Masmiquel L L, Burgos R, Mateo C, Martí R, Segura R M, Simó R
Diabetes Unit, Endocrinology Division, Hospital General Vall d'Hebron, Barcelona, Spain.
Br J Ophthalmol. 1999 Sep;83(9):1056-9. doi: 10.1136/bjo.83.9.1056.
BACKGROUND/AIM: Laminin, a major specific non-collagenous glycoprotein of basement membrane, has been proposed as an index of diabetic retinopathy and high serum concentrations have been reported in patients with proliferative diabetic retinopathy. On the other hand, panretinal photocoagulation (PRP) prevents the progression of severe diabetic retinopathy and reverses preretinal neovascularisation. The aim of the study was to investigate the effect of PRP on serum levels of laminin in patients with diabetes.
20 patients with diabetes undergoing PRP and 15 patients with mild or moderate non-proliferative diabetic retinopathy in whom a PRP was not performed were included in the study. Serum laminin-P1 (Lam-P1), the largest pepsin resistant fragment of laminin, was determined by radioimmunoassay in each patient before starting PRP and 3 months after it was accomplished. Similarly, a baseline and a 4 month sample were analysed in the non-photocoagulated controls.
Serum Lam-P1 concentrations obtained 3 months after PRP were significantly lower when compared with the initial values (1.62 (SD 0.36) U/ml v 1.91 (0.37) U/ml; p <0.001). A decrease of serum levels of Lam-P1 could be seen in all patients. By contrast, in those patients with mild or moderate non-proliferative diabetic retinopathy in whom a PRP was not performed, no significant changes were detected in serum Lam-P1 concentrations (1.72 (0.20) U/ml v 1. 74 (0.17); p=0.250).
PRP decreases serum Lam-P1 levels in patients with severe diabetic retinopathy. Thus, the studies addressed to evaluate the usefulness of Lam-P1 as a marker of diabetic retinopathy should consider previous PRP as an influencing factor. Finally, our results suggest that retinal source of Lam-P1 strongly contributes to serum Lam-P1 in patients with severe diabetic retinopathy.
背景/目的：层粘连蛋白是基底膜主要的特异性非胶原蛋白糖蛋白，被认为是糖尿病视网膜病变的一个指标，且有报道称增殖性糖尿病视网膜病变患者血清浓度较高。另一方面，全视网膜光凝（PRP）可防止严重糖尿病视网膜病变的进展并逆转视网膜前新生血管形成。本研究的目的是探讨PRP对糖尿病患者血清层粘连蛋白水平的影响。
本研究纳入了20例接受PRP治疗的糖尿病患者以及15例未进行PRP治疗的轻度或中度非增殖性糖尿病视网膜病变患者。在每位患者开始PRP治疗前及治疗完成后3个月，通过放射免疫分析法测定血清层粘连蛋白-P1（Lam-P1），即层粘连蛋白最大的抗胃蛋白酶片段。同样，对未接受光凝治疗的对照组进行基线和4个月样本分析。
与初始值相比，PRP治疗3个月后获得的血清Lam-P1浓度显著降低（1.62（标准差0.36）U/ml对1.91（0.37）U/ml；p<0.001）。所有患者血清Lam-P1水平均下降。相比之下，在未进行PRP治疗的轻度或中度非增殖性糖尿病视网膜病变患者中，血清Lam-P1浓度未发现显著变化（1.72（0.20）U/ml对1.74（0.17）；p=·0.250）。
PRP可降低重度糖尿病视网膜病变患者的血清Lam-P1水平。因此，旨在评估Lam-P1作为糖尿病视网膜病变标志物有效性的研究应将先前的PRP视为一个影响因素。最后，我们的结果表明，在重度糖尿病视网膜病变患者中，Lam-P1的视网膜来源对血清Lam-P1有很大贡献。
