[Differences in the levels of serum immunoglobulin E determined by the competitive radio-immuno-sorbent and the paper-radioimmuno-sorbent methods: Removal of these differences by pretreatment of sera with polyethylene glycol (author's transl)].

The serum IgE of patients with chronic nonspecific lung diseases was determined with the competitive radio-immuno-sorbent and the paper-radio-immuno-sorbent methods (Phadebas). Some samples showed markedly higher values with the competitive radio-immuno-sorbent than with the paper-radio-immuno-sorbent method. These discrepancies were abolished by pretreatment of the sera: polyethylene glycol 6000 (final concentration 35 g/l) was added, followed by centrifugation at 0 degrees C for 30 min at 20 000 g, and IgE was determined in the supernatant. This treatment had no effect on the values of the paper-radio-immuno-sorbent method, but the values of the competitive radio-immuno-sorbent method were decreased so that the two values agreed within the experimental confidence limits.