Laboratorio de Líquido Sinovial, Instituto Nacional de Rehabilitación "Luis Guillermo Ibarra-Ibarra (INR-LGII), Calzada México-Xochimilco 289, Colonia Arenal de Guadalupe, 14389, Mexico City, Tlalpan, Mexico.
Laboratorio de Ultrasonido Músculo-Esquelético Articular, INR-LGII, Mexico City, Mexico.
Clin Rheumatol. 2021 Aug;40(8):3239-3246. doi: 10.1007/s10067-021-05610-0. Epub 2021 Feb 17.
INTRODUCTION/OBJECTIVES: Few studies have addressed the detection and clinical impact of different crystals in patients with diverse rheumatologic diagnoses in Latin America. The aim of this study was to assess the consistency between the clinical referring diagnosis and the identification of crystals, such as monosodium urate (MSU) and calcium pyrophosphate (CPP), in the synovial fluid (SF) of patients from a Mexican tertiary care institution.
We reviewed the results of 264 SF analyses to identify any changes in diagnosis upon SF analysis. We reported patient medical file data on sex, age, diagnosis, and microscopic SF analysis results. We performed consistency analyses between referring diagnoses and SF findings with McNemar's test.
The prevalence of MSU crystals in SF was noted in 89.1% of gout cases and 9.09% of cases of calcium pyrophosphate disease (CPPD). CPP crystals were present in 54.5% of CPPD cases, 42.9% of osteoarthritis (OA) cases, and 7.27% of gout cases. Calcium hydroxyapatite (HA) crystals were identified in 5.45% of gout cases, 33.3% of rheumatoid arthritis (RA) cases, 57.1% of OA cases, and 63.6% of CPPD cases. Cholesterol and lipid crystals were present in small proportions in RA cases. Glucocorticoid crystals were observed in 1.85% of gout cases, 44.4% of RA cases, and 42.9% of OA cases. We observed an association of MSU identification with clinical suspicion of gout (P = 0.08), CPP with OA (P = 0.26) and CPPD (P = 0.50). An association was noted between HA and the diagnosis of CPPD (P = 0.84) and OA (P > 0.99). The number of initial diagnoses that changed upon SF analysis was 14.3%.
SF analysis has major diagnostic value regarding MSU crystals and gout. Our findings underscore the importance of SF crystal analysis in identifying the prevalence of crystals in the Mexican population. SF analysis provides for better diagnosis of crystal arthropathies and improves the quality of the medical care that the patient receives. Key Points • Synovial fluid analysis in laboratories from developing countries has been scarce. • In some cases, the initial diagnosis is modified after of synovial fluid analysis. • This study confirmed that synovial fluid analysis exhibits major diagnostic value for urate crystals and gout.
简介/目的：在拉丁美洲，针对不同风湿病诊断患者的不同晶体检测和临床影响，仅有少数研究对此进行了探讨。本研究旨在评估在一家墨西哥三级医疗机构中，关节液（SF）分析中临床送检诊断与尿酸盐（MSU）和焦磷酸钙（CPP）等晶体识别之间的一致性。
我们回顾了 264 例 SF 分析结果，以确定 SF 分析后诊断是否发生变化。我们报告了患者病历数据，包括性别、年龄、诊断和 SF 微观分析结果。我们使用 McNemar 检验对送检诊断和 SF 结果进行一致性分析。
SF 中 MSU 晶体在痛风病例中的检出率为 89.1%，CPP 晶体在 CPPD 病例中的检出率为 9.09%。CPP 晶体存在于 54.5%的 CPPD 病例、42.9%的骨关节炎（OA）病例和 7.27%的痛风病例中。7.27%的痛风病例、5.45%的 OA 病例、33.3%的类风湿关节炎（RA）病例和 57.1%的 CPPD 病例中存在羟磷灰石（HA）晶体。胆固醇和脂质晶体在 RA 病例中占比较小。1.85%的痛风病例、44.4%的 RA 病例和 42.9%的 OA 病例中存在糖皮质激素晶体。我们观察到 MSU 晶体与痛风临床疑似病例相关（P=0.08），CPP 晶体与 OA（P=0.26）和 CPPD（P=0.50）相关。HA 晶体与 CPPD（P=0.84）和 OA（P>0.99）的诊断相关。SF 分析后改变初始诊断的病例有 14.3%。
SF 分析对 MSU 晶体和痛风具有重要的诊断价值。我们的研究结果强调了 SF 晶体分析在确定墨西哥人群中晶体流行率方面的重要性。SF 分析可更好地诊断晶体性关节病并提高患者获得的医疗质量。关键点 • 发展中国家实验室的关节液分析较为少见。 • 在某些情况下，SF 分析后会修改初始诊断。 • 本研究证实 SF 分析对尿酸盐晶体和痛风具有重要的诊断价值。
