Autoimmune predisposition in Down syndrome may result from a partial central tolerance failure due to insufficient intrathymic expression of AIRE and peripheral antigens.

Down syndrome (DS), or trisomy of chromosome 21, is the most common genetic disorder associated with autoimmune diseases. Autoimmune regulator protein (AIRE), a transcription factor located on chromosome 21, plays a crucial role in autoimmunity by regulating promiscuous gene expression (pGE). To investigate if autoimmunity in DS is promoted by the reduction of pGE owing to dysregulation of AIRE, we assessed the expression of AIRE and of several peripheral tissue-restricted Ag genes by quantitative PCR in thymus samples from 19 DS subjects and 21 euploid controls. Strikingly, despite the 21 trisomy, AIRE expression was significantly reduced by 2-fold in DS thymuses compared with controls, which was also confirmed by fluorescent microscopy. Allele-specific quantification of intrathymic AIRE showed that despite its lower expression, the three copies are expressed. More importantly, decreased expression of AIRE was accompanied by a reduction of pGE because expression of tissue-restricted Ags, CHRNA1, GAD1, PLP1, KLK3, SAG, TG, and TSHR, was reduced. Of interest, thyroid dysfunction (10 cases of hypothyroidism and 1 of Graves disease) developed in 11 of 19 (57.9%) of the DS individuals and in none of the 21 controls. The thymuses of these DS individuals contained significantly lower levels of AIRE and thyroglobulin, to which tolerance is typically lost in autoimmune thyroiditis leading to hypothyroidism. Our findings provide strong evidence for the fundamental role of AIRE and pGE, namely, central tolerance, in the predisposition to autoimmunity of DS individuals.

Clinical perspective in relation to age in patients treated with thrombectomy for anterior circulation stroke in a stroke center in Colombia.

BACKGROUND AND AIMS: Endovascular treatment for cerebrovascular disease is accepted as a first-line option with level I evidence in patients with an early and late time of window of onset symptoms, and an additional option in patients who do not respond or with contraindications to systemic thrombolysis; nevertheless the efficacy and outcomes of some groups were not clear, one of them are patients aged 80 years and older, because they were excluded of the trials, so the evidence is controversial with significant heterogeneity, for that reason in our study, we decided to analyze the age in the patients treated in our stroke center, as a predictor of prognosis, and to provide a baseline for the establishment of personalized treatment plans. METHODS: Observational, retrospective study of patients that received endovascular treatment for cerebrovascular disease in a Colombian stroke center between 2016 and 2020, continuous and categorical variables were compared using the Student's t test and Chi-Square. To determine cut-off points in the variable against death and Rankin score variable on 90th day. RESULTS: In total, 108 patients were recruited, 35 of them were of 80 or more years, and the mean age was 72.7 years, we found age as a significant variable to predict the risk in the population over 80 years of age [RR 3.37 CI (95% 1.14-103) p = 0.029]. CONCLUSIONS: Age younger than 80 is a significant predictor for results and long-term outcomes in patients suffering from stroke, and in patients older than 80 years old a Thrombolysis in Cerebral Infarction score 2b-3 is a predictor of good outcomes. Further studies are needed to evaluate the relationship between intrahospital complications and long-term outcomes.

Immunogenetics of primary Sjögren's syndrome in Colombians.

