Using genetic and clinical data to understand response to disease-modifying anti-rheumatic drug therapy: data from the Brigham and Women's Hospital Rheumatoid Arthritis Sequential Study

The objective of this review is to report on the progress of the Brigham and Women's Hospital Rheumatoid Arthritis Sequential Study (BRASS) Registry data collection and summarize previous research in understanding therapeutic response to DMARDs using clinical and genetic data. The BRASS Registry, established in 2003, is a large, single-centre, prospective and observational cohort of 1100 RA patients. Patients with either new-onset or established RA disease are recruited from the practices of rheumatologists. Annual visits collect information on demographics, 28-joint DAS-CRP3 (DAS-28-CRP3), medication use, comorbidities and functional status (Modified Health Assessment Questionnaire, Short Form Health Survey 12). Two published studies have utilized BRASS to examine genetic predictors of treatment response. In a cross-sectional study, examining the association between candidate single nucleotide polymorphisms (SNPs) and disease activity in a subset of 120 RA patients on MTX monotherapy, the minor allele of ATIC rs4673993 was associated with low disease activity (P=0.01, DAS-28-CRP3≤3.2). In an international collaboration, 55 BRASS patients receiving anti-TNF therapy were genotyped for 31 SNPs associated with the risk of RA. With our collaborators, we discovered an SNP at the protein tyrosine phosphatase, receptor type, C (PTPRC) gene locus that was associated with EULAR 'good response'. With accurate data collection and the capacity to run genome-wide association studies and SNP analyses, the BRASS Registry has the ability to determine the contribution of genetic variants to disease onset and to assess their usefulness as biomarkers for treatment response and drug toxicity.

Effectiveness of the pentavalent rotavirus vaccine in preventing gastroenteritis in the United States

OBJECTIVE

In clinical trials, the pentavalent rotavirus vaccine (RV5) was efficacious in preventing severe rotavirus gastroenteritis (RGE) and related health care encounters. We assessed the vaccine effectiveness (VE) of RV5 among US infants during the first 2 rotavirus seasons after vaccine licensure.

METHODS

Using a large, national, health insurance claim database, we monitored 2 cohorts of infants (infants who received 3 doses of RV5 and a concurrent group of infants who received 3 doses of diphtheria-tetanus-acellular pertussis vaccine but did not receive RV5) through the 2007 and 2008 rotavirus seasons (January 1 to May 31), to identify cases of RGE and all-cause acute gastroenteritis (AGE) resulting in medical care encounters. We estimated the VE in reducing hospitalizations, emergency department (ED) and physician office visits, and health care resource utilization, as measured by days and costs of hospitalizations and ED visits.

RESULTS

A total of 33 140 RV5-vaccinated infants and 26 167 infants in the concurrent diphtheria-tetanus-acellular pertussis vaccine cohort were included in the analysis. The VE against RGE (hospitalization and ED) was 100% (95% confidence interval [CI]: 87%-100%), whereas the VE against AGE was 59% (95% CI: 47%-68%). In the outpatient setting, the VE against RGE and AGE was 96% (95% CI: 76%-100%) and 28% (95% CI: 22%-33%), respectively. There was a complete (100%) reduction in RGE hospitalization and ED visit days and a 100% reduction in costs. RV5 was associated with a 66% decrease in AGE-related hospitalization and ED visit days and a 74% reduction in costs.

CONCLUSIONS

In this first nationwide study evaluating VE under conditions of routine use, RV5 was highly effective in preventing RGE and AGE and in reducing health care resource utilization. Further research is needed to assess VE with an incomplete rotavirus vaccination regimen.

Predictors of discontinuation of tumor necrosis factor inhibitors in patients with rheumatoid arthritis

OBJECTIVE

Tumor necrosis factor-alpha (TNF) inhibitors have transformed management of rheumatoid arthritis (RA); however, many patients discontinue TNF inhibitors. Our goal was to determine the discontinuation rate of TNF inhibitors and identify predictors associated with discontinuation.

METHODS

Enrollees in the Brigham RA Sequential Study (BRASS) formed the eligible cohort. Patients reporting use of a TNF inhibitor with at least 6 months of followup were followed until reporting TNF inhibitor discontinuation or their last study visit if they continued therapy. Potential predictor variables, including demographic and clinical data assessed at baseline and 6 months prior to study endpoint, were identified using a Cox proportional regression.

