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Ruben Burgos-Vargas

Publications and source records attributed to Ruben Burgos-Vargas.

10 recordsLinked to original sources
PubMed2006

The Pediatric Rheumatology International Trials Organization/American College of Rheumatology provisional criteria for the evaluation of response to therapy in juvenile systemic lupus erythematosus: prospective validation of the definition of improvement.

OBJECTIVE: To use the Pediatric Rheumatology International Trials Organization (PRINTO) core set of outcome measures to develop a validated definition of improvement for the evaluation of response to therapy in juvenile systemic lupus erythematosus (SLE). METHODS: Thirty-seven experienced pediatric rheumatologists from 27 countries, each of whom had specific experience in the assessment of juvenile SLE patients, achieved consensus on 128 patient profiles as being clinically improved or not improved. Using the physicians' consensus ratings as the gold standard measure, the chi-square, sensitivity, specificity, false-positive and false-negative rates, area under the receiver operating characteristic curve, and kappa level of agreement for 597 candidate definitions of improvement were calculated. Only definitions with a kappa value greater than 0.7 were retained. The top definitions were selected based on the product of the content validity score multiplied by its kappa statistic. RESULTS: The definition of improvement with the highest final score was at least 50% improvement from baseline in any 2 of the 5 core set measures, with no more than 1 of the remaining worsening by more than 30%. CONCLUSION: PRINTO proposes a valid and reproducible definition of improvement that reflects well the consensus rating of experienced clinicians and that incorporates clinically meaningful change in core set measures in a composite end point for the evaluation of global response to therapy in patients with juvenile SLE. The definition is now proposed for use in juvenile SLE clinical trials and may help physicians to decide whether a child with SLE responded adequately to therapy.

Child↗
PubMed2005

Anti-tumor necrosis factor alpha blockade in the treatment of juvenile spondylarthropathy.

OBJECTIVE: Persistent inflammation refractory to standard antirheumatic therapy in children with juvenile spondylarthropathy (SpA) leads to morbidity and reduced quality of life. Tumor necrosis factor alpha (TNFalpha) plays an important role in the pathogenesis of synovitis and enthesitis. This study was undertaken to examine the impact of anti-TNFalpha agents on juvenile SpA that is refractory to nonsteroidal antiinflammatory drugs (NSAIDs), disease-modifying antirheumatic drugs, and corticosteroids. METHODS: Ten juvenile SpA patients with a mean +/- SEM age of 15.0 +/- 0.7 years and disease duration of 4.4 +/- 0.8 years, all of whom were HLA-B27 positive, were followed up for 1 year after initiation of either infliximab (n = 8) or etanercept (n = 2). Outcomes examined were within-subject differences in the tender entheseal count (TEC) and active joint count (AJC), markers of inflammation, functional assessments (Childhood Health Assessment Questionnaire [C-HAQ] score), and requirements for antirheumatic drugs. RESULTS: At baseline, all patients exhibited active arthritis and enthesitis that were resistant to NSAIDs (n = 10), methotrexate (n = 6), sulfasalazine (n = 8), corticosteroids (oral n = 6, intravenous pulse n = 3, and intraarticular n = 6), and bisphosphonates (n = 2). In 2 patients, sulfasalazine (n = 2), corticosteroids (n = 1), and bisphosphonates (n = 1) were stopped after initiation of the anti-TNFalpha agent. In all patients, the arthritis and enthesitis significantly improved as evidenced by remission of the TEC and AJC by 6 months that was sustained during the 1-year followup, markers of inflammation and C-HAQ scores normalized, and there was a reduction in requirements for antirheumatic drugs (reduced dosage or discontinuation of NSAIDs n = 10, methotrexate n = 5, sulfasalazine n = 6, corticosteroids n = 4, and bisphosphonates n = 1). CONCLUSION: Anti-TNFalpha therapy is a potential novel treatment for refractory juvenile SpA. Further prospective studies are required to examine the effectiveness and long-term outcomes of anti-TNFalpha therapy in this cohort.

