Clinical Immunology Unit, Department of Immunology, Northern General Hospital, Herries Road, Sheffield S5 8YD, UK.
Ann Clin Biochem. 2010 Jan;47(Pt 1):8-16. doi: 10.1258/acb.2009.009180.
Cryoglobulins are serum immunoglobulins that precipitate at temperatures below 37 degrees C and re-dissolve on warming. Cryoglobulinaemia leads to variable symptoms including characteristic purpura, ischaemia of extremities, renal failure, peripheral neuropathy, abdominal pain secondary to intestinal ischaemia and arthralgias. Cryoglobulin testing is underutilized in clinical practice. It has been neglected in clinical laboratories and by clinicians due to several factors, such as the length of time it takes for serum cryoglobulin analysis to be performed in the laboratory, the perceived difficulty in getting optimal sampling conditions and a failure to appreciate that even apparently low levels of cryoglobulin can be associated with severe symptoms in some patients. The most important variable confounding standardization of cryoglobulin testing is improper sample handling. A recent report critically appraising the current practice of cryoglobulin evaluation in 137 laboratories in Europe by United Kingdom National External Quality Assurance Scheme (UKNEQAS) illustrated the wide variability in practice. Although many clinical laboratories perform cryoglobulin evaluation, there are widespread differences in the methodology used and the care with which this is carried out and this leads to considerable intralaboratory and interlaboratory variability. The most common sources of error are false-negative results due to loss of cryoprecipitate during transport and storage. Better standardization is needed to avoid missed diagnoses and improve the comparability of results. Laboratories should ensure that sample temperature is maintained at 37 degrees C until the serum is separated. In this article, we briefly review the classification and clinical features of cryoglobulins and suggest best practice guidelines for laboratory detection and identification of cryoglobulins.
冷球蛋白是血清免疫球蛋白，在 37°C 以下温度时沉淀，加热后重新溶解。冷球蛋白血症可导致多种症状，包括特征性紫癜、四肢缺血、肾衰竭、周围神经病、继发于肠缺血的腹痛和关节痛。冷球蛋白检测在临床实践中未得到充分利用。由于多种因素，冷球蛋白检测在临床实验室和临床医生中被忽视，例如血清冷球蛋白分析在实验室中所需的时间、获得最佳采样条件的难度以及未能认识到即使冷球蛋白水平似乎较低，也可能与某些患者的严重症状有关。干扰冷球蛋白检测标准化的最重要变量是不当的样本处理。最近，英国国家外部质量保证计划（UKNEQAS）对欧洲 137 个实验室的冷球蛋白评估当前实践进行了批判性评估报告，说明了实践中的广泛差异。尽管许多临床实验室都进行冷球蛋白评估，但所使用的方法学以及进行评估的谨慎程度存在广泛差异，这导致了实验室内部和实验室之间的显著差异。最常见的错误来源是由于在运输和储存过程中丢失冷沉淀物而导致的假阴性结果。需要更好的标准化来避免漏诊并提高结果的可比性。实验室应确保在将血清分离之前，将样本温度维持在 37°C。在本文中，我们简要回顾了冷球蛋白的分类和临床特征，并提出了实验室检测和鉴定冷球蛋白的最佳实践指南。