OBJECTIVE: Data concerning the immunogenetic characteristics of primary Sjogren's syndrome (SS) in Latin-Americans are scarce. A research project centered on primary SS in Colombians was initiated in January 1996 to better define these characteristics. METHODS: TAP, HLA, IL-10, and microsatellites on 6p21.3 genotyping was performed by polymerase chain reaction techniques. Immunohistochemistry for Bcl-2 antagonist/killer (Bak) was performed. Autoantibodies and serum level of cytokines (IL-10, TNF-alpha, IFN-gamma, IL-4, and IL-12p70) were determined by enzyme-linked immunosorbent assay. RESULTS: The HLA-DRB1*0301-DQB1*0201 haplotype was associated with disease (OR = 4.3, 95% CI: 1.6 to 11.9, P = 0.002), with a more severe histopathologic picture, and with the presence of anti-Ro and anti-La antibodies. D6S439 microsatellite polymorphism was associated with primary SS in an HLA-independent manner. The most likely gene related to the D6S439 chromosomal location appears to be BAK-1 , which codes for Bak protein, expressed in salivary gland's infiltrate from patients with primary SS but not in controls. IL-10 and IFN-gamma concentrations were significantly higher in patients than in controls ( P < 0.01). IL-10 correlated with titers of IgA rheumatoid factor, anti-Ro, and anti-La antibodies, and with the severity of lymphocytic infiltrate (r > 0.3, P < 0.04). Patients who produced high IL-10 levels had significantly more episodes of cutaneous vasculitis and a higher proportion the IL-10.G9 allele. CONCLUSIONS: The HLA-DRB1*0301-DQB1*0201 haplotype and IL-10 participate in the histopathological progression of SS, autoantibody production, and clinical manifestations. Bak protein and its gene polymorphism may participate in the pathology and susceptibility of disease. HLA and cytokine (IL-10 and IFN-gamma) manipulation may be helpful in treating patients with primary SS.

TAP, HLA-DQB1, and HLA-DRB1 polymorphism in Colombian patients with primary Sjögren's syndrome.

OBJECTIVE: Although primary Sjögren's syndrome (pSS) has a worldwide distribution, little data is available on pSS immunogenetics in non-white populations. Thus, we investigated the influence of transporters associated with antigen processing (TAP), human leukocyte antigen (HLA)-DQB1, and HLA-DRB1 gene polymorphism in mestizo Colombian patients with pSS. METHODS: In this cross-sectional and controlled study, all patients met the European criteria for classification of pSS. TAP and HLA typing was performed by polymerase chain reaction techniques. Genetic data analysis was performed to detect deviations from the expected Hardy-Weinberg (H-W) proportions and to determine the presence of population stratification or subdivision and the existence of linkage disequilibrium between pairs of loci. RESULTS: Seventy-three Colombian patients with pSS (95% women) and 76 healthy controls were studied. Although significant associations were not observed between TAP or HLA polymorphism and disease, strong linkage disequilibrium among the loci TAP2 and DQB1 was found in patients. Deviations from the H-W expected value were found in the DQB1 locus of patients (P =.02). HLA-DRB1*0301-DQB1*0201 haplotype was associated with more severe histopathologic disease (odds ratio [OR], 15.5; 95% confidence interval [CI], 1.9-129; P =.001) and the presence of anti-Ro (OR, 3.8; 95% CI, 1-15; P =.04) and anti-La antibodies (OR, 4.3; 95% CI, 1.3-14; P =.01). CONCLUSION: The data show genetic evidence suggesting that, in Colombians, a region immersed or in the vicinity in the HLA class II system is strongly associated with a predisposition to acquire pSS, which is probably located between the TAP2 and HLA-DQB1 locus. Our results confirm that the HLA-DRB1*0301-DQB1*0201 haplotype participates in the pathogenesis of pSS.

Th1/Th2 cytokines in patients with systemic lupus erythematosus: is tumor necrosis factor alpha protective?

