A topical vehicle is a 'carrier system' for an active pharmaceutical (or cosmetic) substance, referred to hereafter as the drug, but a vehicle may also be used on its own as an emollient to ameliorate dry skin. It is well established that the vehicle plays an important role in determining the bioavailability of a given drug at its ultimate target within the skin. Yet in the treatment of atopic eczema/dermatitis (AD), wherein the structure and function of the skin's outer barrier play a pivotal role in the development and course of the condition, the interaction of the vehicle with this barrier carries a particular importance. It is now clear that the often-considered inert excipients of a vehicle bring about changes within the skin at the molecular level that promote barrier restoration and enhance innate immune defenses with therapeutic value to AD patients. Moreover, the vehicle control in randomized controlled trials (RCTs) increasingly displays significant efficacy. In light of this, we consider the implications of vehicle design in relation to AD pathophysiology and the role vehicles play as controls in RCTs of new drug treatments for this condition.

We have examined HLA-DR, DQA and DQB variants in 72 controls, 153 subjects with RA without extra-articular features and in subjects with the rheumatoid pulmonary complications of interstitial fibrosis (23) peripheral airways disease (13) and in 41 subjects with RA and bronchiectasis. Subjects with RA alone showed the expected association with HLA-DR4 (79%) but those with RA and co-existent pulmonary fibrosis were less likely to be DR4 positive (61%). No other HLA-DR variants were significantly increased in the different disease groups. HLA-DQB1*0501 which types serologically as DQw1 was increased in subjects with RA and peripheral airways disease as compared to rheumatoid subjects with normal lung function, but these differences were not statistically significant. DQB1*0601 was increased in subjects with bronchiectasis with or without RA (but only significantly so in RA-BR subjects) DQB1*0301, DQB1*0201 and DQA1*0501 frequencies were also increased in subjects with RA and bronchiectasis as compared to those with RA alone.

This first prospective cardioversion study of a novel anticoagulant in anticoagulation-naïve patients should influence clinical practice.