Université Pierre et Marie Curie, Université Paris 6, Institut National de la Santé et de la Recherche Médicale Unit 702, Physiology, Paris, France.
Clin J Am Soc Nephrol. 2010 May;5(5):756-61. doi: 10.2215/CJN.08511109. Epub 2010 Feb 25.
Sickle cell anemia-associated nephropathy is a growing matter of concern because renal failure affects most aging sickle cell anemia patients. Glomerular damage is a common feature revealed by a microalbuminuria or a macroalbuminuria. Although glomerular hyperfiltration has been described for decades in this population, its prevalence in young adults is unknown.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: To address this issue, as well as the clinical and biologic correlates of hyperfiltration, a single-center, cross-sectional study of 280 homozygous SS disease patients was performed.
The prevalence of hyperfiltration assessed by Modification of Diet in Renal Disease estimated GFR was 51%. Among patients with hyperfiltration, 49% had hyperfiltration alone, whereas 36% and 15% had an associated microalbuminuria or macroalbuminuria, respectively. Estimated GFR sensitivity and specificity for hyperfiltration were 94% and 63%, respectively, in a selected subgroup of 48 patients (measured GFR was assessed by urinary (51)Cr EDTA clearance). In patients with no albuminuria, hyperfiltration status was significantly associated with a young age (years), the absence of alpha thalassemia, a lower hemoglobin level (g/dl), and a lower fetal hemoglobin. The role of chronic hemolysis was further strengthened by multivariate analysis showing a correlation between estimated GFR and a low plasma fetal hemoglobin level, a young age, and a high reticulocyte count (r(2) = 0.54).
Together, the data suggest that the pathophysiology of hyperfiltration would rather be attributable to the hemolysis-associated vasculopathy rather than a viscosity-vaso-occlusive process.
镰状细胞贫血相关性肾病是一个日益受到关注的问题，因为肾衰竭影响大多数老年镰状细胞贫血患者。肾小球损伤是该人群中常见的微量白蛋白尿或大量白蛋白尿特征。尽管几十年来一直描述了该人群的肾小球高滤过，但在年轻成年人中的患病率尚不清楚。
设计、设置、参与者和测量：为了解决这个问题，以及高滤过的临床和生物学相关性，我们对 280 名纯合 SS 疾病患者进行了一项单中心、横断面研究。
通过肾脏病饮食改良法估计肾小球滤过率评估的高滤过患病率为 51%。在高滤过患者中，49% 仅有高滤过，而 36% 和 15% 分别有微量白蛋白尿或大量白蛋白尿。在 48 名患者（通过尿（51）Cr EDTA 清除率评估测量肾小球滤过率）的一个选定亚组中，估计肾小球滤过率的敏感性和特异性分别为 94%和 63%。在无白蛋白尿的患者中，高滤过状态与年龄较小（岁）、无α珠蛋白生成障碍性贫血、较低的血红蛋白水平（g/dl）和较低的胎儿血红蛋白显著相关。多变量分析进一步加强了慢性溶血的作用，显示估计肾小球滤过率与低血浆胎儿血红蛋白水平、年轻年龄和高网织红细胞计数相关（r²=0.54）。
总之，数据表明，高滤过的病理生理学与其说是与血液黏度相关的血管病变，不如说是与慢性溶血相关的血管病变。