OBJECTIVES: To determine the circulating levels of Th1 and Th2 cytokines in patients with systemic lupus erythematosus (SLE) and to elucidate their association with disease activity and autoimmune response. METHODS: We included 52 patients and 25 healthy controls. Serum levels of tumor necrosis factor (TNF) alpha, interferon (IFN) gamma, interleukin (IL)-12p70, IL-10, and IL-4, as well as anti-DNA, -Ro, -La, -RNP, and -Sm antibodies were determined by enzyme-linked immunosorbent assay. Disease activity was recorded according to the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and classified as very active (SLEDAI > or = 13), moderately active (SLEDAI: 3-12), or inactive (SLEDAI < or = 2). RESULTS: The mean age of the patients was 34.2 +/- 12.6 years, and the mean duration of disease was 4.9 +/- 7.6 years. Twelve patients (23%), 20 patients (34.5%), and 20 patients (34.5%) had highly, moderately, and inactive SLE, respectively. Levels of IFN-gamma, TNF-alpha, and IL-12 were significantly higher in patients than in healthy controls (P <.03), as well as the IL-12/IL-10, IL-12/IL-4, IFN/IL-10, IFN/IL-4, TNF/IL-10, and TNF/IL-4 ratios (P <.01), suggesting a major participation of Th1 over Th2 cytokines. Nevertheless, a direct correlation between Th1 (IFN-gamma and TNF-alpha) and Th2 (IL-4 and IL-10) cytokines was observed in patients (r >.5, P <.01), indicating a mutual Th1-Th2 participation. TNF-alpha levels and the TNF/IL-10 ratio were higher in patients with inactive disease compared with patients with very active disease and controls (P <.04). IL-12 levels and IL-12/IL-4, as well as IL-12/IL-10, ratios were higher in patients with very active disease than in those with inactive SLE and controls (P <.01). IL-10 levels were associated with anti-DNA, anti-Ro, and anti-La response (P <.01). CONCLUSION: Our results suggest that TNF-alpha could be a protective factor in SLE patients, whereas IL-12p70 participates in disease activity and IL-10 influences the autoimmune response (autoantibody production).

[Polymorphism of TNF-alpha in autoimmunity and tuberculosis]. / Polimorfismo del TNF-alpha en autoinmunidad y tuberculosis.

Tumor necrosis factor alpha (TNF-alpha) has been incriminated in several autoimmune and infectious diseases. The influence of TNF-alpha -308 polymorphism was examined in patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), primary Sjögren's syndrome (pSS) and tuberculosis. Genomic DNA from patients with RA (N=165), SLE (N=118), pSS (N=67), tuberculosis (N=138), as well as ethnic-matched controls (N=419) were characterized for the TNF-alpha -308 genetic polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. TNF2 allele was associated with RA (OR: 1.6, C.I.95% 1.2-2.3, p=0.008), SLE (OR: 2.3, 95%C.I. 1.6-3.3, p<0.0001), and pSS (OR: 2.7, 95%C.I. 1.7-4.1, p<0.0001). TNF1 was associated with tuberculosis (OR: 1.9, 95%C.I. 1.2-3.1, p=0.02). TNF1/TNF2 heterozygosity was associated with susceptibility for RA (OR: 1.7, 95%C.I. 1.2-2.6, p=0.01), SLE (OR: 3, 95%C.I. 2-4.7, p<0.0001), and pSS (OR: 3.8, 95%C.I. 2.2-6.5, p<0.0001). The homozygous state TNF1/TNF1 was protective for autoimmunity (OR<0.6, p<0.01). In contrast, the TNF1/TNF2 genotype was a protective factor for tuberculosis (OR 0.5, 95%C.I. 0.3-0.9, p=0.02) whereas TNF1/TNF1 homozygosity was associated with susceptibility (OR: 2, 95%C.I. 1.2-3.4, p=0.02). These results indicate that TNF2 is a common susceptibility allele for autoimmune rheumatic diseases and a protective one for tuberculosis. In addition, the data point towards a genetic selection in our population that might be maintained through dominant selection (heterozygote advantage) to infection by M. tuberculosis but susceptible to autoimmunity.

[Anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis: relation with clinical features, cytokines and HLA-DRB1]. / Anticuerpos anti-CCP en artritis reumatoidea: relación con características clínicas, citocinas Th1/Th2 y HLA-DRB1.

