A 69 year old patient with cirrhosis presented to the ER with fever. Her bilirubin was markedly elevated at 7.4 g/dl and her hemoglobin and hematocrit were measured at 13.4 g/dl and 35.6% respectively with a MCV of 103.2 fl and MCH of 38.5 pg. The next day her H/H were 11.9 g/dl and 31.3 % respectively. While her hemoglobin one day later was 11.9 g/dl, the reported hematocrit was 39.3%. Patient had a bilirubin level of 8.7 g/dl at this time.
一名 69 岁的肝硬化患者因发热到急诊室就诊。她的胆红素显着升高至 7.4 g/dl，血红蛋白和血细胞比容分别为 13.4 g/dl 和 35.6%，MCV 为 103.2 fl，MCH 为 38.5 pg。第二天，她的H/H分别为11.9 g/dl和31.3%。一天后，她的血红蛋白为 11.9 g/dl，而报告的血细胞比容为 39.3%。此时患者的胆红素水平为 8.7 g/dl。
The fluctuating numbers together with the discrepancy between hemoglobin and hematocrit over a very short period of time was concerning. We realized that presence of markedly icteric plasma was responsible for these discordant values. Saline replacement and spun crit were performed in order to correct interference by bilirubin. Subsequent measurements of H/H revealed hemoglobin in the range of 12.9 g/dl with a hematocrit of 38% and a MCV of 113 fl. As the bilirubin levels started dropping (in the range of 6.5 g/dl) the hemoglobin level measured by the analyzer fell in the range of 10.3 to 11 g/dl. The instrument (XN-200) gave no error codes and therefore we were able to report out the analyzer results without correction. It was however very important to convey to the clinical team that the H/H values did not truly represent a fall from the previous values. As the two methodologies were different (spun crit and plasma replacement was being no longer performed) the numbers should be interpreted accordingly. Patient was not bleeding actively and did not require any blood transfusion.
在很短的时间内，数字的波动以及血红蛋白和血细胞比容之间的差异令人担忧。我们意识到，明显黄疸血浆的存在是造成这些不一致值的原因。进行生理盐水置换和旋转暴击以纠正胆红素的干扰。随后的 H/H 测量显示血红蛋白在 12.9 g/dl 范围内，血细胞比容为 38%，MCV 为 113 fl。随着胆红素水平开始下降（在 6.5 g/dl 范围内），分析仪测量的血红蛋白水平在 10.3 至 11 g/dl 的范围内下降。仪器（XN-200）没有给出任何错误代码，因此我们能够在不进行校正的情况下报告分析仪结果。然而，向临床团队传达 H/H 值并不真正代表从以前的值下降非常重要。由于两种方法不同（不再进行旋转暴击和血浆置换），因此应相应地解释这些数字。患者没有主动出血，也不需要任何输血。
Interference occurs when a substance or process falsely alters an assay result. Interferences are classified as endogenous or exogenous. Endogenous interference originates from substances present in the patient’s own specimen. Exogenous interferences are substances introduced into the patient’s specimen. Interference from hemolysis, icterus and lipemia are most frequently studied. Protein interferences are most often associated with paraproteins and predominantly with IgM or IgG and rarely with IgA. Drug interference may be due to the parent drug, metabolite(s) or additives in the drug preparation. Determining if interference is significant requires deviation limits from the original result. Once interferences are identified there is a need to establish procedures for handling affected results as part of the quality system.
当物质或过程错误地改变检测结果时，就会发生干扰。干扰分为内源性干扰和外源性干扰。内源性干扰源于患者自身标本中存在的物质。外源性干扰是引入患者标本的物质。最常研究的是溶血、黄疸和脂肪血症的干扰。蛋白质干扰最常与副蛋白相关，主要与 IgM 或 IgG 相关，很少与 IgA 相关。药物干扰可能是由于药物制剂中的母体药物、代谢物或添加剂造成的。确定干扰是否显著需要与原始结果的偏差限制。一旦识别出干扰，就需要建立处理受影响结果的程序，作为质量体系的一部分。
Hemoglobin is quantified based on its absorption characteristics. Conditions such as
hyperlipidemias
, hyperbilirubinemia, a very high white blood cell count, and high serum protein can interfere with this measurement and result in falsely elevated hemoglobin values. When the values of hemoglobin, red cell count, and MCV are affected, MCH and MCHC also become abnormal, since these indices are calculated and are not directly measured. Sometimes a set of spurious values may be the first clue to an otherwise unsuspected clinical condition (e.g., the combination of low hematocrit, normal hemoglobin, and high MCV and MCHC is characteristic of cold agglutinins).
血红蛋白根据其吸收特性进行定量。高脂血症、高胆红素血症、非常高的白细胞计数和高血清蛋白等疾病会干扰该测量并导致血红蛋白值假性升高。当血红蛋白、红细胞计数和MCV的值受到影响时，MCH和MCHC也会变得异常，因为这些指标是计算出来的，而不是直接测量的。有时，一组虚假值可能是其他未被怀疑的临床状况的第一个线索（例如，低血细胞比容、正常血红蛋白以及高 MCV 和 MCHC 的组合是冷凝集素的特征）。
Although one must pay attention to very high amounts of bilirubin within the plasma, most hematology analyzers do not presently demonstrate any interference with bilirubin, at least for concentrations up to 250 mg/l. Above these values attention is however needed.
尽管必须注意血浆中非常高的胆红素含量，但大多数血液学分析仪目前没有显示出对胆红素的任何干扰，至少在浓度高达 250 mg/l 时是这样。然而，在这些值之上，需要注意。
High serum or plasma bilirubin concentrations can cause spectral interference with assays near the bilirubin absorbance peak of ~ 456 nm. Chemical interference e.g. with peroxidase-catalysed reactions may also occur.
高血清或血浆胆红素浓度会导致对胆红素吸光度峰值 ~ 456 nm 附近的测定产生光谱干扰。化学干扰，例如过氧化物酶催化的反应也可能发生。
-Neerja Vajpayee, MD, is the director of Clinical Pathology at Oneida Health Center in Oneida, New York and is actively involved in signing out surgical pathology and cytology cases in a community setting. Previously, she was on the faculty at SUNY Upstate for several years ( 2002-2016) where she was involved in diagnostic work and medical student/resident teaching.
-医学博士 Neerja Vajpayee 是纽约奥奈达市奥奈达健康中心的临床病理学主任，积极参与在社区环境中签署外科病理学和细胞学病例。此前，她在纽约州立大学上州分校任教数年（2002-2016 年），在那里她参与了诊断工作和医学生/住院医师教学。
