Boumans D, Hettema M E, Vonkeman H E, Maatman R G, van de Laar M A
Arthritis Centre Twente at Medisch Spectrum Twente, Enschede, The Netherlands.
Department of Rheumatology, Ziekenhuisgroep Twente (ZGT), PO Box 7600, 7600 SZ, Almelo, The Netherlands.
Clin Rheumatol. 2017 Jul;36(7):1599-1605. doi: 10.1007/s10067-017-3633-6. Epub 2017 Apr 19.
The aim of the study was to assess the added value of synovial fluid (SF) centrifugation for microscopic monosodium urate (MSU) and calcium pyrophosphate (CPP) crystal detection in patients with arthritis. This is a prospective observational study using SF samples from joints of patients undergoing joint arthrocentesis. Two blinded observers assessed the SF smears by polarized light microscopy for the presence of crystals before as well as after centrifugation. SF samples were collected from 98 patients with arthritis. After exclusion, 87 samples were eligible for inclusion. Of each sample, 2 smears before and after centrifugation were prepared and microscopically examined, resulting in 348 smears per observer. Observer 1 identified MSU crystals in 18.4% and CPP in 9.2% of the smears before as well as after centrifugation. No extra MSU crystal-positive smears were identified after centrifugation. However, centrifugation yielded 4 additional CPP crystal-positive smears. Observer 2 identified MSU crystals in 15.5% and CPP crystals in 6.3% of the smears before as well as after centrifugation. Centrifugation yielded 2 additional MSU crystal-positive smears and 4 CPP crystal-positive smears. Monosodium urate crystals were well recognized without centrifugation. Centrifugation of SF had limited additional value for increasing the amount of MSU-positive smears. However, CPP crystals were identified in a higher number of smears after centrifugation than before. Therefore, centrifugation may be of additional value in selected patients with suspected calcium pyrophosphate deposition disease and to a lesser extent for gout.
本研究的目的是评估滑膜液（SF）离心对关节炎患者镜检单钠尿酸盐（MSU）和焦磷酸钙（CPP）晶体检测的附加价值。这是一项前瞻性观察性研究，使用接受关节穿刺术患者关节的SF样本。两名盲法观察者通过偏振光显微镜评估SF涂片在离心前后晶体的存在情况。从98例关节炎患者中收集SF样本。排除后，87个样本符合纳入标准。对每个样本在离心前后各制备2张涂片并进行显微镜检查，每位观察者共检查348张涂片。观察者1在离心前后的涂片中分别有18.4%发现MSU晶体，9.2%发现CPP晶体。离心后未发现额外的MSU晶体阳性涂片。然而，离心后发现了4张额外的CPP晶体阳性涂片。观察者2在离心前后的涂片中分别有15.5%发现MSU晶体，6.3%发现CPP晶体。离心后发现了2张额外的MSU晶体阳性涂片和4张CPP晶体阳性涂片。未离心时MSU晶体很容易识别。SF离心对增加MSU阳性涂片数量的附加价值有限。然而，离心后发现CPP晶体的涂片数量比之前更多。因此，离心对于某些疑似焦磷酸钙沉积病的患者可能具有附加价值，对痛风患者的附加价值较小。