The specificity and sensitivity of anti-cyclic citrullinated peptide antibodies (anti-CCP) was examined in Latin-American patients with rheumatoid arthritis (RA). The variables considered included: 1) relation with the activity of disease, 2) extra-articular manifestations (EAM), 3) synthesis of cytokines (IL-4, IL-10, IL-12, TNF-alpha, and IFN-gamma) and IgM and IgA rheumatoid factor (RF), and 4) the association with HLA-DRB1 polymorphism. Seventy-nine RA patients were assessed (69 with established RA, and 10 with recent-onset RA not receiving any treatment), 56 with ankylosing spondylitis (AS), 25 with systemic lupus erythematosus (SLE), 50 with primary Sjögren's syndrome (pSS), and 10 healthy individuals. Of the 69 patients with established RA, 36 were reexamined 2 years later. The activity of the RA was measured by criteria adopted by the American College of Rheumatology. Anti-CCP2, RF and cytokines levels were determined by ELISA. HLA genotypes were established by first, PCR sequence amplification using sequence-specific primers and then, complete sequencing of the product. Anti-CCP antibodies were observed in 96% of patients with RA during the first evaluation and in 86% at the second evaluation (p = 0.12). No significant change in antibody titre was observed between the two evaluations (131 +/- 58.7 and 130.6 +/- 67.1 IU, respectively). The overall sensitivity and specificity was 94% and 92%, respectively; however, at titres > 60 IU, the values were 84% and 95%, respectively. The anti-CCP likelihood ratio positive test was 12 and the likelihood ratio negative test was 0.06. The positive predictive value was 87%, and the negative predictive value was 96%. Anti-CCP antibodies were observed in 12% of SLE and pSS patients, in 2% of AS patients, and in 10% of healthy controls. In RA patients, these antibodies were not associated with the activity of disease, EAM or HLA-DRB1 alleles; no significant correlation was observed between antibody titre and cytokines level. Although anti-CCP antibodies have potential as a diagnostic tool for RA, they are not useful for monitoring clinical activity or predicting the clinical course of disease. Antibody synthesis is HLA-DRB1 independent and not correlated with Th1/Th2 cytokines.

Autoimmunity and tuberculosis. Opposite association with TNF polymorphism.

OBJECTIVE: To examine the influence of the -308 and -238 single nucleotide polymorphisms (SNP) of tumor necrosis factor-a gene (TNF) on patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), primary Sjogren's syndrome (SS), and tuberculosis (TB). METHODS: Genomic DNA from patients with RA (n = 165), SLE (n = 100), primary SS (n = 67), and TB (n = 135) and ethnically matched controls (n = 430) was genotyped for TNF -308 and -238 SNP by PCR-RFLP. RESULTS: TNF -308A allele was associated with RA (odds ratio, OR 1.8, p = 0.002), SLE (OR 2.6, p < 0.0001), and primary SS (OR 2.9, p < 0.0001). TNF -308G was associated with TB (OR 1.8, p = 0.02). The -308 GG genotype was protective for autoimmunity (p < 0.003). TNF -238A allele was protective for autoimmunity but represented a susceptibility factor for TB (OR 2.2, p < 0.0001). Haplotype -308A-238G was a protective factor against TB, whereas it carried susceptibility for RA, SLE, and primary SS (p < 0.0001). CONCLUSION: The results show an opposite association of TNF polymorphism with autoimmunity and TB, and suggest the existence of heterozygote advantage, sustaining the hypothesis that autoimmune diseases are a consequence of natural selection for enhanced TB resistance. Data also provide genetic evidence supporting the common variants/multiple disease hypothesis, which emphasizes that many disease genes may not be disease-specific, and that similar immunogenetic mechanisms underlie autoimmune diseases.

Interleukin 10 (IL-10) influences autoimmune response in primary Sjögren's syndrome and is linked to IL-10 gene polymorphism.

