{"title":"长期冷冻对诊断马原生动物髓脑炎间接荧光抗体效价的影响","authors":"Claudia Valderrama-Martinez, Andrea Packham, Woutrina Smith, Jorge Eduardo Mendoza-Flores, Shichen Zheng, Munashe Chigerwe, Magdalena Plancarte, Monica Aleman","doi":"10.1111/jvim.70225","DOIUrl":null,"url":null,"abstract":"<div>\n \n \n <section>\n \n <h3> Background</h3>\n \n <p>Long-term freezing storage can alter the stability of proteins, thereby compromising accurate determination of indirect fluorescent antibody test (IFAT) titers that support the diagnosis of equine protozoal myeloencephalitis.</p>\n </section>\n \n <section>\n \n <h3> Objective</h3>\n \n <p>Assess the effect of long-term storage at −80°C on IFAT against <i>S. neurona</i> and <i>N. hughesi</i> in equine serum and cerebrospinal fluid (CSF).</p>\n </section>\n \n <section>\n \n <h3> Samples</h3>\n \n <p>Paired serum and CSF (<i>n</i> = 46), and serum only (<i>n</i> = 25) samples.</p>\n </section>\n \n <section>\n \n <h3> Methods</h3>\n \n <p>Prospective study of samples stored 6–12, 13–18, and 19–24 months. Comparing antibody titers across time points, McNemar and Wilcoxon rank tests were used for statistical analysis.</p>\n </section>\n \n <section>\n \n <h3> Results</h3>\n \n <p>After long-term freezing storage for 19–24 months, <i>N. hughesi</i> IFAT results for CSF were significantly different compared with their fresh-testing time point (<i>p</i> = 0.04), but a similar difference was not observed for serum samples. No statistical differences were observed for serum or CSF samples tested for <i>S. neurona</i> after 6–12, 13–18, or 19–24 months compared with their original fresh testing results. However, the serum to CSF ratio cutoff of ≤ 64 in support of disease changed in 41% (19 of 46) of paired samples.</p>\n </section>\n \n <section>\n \n <h3> Conclusions and Clinical Importance</h3>\n \n <p>Freezing samples at −80°C for more than 18 months might alter test results, leading to possible changes in serum to CSF ratio calculations and affecting the interpretation of results for clinical and research purposes.</p>\n </section>\n </div>","PeriodicalId":49958,"journal":{"name":"Journal of Veterinary Internal Medicine","volume":"39 5","pages":""},"PeriodicalIF":2.2000,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jvim.70225","citationCount":"0","resultStr":"{\"title\":\"Effect of Long-Term Freezing on Indirect Fluorescent Antibody Titers for the Diagnosis of Equine Protozoal Myeloencephalitis\",\"authors\":\"Claudia Valderrama-Martinez, Andrea Packham, Woutrina Smith, Jorge Eduardo Mendoza-Flores, Shichen Zheng, Munashe Chigerwe, Magdalena Plancarte, Monica Aleman\",\"doi\":\"10.1111/jvim.70225\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div>\\n \\n \\n <section>\\n \\n <h3> Background</h3>\\n \\n <p>Long-term freezing storage can alter the stability of proteins, thereby compromising accurate determination of indirect fluorescent antibody test (IFAT) titers that support the diagnosis of equine protozoal myeloencephalitis.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Objective</h3>\\n \\n <p>Assess the effect of long-term storage at −80°C on IFAT against <i>S. neurona</i> and <i>N. hughesi</i> in equine serum and cerebrospinal fluid (CSF).</p>\\n </section>\\n \\n <section>\\n \\n <h3> Samples</h3>\\n \\n <p>Paired serum and CSF (<i>n</i> = 46), and serum only (<i>n</i> = 25) samples.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Methods</h3>\\n \\n <p>Prospective study of samples stored 6–12, 13–18, and 19–24 months. Comparing antibody titers across time points, McNemar and Wilcoxon rank tests were used for statistical analysis.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Results</h3>\\n \\n <p>After long-term freezing storage for 19–24 months, <i>N. hughesi</i> IFAT results for CSF were significantly different compared with their fresh-testing time point (<i>p</i> = 0.04), but a similar difference was not observed for serum samples. No statistical differences were observed for serum or CSF samples tested for <i>S. neurona</i> after 6–12, 13–18, or 19–24 months compared with their original fresh testing results. However, the serum to CSF ratio cutoff of ≤ 64 in support of disease changed in 41% (19 of 46) of paired samples.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Conclusions and Clinical Importance</h3>\\n \\n <p>Freezing samples at −80°C for more than 18 months might alter test results, leading to possible changes in serum to CSF ratio calculations and affecting the interpretation of results for clinical and research purposes.</p>\\n </section>\\n </div>\",\"PeriodicalId\":49958,\"journal\":{\"name\":\"Journal of Veterinary Internal Medicine\",\"volume\":\"39 5\",\"pages\":\"\"},\"PeriodicalIF\":2.2000,\"publicationDate\":\"2025-08-27\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jvim.70225\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Veterinary Internal Medicine\",\"FirstCategoryId\":\"97\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1111/jvim.70225\",\"RegionNum\":2,\"RegionCategory\":\"农林科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"VETERINARY SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Veterinary Internal Medicine","FirstCategoryId":"97","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/jvim.70225","RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"VETERINARY SCIENCES","Score":null,"Total":0}
Effect of Long-Term Freezing on Indirect Fluorescent Antibody Titers for the Diagnosis of Equine Protozoal Myeloencephalitis
Background
Long-term freezing storage can alter the stability of proteins, thereby compromising accurate determination of indirect fluorescent antibody test (IFAT) titers that support the diagnosis of equine protozoal myeloencephalitis.
Objective
Assess the effect of long-term storage at −80°C on IFAT against S. neurona and N. hughesi in equine serum and cerebrospinal fluid (CSF).
Samples
Paired serum and CSF (n = 46), and serum only (n = 25) samples.
Methods
Prospective study of samples stored 6–12, 13–18, and 19–24 months. Comparing antibody titers across time points, McNemar and Wilcoxon rank tests were used for statistical analysis.
Results
After long-term freezing storage for 19–24 months, N. hughesi IFAT results for CSF were significantly different compared with their fresh-testing time point (p = 0.04), but a similar difference was not observed for serum samples. No statistical differences were observed for serum or CSF samples tested for S. neurona after 6–12, 13–18, or 19–24 months compared with their original fresh testing results. However, the serum to CSF ratio cutoff of ≤ 64 in support of disease changed in 41% (19 of 46) of paired samples.
Conclusions and Clinical Importance
Freezing samples at −80°C for more than 18 months might alter test results, leading to possible changes in serum to CSF ratio calculations and affecting the interpretation of results for clinical and research purposes.
期刊介绍：
The mission of the Journal of Veterinary Internal Medicine is to advance veterinary medical knowledge and improve the lives of animals by publication of authoritative scientific articles of animal diseases.
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