Differentiating immune-mediated causes from other causes of anemia and thrombocytopenia can be challenging. Flow cytometry can detect surface-associated immunoglobulin (sIg) on red blood cells (RBC) and platelets (PLT) in dogs and horses. Sample storage parameters for ideal assay performance has not been evaluated in horses. The study objective is to identify optimal storage time and temperature of equine whole blood for the detection of RBC-sIg and PLT-sIg via flow cytometry. Both assays were performed on samples at time 0, 4, 24, 48, and 72 h post collection. RBC-sIg samples were stored at 4 °C and PLT-sIg samples were stored at 4 °C and room temperature. RBC-sIg percentages were stable up to 72 h storage. Platelet surface-associated IgG percent positive platelets increased above baseline at all timepoints and percent positive platelets were inconsistent across timepoints for IgM and IgA. PLT-sIg testing should ideally be performed within 4 h of collection. In instances where this is not feasible, samples should be stored at 4 °C and analyzed no later than 24 h after collection. Whereas cutoff values for RBC-sIg remained similar across timepoints, results for PLT-sIg should be compared to time-specific cutoff or reference intervals established by the laboratory running the test.

将免疫介导的原因与贫血和血小板减少的其他原因区分开来可能具有挑战性。流式细胞术可以检测狗和马的红细胞 (RBC) 和血小板 (PLT) 上的表面相关免疫球蛋白 (sIg)。尚未在马身上评估理想测定性能的样品存储参数。研究目的是确定马全血的最佳储存时间和温度，用于通过流式细胞术检测 RBC-sIg 和 PLT-sIg。两种测定均在收集后 0、4、24、48 和 72 小时的时间对样品进行。RBC-sIg 样品储存在 4 °C 下，PLT-sIg 样品储存在 4 °C 和室温下。RBC-sIg 百分比在储存长达 72 小时内保持稳定。血小板表面相关 IgG 阳性血小板百分比在所有时间点均增加至基线以上，而 IgM 和 IgA 阳性血小板百分比在不同时间点不一致。PLT-sIg 测试最好在采集后 4 小时内进行。在不可行的情况下，样品应储存在 4°C 下，并在采集后不迟于 24 小时进行分析。尽管 RBC-sIg 的截止值在不同时间点保持相似，但 PLT-sIg 的结果应与运行测试的实验室建立的特定时间截止值或参考区间进​​行比较。