas the rheumatoid factor (RF) levels were measured by nephelometric method. The mean age of patients was 51.5 Zapotitlán 13 years. Sera levels of a-CCP where higher in leprosy patients than in CHS (5.9 Zapotitlán 11.6 vs. 0.3 Zapotitlán 0.29) (P<0.0001); the same pattern was found for RF sera titers without reaching statistical significance (16.8 Zapotitlán 22.5 vs. 9.9 Zapotitlán 3) (P = NS). We did not find a correlation between a-CCP and RF Rho =0.02786 (IC 95%) P = 0.8229. However, LL patients had higher a-CCP and RF levels than TT patients. Although an absence in correlation was observed, the serum levels of a-CCP antibodies and RF appeared to be useful in distinguishing LL from TT patients with a limited significance in detecting reactional leprosy patients. Zapotitlán Springer-Verlag 2011

Wide clinical spectrum in Zimmermann-Laband syndrome

Gingival fibromatosis can be present as an isolated form or be part of a genetic disease. The Zimmermann-Laband syndrome (ZLS) is a rare disorder inherited as an autosomal dominant fashion, clinically characterized by gingival fibromatosis, bulbous soft nose, thick floppy ears, nail dysplasia, joint hyperextensibility, hepatosplenomegaly, skeletal anomalies and occasional mental retardation. We studied a girl aged five years with clinical and radiological features of the ZLS, additionally she presented deafness not previously described in the ZLS, as only partial hearing loss was reported in some patients. The father presented some facial features suggestive of ZLS, nevertheless he did not have gingival fibromatosis or hypertrichosis. We suggest that this case supports that ZLS can be part a contiguous genes syndrome or be consequence of a gene mutation with wide variable expression. The present report supports that ZLS has a wide clinical spectrum

Wide clinical spectrum in Zimmermann-Laband syndrome

Gingival fibromatosis can be present as an isolated form or be part of a genetic disease. The Zimmermann-Laband syndrome (ZLS) is a rare disorder inherited as an autosomal dominant fashion, clinically characterized by gingival fibromatosis, bulbous soft nose, thick floppy ears, nail dysplasia, joint hyperextensibility, hepatosplenomegaly, skeletal anomalies and occasional mental retardation. We studied a girl aged five years with clinical and radiological features of the ZLS, additionally she presented deafness not previously described in the ZLS, as only partial hearing loss was reported in some patients. The father presented some facial features suggestive of ZLS, nevertheless he did not have gingival fibromatosis or hypertrichosis. We suggest that this case supports that ZLS can be part a contiguous genes syndrome or be consequence of a gene mutation with wide variable expression. The present report supports that ZLS has a wide clinical spectrum

PADI4 haplotypes in association with RA Mexican patients, a new prospect for antigen modulation.

Peptidyl arginine deiminase IV (PAD 4) is the responsible enzyme for a posttranslational modification called citrullination, originating the antigenic determinant recognized by anti-cyclic citrullinated peptide antibodies (ACPA). Four SNPs (single nucleotide polymorphisms) have been described in PADI4 gene to form a susceptibility haplotype for rheumatoid arthritis (RA); nevertheless, results in association studies appear contradictory in different populations. The aim of the study was to analyze if the presence of three SNPs in PADI4 gene susceptibility haplotype (GTG) is associated with ACPA positivity in patients with RA. This was a cross-sectional study that included 86 RA patients and 98 healthy controls. Polymorphisms PADI4_89, PADI4_90, and PADI4_92 in the PADI4 gene were genotyped. The susceptibility haplotype (GTG) was more frequent in RA patients; interestingly, we found a new haplotype associated with RA with a higher frequency (GTC). There were no associations between polymorphisms and high scores in Spanish HAQ-DI and DAS-28, but we did find an association between RARBIS index and PADI4_89, PADI4_90 polymorphisms. We could not confirm an association between susceptibility haplotype presence and ACPA positivity. Further evidence about proteomic expression of this gene will determine its participation in antigenic generation and autoimmunity

PADI4 haplotypes in association with RA Mexican patients, a new prospect for antigen modulation.

Peptidyl arginine deiminase IV (PAD 4) is the responsible enzyme for a posttranslational modification called citrullination, originating the antigenic determinant recognized by anti-cyclic citrullinated peptide antibodies (ACPA). Four SNPs (single nucleotide polymorphisms) have been described in PADI4 gene to form a susceptibility haplotype for rheumatoid arthritis (RA); nevertheless, results in association studies appear contradictory in different populations. The aim of the study was to analyze if the presence of three SNPs in PADI4 gene susceptibility haplotype (GTG) is associated with ACPA positivity in patients with RA. This was a cross-sectional study that included 86 RA patients and 98 healthy controls. Polymorphisms PADI4_89, PADI4_90, and PADI4_92 in the PADI4 gene were genotyped. The susceptibility haplotype (GTG) was more frequent in RA patients; interestingly, we found a new haplotype associated with RA with a higher frequency (GTC). There were no associations between polymorphisms and high scores in Spanish HAQ-DI and DAS-28, but we did find an association between RARBIS index and PADI4_89, PADI4_90 polymorphisms. We could not confirm an association between susceptibility haplotype presence and ACPA positivity. Further evidence about proteomic expression of this gene will determine its participation in antigenic generation and autoimmunity