Dipartimento di Scienze Mediche Internistiche, University of Cagliari, Cagliari, Italy.
Nephrol Dial Transplant. 2012 Sep;27(9):3547-51. doi: 10.1093/ndt/gfs169. Epub 2012 Jun 13.
Little information is available about the kidney's involvement in patients with β-thalassaemia major (TM). In particular, there are no studies reporting the outcome of renal function over time.
In this retrospective study, we evaluated the changes in estimated glomerular filtration rate (eGFR) in 81 adult patients with TM followed for 10 years. Only patients who had an eGFR of >90 mL/min/1.73 m(2) at presentation were admitted to the study. All patients were regularly followed for at least 10 years.
At 10 years, 66 patients showed a mild decline in eGFR that remained, however, within a normal range (from 119.9 to 113.6 mL/min/1.73 m(2), P = 0.636). In the remaining 15 patients (18.5%), eGFR decreased to <90 mL/min (from 98.1 to 78.2 mL/min/1.73 m(2); P = 0.004). The repeated-measures models showed that the decline in eGFR over time was significantly higher (P = 0.0068) in patients with baseline phosphaturia >1000 mg/24 h (P = 0.0068), while eGFR tended to decline more rapidly in patients with baseline uricuria >700 mg/24 h than in those with lower uricuria (P = 0.0783). Univariate Cox's proportional regression models showed that abnormal levels of calcaemia were associated with the risk of kidney damage [hazard ratio (HR) 0.30, 95% confidence interval 0.09-0.97 for calcaemia 8.4-10.2 mg/dL versus HR not estimable for calcaemia <8.4 or >10.2 mg/dL].
In most adults with TM, the eGFR tends to remain within a normal range after 10 years. However, patients with elevated phosphaturia, elevated uricuria and/or abnormal levels of calcaemia show a significant decline in eGFR over time, suggesting that tubular damage acquired in childhood caused by either TM or its treatment may eventually result in abnormal eGFR. Further studies in a larger cohort of TM patients are needed to further elucidate the long-term impact of TM on renal function.
关于β-地中海贫血症（TM）患者肾脏受累的信息很少。特别是，目前尚无研究报告肾功能随时间的变化。
在这项回顾性研究中，我们评估了 81 例成年 TM 患者的肾小球滤过率估计值（eGFR）在 10 年内的变化。仅纳入在初诊时 eGFR ＞90 mL/min/1.73 m2的患者。所有患者均至少随访 10 年。
10 年后，66 例患者 eGFR 轻度下降，但仍处于正常范围（从 119.9 降至 113.6 mL/min/1.73 m2，P=0.636）。在其余 15 例患者（18.5%）中，eGFR 降至＜90 mL/min（从 98.1 降至 78.2 mL/min/1.73 m2；P=0.004）。重复测量模型显示，基线时磷排泄量＞1000 mg/24 h 的患者，eGFR 随时间的下降速度显著更高（P=0.0068）（P=0.0068），而基线时尿酸排泄量＞700 mg/24 h 的患者，eGFR 下降速度快于尿酸排泄量较低的患者（P=0.0783）。单变量 Cox 比例风险回归模型显示，血钙水平异常与肾脏损害风险相关[风险比（HR）0.30，95%置信区间 0.09-0.97，血钙 8.4-10.2 mg/dL 与 HR 不可估计，血钙＜8.4 或＞10.2 mg/dL]。
在大多数成年 TM 患者中，10 年后 eGFR 趋于保持在正常范围内。然而，高磷尿症、高尿酸尿症和/或血钙水平异常的患者，eGFR 随时间显著下降，表明儿童时期由 TM 或其治疗引起的肾小管损伤最终可能导致 eGFR 异常。需要在更大的 TM 患者队列中进行进一步研究，以进一步阐明 TM 对肾功能的长期影响。
