Pharmacogenetic differences in response to albuterol between Puerto Ricans and Mexicans with asthma.

Background: In the United States, Puerto Ricans and Mexicans have the highest and lowest asthma prevalence, morbidity, and mortality, respectively. Ethnic-specific differences in the response to drug treatment may contribute to differences in disease outcomes. Genetic variants at the beta(2)-adrenergic receptor (beta(2)AR) may modify asthma severity and albuterol responsiveness.

Particular HLA-DRB1 shared epitope genotypes are strongly associated with rheumatoid vasculitis.

Objective: To examine the relationship of the HLA-DRB1 shared epitope (SE) to rheumatoid vasculitis, using individual patient data (IPD) meta-analytic methods.

Methods: Published studies that enrolled adult patients with rheumatoid arthritis (RA) were identified by searches of Medline and Embase, and by manual searches of medical journals. All authors were contacted for IPD.

Systematic reviews and meta-analyses: an illustrated, step-by-step guide.

Systematic reviews and meta-analyses synthesize data from existing primary research, and well-conducted reviews offer clinicians a practical solution to the problem of staying current in their fields of interest. A whole generation of secondary journals, pre-appraised evidence libraries and periodically updated electronic texts are now available to clinicians. However, not all systematic reviews are of high quality, and it is important to be able to critically assess their validity and applicability.

Lack of association of the HLA-DRB1 shared epitope with rheumatoid nodules: an individual patient data meta-analysis of 3,272 Caucasian patients with rheumatoid arthritis.

Objective: The objective of this individual patient data (IPD) meta-analysis was to examine the relationship of rheumatoid nodules to the HLA-DRB1 shared epitope (SE) and to individual SE genotypes.

Methods: English-language studies that enrolled adult non-Hispanic Caucasian patients with rheumatoid arthritis (RA) were identified by searches of Medline and Embase, and by manual searches of medical journals. All authors were contacted for IPD.

Impact of shared epitope genotype and ethnicity on erosive disease: a meta-analysis of 3,240 rheumatoid arthritis patients.

Objective: The strongest known genetic association in rheumatoid arthritis (RA) is with HLA-DRB1 alleles that share a similar amino acid sequence, termed the shared epitope (SE). Although many studies have examined the association of the SE with disease severity, the results have been inconsistent, which may reflect the relatively small sample sizes or ethnic differences. The aim of this study was to assess the association of HLA-DRB1 SE alleles and genotype with the development of bony erosions in RA by meta-analysis.

Responsiveness and discriminative capacity of the assessments in ankylosing spondylitis disease-controlling antirheumatic therapy core set and other outcome measures in a trial of etanercept in ankylosing spondylitis.

Objective: To investigate the responsiveness and discriminative capacity, and the relationship between both, of instruments selected for the disease-controlling antirheumatic therapy (DC-ART) core set by the Assessments in Ankylosing Spondylitis Working Group (ASAS).

Methods: Responsiveness and discriminative capacity of different measures reflecting disease activity and function, either included in the ASAS DC-ART core set or not, were evaluated in a randomized controlled clinical trial comparing etanercept with placebo in patients with ankylosing spondylitis. Guyatt's method was used as the primary analysis for responsiveness, and Student's t-test for discriminative capacity.

Treatment of ankylosing spondylitis by inhibition of tumor necrosis factor alpha.

Background: There are few effective treatments for ankylosing spondylitis, which causes substantial morbidity. Because of the central role of tumor necrosis factor alpha in the spondyloarthritides, we performed a randomized, double-blind, placebo-controlled trial of etanercept, a recombinant human tumor necrosis factor receptor (p75):Fc fusion protein, in patients with ankylosing spondylitis.

Methods: Forty patients with active, inflammatory ankylosing spondylitis were randomly assigned to receive twice-weekly subcutaneous injections of etanercept (25 mg) or placebo for four months.

The shared epitope and severity of rheumatoid arthritis.

After two decades of research involving thousands of RA patients, it is still not possible to precisely define the relation of HLA-DRB1 SE alleles to RA severity. Improvements in our understanding require more careful consideration of several factors such as ethnicity, gender, and the specific SE allele and genotype inherited. Large studies of heterogeneous groups of patients are required and indicate the need for collaborative efforts among researchers.