Jalali Amir, Khalilian Hamid, Ahmadzadeh Ali, Sarvestani Somie, Rahim Fakher, Zandian Khodamorad, Asar Shideh
Department of Pharmacology and Toxicology, School of Pharmacy, Toxicology Research Center, Jundishapur University of Medical Sciences, Ahvaz, Iran.
Hematology. 2011 Jul;16(4):249-54. doi: 10.1179/102453311X12953015767662.
In this study, the relationship between glomerular and tubular function and creatinine, glomerular filtration rate (GFR) and urine NAG in thalassemia major patients aged 7-16 years was investigated.
This is a case-control study comprising 280 individuals [144 (51·4%), males; 136 (48·6%), females].
Patients were divided in groups of 14 individuals and age groups of 7-16 years. Sodium excretion fraction, fraction excretion of potassium, calcium-to-creatinine and uric acid-to-creatinine ratios, and duration of specific blood transfusion were determined in all age groups receiving deferoxamine.
GFR decreased with increasing age, but the correlation was not statistically significant. There was no significant correlation between the ferritin levels and the GFR changes. The mean value of NAG activity between thalassemic patients and controls has no significant difference. The difference in mean age of the groups with high NAG activity and normal NAG activity was statistically significant. Thirty-seven patients (52·1%) in the group with normal NAG activity, and 45 patients (6·25%) in the group with NAG activity above normal were observed with uricosuric effects with no significant difference. Four patients (6·9%) in the group with normal NAG activity and six patients (7·3%) in the group with NAG activity above normal were shown to have hematuria with no significant difference. The results show that the increase in serum ferritin is significantly correlated with the increase in NAG activity (P<0·001, r = 0·2). Of patients with normal NAG activity 1 (1·7%) and with NAG activity higher than normal, 13 (15·9%) cases experienced hypercalciuria that significant difference was existing. The data also indicated that the NAG changes do not correlate with GFR changes.
The results showed that kidney dysfunction in thalassemia increases with increasing age, duration, and levels of blood transfusion and hypercalciuria. It is therefore recommended that the presence of severe renal dysfunction in thalassemic patients should be investigated using sensitive and specific tests, mainly NAG, to prevent progress towards the complications.
本研究调查了7至16岁重型地中海贫血患者肾小球和肾小管功能与肌酐、肾小球滤过率（GFR）及尿N-乙酰-β-D-氨基葡萄糖苷酶（NAG）之间的关系。
这是一项病例对照研究，包含280名个体[男性144名（51.4%）；女性136名（48.6%）]。
患者按14人一组分为7至16岁的年龄组。在所有接受去铁胺治疗的年龄组中测定钠排泄分数、钾排泄分数、钙与肌酐比值、尿酸与肌酐比值以及特定输血的持续时间。
GFR随年龄增长而降低，但相关性无统计学意义。铁蛋白水平与GFR变化之间无显著相关性。地中海贫血患者与对照组之间NAG活性的平均值无显著差异。NAG活性高的组与NAG活性正常的组之间平均年龄差异有统计学意义。NAG活性正常组中有37名患者（52.1%），NAG活性高于正常组中有45名患者（6.25%）出现尿酸排泄增多效应，差异无统计学意义。NAG活性正常组中有4名患者（6.9%），NAG活性高于正常组中有6名患者（7.3%）出现血尿，差异无统计学意义。结果显示血清铁蛋白升高与NAG活性升高显著相关（P<0.001，r = 0.2）。NAG活性正常的患者中有1名（1.7%），NAG活性高于正常的患者中有13名（15.9%）出现高钙尿症，存在显著差异。数据还表明NAG变化与GFR变化无关。
结果表明，地中海贫血患者的肾功能障碍随着年龄、输血持续时间和输血次数以及高钙尿症的增加而增加。因此，建议使用敏感且特异的检测方法，主要是NAG，来调查地中海贫血患者是否存在严重肾功能障碍，以防止并发症的进展。
