- 期刊
C-反應蛋白之量測差異性與台灣族群參考值分佈
C-Reactive Protein Measurement Variation and the Taiwan Population Distribution
摘要
C-反應蛋白(CRP)檢測值可以預測發炎與血管粥狀硬化症狀，因此對於分析過程須標準化，避免心血管風險之誤判。本研究收集2組病患（每組13人）具Li-Heparin、SST Ⅱ、K2EDTA三種試管之檢体，分別以Beckman LX-20與Beckman Immage儀器檢測一般CRP與hsCRP。結果發現使用不同採血管或不同檢驗方法其CRP濃度不具統計學差異。Immage與LX-20的不精密性小於廠商宣稱的10%以內。兩台分析儀的靈敏度爲0.02-0.03 mg/dL (0.8-9.3%)。CRP在攝氏4度下儲存28天仍極穩定。2674位健檢年齡與hsCRP値的分佈顯示不具相關(R^2=0.001)。各年齡層中位數爲0.20-0.31 mg/dL。本研究也採集1031位血液培養陽性（共1418株菌），且其當天或隔天具有CRP檢驗報告的病患個案檢體，以血液培養爲標準，評估CRP的偽陰性率。結果顯示Escherichia coli、Klebsiella pneumoniae、Pseudomonas aeruginosa、Staphylococcus aureus的感染檢體中，其CRP偽陰性率分別爲5.2%、4.6%、7.7%、8.5%。本研究結果顯示經由與血液培養結果作比較，可進一步瞭解利用BeckmanLX-20與Beckman Immage來量測CRP的精密性與靈敏度，更進一步了解量測CRP的僞陰性率。除了注意檢體採集與保存方式外，研究結果不支持hsCRP參考值會隨年紀增長而增加的論點。
並列摘要
Objective: C-reactive protein (CRP) is a well-known indicator of inflammation and atherogenesis. One of the issues related to CRP levels is the analytical process. This must be considered and standardized to avoid potential misclassification of cardiovascular risk. We collected two groups of patients (13 patients per group) and each patient had samples collected using three different types of collection system, namely Li-Heparin, SST Ⅱ and K2EDTA. Using these samples, CRP and hsCRP levels were measured using either a Beckman LX-20 or a Beckman Immage analyzer. Results showed that different tubes/methods resulted in no significant statistical variation in the CRP values. Furthermore, the level of imprecision for CRP measurement by either Immage or LX-20 met the criteria stated in manufacture's claims (＜10%). The sensitivity of both analyzers was 0.02-0.03 mg/dL (0.8-9.3%). CRP was shown to be fibrously stable at 4℃ for 28 days. Distribution of collected CRP results stratified and showed no statistically significant relationship (r^2=0.001) according to sample age, using a population of 2674 individuals from a health care department. The median hsCRP concentration for the various age groups was 0.20-0.31 mg/dL. To evaluate the false negative rate on CRP measurement, we also collected positive blood cultures from 1031 cases involving 1418 bacterial strains. The CRP results of the samples available from the same or the next day were used for comparison. The false negative rates for CRP measurement varied with different bacterial infections: Escherichia coli 5.2% (10/194), Klebsiella pneumoniae 4.6% (3/65), Pseudomonas aeruginosa 7.7% (2/26), and Staphylococcus aureus 8.5% (4/47). Based on the results of this study, the precision and sensitivity of CRP analysis by Beckman LX-20 or Beckman Immage analyzer were evaluated. Furthermore, a closer evaluation at the false negative rate for CRP measurement was achieved. Our results emphasized importance of specimen collection and storage, but did not support previous findings that hsCRP reference value is increased in proportion to age.