Temurhan S, Akgul S U, Caliskan Y, Artan A S, Kekik C, Yazici H, Demir E, Caliskan B, Turkmen A, Oguz F S, Sever M S
Department of Medical Biology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Division of Nephrology, Department of Internal Medicine, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Transplant Proc. 2017 Apr;49(3):541-545. doi: 10.1016/j.transproceed.2017.02.003.
The serum levels of galactose-deficient immunoglobulin (Ig)A1 (Gd-IgA1) represent the most promising candidate biomarker for IgA nephropathy (IgAN). The aim of this study was to evaluate the serum levels of Gd-IgA1 as a novel noninvasive biomarker for post-transplant IgAN recurrence.
Serum Gd-IgA1 levels of 18 patients with recurrent IgAN were compared with control renal transplant recipients (n = 23) with non-recurrent IgAN and control non-transplant IgAN patients (n = 44) and healthy relatives (n = 11). Serum Gd-IgA1 levels of patients were measured with the use of KM55 enzyme-linked immunosorbent assay (ELISA). The effects of serum Gd-IgA1 concentrations on IgAN recurrence, post-transplant events, and graft survival were evaluated.
All recurrent IgAN patients presented with renal dysfunction (mean serum creatinine, 1.62 ± 0.39 mg/dL) and detectable proteinuria at the time of diagnosis. Serum Gd-IgA1 levels of recurrent IgAN patients (8735 ± 10854 ng/mL [log10: 3.71 ± 0.45]) were significantly higher than those of non-recurrent IgAN patients (4790 ± 6089 ng/μL [log10: 3.31 ± 0.64]) (P = .027). Serum Gd-IgA1 levels of non-transplant IgAN patients were significantly higher (8791 ± 8700 ng/μL [log10: 3.79 ± 0.36]) than those of non-recurrent IgAN patients (4790 ± 6089 ng/μL [log10: 3.31 ± 0.64]) and healthy relatives (2615 ± 1611 ng/μL [log10: 3.34 ± 0.27]) (P < .001 and P = .021, respectively). Receiver-operating characteristic curve analysis revealed that the area under the curve for recurrence of IgAN was 0.69 (0.53-0.85) for serum Gd-IgA1 (P = .038). Biopsy-confirmed allograft rejection rates were similar in the recurrent IgAN group [3 (17%)] compared with the non-recurrent IgAN [6 (26%)] group (P = .47). Graft failure rate was not also significantly different in the recurrent IgAN group [4 (22.2%)] compared with the non-recurrent IgAN group [2 (8.7%)] (P = .224).
This novel lectin-independent Gd-IgA1 ELISA that can detect serum Gd-IgA1 in patients with recurrent IgAN can be used as a biomarker for diagnosis and activity assessment of post-transplant recurrent IgAN.
血清中缺乏半乳糖的免疫球蛋白A1（Gd-IgA1）水平是IgA肾病（IgAN）最具前景的候选生物标志物。本研究旨在评估血清Gd-IgA1水平作为移植后IgAN复发的新型非侵入性生物标志物的价值。
将18例复发性IgAN患者的血清Gd-IgA1水平与非复发性IgAN的肾移植受者对照组（n = 23）、非移植IgAN患者对照组（n = 44）以及健康亲属对照组（n = 11）进行比较。采用KM55酶联免疫吸附测定（ELISA）法检测患者血清Gd-IgA1水平。评估血清Gd-IgA1浓度对IgAN复发、移植后事件及移植物存活的影响。
所有复发性IgAN患者在诊断时均出现肾功能不全（平均血清肌酐1.62±0.39mg/dL）且可检测到蛋白尿。复发性IgAN患者的血清Gd-IgA1水平（8735±10854ng/mL [log10：3.71±0.45]）显著高于非复发性IgAN患者（4790±6089ng/μL [log10：3.31±0.64]）（P = 0.027）。非移植IgAN患者的血清Gd-IgA1水平（8791±8700ng/μL [log10：3.79±0.36]）显著高于非复发性IgAN患者（4790±6089ng/μL [log10：3.31±0.64]）和健康亲属（2615±16~11ng/μL [log10：3.34±0.27]）（分别为P < 0.001和P = 0.021）。受试者工作特征曲线分析显示，血清Gd-IgA1对IgAN复发的曲线下面积为0.69（0.53 - 0.85）（P = 0.038）。复发性IgAN组经活检证实的移植肾排斥率[3例（17%）]与非复发性IgAN组[6例（26%）]相似（P = 0.47）。复发性IgAN组的移植肾失功率[4例（22.2%）]与非复发性IgAN组[2例（8.7%）]相比也无显著差异（P = 0.224）。
这种新型的不依赖凝集素的Gd-IgA1 ELISA能够检测复发性IgAN患者的血清Gd-IgA1，可作为移植后复发性IgAN诊断及活动评估的生物标志物。
