Department of Laboratory Medicine and Pathology, Mayo Clinic Arizona, Scottsdale, AZ, USA.
Department of Pharmacy, Mayo Clinic Arizona, Phoenix, AZ, USA.
J Anal Toxicol. 2019 Aug 23;43(7):587-590. doi: 10.1093/jat/bkz019.
Drug screening during pre-transplant evaluations can have major implications for patient care, particularly because drug abuse has been associated with poor transplant outcomes. Although urine drug screening is usually preferred, serum testing is available for situations such as anuria due to end stage renal disease. However, there are few studies evaluating serum drug screening in specific populations such as patients undergoing kidney transplant evaluation. All serum drug screens ordered between January 2015 and November 2017 on patients being evaluated for renal transplant were compared against a large population of serum drug screens ordered from other institutions. Cocaine screening and confirmation results were evaluated to determine false positives. Cocaine screens were positive in 23 of 537 (4.3%) pre-transplant samples, and 211 of 5,115 (4.1%) comparison samples. Confirmation testing demonstrated that 14 (60.9%) pre-transplant samples were false positives, which was significantly (P < 0.01) higher than the rate of false positives in the comparison group (47/211, 22.3%). No common medication or other cross-reacting substance could be identified in the pre-transplant cohort to explain the false-positive results. Although serum cocaine screening had a low overall false-positive rate, the proportion of false positives was significantly higher in pre-transplant patients. Given the poor transplant outcomes associated with drug abuse, failure to properly interpret screening results as being false positives could negatively affect patient care. All members of the transplant team should recognize the importance of confirmation testing in this setting, to avoid unintended consequences due to false-positive screening results.
药物筛选在移植前评估中具有重要意义，特别是因为药物滥用与移植结果不良有关。尽管尿液药物筛选通常是首选，但在终末期肾病导致无尿等情况下，也可进行血清检测。然而，评估特定人群（如接受肾移植评估的患者）的血清药物筛选的研究很少。将 2015 年 1 月至 2017 年 11 月间对接受肾移植评估的患者所开的所有血清药物筛查与其他机构所开的大量血清药物筛查进行比较。评估可卡因筛选和确认结果以确定假阳性。在 537 例移植前样本中有 23 例（4.3%）可卡因筛查呈阳性，5115 例对照样本中有 211 例（4.1%）可卡因筛查呈阳性。确认检测显示，14 例（60.9%）移植前样本为假阳性，这明显（P < 0.01）高于对照组的假阳性率（211 例中的 47 例，22.3%）。在移植前队列中，无法确定常见药物或其他交叉反应物质来解释假阳性结果。尽管血清可卡因筛选的总假阳性率较低，但移植前患者的假阳性率明显更高。鉴于药物滥用与移植结果不良有关，未能正确解释筛查结果为假阳性可能会对患者护理产生负面影响。移植团队的所有成员都应认识到在这种情况下确认检测的重要性，以避免因假阳性筛查结果而产生意外后果。
