Lipsett Susan C, Branda John A, McAdam Alexander J, Vernacchio Louis, Gordon Caroline D, Gordon Catherine R, Nigrovic Lise E
Division of Emergency Medicine.
Department of Pathology, Massachusetts General Hospital, Boston.
Clin Infect Dis. 2016 Oct 1;63(7):922-8. doi: 10.1093/cid/ciw427. Epub 2016 Jun 28.
The commercially-available C6 Lyme enzyme immunoassay (EIA) has been approved to replace the standard whole-cell sonicate EIA as a first-tier test for the diagnosis of Lyme disease and has been suggested as a stand-alone diagnostic. However, the C6 EIA has not been extensively studied in pediatric patients undergoing evaluation for Lyme disease.
We collected discarded serum samples from children and adolescents (aged ≤21 years) undergoing conventional 2-tiered testing for Lyme disease at a single hospital-based clinical laboratory located in an area endemic for Lyme disease. We performed a C6 EIA on all collected specimens, followed by a supplemental immunoblot if the C6 EIA result was positive but the whole-cell sonicate EIA result was negative. We defined a case of Lyme disease as either a clinician-diagnosed erythema migrans lesion or a positive standard 2-tiered serologic result in a patient with symptoms compatible with Lyme disease. We then compared the performance of the C6 EIA alone and as a first-tier test followed by immunoblot, with that of standard 2-tiered serology for the diagnosis of Lyme disease.
Of the 944 specimens collected, 114 (12%) were from patients with Lyme disease. The C6 EIA alone had sensitivity similar to that of standard 2-tiered testing (79.8% vs 81.6% for standard 2-tiered testing; P = .71) with slightly lower specificity (94.2% vs 98.8% 2; P < .002). Addition of a supplemental immunoblot improved the specificity of the C6 EIA to 98.6%.
For children and adolescents undergoing evaluation for Lyme disease, the C6 EIA could guide initial clinical decision making, although a supplemental immunoblot should still be performed.
市售的C6莱姆病酶免疫测定法（EIA）已被批准替代标准全细胞超声裂解物EIA作为莱姆病诊断的一线检测方法，并且有人建议将其作为独立诊断方法。然而，C6 EIA尚未在接受莱姆病评估的儿科患者中进行广泛研究。
我们从一家位于莱姆病流行地区的医院临床实验室收集了接受莱姆病常规两级检测的儿童和青少年（年龄≤21岁）废弃血清样本。我们对所有收集的标本进行C6 EIA检测，如果C6 EIA结果为阳性但全细胞超声裂解物EIA结果为阴性，则进行补充免疫印迹检测。我们将莱姆病病例定义为临床医生诊断的游走性红斑病变，或有莱姆病相关症状患者的标准两级血清学检测结果呈阳性。然后，我们比较了单独使用C6 EIA以及作为一线检测后进行免疫印迹检测与标准两级血清学检测在莱姆病诊断中的性能。
在收集的944份标本中，114份（12%）来自莱姆病患者。单独使用C6 EIA的敏感性与标准两级检测相似（分别为79.8%和81.6%；P = 0.71），特异性略低（分别为94.2%和98.8%；P < 0.002）。补充免疫印迹检测将C6 EIA的特异性提高到98.6%。
对于接受莱姆病评估的儿童和青少年，C6 EIA可指导初始临床决策，尽管仍应进行补充免疫印迹检测。
