视网膜分支静脉阻塞患者急性期和恢复期血浆同型半胱氨酸水平的变化

Acute and convalescent changes in plasma homocysteine concentrations in branch retinal vein occlusion

目的探讨视网膜分支静脉阻塞(branch retinal vein occlusion,BRVO)患者急性期及恢复期血浆同型半胱氨酸(homocysteine,Hcy)水平的变化。方法连续收集42例BRVO患者作为观察对象,选择42名年龄、性别与观察对象相匹配的、无其他影响Hcy病史的非视网膜疾病患者作为对照组。BRVO发生后3 d、1个月、3个月、6个月抽取BRVO患者的空腹静脉血,对照组抽取单次空腹血,采用高效液相色谱荧光检测法检测Hcy,用放射免疫法测定维生素B12、叶酸水平,C677T MTHFR基因多态性采用聚合酶链反应进行分析。结果 BRVO患者阻塞发生后3 d Hcy水平(11.01±4.09)μmol·L-1与对照组(10.04±3.67)μmol·L-1相比,差异无统计学意义(P=0.257)。BRVO患者的Hcy水平在发生阻塞后逐渐升高,BRVO发生后1个月Hcy达到高峰(13.27±5.81)μmol·L-1,6个月时下降到正常水平(11.17±4.36)μmol·L-1。同时,BRVO患者Hcy水平在BRVO发生后3 d(r=0.343)、1个月(r=0.381)、3个月(r=0.432)、6个月(r=0.360)都与黄斑区视网膜厚度呈显著的正相关(均为P<0.05)。然而,BRVO患者Hcy水平的变化与维生素B12、叶酸水平以及C677T MTHFR基因多态性无关(均为P>0.05)。结论患者发生BRVO后Hcy水平一过性升高,本研究结果不支持Hcy是BRVO的独立危险因素的推测,然而Hcy水平的变化可能是疾病本身引起的。

Objective To measure fasting total plasma homocysteine（ Hcy） concentrations immediately after branch retinal vein occlusion（ BRVO） and in the convalescent period to investigate this controversy. Methods Hcy concentrations in 42 consecutive patients with BRVO were measured at 3 days,1 month,3 months and 6 months after BRVO and once in 42 control subjects. The vitamin B12,and folate levels and presence of C677 T MTHFR polymorphisms were analyzed in all patients and controls. Results Hcy concentrations at 3 days after BRVO（ 11. 01 ± 4. 09） μmol·L- 1 was not significantly higher than that in matched control subjects（ 10. 04 ± 3. 67） μmol·L- 1（ P = 0. 257）. However,Hcy levels increased gradually after BRVO,reached a peak at 1 month after BRVO（ 13. 27 ± 5. 81） μmol·L- 1,and declined to the normal values at 6 months after BRVO. In addition,Hcy levels were correlated with the macular retinal thickness,and this correlation was significant at all time points（ r = 0. 343,0. 381,0.432,0. 360; all P〈0. 05）. However,Hcy level changes was not correlated with serum folate,vitamin B12 concentrations and MTHFR C677 T genotype. Conclusion Hcy levels are not immediately elevated after BRVO but transiently increase in the convalescent period. These data do not support the hypothesis that raised Hcy concentrations are an independent risk factor for BRVO. Instead,it is possible that changed Hcy levels may be caused by the disease process itself.