Gottenberg J-E, Aucouturier F, Goetz J, Sordet C, Jahn I, Busson M, Cayuela J-M, Sibilia J, Mariette X
Rhumatologie, Université Paris-Sud 11, INSERM U802, Hôpital Bicêtre, Assistance Publique des Hôpitaux de Paris, Le Kremlin Bicêtre, France.
Ann Rheum Dis. 2007 Jan;66(1):23-7. doi: 10.1136/ard.2006.052159. Epub 2006 Mar 28.
B cell activation may result in an increased secretion of immunoglobulin free light chains (FLCs) in autoimmune diseases.
To analyse serum FLC levels in patients with rheumatoid arthritis and in those with primary Sjögren's syndrome (pSS).
Blood samples were collected from 80 healthy blood donors, 50 patients with rheumatoid arthritis and 139 patients with pSS. Serum FLC level was measured using a new quantitative immunoassay.
Mean (standard error (SE)) serum kappa and lambda FLC levels were significantly higher in patients with rheumatoid arthritis and in those with pSS than in controls (kappa : 18.9 (1.1) and 16.3 (1.4) v 10.5 (0.4) mg/l, p<0.001 and p = 0.001, respectively; lambda: 16.7 (1.2) and 19.3 (1.5) v 11.6 (0.6) mg/l, p<0.001 for both). 18 (36%) patients with rheumatoid arthritis and 31 (22.3%) patients with pSS had abnormal serum FLC levels (increased kappa or lambda levels and abnormal ratio of kappa:lambda). Serum kappa and lambda levels were correlated with other B cell activation markers in both diseases. FLC levels increased with disease activity, because, unlike total gammaglobulin and immunoglobulin G levels, they were significantly correlated with Disease Activity Score 28 in patients with rheumatoid arthritis (p = 0.004 for kappa, p = 0.05 for lambda) and with extraglandular involvement in pSS (p = 0.01 for kappa, p = 0.04 for lambda).
FLC levels are increased and correlate with disease activity in patients with rheumatoid arthritis and in those with pSS, two diseases in which increased risk of lymphoma could result from persistent B cell activation and disease activity. Further studies are required to determine whether FLC assessment could represent a relevant biomarker for response to treatment (especially B cell depletion) and for the risk of lymphoma in autoimmune diseases.
在自身免疫性疾病中，B细胞活化可能导致免疫球蛋白游离轻链（FLC）分泌增加。
分析类风湿关节炎患者和原发性干燥综合征（pSS）患者的血清FLC水平。
采集80名健康献血者、50名类风湿关节炎患者和139名pSS患者的血样。使用一种新的定量免疫测定法测量血清FLC水平。
类风湿关节炎患者和pSS患者的血清κ和λFLC平均（标准误）水平显著高于对照组（κ：18.9（1.1）和16.3（1.4）对比10.5（0.4）mg/L，p<0.001和p = 0.001；λ：16.7（1.2）和19.3（1.5）对比11.6（0.6）mg/L，两者p<0.001）。18名（36%）类风湿关节炎患者和31名（22.3%）pSS患者的血清FLC水平异常（κ或λ水平升高以及κ:λ比例异常）。在这两种疾病中，血清κ和λ水平均与其他B细胞活化标志物相关。FLC水平随疾病活动度增加，因为与总γ球蛋白和免疫球蛋白G水平不同，它们在类风湿关节炎患者中与疾病活动评分28显著相关（κ为p = 0.004，λ为p = 0.05），在pSS中与腺外受累相关（κ为p = 0.01，λ为p = 0.04）。
在类风湿关节炎患者和pSS患者中，FLC水平升高且与疾病活动度相关，这两种疾病中持续的B细胞活化和疾病活动可能导致淋巴瘤风险增加。需要进一步研究以确定FLC评估是否可作为治疗反应（尤其是B细胞清除）和自身免疫性疾病淋巴瘤风险的相关生物标志物。
