Anthony Barrington Kay

Effect of T-cell peptides derived from Fel d 1 on allergic reactions and cytokine production in patients sensitive to cats: a randomised controlled trial

BACKGROUND Some patients with asthma who are allergic to cats and are injected intradermally with short, overlapping, T-cell peptides derived from Fel d 1 develop late asthmatic reactions to the peptides, which are associated with a reduction in late-phase skin reactions induced by whole allergens and bronchial hyporesponsiveness to the peptides on the second injection. We aimed to ascertain the effect of multiple injections on the magnitude of the early and late phase skin reactions to intact allergens. METHODS After a 9-week run-in period, we randomly assigned patients with asthma and allergies to cats to receive either Fel d 1 peptides (90 microg in increasing divided doses) or placebo. The primary outcome was late-phase cutaneous reactions to whole cat dander. Outcomes were measured at baseline, 4-8 weeks, and 3-9 months. Analysis was by intention to treat. FINDINGS 16 patients were randomly assigned to the peptides, and eight to placebo. All patients completed the course of injections. Four of the 16 patients on Fel d 1 peptides had initial late asthmatic reactions, but could be desensitised to the higher dose of peptide. Patients in the peptide group but not the placebo group had a significant reduction in the size of their late reaction to whole cat dander between baseline and both follow-ups, but the difference between groups was not significant (first follow-up, difference -422.8 mm(2) [95% CI -1115.0 to 269.4], p=0.43; second follow-up -1180.8 mm(2) [-2216.8 to -144.8], p=0.058). The size of the late reaction to Fel d 1 significantly differed between treatment groups at both follow-ups. At second follow-up, the size of the early reaction to Fel D 1, but not to whole cat dander was significantly reduced in those on peptides compared with those on placebo. The concentration of interferon gamma and of interleukin 4 and 13, and the amount of proliferation, significantly decreased between baseline and second follow-up, and the concentration of interleukin 10 was significantly higher in patients on peptides, however, none of these values differed significantly between groups. Patients on peptides had a significantly greater decrease in the concentration of interferon gamma and interleukin 13, and in the amount of proliferation between baseline and first follow-up than did those on placebo. INTERPRETATION Several, short, overlapping Fel d 1 T-cell peptides have potential in treatment of cat allergy.

Trial of cyclosporin in corticosteroid-dependent chronic severe asthma

The treatment of chronic severe asthma is unsatisfactory for many patients. In a randomised, double-blind, placebo-controlled, crossover trial we have tested whether cyclosporin, which is thought to act primarily by inhibition of T lymphocyte activation, improves lung function in corticosteroid-dependent asthmatics. After a 4-week run-in period, 33 patients with longstanding asthma (mean duration 27 years), and who had required continuous oral corticosteroids for a mean of 9.3 years, were randomised to receive either cyclosporin (initial dose 5 mg/kg per day) or placebo for 12 weeks, crossing over after a 2-week washout period. Mean baseline forced expiratory volume in 1 s (FEV1) was 60.1% of the predicted value. 2 patients failed to complete the protocol and 1 withdrew because of hypertrichosis. Cyclosporin therapy resulted in a mean increase above placebo of 12.0% in morning peak expiratory flow rate (PEFR; p less than 0.004) and 17.6% in FEV1 (p less than 0.001). The frequency of disease exacerbations requiring an increased prednisolone dose was reduced by 48% in patients on cyclosporin compared with placebo (p less than 0.02). Diurnal variation in PEFR decreased by a mean of 27.6% (p = 0.04). Cyclosporin for 12 weeks was well tolerated by this group of chronic asthmatics, in whom the mean whole-blood trough concentration was 152 micrograms/l. These findings provide further evidence of a role for activated T lymphocytes in the pathogenesis of asthma. Specific pharmacological targeting of this cell could form the basis of a novel approach to the treatment of asthma.