SOLUBLE INTERLEUKIN-4 RECEPTOR IN ATOPIC CHILDREN

The levels of natural soluble interleukin- 4 receptor (shuIL-4R) were determined in the peripheral blood of 29 children with stable asthma, 10 children with asthma and acute respiratory infection, 11 healthy ch ildren with acute airway infection and 31 healthy controls. Healthy co ntrols revealed the highest levels (median 1,082 pg/ml, range 524-1,90 0 pg/ml); which differed significantly from levels obtained with the b lood of stable asthmatics (p<0.01, median 658 pg/ml, range 329-1288 pg /ml), patients with asthma and acute respiratory infection (p<0.01, me dian 663 pg/ml, range 0-1,250 pg/ml) and patients with respiratory inf ection alone (p < 0.01, median 674 pg/ml, range 466-1,110 pg/ml). In c ontrast, there was no significant difference in shuIL-4R content of co rd blood obtained from newborns with a high or low risk of atopy. Addi tional analysis of interleukin-4 receptor (huIL-4R) on cultured lympho cytes from 13 stable asthmatic children and 14 healthy children indica ted higher expression on CD4 cells (p<0.05, median 2.2%, range 0.8-7.8 %) compared to healthy controls (median 1.3%, range 0.73.3%). Therefor e, diminished shuIL-4R concentrations in plasma may be related to infl ammatory states but not specifically to atopy. The results support the notion that huIL-4R expressed on the cell surface may be regulated di fferently from the soluble form.