Assessment of Serum sRANKL, sRANKL/OPG Ratio, and Other Bone Turnover Markers with the Estimated 10-Year Risk of Major and Hip Osteoporotic Fractures in Rheumatoid Arthritis: A Cross-Sectional Study.

BACKGROUND: Fracture risk assessment tool (FRAX) index was developed for estimating of the 10-year risk of major or hip osteoporotic fracture. To date, there is insufficient information regarding the correlation between FRAX and serum bone turnover markers (BTMs), such as soluble ligand of receptor activator of nuclear factor-κB (sRANKL), osteoprotegerin (OPG), and other molecules related with secondary osteoporosis in rheumatoid arthritis (RA). Therefore, this study is aimed at assessing the correlation between the FRAX and serum levels of sRANKL, OPG, sRANKL/OPG ratio, Dickkopf-1 (DKK-1), and sclerostin (SOST) in RA. METHODS: Cross-sectional study included 156 postmenopausal women with RA. Bone mineral density (BMD) was measured at lumbar spine (L1-L4) and total hip using dual-energy X-ray absorptiometry (DXA). RA patients were divided into (A) RA + osteoporosis and (B) RA without osteoporosis. FRAX scores were calculated including the total hip BMD. Serum sRANKL, OPG, DKK-1, and SOST levels were measured by ELISA. Pearson tests were used for assessing the correlation between serum levels of these molecules and FRAX scores in RA. RESULTS: The RA + osteoporosis group had elevated sRANKL levels (p = 0.005), higher sRANKL/OPG ratio (p = 0.017), decreased DKK-1 (p = 0.028), and lower SOST levels (p < 0.001). Low total hip BMD correlated with high sRANKL (p = 0.001) and sRANKL/OPG ratio (p = 0.005). Total hip and lumbar spine BMD correlated with DKK-1 (p = 0.009 and p = 0.05, respectively) and SOST levels (p < 0.001 and p < 0.001, respectively). Higher sRANKL levels and sRANKL/OPG ratio correlated with estimated 10-year risk of a major osteoporotic fractures (p = 0.003 and p = 0.003, respectively) and hip fracture (p = 0.002 and p = 0.006, respectively). High serum SOST levels were associated with a low estimated 10-year risk of a major osteoporotic fracture (p = 0.003) and hip fracture (p = 0.009). CONCLUSION: High sRANKL levels and sRANKL/OPG ratio can be useful to detect a subgroup of RA patients who has an increased 10-year risk of major and hip osteoporotic fractures.

Polymorphisms CYP2R1 rs10766197 and CYP27B1 rs10877012 in Multiple Sclerosis: A Case-Control Study.

BACKGROUND: Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease. Low vitamin D levels have been reported to be a risk factor for MS, and genetic variances could be implicated. The aim of this study was to evaluate the association of MS with rs10766197 polymorphism of CYP2R1 gene and rs10877012 polymorphism of CYP27B1 gene. The second aim was to analyse whether these polymorphisms are associated with the severity of the progression of MS. Material and Methods. In a case-control study, we included 116 MS patients and 226 controls, all of whom were Mexican Mestizo. MS was diagnosed by McDonald criteria (2017). A complete neurological evaluation was performed to evaluate the severity of disease progression. Serum 25-hydroxyvitamin D [25(OH) vitamin D] levels were measured by ELISA. Single nucleotide polymorphisms rs10766197 of CYP2R1 gene and rs10877012 SNP of CYP27B1 gene were genotyped by real-time PCR. RESULTS: Serum 25(OH) vitamin D levels were lower in MS patients than in controls (p = 0.009). No differences were observed between serum 25(OH) vitamin D levels of MS patients with severe progression compared to low progression (p = 0.88). A higher frequency of the A allele of CYP2R1 rs10766197 was observed between MS patients and controls (p = 0.05). No differences were observed in the frequency of T allele of CYP27B1 rs10877012 (p = 0.65). In subanalysis, patients with GA + AA genotypes of CYP2R1 rs10766197 had an increased risk of MS compared to controls (p = 0.03). No increased risk was observed in GT + TT genotypes of CYP27B1 rs10877012 (p = 0.63). No differences were observed in allele frequencies of either polymorphism between patients with severe vs. low disease progression. CONCLUSION: Lower serum 25(OH) vitamin D levels were observed in MS patients than in controls, although these levels were not associated with disease progression. Carriers of GA + AA genotypes of CYP2R1 rs10766197 had an increased risk of MS. None of these polymorphisms was associated with severe progression of MS.