OBJECTIVE: To investigate the association between serum levels of interleukin 10 (IL-10), the synthesis of autoantibodies, salivary gland disease activity, clinical manifestations, and IL-10 microsatellite polymorphism in patients with primary Sjögren's syndrome (pSS). METHODS: Serum IL-10 and autoantibody levels [IgG anti-Ro and anti-La, total and IgA rheumatoid factor (RF)] were measured by ELISA. A minor salivary gland (MSG) biopsy was performed in all patients and the focus score was determined as a measure of salivary gland disease activity. In addition, IL-10 microsatellite typing was performed by polymerase chain reaction technique. RESULTS: IL-10 concentration was higher in patients (n = 39) than in controls (n = 15) (21.4 +/- 6.7 vs 2.5 +/- 3.5 pg/ml; p = 0.001). We found a significant positive correlation between IL-10 levels and titers of IgA RF, anti-Ro, and anti-La antibodies, as well as focus score. In comparison with patients with low IL-10 production (< 9.5 pg/ml), patients producing high IL-10 had significantly more episodes of cutaneous vasculitis and a higher proportion of them carried the IL-10.G9 allele. CONCLUSION: Autoimmune response in pSS patients as well as salivary gland disease activity and cutaneous involvement appears to be mediated by IL-10 levels; in turn, there is a linkage with IL-10 gene polymorphism.

Endothelial nitric oxide synthase gene polymorphism is associated with systemic lupus erythematosus.

OBJECTIVE: In systemic lupus erythematosus (SLE), endothelial nitric oxide synthase (eNOS) gene locus has been found to be suggestive of linkage with disease, nitric oxide (NO) is produced in significant amounts, and endothelial cell dysfunction is observed. eNOS gene polymorphism may affect both the synthesis of eNOS protein and its enzymatic activity. We examined the influence of eNOS gene polymorphisms on susceptibility to SLE. METHODS: Genomic DNA from 88 Northwestern Colombian women with SLE, as well as 199 controls matched for sex, age, and ethnicity, was genotyped for the -786T -- > C polymorphism in the promoter region, the intron 4 variable number of tandem repeats, and the Glu298Asp polymorphism in exon 7 of the eNOS gene by polymerase chain reaction and restriction fragment length polymorphism techniques. Haplotype and allele frequency comparisons, a Hardy-Weinberg equilibrium test, and linkage disequilibrium (LD) analysis were performed. RESULTS: The intron 4b allele was associated with SLE (OR 2.2, 95% CI 1.29-3.60, pc = 0.005) as was the 4bb genotype (OR 2.9, 95% CI 1.61-5.33, pc = 0.0009), while the 4a allele was protective (OR 0.4, 95% CI 0.26-0.76, pc = 0.005), as was the 4ab genotype (OR 0.29, 95% CI 0.15-0.56, pc < 0.0001). In controls, all loci were in linkage disequilibrium (p < 0.02). In patients, intron 4 was in Hardy-Weinberg disequilibrium, due to an excess of homozygotes (p = 0.01). CONCLUSION: eNOS polymorphism influences SLE predisposition. Since intron 4bb genotype is responsible for higher levels of eNOS synthesis and intron 4 ab genotype is associated with lower synthesis, our results might provide insight into the elevated levels of NO observed in SLE patients.

D6S439 microsatellite identifies a new susceptibility region for primary Sjögren's syndrome.

OBJECTIVE: To examine genetic variations in the region surrounding loci of the major histocompatibility complex, and to investigate the probable location of a new candidate region on the short arm of chromosome 6 predisposing to primary Sjögren's syndrome (SS). METHODS: We conducted an association study and positional candidate gene approach by microsatellite analysis. Five polymorphic microsatellite markers, D6S273, D6S439, D6S1645, D6S291, and DS61019, spanning the region 6p21.3, and establishing particular landmarks to discriminate between the human leukocyte antigen class II and tumor necrosis factor-a loci, were genotyped by polymerase chain reaction technique. RESULTS: A total of 64 patients with primary SS and 120 matched controls were examined. There was no genetic stratification among cases and controls. Genotype distribution analysis disclosed a significantly higher number of homozygotes for D6S439 locus in patients than in controls [odds ratio (OR): 3, 95% confidence interval (CI): 1.46-6.14, p = 0.004]. Confirmation of this homozygosity was established by the gene correlation intra-locus test (Fis value = +0.233, p = 0.0007). Allele D6S439*274 was associated to disease (OR: 3, 95% CI: 1.35-6.65, p = 0.006, pc = 0.04). Among patients, no significant linkage disequilibrium (LD) value was found between the studied microsatellites and TAP, HLA-DRB1, or HLA-DQB1 loci. In controls, there was LD between D6S1645 and D6S291 loci. CONCLUSION: Our results indicate that D6S439 microsatellite defines a new susceptibility region for primary SS, independent of LD with TAP and HLA DQ/DR. These findings might imply that a gene surrounding this location is causally related to the disease.

