慢性肾脏病患者甲状旁腺激素水平对肾性贫血的影响

目的 探讨慢性肾脏病（CKD）患者甲状旁腺激素（PTH）升高致红细胞寿命缩短的机制。 方法 以住院初治的CKD患者75例（按eGFR分为1～2期、3～4期和5期）和健康对照组30例为对象。免疫发光法测全段甲状旁腺激素（iPTH）；流式细胞术测红细胞表面磷脂酰丝氨酸（PS）外翻水平及红细胞内钙离子浓度（[Ca2+]i）。 结果 （1）随着肾功能的减退，CKD3～4期及5期患者 iPTH、[Ca2+]i及红细胞表面PS外翻水平逐渐升高、贫血逐渐加重，明显高于CKD1～2期和对照组（均P < 0.05）。（2）CKD3～4期或5期患者Hb与iPTH和红细胞表面PS外翻水平呈负相关（r = -0.830和-0.791，均P < 0.01）；iPTH与 [Ca2+]i和红细胞表面PS外翻水平呈正相关（r = 0.882和0.924，均P < 0.01），与血钙浓度呈负相关（r = -0.544， P < 0.01）；红细胞表面PS外翻水平与 [Ca2+]i呈正相关（r = 0.923，P < 0.01），与血钙浓度无相关（r = -0.138，P = 0.365）。（3）[Ca2+]i（Y）对iPTH（X）的直线回归方程：Y=3.327+0.213X（F=21.529，P < 0.05）；红细胞表面PS外翻水平（Y）对iPTH（X1）及[Ca2+]i（X2）的多元线性回归方程：Y=-0.303+0.283X2+0.139X1（F = 6.59，P < 0.01）。 结论 iPTH增加红细胞内钙离子浓度，引起红细胞表面PS外翻增多，致红细胞寿命缩短而加重肾性贫血。

Effect of parathyroid hormone on renal anemia in patients with chronic kidney disease

Objective To observe the mechanism of elevated parathyroid hormone(PFH) leading to erythrocytes life span shortened in the patients with chronic kidney disease(CKD).Methods Serum samples of 30 healthy people and 75 CKD patients were collected.Patients were divided into three groups according to their renal function.Intact parathyroid hormone(iPTH)was detected by immunochemiluminometry.The erythrocytes phosphatidylserine (PS) exposure and intracellular calcium concentration ([Ca2+]i)were measured by flow cytometry. Results (1)Levels of serum iPTH,[Ca2+]i and erythrocytes PS exposure increased gradually with the decline of renel function in stages 3 to 5 of CKD,the differences were significant with CKD 1 to 2 stages and healthy control group(all P＜0.05).(2)Pearson correlation analysis revealed,during CKD 3 to 5 stages,Hb was negatively correlated with iPTH and erythrocyte PS exposure respectively (r=-0.830 and-0.791,all P＜0.01);iPTH was positively correlated with[Ca2+]i and erythrocyte PS exposure (r=0.882 and 0.924,all P＜0.01),whereas negatively correlated with serum Ca respectively(r=-0.544,P＜0.01);erythrocyte PS exposure was positively correlated with[Ca2+]i(r=0.923,P＜0.01)and not correlated with serum Ca(r=-0.138,P=0.365).(3)The linear regression equation of[Ca2+]i(Y)for iPTH(X)was Y=3.327+0.213X(F=21.529,P＜0.05).The multiple linear regression equation of erythrocytes PS exposure(Y)for PTH (X1)and[Ca2+]i(X2)was Y=-0.303+0.283X2+0.139X1(F=6.59,P＜0.01). Conclusions By increasing intracellular calcium,iPTH can lead to an increase of the erythrocyte PS exposure.which will cause the occurrence of erythrocytes life span being shortened.As a result,the renal anemia will become more severe.