The -675 4G/5G PAI-1 polymorphism confers genetic susceptibility to systemic lupus erythematosus, its clinical manifestations, and comorbidities in Mexican-Mestizo population.

Systemic lupus erythematosus (SLE) involves a broad range of factors that contribute to the development of the disease and its comorbidities. Genetic predisposition influences the development of SLE, and the -675 4G/5G PAI-1 polymorphism has been associated with several pathologies with a chronic inflammatory component. Our objective was to investigate the genetic association between the -675 4G/5G PAI-1 polymorphism with SLE, its clinical manifestations, and comorbidities in a Mexican-Mestizo population. The -675 PAI-1 polymorphism was determined by PCR-RFLP in 716 subjects: 293 SLE patients and 423 control subjects. Significant associations for SLE genetic susceptibility were found in carriers of 4G/5G (OR = 2.63; CI 1.81-3.87; p < .001) and 4G/4G (OR = 2.70; CI 1.62-4.51; p < .001) genotype in comparison with the 5G/5G genotype; 4G allele carriers also presented genetic risk for SLE (OR = 1.63; CI 1.31-2.03; p < .001) compared to the 5G allele. Following a dominant genetic model, a similar association was found with the 4G allele to SLE (OR = 2.66; CI1.84-3.84; p < .001). The 4G/5G genotype was associated with shorter disease duration (p = .039), as well as lower levels of haemoglobin (p = .001) and haematocrit (p = .009); the need for prednisone treatment (p = .001), higher BMI (p = .03), presence of type 2 DM (p = .015), clinical activity (Mex-SLEDAI = 57%; p = .047), Chronicity (SLICC-ACR = 0; p = .015) and CRP levels (p = .015) were associated with 5G/5G genotypes. In conclusion, the -675 4G/5G and 4G/4G PAI-1genotypes were found as genetic risk markers of susceptibility for SLE in the Mexican-Mestizo population, and each genotype could influence the clinical manifestations and comorbidities differently in SLE.

Serum P-glycoprotein level: a potential biomarker of DMARD failure in patients with rheumatoid arthritis.

OBJECTIVES: To evaluate the utility of elevated serum P-glycoprotein (P-gp) as a risk marker of therapeutic response failure in rheumatoid arthritis (RA) patients treated with disease-modifying antirheumatic drugs (DMARDs). METHODS: A cross-sectional study was conducted in 151 RA patients. Patients were classified into two groups according to the response achieved in terms of the disease activity score (DAS)28 after ≥ 6 months: (1) patients with a therapeutic response to DMARDs, with DAS28 < 3.2; and (2) patients without a response to DMARDs, with persistent DAS28 ≥ 3.2. We explored a wide group of clinical factors associated with therapeutic resistance. Serum P-gp levels were measured by ELISA. The risk of P-gp elevation as a marker of failure to achieve a therapeutic response to DMARDs was computed using multivariate logistic regression. RESULTS: Serum P-gp levels were significantly higher in RA patients (n = 151) than in the controls (n = 30) (158.70 ± 182.71 ng/mL vs. 14.12 ± 8.97 ng/mL, p < 0.001). The P-gp level was correlated with the DAS28 score (r = 0.39, p < 0.001). RA patients with DMARD failure had higher serum P-gp levels than patients with a therapeutic response (206 ± 21.47 ng/mL vs 120.60 ± 15.70 ng/mL; p = 0.001). High P-gp levels increased the risk of DMARD failure (OR 3.36, 95% CI 1.54-7.27, p = 0.001). After adjusting for confounding variables, elevated P-gp remained associated with DMARD failure (OR 2.64, 95% CI 1.29-5.40, p = 0.01). CONCLUSION: Elevated serum P-gp is associated with DMARD failure. The P-gp level can be considered a clinical tool for evaluating the risk of DMARD failure in patients; however, future prospective studies should be performed to evaluate the utility of this marker in predicting long-term responses.

