檢體處理方式對intact PTH檢測值之影響

Effect of Specimen Processing Methods on Test Results for intact PTH

鄭敏琳(Min-Lin Cheng) ； 黃凱琳(Kai-Lin Iluang) ； 文耀閣(Yao-Ko Wen) ； 張正雄(Cheng-Shyong Chang) ； 李靜惠(Ching-Hui Lee) ； 楊郁(Yu Yang) ； 王寶田(Bao-Tyan Wang)

《The Changhua Journal of Medicine》 7卷1期 (2002/01) Pp. 8-13

摘要

背景：本項研究分別以不同採血管、血量、儲存時間及溫度，測得intact parathyroid hormone (iPTH)值，並分組比較，希望將iPTH檢體採集及處理標準化，並找到可簡化檢體處理流程的方法，以提升檢驗報告品質。
方法：我們收集46位洗腎病人洗腎前之血液；分別置於SST試管及EDTA試管。將自EDTA試管分離之血漿，按不同採血量(5ml或2ml)、不同儲存時間（採血後立即檢測、放置後4小時或48小時後檢測）及不同溫度（4℃低溫及室溫）分組，以化學冷光免疫分析法分別檢測iPTH值，計算其平均值，並將各組數據分別與標準SST試管〔採5ml檢體，以4℃低溫傳送，立即檢測或4小時後檢測〕之檢測值以Pearson相關係數與迴歸方程式做相關性分析比較。
結果：以SST試管採集之5ml檢體經放置室溫4小時後檢測之平均值明顯較標準SST試管(採5ml檢體，以4℃低溫傳送，立即檢測)所得的數值為低(P值＜0.001)。EDTA試管5ml檢體以室溫傳送，立即測得或經放置48小時後測得之iPTH平均值與標準SST試管測得的數值無顯著差異。EDTA試管採集2ml檢體以室溫傳送，立即測得之iPTH平均值顯著低於較標準SST試管測得的值。
結論：本項研究顯示，EDTA試管採血5ml應可取代標準SST試管，其優點是採檢後不需低溫傳送，且於室溫穩定度較高，對病房採檢者及臨床實驗室操作者而言，比較無需立即處理檢體之壓力，但其缺點是所需血量較多，較不適用於小兒科病童。

關鍵字

iPTH ； SST試管 ； EDTA試管 ； 化學冷光免疫分析法

並列摘要

To establish a standard specimen processing procedure for iPTH (intact parathyroid hormone) tests using different blood processing conditions by varying the collection tube, the blood volume, the time interval before test and the temperature during transport and holding in this study.
Blood specimens were drawn into two different collecting tubes, one standard SST tube and one EDTA tube, from each of the 46 patients entered in this study. The plasma collected from EDTA tubes was aliquoted into centrifuge tubes, divided into groups and then tested with chemiluminescent immunometric assay for iPTH. The effects of different conditions, including the blood volume, the time interval before test, and the effect of temperature during transport and holding, were determined for iPTH test outcomes. Data thus obtained were calculated for standard 5ml SST tubes and EDTA tubes, and analyzed using Pearson’s correlation coefficient and linear regression methods.
The average iPTH value in 5ml SST tubes after 4 hours at room temperature was significantly lower than that of standard SST 5ml tubes transported in ice and tested immediately (P＜0.00l). The average iPTH values obtained from samples collected in 5m1 EDTA tubes, transported at room temperature and tested immediately, or at up to 48 hours after collection, were not significantly different from results using standard SST tubes. However, the average iPTH value for samples collected 2m1 in EDTA tubes transported at room temperature and tested immediately, is significantly different from that of 5m1 blood collected in standard SST tubes (P＜0.001).
Our data indicated that the 5ml EDTA tube should be used in place of the standard 5ml SST tube to collect blood samples for iPTH tests. The advantages of using 5m1 EDTA tube over the standard 5m1 SST tube for blood collection are that the blood specimen stays stable at least for 2 hours at room temperature, the sample does not require low temperature during transit and the sample does not require immediate processing. However, the 5m1 EDTA tube requires 5ml volume of blood and therefore is not adequate for use on pediatric patients.

並列關鍵字

iPTH ； SST tubes ； EDTA tubes ； chemiluminescent immunometric assay