RESULTS

Among 961 patients in BRASS, 503 were using a TNF inhibitor with at least 6 months of followup in BRASS (mean length of followup 39 mo, SD 13). Two hundred ten patients (42%) reported discontinuation of TNF inhibitor. Higher physician global scores (hazard ratio 1.27, 95% CI 1.18-1.38) and RA Disease Activity Index scores (HR 1.13, 95% CI 1.05-1.22) 6 months prior to stopping the TNF inhibitor and higher number of TNF inhibitors used previously (HR 1.30, 95% CI 1.03-1.66) were associated with discontinuation of TNF inhibitor. Prior use of synthetic disease modifying antirheumatic drugs (HR 0.50, 95% CI 0.34-0.72) and more years of cumulative methotrexate use (HR 0.24, 95% CI 0.12-0.47) were inversely associated with discontinuation of TNF inhibitor.

CONCLUSION

These data demonstrate that a significant number of patients with RA discontinue TNF inhibitors. Several easily characterized clinical variables have a modest predictive association with reduced probability of TNF inhibitor discontinuation.

Associations between human leukocyte antigen, PTPN22, CTLA4 genotypes and rheumatoid arthritis phenotypes of autoantibody status, age at diagnosis and erosions in a large cohort study

BACKGROUND

HLA-DRB1 shared epitope (HLA-SE), PTPN22 and CTLA4 alleles are associated with cyclic citrullinated peptide (CCP) and rheumatoid arthritis (RA).

OBJECTIVE

We examined associations between HLA-SE, PTPN22, CTLA4 genotypes and RA phenotypes in a large cohort to (a) replicate prior associations with CCP status, and (b) determine associations with radiographic erosions and age of diagnosis.

METHODS

A total of 689 RA patients from the Brigham RA Sequential Study (BRASS) were genotyped for HLA-SE, PTPN22 (rs2476601) and CTLA4 (rs3087243). Association between genotypes and CCP, rheumatoid factor (RF) erosive phenotypes and age at diagnosis were assessed with multivariable models adjusting for age, sex and disease duration. Novel causal pathway analysis was used to test the hypothesis that genetic risk factors and CCP are in the causal pathway for predicting erosions.

RESULTS

In multivariable analysis, presence of any HLA-SE was strongly associated with CCP+ (odds ratio (OR) 3.05, 95% CI 2.18-4.25), and RF+ (OR 2.53, 95% CI 1.83-3.5) phenotypes; presence of any PTPN22 T allele was associated with CCP+ (OR 1.81, 95% CI 1.24-2.66) and RF+ phenotypes (OR 1.84, 95% CI 1.27-2.66). CTLA4 was not associated with CCP or RF phenotypes. While HLA-SE was associated with erosive RA phenotype (OR 1.52, 95% CI 1.01-2.17), this was no longer significant after conditioning on CCP. PTPN22 and CTLA4 were not associated with erosive phenotype. Presence of any HLA-SE was associated with an average 3.6 years earlier diagnosis compared with absence of HLA-SE (41.3 vs 44.9 years, p = 0.002) and PTPN22 was associated with a 4.2 years earlier age of diagnosis (39.5 vs 43.6 years, p = 0.002). CTLA4 genotypes were not associated with age at diagnosis of RA.

CONCLUSIONS

In this large clinical cohort, we replicated the association between HLA-SE and PTPN22, but not CTLA4 with CCP+ and RF+ phenotypes. We also found evidence for associations between HLA-SE, and PTPN22 and earlier age at diagnosis. Since HLA-SE is associated with erosive phenotype in unconditional analysis, but is not significant after conditioning on CCP, this suggests that CCP is in the causal pathway for predicting erosive phenotype.

Cognitive impairment screening in second offense DUI programs

Patients enrolled in alcohol treatment programs for driving under the influence (DUI) offenders are at elevated risk of cognitive impairment, but are not systematically screened. We developed a 30-min screening battery that can be administered in a group setting to test patients' ability to handle the cognitive demands of psychoeducational treatment. Testing of 134 volunteers identified 73% as having one or more clinically significant cognitive deficits. A majority of subjects scored below the 50th percentile on tests of word fluency, vocabulary, sustained attention, memory, executive functioning, and impulse control. The prevalence of cognitive impairment in the repeat DUI offender population is extremely high, making DUI treatment programs an ideal venue for screening and referral. Treatment programs should be responsive to the special needs of this population, incorporating teaching techniques that address short attention span, poor memory, lack of verbal fluency, and lack of impulse control.