Polymorphism rs2073618 of the TNFRSF11B (OPG) Gene and Bone Mineral Density in Mexican Women with Rheumatoid Arthritis.

Osteoporosis (OP) is highly prevalent in rheumatoid arthritis (RA) and is influenced by genetic factors. Single-nucleotide polymorphism (SNP) rs2073618 in the TNFRSF11B osteoprotegerin (OPG) gene has been related to postmenopausal OP although, to date, no information has been described concerning whether this polymorphism is implied in abnormalities of bone mineral density (BMD) in RA. We evaluated, in a case-control study performed in Mexican-Mestizo women with RA, whether SNP rs2073618 in the TNFRSF11B gene is associated with a decrease in BMD. RA patients were classified as follows: (1) low BMD and (2) normal BMD. All patients were genotyped for the rs2073618 polymorphism by PCR-RFLP. The frequency of low BMD was 74.4%. Higher age was observed in RA with low BMD versus normal BMD (62 and 54 years, resp.; p < 0.001). Worse functioning and lower BMI were observed in RA with low BMD (p = 0.003 and p = 0.002, resp.). We found similar genotype frequencies in RA with low BMD versus RA with normal BMD (GG genotype 71% versus 64.4%, GC 26% versus 33%, and CC 3% versus 2.2%, resp.; p = 0.6). We concluded that in Mexican-Mestizo female patients with RA, the rs2073618 polymorphism of the TNRFS11B gene is not associated with low BMD.

Association between -174G/C and -572G/C interleukin 6 gene polymorphisms and severe radiographic damage to the hands of Mexican patients with rheumatoid arthritis: a preliminary report.

Several interleukin 6 gene (IL6) polymorphisms are implicated in susceptibility to rheumatoid arthritis (RA). It has not yet been established with certainty if these polymorphisms are associated with the severe radiographic damage observed in some RA patients, particularly those with the development of joint bone ankylosis (JBA). The objective of the present study was to evaluate the association between severe radiographic damage in hands and the -174G/C and -572G/C IL6 polymorphisms in Mexican Mestizo people with RA. Mestizo adults with RA and long disease duration (>5 years) were classified into two groups according to the radiographic damage in their hands: a) severe radiographic damage (JBA and/or joint bone subluxations) and b) mild or moderate radiographic damage. We compared the differences in genotype and allele frequencies of -174G/C and -572G/C IL6 polymorphisms (genotyped using polymerase chain reaction-restriction fragment length polymorphism) between these two groups. Our findings indicated that the -174G/C polymorphism of IL6 is associated with severe joint radiographic damage [maximum likelihood odds ratios (MLE_OR): 8.03; 95%CI 1.22-187.06; P = 0.03], whereas the -572G/C polymorphism of IL6 exhibited no such association (MLE_OR: 1.5; 95%CI 0.52-4.5; P = 0.44). Higher anti-cyclic citrullinated peptide antibody levels were associated with more severe joint radiographic damage (P = 0.04). We conclude that there is a relevant association between the -174G/C IL6 polymorphism and severe radiographic damage. Future studies in other populations are required to confirm our findings.

The -174G/C Interleukin-6 Gene Promoter Polymorphism as a Genetic Marker of Differences in Therapeutic Response to Methotrexate and Leflunomide in Rheumatoid Arthritis.

