テオフィリンの体液中濃度測定におけるHomogeneous Enzyme Immunoassayを応用したSyva System (AC-5000) の評価

The applicability of recently developed instrument, automatic Syva System AC-5000 (EMIT-AC), was evaluated. The concentration of total or free theophylline (TH) in plasma, serum, saliva, and spiked sample was measured by EMIT-AC. The results were compared with those obtained by high performance liquid chromatography (HPLC) or substratelabeled fluorescent immunoassay (SLFIA). There was no significant difference (P>0.05) between the results obtained by EMIT-AC and HPLC method using TH spiked samples. The within-day precision of EMIT-AC method was less than 4.5% as the coefficient of variation (C.V.). The C. V. value for between-day precision was 6.3% for EMIT-AC and 3.7% for HPLC method and no significant difference (P>0.05) was observed between the mean values. A good correlation was obtained between EMIT-AC and HPLC method (n=54, r=0.988, P<0.001 for plasma; n= 22, r= 0.998, P<0.001 for serum) in the assay of total TH level. Similar observation was obtained in the free level assay. It was clarified that saliva level can also be analyzed by EMIT-AC method as well as SLFIA method. These findings show that EMIT-AC method is a satisfactory analytical device for giving correct results and applicable for the determination of TH level in body fluid especially in clinical drug monitoring requiring rapidity.