Bisulfite genomic sequencing to uncover variability in DNA methylation: Optimized protocol applied to human T cell differentiation genes

DNA methylation, which most commonly occurs at the C5 position of cytosines within CpGdinucleotides, is one of several epigenetic mechanisms that cells use to control gene expression. The importance of DNA methylation in a variety of biological processes (i.e., embryonic development, cellular proliferation and differentiation, chromosome stability) has led to a demand for a precise and (..) (AU)

La metilación del ADN es uno de los mecanismos epigenéticos que las células usan para controlar la expresión génica. La metilación del ADN es muy importante en varios procesos biológicos (como en el desarrollo embrionario y en la proliferación y diferenciación celular)y este hecho ha generado la necesidad de desarrollar métodos precisos y (..) (AU)

Polimorfismo del TNF- alfa en autoinmunidad y tuberculosis

El factor de necrosis tumoral alfa (TNF-alfa ) está incriminado tanto en enfermedades autoinmunes como en infecciosas. En el presente estudio se examinó el polimorfismo de la región promotora -308 del gen del TNF-alfa en enfermedades autoinmunes; 091; lupus eritematoso sistémico (LES), artritis reumatoidea (AR), síndrome de Sjögren primario (SSp) 093; ; y en tuberculosis. La genotipificación del polimorfismo -308 del TNF-alfa se realizó en ADN de pacientes con AR (N=165), LES (N=118), SSp (N=67), tuberculosis (N=138) y controles sanos (N=419), mediante reacción en cadena de la polimerasa con polimorfismos en los tamaños de los fragmentos de restricción (PCR-RFLP). El alelo TNF2 se asoció con la AR (OR=1,6; IC95% 1,2-2,3, p=0,008), el LES (OR=2,3; IC95% 1,6-3,3, p<0,0001) y el SSp (OR=2,7; IC95% 1,7-4,1, p<0,0001). El alelo TNF1 se asoció con la tuberculosis (OR=1,9: IC95% 1,2-3,1, p=0,02). La heterocigosis TNF1/TNF2 fue factor de riesgo para AR (OR=1,7; IC95% 1,2-2,6, p=0,01), LES (OR=3; IC95% 2-4,7, p<0,0001) y SSp (OR=3,8; IC95% 2,2-6,5, p<0,0001), mientras que la homocigosis TNF1/TNF1 fue protectora para autoinmunidad (OR<0,6, p<0,01). Por el contrario, el genotipo TNF1/TNF2 fue protector para tuberculosis (OR=0,5; IC95% 0,3-0,9, p=0,02) y la homocigosis TNF1/TNF1 se asoció con susceptibilidad a la misma (OR=2; IC95% 1,2-3,4, p=0,02). Los resultados indican que el alelo TNF2 es un factor común de riesgo para enfermedades autoinmunes reumatológicas pero protector para tuberculosis. Esto sugiere una selección genética en nuestra población.