Objective. To evaluate the association of -174G/C IL-6 polymorphism with failure in therapeutic response to methotrexate (MTX) or leflunomide (LEF). This prospective, observational cohort included 96 Mexican-Mestizo patients with moderate or severe rheumatoid arthritis (RA), initiating MTX or LEF, genotyped for IL-6 -174G/C polymorphism by PCR-RFLP. Therapeutic response was strictly defined: only if patients achieved remission or low disease activity (DAS-28 < 3.2). Results. Patients with MTX or LEF had significant decrement in DAS-28 (p < 0.001); nevertheless, only 14% and 12.5% achieved DAS-28 < 3.2 at 3 and 6 months. After 6 months with any of these drugs the -174G/G genotype carriers (56%) had higher risk of therapeutic failure compared with GC (RR: 1.19, 95% CI: 1.07-1.56). By analyzing each drug separately, after 6 months with LEF, GG genotype confers higher risk of therapeutic failure than GC (RR = 1.56; 95% CI = 1.05-2.3; p = 0.003), or CC (RR = 1.83; 95% CI = 1.07-3.14; p = 0.001). This risk was also observed in the dominant model (RR = 1.33; 95% CI = 1.03-1.72; p = 0.02). Instead, in patients receiving MTX no genotype was predictor of therapeutic failure. We concluded that IL-6 -174G/G genotype confers higher risk of failure in therapeutic response to LEF in Mexicans and if confirmed in other populations this can be used as promissory genetic marker to differentiate risk of therapeutic failure to LEF.

Association between bone turnover markers, clinical variables, spinal syndesmophytes and bone mineral density in Mexican patients with ankylosing spondylitis.

OBJECTIVES: To compare bone turnover marker (BTM) levels and bone mineral density (BMD) between patients with ankylosing spondylitis (AS) and healthy controls (HC) and to evaluate, in AS, the association between BTM levels and clinical variables, spinal syndesmophytes, and BMD using multivariate analysis. METHOD: Seventy-eight AS patients were compared with 58 HC matched by gender. Spinal syndesmophytes in AS and other characteristics were assessed. C-terminal telopeptide fragments of type I collagen (CTX), bone-specific alkaline phosphatase (BAP), osteocalcin (OC) serum levels, and BMD of the lumbar spine, femoral neck, and forearm were evaluated. RESULTS: AS males and females had lower BAP levels than their respective HC (p < 0.001 and p = 0.001). AS patients with bridging syndesmophytes had higher OC levels than AS patients either with non-bridging syndesmophytes (p = 0.001) or without spinal syndesmophytes (p < 0.001). OC and CTX levels correlated significantly with the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). In the multivariate linear regression adjusted by age, gender, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), BMD in the lumbar spine, and C-reactive protein (CRP), we observed an association between BAP levels and anti-tumour necrosis factor (anti-TNF) use (p = 0.05) whereas OC levels were associated with mSASSS (p < 0.001) and anti-TNF use (p = 0.05), and CTX levels were exclusively associated with mSASSS (p = 0.03). In the logistic regression analysis, only OC levels were associated with the presence of syndesmophytes in AS [odds ratio (OR) 2.42, 95% confidence interval (CI) 1.19-5.75]. CONCLUSIONS: We observed an increase in OC levels in AS patients with syndesmophytes. BTM levels were associated with the severity of spinal damage. Future longitudinal studies should evaluate whether these BTMs should be included as tools to determine the prognosis and progression of spinal damage.

The -174G/C and -572G/C interleukin 6 promoter gene polymorphisms in mexican patients with rheumatoid arthritis: a case-control study.

OBJECTIVE: There is a lack of information about the genotype frequencies of IL-6 -174G/C and -572G/C polymorphisms in Mexicans with rheumatoid arthritis (RA). Therefore, the aim of this study was to evaluate the association of the IL-6 -174G/C and -572G/C polymorphisms in Mexican mestizo with RA. METHODS: We included 137 patients with RA and 102 healthy controls. Patients were assessed for clinical characteristics. IL-6 -174G/C and -572G/C polymorphisms were genotyped using PCR-RFLP analysis. Allele and genotype frequencies and the Hardy-Weinberg equilibrium were computed. Odds ratios (ORs) were computed to identify the risk for RA associated with the presence of GG genotype in comparison with the GC or CC genotypes. RESULTS: The genotype -174GG occurred at a higher frequency in cases and controls (77.4% versus 78.4%, P = 0.845). We found similar results for the genotype -572GG (54% in patients versus 60.8% in controls, P = 0.295). CONCLUSIONS: This is the first study to evaluate the association of -174G/C and -572G/C polymorphisms of the IL-6 gene with RA in Mexican mestizo patients. These two polymorphisms were not associated with RA in the studied sample. Additional studies are required to evaluate if these IL-6 polymorphisms have relevance to the development of more severe disease.

