La'ulu Sonia L, Suh-Lailam Brenda B, Davis K Wayne, Straseski Joely A, Tebo Anne E
1 ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT, USA.
2 ARUP Laboratories, Salt Lake City, UT, USA.
Ann Clin Biochem. 2017 Mar;54(2):240-245. doi: 10.1177/0004563216651888. Epub 2016 Sep 28.
Background Lupus nephritis is one of the most serious complications of systemic lupus erythematosus. This study evaluates the prevalence and correlation between neutrophil gelatinase-associated lipocalin and other biomarkers associated with renal involvement in systemic lupus erythematosus. Methods Paired serum and urine specimens from 50 suspected systemic lupus erythematosus patients, characterized by antinuclear antibodies detected by indirect immunofluorescence assay and varying positive concentrations of anti-double stranded DNA antibodies by Crithidia luciliae immunofluorescence assay, were investigated. Of these 50 patients, 18 were identified with renal involvement based upon laboratory serology. Patients and healthy control serum samples ( n = 50) were also evaluated for high avidity double stranded DNA IgG antibodies, anti-C1q IgG antibodies, and serum creatinine. The prevalence and relationship between biomarkers were evaluated using statistical methods. Results Serum and urine neutrophil gelatinase-associated lipocalin concentrations were significantly elevated in patients compared to controls, with a prevalence of 24% and 36%, respectively. These concentrations were also more markedly increased in systemic lupus erythematosus patients with renal involvement than those without. Spearman's correlations between neutrophil gelatinase-associated lipocalin and other biomarkers tested ranged from 0.06 to 0.66 in all patients. Combined concordance as determined by Cronbach alpha coefficient between biomarkers was reduced from 0.71 to 0.58 (serum) and 0.62 (urine) when neutrophil gelatinase-associated lipocalin was removed. Conclusions Neutrophil gelatinase-associated lipocalin concentrations are elevated and demonstrate variable associated with other laboratory markers for renal involvement in systemic lupus erythematosus. Prospective longitudinal studies are needed to determine the optimal biomarker combinations for use in routine management of systemic lupus erythematosus patients at-risk for lupus nephritis.
背景 狼疮性肾炎是系统性红斑狼疮最严重的并发症之一。本研究评估了中性粒细胞明胶酶相关脂质运载蛋白与系统性红斑狼疮肾受累相关的其他生物标志物之间的患病率及相关性。方法 对50例疑似系统性红斑狼疮患者的配对血清和尿液标本进行研究，这些患者通过间接免疫荧光法检测抗核抗体，通过克氏锥虫免疫荧光法检测抗双链DNA抗体的阳性浓度各不相同。在这50例患者中，根据实验室血清学确定有18例存在肾受累。还对患者和健康对照血清样本（n = 50）进行了高亲和力双链DNA IgG抗体、抗C1q IgG抗体和血清肌酐的评估。使用统计方法评估生物标志物之间的患病率和关系。结果 与对照组相比，患者血清和尿液中中性粒细胞明胶酶相关脂质运载蛋白浓度显著升高，患病率分别为24%和36%。在有肾受累的系统性红斑狼疮患者中，这些浓度的升高也比无肾受累者更为明显。在所有患者中，中性粒细胞明胶酶相关脂质运载蛋白与其他检测的生物标志物之间的Spearman相关性在0.06至0.66之间。当去除中性粒细胞明胶酶相关脂质运载蛋白时，生物标志物之间由Cronbachα系数确定的联合一致性从0.71降至0.58（血清）和0.62（尿液）。结论 中性粒细胞明胶酶相关脂质运载蛋白浓度升高，并且与系统性红斑狼疮肾受累的其他实验室标志物存在不同程度的相关性。需要进行前瞻性纵向研究以确定用于狼疮性肾炎高危系统性红斑狼疮患者常规管理的最佳生物标志物组合。
