Renal Division, Department of Medicine, Peking University First Hospital, Beijing 100034, China.
BMC Nephrol. 2014 Jan 14;15:11. doi: 10.1186/1471-2369-15-11.
Hyperuricemia appeared to be a common symptom in IgA nephropathy (IgAN), even in those with normal eGFR. IgAN was characterized by variation of pathological features, especially variable tubulointerstitial lesions. Since tubular reabsorption and excretion appeared to be more important in determination of plasma uric acid levels in persons without obvious decrease of glomerular filtration rate, we took advantage of our IgAN cohort to investigate whether plasma uric acid level associated with tubular interstitial lesions, and could be considered as a maker for tubular interstitial lesions, especially at early stage with normal eGFR.
623 IgAN patients were involved in the present study. Morphological changes were evaluated with Oxford classification scoring system as well as Beijing classification system of IgAN. Statistical analysis was done with SPSS 13.0.
We found that plasma uric acid level associated with percentage of interstitial fibrosis/tubular atrophy. Higher plasma uric acid levels indicated higher tubulointerstitial scores, either with Oxford system (P = 0.012) or with Beijing classification system (P = 4.810-4) in the whole cohort. We also found that in the subgroup of 258 IgAN cases with normal baseline eGFR (eGFR > =90 ml/min/1.73 M2), higher plasma uric acid associated with more severe tubulointerstitial lesions with Beijing scoring system (P = 3.410-5). The risk of having more than 10% tubulointerstitial lesions in patients with hyperuricemia increased 58% compared with normal uric acid level. In subgroup with normal eGFR, only hyperuricemia predicted tubulointerstitial leisions, and the risk of having more tubulointerstitial changes increased 100%. Among these patients, hyperuricemia was associated with more tubulointerstitial lesions with a specificity of 60.3%. Specificity increased to 65% among those patients with eGFR > =90 ml/min/1.73 m2.
Plasma uric acid levels indicate tubular interstitial lesions in IgAN and hyperuricemia may be considered as a marker for tubulointerstitial lesions.
高尿酸血症似乎是 IgA 肾病（IgAN）的常见症状，即使在 eGFR 正常的患者中也是如此。IgAN 的病理特征存在差异，尤其是肾小管间质病变存在差异。由于肾小管重吸收和排泄似乎在确定肾小球滤过率无明显下降的个体的血浆尿酸水平方面更为重要，因此我们利用我们的 IgAN 队列来研究血浆尿酸水平是否与肾小管间质病变相关，并且可以被认为是肾小管间质病变的标志物，尤其是在 eGFR 正常的早期阶段。
本研究纳入了 623 例 IgAN 患者。采用 Oxford 分类评分系统和北京 IgAN 分类系统评估形态学变化。使用 SPSS 13.0 进行统计分析。
我们发现血浆尿酸水平与间质纤维化/肾小管萎缩的百分比相关。在整个队列中，较高的血浆尿酸水平与更高的肾小管间质评分相关，无论是使用 Oxford 系统（P = 0.012）还是北京分类系统（P = 4.810-4）。我们还发现，在 258 例基线 eGFR（eGFR > =90 ml/min/1.73 m2）正常的 IgAN 病例亚组中，较高的血浆尿酸与更严重的北京评分系统肾小管间质病变相关（P = 3.410-5）。与尿酸正常水平相比，高尿酸血症患者发生 10%以上肾小管间质病变的风险增加了 58%。在 eGFR 正常的亚组中，只有高尿酸血症预测肾小管间质病变，发生更多肾小管间质变化的风险增加了 100%。在这些患者中，高尿酸血症与更多的肾小管间质病变相关，特异性为 60.3%。在 eGFR > =90 ml/min/1.73 m2 的患者中，特异性增加至 65%。
血浆尿酸水平提示 IgAN 存在肾小管间质病变，高尿酸血症可能被视为肾小管间质病变的标志物。
