Value of serial peak expiratory flow measurements in assessing treatment response in chronic airflow limitation.

A double blind, randomised, placebo controlled, crossover trial of prednisolone (40 mg/day for 14 days) was carried out in 33 patients with chronic airflow limitation (mean age 62 years, mean FEV1 1.01 litres, mean FEV1/FVC ratio 44%), to assess the value of serial peak expiratory flow (PEF) measurements, taken five times daily in evaluating treatment response by comparison with other objective measurements and with measurements of symptoms. The mean serial PEF after a one week run in period was 189 1 min-1, during the second week of placebo 193 1 min-1, and during the second week on prednisolone 231 1 min-1. The difference in mean PEF values between placebo and prednisolone was significant (p less than 0.01). With regard to the response to steroids of the individual patients, 13 of the 33 had a detectable trend of improvement on visual inspection of serial PEF measurements during prednisolone treatment but only one during placebo administration. Of all the objective measurements made after the run in and after each treatment phase (12 minute walking distance, FEV1, forced vital capacity (FVC), serial PEF), the serial PEF chart provided the best discrimination between placebo and prednisolone treatment. There was no statistically significant association between steroid induced improvement in serial PEF measurements and in breathlessness, partly because of placebo improvements in symptoms in those who had no improvement in serial PEF values. This study indicates the importance of making objective measurements to identify a genuine steroid response rather than relying on symptomatic improvement alone. The best simple measurement to make is serial PEF during steroid trials. This is more sensitive in detecting a steroid response than are the 12 minute walking distance, FEV1, or FVC, and is also less likely than these measurements to show spurious placebo responses.

Renal carcinoma in Lindau's disease.

A case of Lindau's disease is presented where renal carcinoma was detected 2.5 years after surgical removal of a cerebellar haemangioblastoma. This patient had no retinal lesions. The importance of screening for renal carcinoma in patients showing one or more manifestations of the disease and screening relatives is emphasized.

Effects of prednisolone in chronic airflow limitation.

A double-blind, randomised, placebo-controlled, crossover trial of prednisolone (40 mg daily for 14 days) was carried out in 43 patients with chronic airflow limitation (mean age 60 years, mean FEV1 1.02 litres, FEV1/FVC ratio 43.7%). Several subjective and objective variables for response were measured. Significant improvements occurred with prednisolone in most variables measured, but improvements also occurred with placebo in some variables. The improvements with prednisolone in general wellbeing, 12 min walk distance, peak expiratory flow, FEV1, and relaxed vital capacity were significantly greater than those with placebo. Clinical assessment and assessment of atopic status did not reveal any feature of major predictive value for steroid responsiveness. A proportion of patients with chronic airflow limitation do improve on oral corticosteroids and the continued use of such trials in clinical practice is justified, though a placebo period should be included, and several variables for response should be measured.

Screening for IgE-mediated allergy.

Sera from 425 patients were analysed with Phadebas RAST reagents against a panel of 19 allergens and the most commonly positive results were to grass pollen, Dermatophagoides pteronyssinus and cat epithelium. Of the 275 sera RAST-positive to any allergen, 261 were positive by a RAST technique which used a mixture of the three most common U.K. allergens; the remainder were usually positive to a mould. We conclude that 1) when a positive result is obtained after screening by the mixed-allergen RAST and a representative mould RAST, then other positive RAST results are possible, but that the extent of the investigation can be guided by a knowledge of the total serum IgE level and a computer-based history analysis; 2) when a mixed-allergen RAST and a representative mould RAST is negative, then a more specified RAST including all 19 allergens used in this investigation will be negative; 3) a positive mixed-allergen RAST result is likely to be associated with a total serum IgE level over 40 U/ml and a positive symptom pattern score derived from the computer-based history analysis.