Polymorphism of TNF - alpha in autoimmunity and tuberculosis Tumor necrosis factor alpha (TNF-alpha ) has been incriminated in several autoimmune and infectious diseases. The influence of TNF-a -308 polymorphism was examined in patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), primary Sjögren's syndrome (pSS) and tuberculosis. Genomic DNA from patients with RA (N=165), SLE (N=118), pSS (N=67), tuberculosis (N=138), as well as ethnic-matched controls (N=419) were characterized for the TNF-a -308 genetic polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. TNF2 allele was associated with RA (OR: 1.6, C.I.95% 1.2-2.3, p=0.008), SLE (OR: 2.3, 95%C.I. 1.6-3.3, p<0.0001), and pSS (OR: 2.7, 95%C.I. 1.7-4.1, p<0.0001). TNF1 was associated with tuberculosis (OR: 1.9, 95%C.I. 1.2-3.1, p=0.02). TNF1/TNF2 heterozygosity was associated with susceptibility for RA (OR: 1.7, 95%C.I. 1.2-2.6, p=0.01), SLE (OR: 3, 95%C.I. 2-4.7, p<0.0001), and pSS (OR: 3.8, 95%C.I. 2.2-6.5, p<0.0001). The homozygous state TNF1/TNF1 was protective for autoimmunity (OR<0.6, p<0.01). In contrast, the TNF1/TNF2 genotype was a protective factor for tuberculosis (OR 0.5, 95%C.I. 0.3-0.9, p= 0.02) whereas TNF1/TNF1 homozygosity was associated with susceptibility (OR: 2, 95%C.I. 1.2-3.4, p=0.02). These results indicate that TNF2 is a common susceptibility allele for autoimmune rheumatic diseases and a protective one for tuberculosis. In addition, the data point towards a genetic selection in our population that might be maintained through dominant selection (heterozygote advantage) to infection by M. tuberculosis but susceptible to autoimmunity.

Anticuerpos anti-CCP en artritis reumatoidea: relación con características clínicas, citocinas Th1/Th2 y HLA-DRB1 / Anti-cyclic citrullinated peptide antibodies in rheumatoid arthritis: relation with clinical features, cytokines and HLA-DRB1

En el presente estudio se examinó la especificidad y la sensibilidad de los anticuerpos antipéptidos citrulinados cíclicos (CCP) en pacientes latinoamericanas con artritis reumatoidea (AR), así como su relación con la actividad de la enfermedad, manifestaciones extraarticulares (MEA), síntesis de citocinas (IL-4, IL-10, IL-12, TNF-µ e IFN-gamma ) y factor reumatoideo (FR) IgM e IgA, y con el polimorfismo del HLA-DRB1. Se examinaron 79 pacientes con AR (69 con AR establecida y 10 con AR temprana sin previo tratamiento), 56 pacientes con espondilitis anquilosante (EA), 25 con lupus eritematoso sistémico (LES), 50 con síndrome de Sjögren primario (SSp) y diez individuos sanos. De las 69 pacientes con AR establecida, 36 fueron reevaluadas 2 años después. La actividad de la AR se examinó según los criterios del Colegio Americano de Reumatología. Los anticuerpos anti-CCP2, el FR y los niveles de citocinas se determinaron mediante inmunoensayo, y la genotipificación del HLA se llevó a cabo por reacción en cadena de la polimerasa utilizando mezclas de iniciadores específicos. Los anticuerpos anti-CCP se observaron en 96% de los pacientes con AR en la primera evaluación y en 86% en la segunda ( p=0,12), sin modificación significativa en los valores (131±58,7 vs. 130,6±67,1 UI). Su sensibilidad y especificidad global fue de 94% y 92%, respectivamente, pero cuando sólo se consideraron los niveles altos (>60 UI) fueron de 84% y 95%, respectivamente. La razón de probabilidades (RP) positiva fue de 12 y la RP negativa de 0,06. El valor predictivo (VP) positivo fue de 87% y el VP negativo de 96%. Los anticuerpos anti-CCP se observaron en 12% de los pacientes con LES y con SSp, en 2% de los de EA y en 10% de los controles sanos. En los pacientes con AR no se asociaron con la actividad de la enfermedad, MEA y alelos del HLA-DRB1. Tampoco se observaron correlaciones significativas entre sus valores y los niveles de citocinas. En conclusión, los anticuerpos anti-CCP tienen un interés diagnóstico para la AR en nuestra población, pero su utilidad en el seguimiento clínico es limitada y su síntesis es independiente del HLA-DRB1 y no se correlacionan con niveles de citocinas Th1/Th2.

