Chronic Wasting Disease Diagnostic Discrepancies: The Importance of Testing Both Medial Retropharyngeal Lymph Nodes
Chronic Wasting Disease Diagnostic Discrepancies: The Importance of Testing Both Medial Retropharyngeal Lymph Nodes
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DOI：
10.7589/jwd-d-20-00007
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发表时间：
2021-01-01
影响因子：
1.3
通讯作者：
Straka, Kelly
中科院分区：
文献类型：
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作者：
Bloodgood, Jennifer;Kiupel, Matti;Straka, Kelly
白色尾鹿的慢性消耗性疾病（CVVD）是一种正在北美蔓延的致命性神经系统疾病。目前，CWD的常见监测方案包括用酶联免疫吸附试验（ELISA）进行筛查，然后用免疫组织化学（IHC）进行确证性检测。咽后内侧淋巴结（MRPLN）是诊断自由放养白尾鹿慢性消耗病的首选组织。我们检查了2015年至2019年收获的101只ELISA阳性鹿的左右MRPLN，以确定IHC未检测到朊病毒蛋白的病例的患病率以及对侧淋巴结之间IIIC标记的差异。在5.9%（6/101）的病例中，使用IHC在MRPLN中未检出朊病毒蛋白。IHC阳性卵泡数与ELISA光密度值呈显著但弱的正相关（R-2=0.08，P=0.039）。IHC阳性MRPLN的平均光密度值高于IHC阴性MRPLN;然而，这不具有统计学显著性（P：21.260）。未能用IHC确认ELISA诊断可能是因为该方法测试了MRPLN的不同区域，或者测试灵敏度或抗体亲和力存在差异。另外5.9%（6/101）的病例有一个IHC阳性MRPLN，而对侧MRPLN为IHC阴性。因此，无论采用何种方法，测试单个MRPLN的CWD都可能导致假阴性结果，这凸显了收集和测试两个MRPLN的重要性。
Chronic wasting disease (CVVD) of white tailed deer (Odocoileus virginianus) is a fatal neurologic disease that is spreading across North America. A common surveillance protocol for CWD currently involves screening with an enzyme-linked immunosorbent assay (ELISA) followed by confirmatory testing with immunohistochemistry (IHC). Medial retropharyngeal lymph nodes (MRPLN) are the tissue of choice to diagnose CWD in free-ranging white-tailed deer. We examined left and right MRPLN from 101 ELISA-positive deer harvested from 2015 to 2019 to determine the prevalence of cases in which prion protein was not detected by IHC as well as differences in IIIC labeling between contralateral lymph nodes. Prion protein was not detected using IHC in either MRPLN in 5.9% (6/101) of cases. There was a significant but weak positive relationship between the number of IHC-positive follicles and ELISA optical density values (R-2=0.08, P=0.039). Mean optical density values in IHC-positive MRPLN were higher than in IHC-negative MRPLN; however, this was not statistically significant (P:21.260). Failure to confirm ELISA diagnoses with IHC may have been because the methods tested different areas of MRPLN, or that there were differences in test sensitivity or antibody affinity. An additional 5.9% (6/101) of cases had one IHC-positive MRPLN, whereas the contralateral MRPLN was IHC negative. Therefore, testing a single MRPLN for CWD may lead to false-negative results, regardless of methodology, which highlights the importance of collecting and testing both MRPLN.