Association analysis of vitamin D receptor gene polymorphisms and bone mineral density in postmenopausal Mexican-Mestizo women.

We investigated associations between vitamin D receptor (VDR) gene polymorphisms, FokI T>C (rs2228570), BsmI G>A (rs1544410), ApaI G>T (rs7975232), and TaqI T>C (rs731236), with bone mineral density (BMD) in postmenopausal Mexican-Mestizo women. Three hundred and twenty postmenopausal women participated, who were classified according to World Health Organization criteria as non-osteoporotic (Non-OP; N = 88), osteopenic (Opn; N = 144), and osteoporotic (OP; N = 88). BMD measurements at the lumbar (L1-L4) spine and at the left and right femoral neck were obtained by dual-energy X-ray absorptiometry. Single nucleotide polymorphisms (SNPs) were genotyped using real-time polymerase chain reaction and TaqMan probes. Genotype and allelic frequencies of the 4 VDR SNPs were similar among the 3 groups. Polymorphic allele frequencies were as follows: FokI (C) 0.53, 0.49, 0.56; BsmI (A) 0.26, 0.22, 0.23; ApaI (T) 0.43, 0.39, 0.44; TaqI (C) 0.27, 0.22, 0.23 for the Non-OP, Opn, and OP groups, respectively. Although no associations were found between the SNPs and BMD, based on the putative function of the FokI SNP, we constructed, for the first time, the haplotype with the 4 VDR SNPs, and found that the CGGT haplotype differed between the Non- OP and OP groups (21.8 vs 31.8%, P < 0.05). The risk analysis for this haplotype was nearly significant under the dominant model (OR = 1.783, 95%CI = 0.98-3.25, P = 0.058). This result suggests a possible susceptibility effect of the C allele of the FokI SNP for the development of osteoporosis in postmenopausal Mexican-Mestizo women.

Pulmonary function in ankylosing spondylitis: association with clinical variables.

To evaluate the association between pulmonary function and clinical variables in ankylosing spondylitis (AS) and to compare the pulmonary function of patients with AS with that of healthy controls, 61 AS patients and 74 healthy controls were included. In AS, we assessed clinical disease indices (BASDAI, BASFI, BASG), morning stiffness, number of hypersensitive entheses, metrology measures, 6-min walking test, acute phase reactants, radiological presence of "bamboo spine," and severity of radiological involvement in sacroiliac and vertebral joints. AS and healthy controls had similar age and gender. All the parameters of pulmonary function were significantly diminished in AS than in healthy controls (p < 0.001), with a higher proportion of restrictive pattern (57.4 vs. 5.4 %). In AS, pulmonary function correlated negatively with BASDAI, BASFI, BASG, morning stiffness, number of hypersensitive entheses, occiput-wall distance, and ESR, and positively with 6-min walking test. There was no association between pulmonary function with radiological stage of vertebral joints and sacroiliac joints, "bamboo spine," disease duration, or chest expansion. A higher frequency of AS patients had a decreased pulmonary function and results of the 6-min walking test. These abnormalities in AS were more related with disease activity than with mobility limitation.

Prescription for antiresorptive therapy in Mexican patients with rheumatoid arthritis: is it time to reevaluate the strategies for osteoporosis prevention?

Glucocorticoids are frequently used in rheumatoid arthritis (RA) in order to alleviate symptoms of joint inflammation, retard erosions and to treat extra-articular manifestations, although these drugs may increase the risk of bone mineral loss and osteoporotic fractures. To date, in Mexico there are no studies that identify the frequency of patients with RA with corticosteroids, receiving therapy for osteoporosis. Therefore, we evaluated the prevalence and factors related to the prescription of antiresorptives in 520 Mexican patients with RA. We used a multivariate model to identify variables associated with antiresorptives prescription. We identified that although 79% of patients were under treatment with glucocorticoids, only 13% received antiresorptive agents as preventive therapy for osteoporosis. The multivariate analysis identified that higher proportions of antiresorptive drugs prescriptions were associated with female patients (OR 11.40, 95% CI: 1.5-84.3, P = 0.02), an age of 40 years or more (OR 3.22, 95% CI: 1.3-8.3, P = 0.02) and to consume a lower number of cointerventions with other drugs (OR 1.09, 95% CI: 1.0-1.2, P = 0.03). Corticosteroid treatment was not associated with the prescription of antiresorptives (P = 0.31). In conclusion, a low proportion of Mexicans with RA receive antiresorptive therapy independently regardless of whether they consume or not chronically corticosteroids. Additional strategies should be evaluated to encourage the prevention and early treatment for osteoporosis in patients with RA.

