Department of Internal Medicine, Mayo Clinic, Scottsdale, AZ, USA.
Department of Medical Education and Medical Libraries, Mayo Clinic, Scottsdale, AZ, USA.
Int J Rheum Dis. 2021 Jan;24(1):10-20. doi: 10.1111/1756-185X.14019. Epub 2020 Nov 5.
To identify the appropriate methods of synovial fluid (SF) specimen storage, manipulation and handling for crystal associated arthritides (CAA) diagnosis.
A systematic literature review was conducted using 5 medical databases to identify diagnostic studies assessing SF specimen handling for calcium pyrophosphate (CPP) and monosodium urate (MSU) crystals identification. All included studies were rated for quality using the Quality Assessment of Diagnostic Accuracy Studies 2.
Fifteen studies, including 2 non-English language manuscripts, were included. Eight studies examined both types of crystals, while 3 studies examined CPP and 4 studies examined MSU crystals only. Overall, MSU crystals were more stable over time compared to CPP crystals. MSU stability was generally independent of time, preservative and temperature. CPP crystals deteriorated with time and were more stable if refrigerated. Ethylenediaminetetraacetic acid (EDTA) was a suitable preservative. Re-examining an initially negative SF sample at 24 hours facilitated detection of additional cases. Very few studies had an overall low risk of bias and applicability.
Monosodium urate crystals remain stable over time independent of storage time, temperature and preservative. CPP crystals are mostly stable for 24-48 hours but can deteriorate with time. Overall, SF crystal examination should ideally be done within 24-48 hours. They may be stored at room temperature without any preservative. Otherwise, refrigeration (4°C/39°F) and EDTA preservation is reasonable. Stored SF re-examination, at 24 hours, helps identify a small number of additional MSU and CPP cases. Centrifugation techniques allow better and easier crystal identification, particularly CPP. Most studies were of unclear or low quality.
确定用于诊断晶体相关性关节炎（CAA）的滑液（SF）标本储存、操作和处理的适当方法。
使用 5 个医学数据库系统地进行文献回顾，以确定评估 SF 标本处理用于鉴定焦磷酸钙（CPP）和单钠尿酸盐（MSU）晶体的诊断研究。使用诊断准确性研究质量评估 2 对所有纳入的研究进行质量评分。
纳入了 15 项研究，包括 2 项非英语语言的手稿。8 项研究同时检测了两种晶体，3 项研究检测 CPP 晶体，4 项研究仅检测 MSU 晶体。总体而言，MSU 晶体随时间推移更稳定，而 CPP 晶体则随着时间的推移而恶化。MSU 晶体的稳定性通常与时间、防腐剂和温度无关。CPP 晶体随时间的推移而恶化，冷藏时更稳定。乙二胺四乙酸（EDTA）是一种合适的防腐剂。在 24 小时后重新检查最初为阴性的 SF 样本可有助于检测到更多的病例。只有极少数的研究具有总体低偏倚和适用性风险。
MSU 晶体随时间推移保持稳定，与储存时间、温度和防腐剂无关。CPP 晶体在 24-48 小时内大多稳定，但随着时间的推移会恶化。总体而言，SF 晶体检查理想情况下应在 24-48 小时内进行。它们可以在室温下储存，无需任何防腐剂。否则，冷藏（4°C/39°F）和 EDTA 保存是合理的。在 24 小时时重新检查储存的 SF 有助于识别少量额外的 MSU 和 CPP 病例。离心技术可更好、更轻松地进行晶体鉴定，尤其是 CPP 晶体。大多数研究的质量为不清楚或低质量。
