Evaluation of a novel immunochromatographic device for rapid and accurate clinical detection of Porphyromonas gingivalis in subgingival plaque

An important goal for the improved diagnosis and management of infectious and inflammatory diseases, such as periodontitis, is the development of rapid and accurate technologies for the decentralized detection of bacterial pathogens. The aim of this prospective multicenter study was to evaluate the clinical use of a novel immunochromatographic device with monoclonal antibodies for the rapid point-of-care detection and semi-quantification of Porphyromonas gingivalis in subgingival plaque. Sixty-three patients with chronic periodontitis and 28 periodontally healthy volunteers were subjected to clinical and microbiological examinations. Subgingival plaque samples were analyzed for the presence of P. gingivalis using a novel immunochromatography based device DK13-PG-001, designed to detect the 40k-outer membrane protein of P. gingivalis, and compared with a PCR-Invader method. In the periodontitis group, a significant strong positive correlation in detection results was found between the test device score and the PCR-Invader method (Spearman rank correlation, r=0.737, p<0.0001). The sensitivity, specificity, and positive and negative predictive values of the test device were 96.2%, 91.8%, 90.4% and 96.7%, respectively. The detection threshold of the test device was determined to be approximately 10(4) (per two paper points). There were significant differences in the bacterial counts by the PCR-Invader method among groups with different ranges of device scores. With a cut-off value of ≥0.25 in device score, none of periodontally healthy volunteers were tested positive for the subgingival presence of P. gingivalis, whereas 76% (n=48) of periodontitis subjects were tested positive. There was a significant positive correlation between device scores for P. gingivalis and periodontal parameters including probing pocket depth and clinical attachment level (r=0.317 and 0.281, respectively, p<0.01). The results suggested that the DK13-PG-001 device kit can be effectively used for rapid, chair-side detection and semi-quantification of P. gingivalis in subgingival plaque.

TRIAL REGISTRATION

UMIN Clinical Trials Registry (UMIN-CTR) UMIN000011943.

Ten-year incidences of self-reported non-vertebral fractures in Japanese patients with rheumatoid arthritis: discrepancy between disease activity control and the incidence of non-vertebral fracture

Despite improvements in rheumatoid arthritis disease activity of in the past 10 years, the incidence of self-reported non-vertebral fractures did not decrease in our cohort of 9,987 patients. This study may indicate that osteoporosis treatment and non-vertebral fracture prevention remain important regardless of the rheumatoid arthritis disease activity.

INTRODUCTION

Although rheumatoid arthritis (RA) is a risk factor for osteoporosis and fractures, few studies have described the association between disease activity and the fracture incidence in patients with RA. This study aimed to investigate changes in the non-vertebral fracture incidence between 2001 and 2010 in our Institute of Rheumatology Rheumatoid Arthritis (IORRA) cohort.

METHODS

The IORRA is a prospective observational cohort study of Japanese RA patients. A total of 9,987 patients with RA were enrolled in this cohort from 2000 to 2010. The clinical parameter and non-vertebral fracture occurrence data were collected biannually through self-reported questionnaires. Incidences of self-reported non-vertebral fractures were also analyzed via standardization according to gender, age, and disease activity during each 2-year period.

RESULTS

From 2001 to 2010, the percentage of patients with 28-joint disease activity score remission increased from 7.8 to 39.7%, prednisolone intake decreased from 51.4 to 41.3%, and bisphosphonate intake increased from 5.0 to 23.4%. The non-vertebral fracture incidence rates were 24.6/1,000 person-years in 2001 and 35.5/1,000 person-years in 2010, with no apparent change even after standardization. The overall non-vertebral fracture incidence was significantly higher in the autumn/winter than in the spring/summer (p = 0.02).

CONCLUSION

Despite improvements in disease activity and functional disability, the non-vertebral fracture incidence exhibited no apparent change between 2001 and 2010 in our patients with RA. Osteoporosis treatment and non-vertebral fracture prevention remain important regardless of the disease control in patients with RA.

Vaccination against seasonal influenza is effective in Japanese patients with rheumatoid arthritis enrolled in a large observational cohort

OBJECTIVE

To investigate the effectiveness of influenza vaccination in patients with rheumatoid arthritis (RA) from a large practice-based cohort.

METHOD

Patients with RA enrolled in the Institute of Rheumatology, Rheumatoid Arthritis (IORRA) cohort completed self-administered questionnaires as part of the April IORRA surveys of 2001, 2002, 2003, and 2007, which included their influenza vaccination status and occurrence of an actual influenza attack. Vaccine coverage rate and attack rates were calculated in each season. Relative risks (RRs) of vaccination for an actual influenza attack were evaluated and risk factors for influenza infection were determined by multiple logistic regression analysis.

RESULTS

Data from 3529, 4518, 4816, and 4872 patients in the 2000/01, 2001/02, 2002/03, and 2006/07 seasons, respectively, were analysed. Coverage rates were increased from 12.2% in the 2000/01 season to 38.7% in the 2006/07 season. For each season, the attack rates in vaccinated patients trended lower than the rates in unvaccinated patients but the differences were not significant; however, by combining these four seasonal results, the attack rate was significantly lower for vaccinated patients [RR 0.83, 95% confidence interval (CI) 0.71-0.95, p < 0.01]. Male gender [odds ratio (OR) 1.48, 95% CI 1.25-1.76, p < 0.001] was associated with increased risk whereas vaccination was associated with reduced risk for influenza attack (OR 0.76, 95% CI 0.63-0.91, p < 0.01). There were no associations between influenza attacks and RA disease activity, treatment with methotrexate (MTX) or corticosteroids.

CONCLUSION

Influenza vaccination was effective in patients with RA regardless of disease activity or treatment.