Adolescent↗
PubMed2004

A randomized trial of parenteral methotrexate comparing an intermediate dose with a higher dose in children with juvenile idiopathic arthritis who failed to respond to standard doses of methotrexate.

OBJECTIVE: To compare the safety and efficacy of parenteral methotrexate (MTX) at an intermediate dosage (15 mg/m(2)/week) versus a higher dosage (30 mg/m(2)/week) in patients with polyarticular-course juvenile idiopathic arthritis (JIA) who failed to improve while receiving standard dosages of MTX (8-12.5 mg/m(2)/week). METHODS: In the screening phase, 595 patients who were newly started on a standard dose of MTX were followed up for 6 months. Subsequently, the nonresponders, defined according to the American College of Rheumatology (ACR) pediatric 30% improvement criteria (pediatric 30), were randomized to receive an intermediate dose or higher dose of parenteral MTX for an additional 6 months. Improvement in the screening and randomization phase was defined by the ACR pediatric 30 response, as well as by the 50% and 70% response levels (ACR pediatric 50 and ACR pediatric 70, respectively). RESULTS: In the screening phase, after receiving standard doses of MTX, 430 patients (72%) improved according to the ACR pediatric 30, while 360 (61%) met the ACR pediatric 50 and 225 (38%) met the ACR pediatric 70; among these patients, 69 (12%) also met the definition of complete disease control. Of the 133 nonresponders, 80 were randomized to receive an intermediate dose or higher dose of MTX. In the randomization phase, the ACR pediatric 30 response rate was 25 of 40 children (62.5%) in the intermediate-dose group versus 23 of 40 children (57.5%) in the higher-dose group. An ACR pediatric 50 response rate was attained by 23 patients (57.5%) receiving an intermediate dose versus 22 (55%) in the higher-dose group. An ACR pediatric 70 response rate was seen in 18 children (45%) receiving an intermediate dose versus 19 (47.5%) receiving a higher dose. Five children (12.5%) in the intermediate-dose group versus 4 (10%) receiving the higher dose of MTX also met the definition of complete disease control. None of the intergroup differences in response rate were significant. There were no significant differences in the frequency of adverse events or laboratory abnormalities between the 2 randomized groups. CONCLUSION: This study shows that the plateau of efficacy of MTX in JIA is reached with parenteral administration of 15 mg/m(2)/week and that a further increase in dosage is not associated with any additional therapeutic benefit. MTX should be administered for up to 9-12 months to appreciate its full therapeutic effect.

Antirheumatic Agents↗
PubMed2003

Serious lower gastrointestinal clinical events with nonselective NSAID or coxib use.

BACKGROUND & AIMS: Epidemiologic studies suggest nonsteroidal anti-inflammatory drugs (NSAIDs) increase the risk for lower gastrointestinal (GI) clinical events, but data from prospective trials are lacking. Cyclooxygenase (COX)-2-selective inhibitors decrease upper GI clinical events but the effect on lower GI events has not been determined. We performed a post hoc analysis of serious lower GI clinical events with a nonselective NSAID and a COX-2-selective agent in a prospective, double-blind, randomized GI outcomes trial. METHODS: A total of 8076 rheumatoid arthritis patients 50 years or older (or 40 years or older on corticosteroid therapy) expected to require NSAIDs for 1 year or greater were randomly assigned to naproxen 500 mg twice daily or rofecoxib 50 mg daily. The rate of serious lower GI clinical events, defined as bleeding with a 2 g/dL drop in hemoglobin or hospitalization, or hospitalization for perforation, obstruction, ulceration, or diverticulitis, was determined. RESULTS: The rate of serious lower GI events per 100 patient-years was 0.41 for rofecoxib and 0.89 for naproxen (relative risk, 0.46; 95% confidence interval [CI], 0.22-0.93; P = 0.032). Serious lower GI events accounted for 39.4% of all serious GI events (complicated upper GI event or lower GI event) among patients taking naproxen and 42.7% among those taking rofecoxib. CONCLUSIONS: Serious lower GI events occurred at a rate of 0.9% per year in rheumatoid arthritis patients taking the nonselective NSAID naproxen, accounting for nearly 40% of the serious GI events that developed in these patients. Serious lower GI events were 54% lower with the use of the selective COX-2 inhibitor rofecoxib.

