紅血球脆性試驗生物參考區間驗證及判讀方法的改善

Validation of Biological Reference Interval and Effects Evaluation on Result Interpretation by a Modified RBC Fragility Test

紅血球脆性試驗(RBC fragility test)是利用不同濃度的低張氯化鈉溶液來測定紅血球細胞膜滲透壓的耐受性，臨床上常用於遺傳性球形紅血球增多症的輔助診斷。將血液檢體於37℃孵育24小時後進行此試驗（孵育型紅血球脆性試驗），可提高診斷遺傳性球形紅血球增多症的敏感度，但此方法之參考值卻顯少被討論。由於環境與技術因素會影響到紅血球脆性試驗的檢驗結果，因此本研究目標主要為建立與驗證本實驗室之生物參考區間。肉眼觀察試管判讀紅血球脆性試驗結果存在些干擾與限制，本研究發現，藉由肉眼觀察96孔盤判讀開始溶血濃度比傳統肉眼觀察試管判讀結果來得容易，此外，在生物參考區間附近增加四個氯化鈉溶液濃度，以及比對參考溶血百分比結果，可提升紅血球脆性試驗結果判讀的容易性與正確性。

The RBC fragility test is used to evaluate the capacity of red blood cells which resist osmotic stress in various concentrations of hypotonic sodium chloride (NaCl) solution. This test is clinically useful for the diagnosis of hereditary spherocytosis. Previous studies indicated sensitivity of the test can be improved through incubating blood samples at 37℃ for 24 hours. However, the reference value of the incubated method is rarely discussed. Furthermore, certain environmental and technical factors might also influence the measurement results of the test. Therefore, we aimed to determine and validate in house biological reference interval on the RBC fragility test. There are some interference and limiting conditions that may affect visual selection of the proper NaCl concentrations of the minimal and maximal hemolysis. Results of this study indicated that it is easier to observe the minimal degree of hemolysis in 96-well microplate than in glass tube. Moreover, by adding four NaCl concentrations within reference range and using the calculated percentage of hemolysis, accuracy of the RBC fragility test is improved. Taken together, a modified procedure to evaluate the RBC fragility test was developed and its biological reference interval was validated.