The ACTN3 R577X polymorphism is associated with inflammatory myopathies in a Mexican population.

BACKGROUND: The ACTN3 gene encodes the fast muscle protein α-actinin-3. The ACTN3 R577X polymorphism is a premature stop codon and results in absence of α-actinin-3 in 577XX homozygotes. The aim of this study was to determine the ACTN3 genotype in idiopathic inflammatory myopathies (IIMs). METHODS: We performed ACTN3 genotyping on 27 patients with dermatomyositis (DM), 10 with polymyositis (PM), and 85 healthy subjects. Muscle enzyme levels of creatine phosphokinase (CPK), lactic dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were recorded at the time of diagnosis and recruitment. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the allele frequency was analysed. RESULTS: A total of 36% of healthy subjects had the ACTN3 577XX polymorphism (α-actinin-3 deficiency), 18% had the 577RR (homozygous wild type) genotype, and 46% 577RX (heterozygous). In DM/PM, 70% had the ACTN3 577XX polymorphism, 6% RR, and 24% RX [odds ratio (OR) 4.12, 95% confidence interval (CI) 1.67-10.33, p < 0.001]. In healthy subjects, the R allele was present in 41% and the X allele in 59% compared to 18% and 82%, respectively, in the IIM group (OR 3.21, 95% CI 1.57-6.66, p < 0.001). Thus, the ACTN3 577X allele seemed to increase the risk of developing IIM, and DM in particular, although this was not related to severity of expression of the phenotype. CONCLUSIONS: The ACTN3 577X allele appeared to increase the risk of developing IIM; 70% of IIM patients were deficient in α-actinin-3. By contrast, ACTN3 577XX patients seemed to have less severe disease as reflected in lower muscle enzyme levels.

Cervical human papillomavirus infection in Mexican women with systemic lupus erythematosus or rheumatoid arthritis.

Cervical human papillomavirus (HPV+) infection is associated with an increased risk of cervical dysplasia. Although the frequency of HPV+ in systemic lupus erythematosus (SLE) has been investigated in some races its prevalence in Hispanic women is still unknown. This cross-sectional study evaluated the prevalence of cervical HPV+ in Mexican women with SLE (n = 34) or rheumatoid arthritis (RA) (n = 43) and in healthy controls (n = 146). These women were interviewed about risk factors for sexually transmitted infections and cervical cytology analysis was performed. HPV+ viral types were identified using PCR: HPV+ was observed in 14.7% of SLE, 27.9% of RA and 30.8% of controls. High-risk HPV types were observed in 11.7% of women with SLE, 27.9% of women with RA, and in 26% of the controls. High-risk viral types 58, 35 and 18 were the most frequently identified in SLE. Two women with SLE had a high-grade squamous intraepithelial lesion and one had cervical cancer. An association was observed between methotrexate utilization, longer duration of therapy with prednisone, and HPV+ in RA or SLE. Thus, there is a high prevalence of cervical HPV infection in Mexican women with SLE or RA, and physicians must be vigilant in preventing the development of cervical dysplasia.

Polymorphisms C677T and A1298C in the MTHFR gene in Mexican patients with rheumatoid arthritis treated with methotrexate: implication with elevation of transaminases.

