■血清蛋白电泳(SPE),传统上,尿蛋白电泳和免疫固定电泳用于诊断单克隆免疫球蛋白病。据报道,定量无血清轻链(SFLC)测定更灵敏,并且已经被引入到最近的临床指南中。
■本研究旨在调查SFLC检测的使用情况,并描述SFLC比值异常患者的SPE结果。
■在开普敦对SFLC分析进行了回顾性审计,南非,从2018年5月到2020年4月。在筛选单克隆丙种球蛋白的患者亚组中确定了异常SFLC比率与SPE结果之间的一致性。使用Freelite®κ和Lambda测定法分析无血清轻链。
■在纳入审核的1425名患者中,741(52%)的SFLC比率异常;636(45%)的SFLC比率增加,105(7%)的SFLC比率降低。在117例SFLC比率异常的新患者的亚组分析中,57在SPE上有单克隆蛋白(M蛋白)(49%),60(51%)没有。60名没有M蛋白的患者中有4名患有浆细胞发育不良,而肾功能损害或炎症反应占其余。在57例M蛋白和SFLC比例异常的患者中,41人(72%)有浆细胞发育不良,7例(12%)患者患有淋巴瘤,9例(16%)患者无法分类.
■当临床怀疑指数高时,应要求无血清轻链。在筛选单克隆丙种球蛋白病时,SFLC和SPE均不应单独进行,确保没有病人被遗漏。
■这项研究增加了SFLC测试利用的证据。仅血清蛋白电泳可能会错过轻链骨髓瘤的病例,而单独进行的SFLC可能会在炎症性疾病或肾功能损害的情况下产生假阳性结果,导致不必要的进一步调查。
UNASSIGNED: Serum protein electrophoresis (SPE), urine protein electrophoresis and immunofixation electrophoresis were traditionally utilised for the diagnosis of monoclonal gammopathies. The quantitative serum-free light chain (SFLC) assay is reportedly more sensitive and has been introduced to recent clinical guidelines.
UNASSIGNED: This study aimed to investigate SFLC test utilisation and describe SPE findings in patients with abnormal SFLC ratios.
UNASSIGNED: A retrospective audit of SFLC analyses was conducted in Cape Town, South Africa, from May 2018 to April 2020. Agreement between abnormal SFLC ratios and SPE results was determined in a sub-group of patients screened for monoclonal gammopathies. Serum-free light chains were analysed using Freelite® Kappa and Lambda assays.
UNASSIGNED: Of the 1425 patients included in the audit, 741 (52%) had abnormal SFLC ratios; 636 (45%) had increased and 105 (7%) had decreased SFLC ratios. In a sub-group analysis of 117 new patients with an abnormal SFLC ratio, 57 had a monoclonal protein (M-protein) on SPE (49%), and 60 (51%) did not. Four out of 60 patients without M-protein had a plasma cell dyscrasia, while renal impairment or inflammatory response accounted for the rest. Of the 57 patients with a M-protein and abnormal SFLC ratio, 41 (72%) had a plasma cell dyscrasia, seven (12%) had lymphomas and nine patients (16%) were unclassifiable.
UNASSIGNED: Serum-free light chains should be requested when there is a high index of clinical suspicion. Neither SFLC nor SPE should be performed in isolation when screening patients for monoclonal gammopathy, to ensure that no patient is missed.
UNASSIGNED: The study adds to the evidence on SFLC test utilisation. Serum protein electrophoresis alone may miss cases of light chain myeloma, while SFLC performed in isolation may produce false positive results in the setting of inflammatory disorders or renal impairment, leading to unnecessary further investigation.