Persistence of low disease activity after tumour necrosis factor inhibitor (TNFi) discontinuation in patients with psoriatic arthritis

Objective

To determine the duration of clinical benefit among patients with psoriatic arthritis (PsA) discontinuing tumour necrosis factor inhibitor (TNFi) therapy while in low disease activity (LDA), and to identify patient characteristics associated with prolonged clinical benefit.

Methods

We performed an observational cohort study assessing patients with PsA from the Consortium of Rheumatology Researchers of North America (CORRONA) registry who had discontinued TNFi after achieving LDA, defined as clinical disease activity index (CDAI) score ≤10 and physician's global assessment (PGA) of skin psoriasis ≤20/100. Kaplan–Meier method was used to estimate the duration of clinical benefit.

Results

Of the 5945 patients with PsA in CORRONA, 302 patients had discontinued TNFi (n=325) while in LDA and had follow-up data available. At time of discontinuation, mean PsA duration was 9.8 years, mean CDAI was 3.9, and mean duration of TNFi use was 1.5 years; 52.6% of patients had discontinued their first TNFi. Median time to loss of benefit was 29.2 months. 179 (55.1%) patients had persistent benefit at their previous clinic visit. An increased risk of losing clinical benefit was seen among patients with higher disease activity at discontinuation (CDAI≥3.2 vs <3.2; HR 1.43 (p=0.32)) and among smokers (HR 1.78 (p=0.027)).

Conclusions

Patients with PsA who achieve LDA may maintain clinical benefit after discontinuation of TNFi therapy.

Environmentally friendly power generator based on moving liquid dielectric and double layer effect

An electrostatic power generator converts mechanical energy to electrical energy by utilising the principle of variable capacitance. This change in capacitance is usually achieved by varying the gap or overlap between two parallel metallic plates. This paper proposes a novel electrostatic micro power generator where the change in capacitance is achieved by the movement of an aqueous solution of NaCl. A significant change in capacitance is achieved due to the higher than air dielectric constant of water and the Helmholtz double layer capacitor formed by ion separation at the electrode interfaces. The proposed device has significant advantages over traditional electrostatic devices which include low bias voltage and low mechanical frequency of operation. This is critical if the proposed device is to have utility in harvesting power from the environment. A figure of merit exceeding 10000(10⁸μW)/(mm²HzV²) which is two orders of magnitude greater than previous devices, is demonstrated for a prototype operating at a bias voltage of 1.2 V and a droplet frequency of 6 Hz. Concepts are presented for large scale power harvesting.

Breast cancer worry among women awaiting mammography: is it unfounded? Does prior counseling help?

The purpose of this study was to explore the prevalence of breast cancer anxiety and risk counseling in women undergoing mammography, and the association with known risk factors for cancer. Women awaiting mammography were surveyed regarding anxiety, prior breast cancer risk counseling, demographic and risk factors. Anxiety was assessed via 7-point Likert-type scale (LS). Risk was defined by Gail model or prior breast cancer. Data were analyzed by nonparametric methods; significance determined at alpha = 0.05. Of 227 women surveyed, 54 were classified "higher risk". Counseling prevalence was similar (52%) for all ethnic groups, but higher (72%, P<0.001) for "higher risk" women. On average, women awaiting screening/diagnostic mammography were somewhat worried (median LS = 4). Worry was significantly higher (P<0.05) in "higher risk" women (LS = 5), and in women living outside Honolulu (LS = 6). Counseling by primary care physicians (PCP) did not correlate with lower worry scores. It was concluded that most women awaiting mammography are not unduly anxious. Additionally, the findings showed a correlation between a woman's concern about developing cancer with known risk factors and rural residence.