The specificity and sensitivity of anti-cyclic citrullinated peptide antibodies (anti-CCP) was examined in Latin-American patients with rheumatoid arthritis (RA). The variables considered included: 1) relation with the activity of disease, 2) extra-articular manifestations (EAM), 3) synthesis of cytokines (IL-4, IL-10, IL-12, TNF-alpha , and IFN-gamma ) and IgM and IgA rheumatoid factor (RF), and 4) the association with HLA-DRB1 polymorphism. Seventy-nine RA patients were assessed (69 with established RA, and 10 with recent-onset RA not receiving any treatment), 56 with ankylosing spondylitis (AS), 25 with systemic lupus erythematosus (SLE), 50 with primary Sjögren’s syndrome (pSS), and 10 healthy individuals. Of the 69 patients with established RA, 36 were reexamined 2 years later. The activity of the RA was measured by criteria adopted by the American College of Rheumatology. Anti-CCP2, RF and cytokines levels were determined by ELISA. HLA genotypes were established by first, PCR sequence amplification using sequence-specific primers and then, complete sequencing of the product. Anti-CCP antibodies were observed in 96% of patients with RA during the first evaluation and in 86% at the second evaluation ( p=0.12). No significant change in antibody titre was observed between the two evaluations (131±58.7 and 130.6±67.1 IU, respectively). The overall sensitivity and specificity was 94% and 92%, respectively; however, at titres >60 IU, the values were 84% and 95%, respectively. The anti-CCP likelihood ratio positive test was 12 and the likelihood ratio negative test was 0.06. The positive predictive value was 87%, and the negative predictive value was 96%. Anti-CCP antibodies were observed in 12% of SLE and pSS patients, in 2% of AS patients, and in 10% of healthy controls. In RA patients, these antibodies were not associated with the activity of disease, EAM or HLA-DRB1 alleles; no significant correlation was observed between antibody titre and cytokines level. Although anti-CCP antibodies have potential as a diagnostic tool for RA, they are not useful for monitoring clinical activity or predicting the clinical course of disease. Antibody synthesis is HLA-DRB1 independent and not correlated with Th1/Th2 cytokines.

Polimorfismo de genes TAP1 y TAP2 en pacientes con lupus eritematosa sistemico: TAP2*0201 es un marcador de susceptibilidad / TAP2*0201 allele is a strong marker of SLE susceptibility

Objetivos: examinar la influencia del polimorfismo de los genes TAP1 y TAP2 en la susceptibilidad y el curso clínico del lupus eritematoso sistémico (LES). Métodos: estudio exploratorio, transversal, controlado en mujeres con diagnóstico de LES clasificadas de acuerdo a (os criterios del Colegio Americano de Reumatología (ACR 82), e individuos sanos apareados a las pacientes por género, edad y geografía. El polimorfismo de los genes TAP1 y TAP2 se examinó mediante el método de reacción en cadena de la polimerasa con amplificación de sistemas de mutación refractaria. Los anticuerpos antinucleares y anti-DNA se determinaron por IFI y los anti-cromatina y los extractables del núcleo (Ro, La, Sm, RNP) por ELISA. La severidad de la enfermedad se evaluó según el puntaje de daño SLICC/ACR. Resultados: se examinaron 65 pacientes y 80 controles. Los alelos TAP1 y TAP2 más frecuentemente encontrados en la población, tanto de pacientes como de controles, fueron el TAPr0101 (75 por ciento vs. 71 por ciento) y TAP2*0101 (82 por ciento vs. 70 por ciento). El alelo TAP2*0201 se asoció al LES (77 por ciento vs. 39 por ciento, OR: 5.3, IC95 por ciento: 2.6-11, p<0.0001), sin embargo no se observó influencia de ningún alelo TAP1 o TAP2 sobre el curso de la enfermedad, la presencia de autoanticuerpos específicos ni sobre la severidad de la misma. Conclusión: los resultados indican que, en la población estudiada, el alelo TAP2*0201 es un marcador de susceptibilidad para LES, y que los alelos TAP1 y TAP2 no afectan la expresión clínica ni la respuesta inmune de estos pacientes. Estos hallazgos confirman la hipótesis que los genes que confieren riesgo para desarrollar LES pueden ser diferentes a los que influyen en la producción de autoanticuerpos.