Adult↗
PubMed2002

Use of a numerical rating scale as an answer modality in ankylosing spondylitis-specific questionnaires.

OBJECTIVES: To determine the agreement of scores on the original visual analog scale (VAS) or Likert scale of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), and Dougados Functional Index (DFI) with scores on a numerical rating scale (NRS). To assess the reproducibility and responsiveness of the instruments with the original scale and NRS. METHODS: Five hundred thirty-six patients with ankylosing spondylitis from the Netherlands, Mexico, and Switzerland completed a questionnaire in which all questions from the BASDAI, BASFI, and DFI were presented twice in random order with an 11-point NRS and either a 10-cm VAS (BASDAI and BASFI) or a 5-point Likert scale (DFI). Agreement of scores using Bland-Altman plots and intraclass correlation coefficients (ICCs), reproducibility using ICCs, and responsiveness were assessed. RESULTS: Large variability between the scores on the original scales and the NRS was found in individual questions of all 3 questionnaires, although total scores showed ICCs of at least 0.88. Reproducibility of all answer modalities showed low ICCs in individual questions, but moderate to good ICCs in total scores (Dutch group 0.62-0.89; Mexican group 0.53-0.72). Moderate to large effects (0.48-1.04) were found in responsiveness scores in the 3 questionnaires. No major differences in reproducibility and responsiveness between the answer modalities were found. CONCLUSION: Although large variability between the scores on the original answer scales and the NRS was observed, the BASDAI, BASFI, and DFI can be administered with an NRS, which does not show important differences compared with the original scales.

Adult↗
PubMed2002

Differences in idiopathic inflammatory myopathy phenotypes and genotypes between Mesoamerican Mestizos and North American Caucasians: ethnogeographic influences in the genetics and clinical expression of myositis.

OBJECTIVE: As part of a larger, worldwide study of the ethnogeography of myositis, we evaluated the clinical, serologic, and immunogenetic features of Mestizo (Mexican and Guatemalan) and North American Caucasian patients with idiopathic inflammatory myopathy (IIM). METHODS: Clinical manifestations, autoantibodies, HLA-DRB1 and DQA1 alleles, and immunoglobulin Gm/Km allotypes were compared between 138 Mestizos with IIM and 287 Caucasians with IIM, using the same classification criteria and standardized questionnaires. RESULTS: IIM in Mestizo patients was characterized by a higher proportion of dermatomyositis (69% of adult Mestizos versus 35% of adult Caucasians; P < 0.001) and anti-Mi-2 autoantibodies (30% versus 7% of adults, respectively, and 32% versus 4% of children, respectively; P < 0.01). Genetic risk factors also differed in these populations. Whereas Mestizos had no HLA risk factors for IIM, HLA-DRB1*0301, the linked allele DQA1*0501, and DRB1 alleles sharing the first hypervariable region motif (9)EYSTS(13) were major risk factors in Caucasian patients with IIM. Furthermore, different HLA-DRB1 and DQA1 alleles were associated with anti-Mi-2 autoantibodies (DRB1*04 and DQA1*03 in Mestizos and DRB1*07 and DQA1*02 in Caucasians). Immunoglobulin gamma-chain allotypes Gm(1), Gm(17) (odds ratio for both 11.3, P = 0.008), and Gm(21) (odds ratio 7.3, P = 0.005) and kappa-chain allotype Km(3) (odds ratio 7.3, P = 0.005) were risk factors for IIM in Mestizos; however, no Gm or Km allotypes were risk or protective factors in Caucasians. In addition, Gm and Km phenotypes were unique risk factors (Gm 1,3,17 5,13,21 and Gm 1,17 23 21 and Km 3,3) or protective factors (Km 1,1) for the development of myositis and anti-Mi-2 autoantibodies (Gm 1,2,3,17 23 5,13,21) in adult Mestizos. CONCLUSION: IIM in Mesoamerican Mestizos differs from IIM in North American Caucasians in the frequency of phenotypic features and in the immune-response genes predisposing to and protecting from myositis and anti-Mi-2 autoantibodies at 4 chromosomal loci. These and other data suggest the likelihood that the expression of IIM is modulated by different genes and environmental exposures around the world.

