気管支喘息における Eosinophil Cationic Protein 血清中濃度測定の臨床的意義  [in Japanese] MEASUREMENT OF SERUM EOSINOPHIL CATIONIC PROTEIN LEVELS IN BRONCHIAL ASTHMA  [in Japanese]

小児気管支喘息患者において, 好酸球中に含まれる顆粒蛋白の一つである eosinophil cationic protein (ECP) の血中濃度を測定し臨床的パラメータ-との関連, 日内変動の有無について検討した. 対象は重症気管支喘息患児89名, 非アレルギー正常小児及び成人16名で, 6, 12, 17, 21, 翌朝6時に血清 ECP, 好酸球数(Eo), 肺機能を測定し, 臨床症状と合わせて検討した. ECP は radioimmunoassay にて測定した. 血清 ECP, Eo ともに非アレルギー群と比較して喘息群で高く特に採血時に喘息発作が認められたとき有意に高値を示した. 発作前後の変動では血清 ECP は発作後24時間まで高値であり, 7日以内に発作前値に戻った. 一方, 一定の日内変動リズムは認められなかったが, 喘息群 (非発作群) では有意に変動幅が大きく, 不安定であった. ECP と採血前2ないし8週間の発作点数の合計, 肺機能とは相関はなかった. 以上より血清 ECP は喘息特にその活動期に高値となり, 好酸球の活性化の状態を反映している可能性が考えられた. 今後, 気管支喘息の臨床評価の一手段として有用であると思われた.

We investigated the possibility of a relationship between the serum levels of eosinophil cationic protein (ECP) and the clinical parameters in asthma. A specific question was whether or not serum ECP Changes with a circadian rhythm. Eighty nine children with bronchial asthma and sixteen normal, non-atopic subjects were studied. Serum ECP, eosinophil counts (Eo) and pulmonary functions were measured 4 or 5 times a day. ECP was quantitated by a spetific radioimmunoassay. Serum ECP and Eo were significantly higher in the patients with bronchial asthma than in non-atopic subjects. Serum ECP levels were higher during asthma attacks and at 24 hours after attacks than those in stable conditions (free of attacks for more than 7 days). Although no circadian rhythm was observed in ECP changes, the patients with bronchial asthma showed a significantly greater variation of serum ECP levels than the non-atopic subjects. There was no significant correlation between serum ECP levels and 2- or 8-week attack score before the ECP measurement. These results suggest that serum ECP increases in bronchial asthma, especially in its acute exacerbation phase, and may reflect eosinophil activation in vivo.