Rheumatoid arthritis (RA) is the prototype of the rheumatic diseases worldwide. Methotrexate (MTX) is the drug of first choice in the treatment of this disease due to its immunosuppressant effect. However, side events are present in 30% of the patients. The C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene are involved in the metabolism of MTX. Earlier studies reported an association between these polymorphisms and elevation of hepatic enzymes. We analyzed the frequencies of both polymorphisms and the presence of transaminasemia in 70 Mexican patients with rheumatic arthritis treated with MTX. The 19% (13/70) of patients had an increase in the serum level of transaminases. The A1298C polymorphism was associated with elevation of transaminases (P=0.024). The identification of MTHFR genotypes for C677T and A1298C polymorphisms could lead clinicians to identify patients in risk of elevation of transaminases, and give them an individualized treatment, as is a goal of pharmacogenetics.

Autoantibodies to a miRNA-binding protein Argonaute2 (Su antigen) in patients with hepatitis C virus infection.

OBJECTIVES: Chronic liver diseases caused by hepatitis B (HBV) or C virus (HCV) are common worldwide. Despite reports on autoimmunity in viral hepatitis, studies on autoantibodies associated with systemic rheumatic diseases are inconsistent. Testing of a small number of selected autoantibody specificities using ELISA appears to be one reason for inconsistency. Sera from patients with viral hepatitis were tested by immunoprecipitation that will allow unbiased screening of autoantibodies found in systemic rheumatic diseases. METHODS: Ninety Mexican patients (37 male, 53 female, 26 HBV, 6 HBV+HCV, 58 HCV) with chronic viral hepatitis, confirmed by nested or RT-nested-PCR, HBsAg and anti-HCV antibodies, were studied. Autoantibodies were tested by immunofluorescence, immunoprecipitation and ELISA. Specificities were verified using reference sera. RESULTS: Antinuclear antibodies were found in 38% HBV, 17% HBV+HCV, and 28% in HCV. Autoantibodies to Argonaute (Ago2, Su antigen), a microRNA binding protein that plays a key role in RNA-induced silencing complex (RISC), was found in 5% (4/64) of HCV or HBV+HCV coinfected patients but not in HBV (0/26). Anti-Ago2/Su was found in 1/2 of I-IFN-treated case vs. 3/62 in cases without I-IFN. HCV did not have other lupus autoantibodies whereas 19% (5/26) of HBV had anti-U1RNP+Ku, Ro+La, RNA polymerase II, or possible U5snRNPs. CONCLUSIONS: Lupus autoantibodies were uncommon in HCV except anti-Ago2/Su. HCV and I-IFN have many ways to affect TLR signaling, miRNA and miRNA binding protein Ago2/Su. To understand the mechanism of specific targeting of Ago2 in HCV may provide a clue to understand the mechanism of specific autoantibody production.

The -383A>C TNFRI polymorphism is associated with soluble levels and clinical activity in rheumatoid arthritis.

Tumor necrosis factor-alpha (TNF-alpha) plays a central role in inflammation, and it has been directly implicated in the pathogenesis of rheumatoid arthritis (RA). TNF-alpha activity is mediated through TNFRI and TNFRII cell surface receptors, which act as physiological attenuators of TNF-alpha activity. We recruited 190 RA patients and 190 healthy subjects (HS) in order to associate the -383A>C TNFRI polymorphism with sTNFRI levels and DAS28 score in RA. In results, sTNFRI levels were higher in RA patients than HS (P = 0.04). The -383A>C TNFRI polymorphism did not show significant differences in both studied groups. However, in the RA group the sTNFRI levels were significantly elevated (P = 0.004) in A/A genotype carriers. In addition, the A/A genotype carriers had the higher DAS28 score than A/C genotype (P = 0.02). These data suggest that -383A>C TNFRI polymorphism is not a susceptibility marker in RA, whereas the increased levels of sTNFRI could reflect the clinical activity in RA patients.

Factors associated with hyperhomocysteinaemia in Mexican patients with rheumatoid arthritis.