Child passenger safety: decisions about seating location, airbag exposure, and restraint use

The installation of passenger-side airbags in new vehicles complicates efforts to maximize child safety in motor vehicle crashes. It has been recommended by both public and private organizations that children sit in the rear seat with proper restraint to achieve maximum safety. Drivers now need to decide whether a child should be restrained, where the child should be seated (front versus rear), and whether the child should be seated in front of a passenger-side airbag. This research was undertaken to determine which choice minimizes the risk of fatality to children. Using data from the U.S. Fatality Analysis Reporting System for calendar years 1989 to 1998, fatal vehicle crashes with child passengers younger than 13 years were analyzed. The effectiveness of passenger-side airbags and rear seating for children, by age category and restraint use, was estimated using the double-pair comparison method. For each of four age categories, the fatality risk of each possible combination of restraint use, seating location, and airbag presence was also estimated using logistic regression. Passenger airbags were associated with an increase in child fatality risk of 31% for restrained children, and 84% for unrestrained children. Passenger airbags did appear to offer protection to restrained 9- to 12-year-old children. Restraint use and rear seating were associated with statistically significant reductions in the odds of a child dying in a crash. In order to minimize child fatality risk, parents should seat children in the rear of the vehicle while using the proper child restraint system, especially in vehicles with passenger airbags. These findings support current public education efforts in the United States.

Osteosarcoma metastatic to the pancreas in young patients

Two rare cases of pancreatic metastases from osteosarcoma are reported. Metastatic spread occurred after treatment with chemotherapy. This unusual phenomenon represents an alternation in the natural history of osteosarcoma with increased long-term survival of patients who are successfully treated with chemotherapy.

Cultural practices in the control of bean root rot

Bean root rot (a complex of Apharwmyces spp., Fusarium solani f. sp. phaseoli, Pythium spp. and Rhizoctonia solani) affects winter-grown fresh beans at Gympie, Queensland. In 5 trials conducted in 1986-88, cultural practices (depth of planting, depth of cultivation, hilling) and a fungicide treatment were examined as methods of control of the disease. The experiments were sited on a clay-loam soil, and under these conditions, shallow planting (25 mm) was the most effective treatment, significantly (P<0.05) reducing the severity of root rot relative to the standard depth of 50 mm.

Fungicide resistance in cucurbit powdery mildew (Sphaerotheca fuliginea) and its effect on field control

Decreased fungicidal control of powdery mildew (Sphaerotheca fuliginea (Schlecht: Fr.) Poll.) in commercial cucurbit crops led to an investigation to determine whether fungicide resistant strains were present. In field trials, fungicides such as bupirimate (100 mg a.i. L-I), dimethirimol (250 mg a.i. L-1), fenarimol (36 mg a.i. L-1), penconazole (40 mg a.i. L-l) and triadimefon (125 mg a.i. L-1) were less effective (P=0.01) in controlling the disease than oxythioquinox (100 mg a.i. L-1). This disagreed with earlier trial results and suggested that fungicide resistant strains may have developed. The sensitiyities of 6 isolates of S. fuliginea to 12 fungicides were determined using a leaf disc technique. Two isolates collected in fields where fungicides had been used intensively showed reduced sensitivity to fungicides from several chemical groups including the ergosterol biosynthesis inhibitors, hydroxypyrimidines, organophosphates and benzimidazoles. Several spraying strategies were compared. The S. fuliginea populations receiving spray schedules which included the protectant fungicide oxythioquinox alone, or in alternation with a systemic (triadimefon) developed a lower proportion (66-73%) of resistant strains than those treated with systemic fungicide alone (89%). These findings suggest that S. fuliginea can develop strains with low sensitivity to several fungicides against powdery mildew. To prolong their efficacy, systemic fungicides should not be used continuously but should be reserved for use during the latter part of crop growth when disease risk is highest. Alternating or tank mixing with an effective protectant fungicide is also recommended.