Adult↗
PubMed2002

Innate immunity in host-microbial interactions: beyond B27 in the spondyloarthropathies.

The spondyloarthropathies are diseases influenced by genetic predisposition and, to a varying extent, infectious triggers. A causal role for bacterial infections is most clear for reactive arthritis. Recent insights into arthritogenic components of bacteria may set the stage for a better understanding of disease pathogenesis, the role of heat shock proteins in antigen processing and immune activation, and the adjuvant effect of CpG-DNA. Recent developments in the area of innate immunity broaden current concepts of genetically defined factors in host-pathogen interactions. In particular, the biology of toll-like receptors as important elements in the innate immune response to pathogens is being defined. These factors in innate immunity may have important implications for sequelae of infections, such as reactive arthritis.

Animals↗
PubMed2002

High response rate in the phase I/II study of meloxicam in juvenile rheumatoid arthritis.

OBJECTIVE: Use of meloxicam as a selective COX-2 inhibitor for treatment of adult rheumatic diseases decreases the frequency of gastrointestinal (GI) side effects in comparison with nonselective COX inhibitors. Up to 50% of children with juvenile rheumatoid arthritis (JRA) also develop GI side effects through nonselective COX inhibitors. In this 12 week Phase I/II study, with an additional open extension lasting up to 52 weeks, the safety, efficacy, and pharmacokinetics of meloxicam in JRA were investigated. METHODS: Meloxicam suspension 0.25 mg/kg once daily was given to 36 patients with JRA who required a nonsteroidal antiinflammatory drug. Safety evaluation and periodic measurement of efficacy were carried out using the Pediatric Rheumatology International Trials Organisation (PRINTO) criteria. Eighteen patients underwent pharmacokinetic (PK) evaluation. RESULTS: Thirty-one patients completed the study. Four were dropped due to administrative reasons. One patient, who found the drug ineffective, discontinued participation. A response was seen according to PRINTO outcome criteria in 44% of the patients at Week 4, 62% at Week 12, and 74% at Week 52. Drug related adverse events were observed in 5 patients. PK evaluation showed that the maximum plasma concentration Cmax of -34% and AUC(0-infinity) of -28% tended to be lower in younger children (2-6 years) versus older children. Plasma elimination half-life (13 h) was similar in all patients. CONCLUSION: Meloxicam suspension 0.25 mg/kg once daily seems to be effective and safe for treating active JRA over a period of 52 weeks.

Adolescent↗
PubMed2002

Clues to pathogenesis of spondyloarthropathy derived from synovial fluid mononuclear cell gene expression profiles.

OBJECTIVE: To use gene expression profiles of spondyloarthropathy (SpA) synovial fluid mononuclear cells (SFMC) to determine if there are transcripts that support the unfolded protein response (UPR) hypothesis, and to identify which cytokines/chemokines are being expressed and which cell fractions are involved. METHODS: Gene expression profiles were generated by microarray screening of SFMC of 5 patients with SpA, 5 patients with rheumatoid arthritis (RA), and peripheral blood mononuclear cells (PBMC) of 6 controls. Results were validated by reverse transcription polymerase chain reaction using samples from a larger panel of subjects. RESULTS: The repertoires of proinflammatory cytokines/chemokines expressed by SpA and RA SFMC were very similar: monocyte chemotractant protein 1 (MCP-1), interleukin 8 (IL-8), IL-1beta, endothelial-monocyte activating polypeptide II, interferon-gamma, and tumor necrosis factor-alpha. MCP-1 was highly expressed in SpA SFMC. There was enhanced expression of immunoglobulin heavy chain binding protein (BiP) in SpA, which is compatible with the UPR hypothesis. BiP was most highly expressed in the adherent fraction of SpA SFMC. CONCLUSION: Previous data postulating UPR in SpA are based on in vitro experiments with transfected cell lines. Our patient derived data suggest that it also occurs in vivo in the macrophages of SpA joints.

Adolescent↗