BACKGROUND: Hyperhomocysteinaemia is a factor related to the development of atherosclerosis in rheumatoid arthritis (RA). However, Hispanics with RA develop high rates of coronary disease; there are no studies about the frequency and factors related to high levels of homocysteine in Mexican patients. OBJECTIVE: To evaluate the prevalence and characteristics associated with hyperhomocysteinaemia in Mexican patients with RA. METHODS: One hundred and fifty-two patients with RA were compared with 153 controls. The assessment in RA included clinical characteristics, disease activity (RADAR), functioning (HAQ-Di and global functional status), comorbidity, and radiological damage. Laboratory determinations included total serum homocysteine (tHcy), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), and lipid profile. RESULTS: Median levels of homocysteine were higher in RA compared with controls (11.3 vs. 9.3, p<0.001). Twenty per cent of the patients with RA had hyperhomocysteinaemia (>15 micromol/L) compared with 6% in controls (p<0.001). There was statistical association between hyperhomocysteinaemia in RA with male gender (p<0.001), impairment in the global functional status (p = 0.004), higher radiological damage (p = 0.001), and CRP (p = 0.04). There was no association with RADAR, HAQ-Di, or RF, methotrexate dose or duration of use. In the adjusted multivariate model, the two variables associated with higher risk for hyperhomocysteinaemia were male gender (OR = 4.2, 95% CI 2 to 12, p = 0.006) and higher radiological damage (III-IV) (OR = 3.4, 95% CI 1.3 to 9, p = 0.01). CONCLUSIONS: Our data show a high prevalence of hyperhomocysteinaemia in Mexican patients with RA. More effort is required to evaluate and treat earlier this coronary risk factor.

Serum concentrations of aminoterminal propeptide of type III procollagen and propeptide of human type I procollagen in systemic lupus erythematosus.

The purpose of this study was to assess the association between the serum levels of aminoterminal propeptide of type III procollagen (PIIINP) and carboxyterminal propeptide of type I procollagen (PICP) with disease activity and damage in systemic lupus erythematosus (SLE). Thirty-three patients with SLE were compared with 31 controls. The assessment in SLE included disease activity indices (SLEDAI, MEX-SLEDAI) and damage index (SLICC/ACR). PIIINP and PICP were measured by radioimmunoassay. Compared with controls, mean levels of PIIINP were higher in SLE (2.9+/-1.8 vs. 1.8+/-1.2, P=0.006). PICP was also increased in SLE versus controls (163+/-94 vs. 102+/-62, P=0.007). PIIINP was correlated with SLICC/ACR (r=0.33, P=0.048). No correlation was observed between PICP and PIIINP with other clinical or therapeutic variables. These preliminary data suggests a role of PIIINP as a marker for chronic damage. Follow-up studies are required to evaluate its utility in predicting future damage.

[Patterns of health care in an out patient rheumatologic clinic]. / La atención médica en reumatología en un hospital de segundo nivel de atención.

INTRODUCTION: Studies evaluating the pattern of diseases evaluated by rheumatology services are required to improve the planning of healthcare resource distribution. AIM: To describe the pattern of diseases motivating consultations in an outpatient clinic of a secondary care center in Guadalajara, Mexico. MATERIAL AND METHODS: A cross-sectional, descriptive study was performed. Data on the diseases evaluated in the rheumatology service and other healthcare indicators were obtained through a search of the hospital's computerized database. The number of initial and repeat consultations, their distribution by age and sex, the mean monthly number of prescriptions, and other indicators of performance were identified. RESULTS: There were 5,790 consultations in 1 year (26% were initial visits). The three most frequent diseases were: rheumatoid arthritis (47.1%, 95% CI 46-48%), systemic lupus erythematosus (12.7%, 95% CI 12-14%), and ankylosing spondylitis (7.7%, 95% CI 7-8%). Four women were attended for each man. Consultations were most frequent in the group aged 30-59 years old. The mean number of consultations per rheumatologist/month was 242, with a mean of 2.5 prescriptions per patient. The rate of compliance with appointments was 85%. A mean of 7.5 were diagnosed with temporary work disability for each rheumatologist/month. CONCLUSIONS: The most prevalent disorders in our outpatient rheumatology clinic were inflammatory joint diseases and systemic autoimmune diseases. These disorders required a high proportion of health-care resource. Further studies are required to evaluate the costs of these resources with the aim of establising better strategies for the health care needs in these patients.