Plasma fibronectin as an indicator of microvascular damage in diabetic patients. Rapid and sensitive evaluation by a radial immunodiffusion technique.

Plasma fibronectin might be considered as an indicator of early and advanced microvascular damage in diabetic patients. We have therefore studied plasma fibronectin, using a radial immunodiffusion technique (LC-Partigen Fibronectin), in insulin-dependent and non-insulin-dependent diabetic patients with and without microangiopathic and neurological complications, i.e. retinopathy, nephropathy and autonomic and peripheral neuropathy. Steady and progressive increases of plasma fibronectin levels in association with the worsening of both diabetic retinopathy and nephropathy have been observed. However, significant variations of plasma fibronectin levels were already found in diabetic patients without microangiopathy when compared with healthy control subjects. Fibronectin levels were also higher in diabetic patients with autonomic and peripheral neuropathy than in control subjects and diabetic patients without neurological changes. The evaluation of plasma fibronectin by a specific radial immunodiffusion procedure might represent an important approach in the study and prevention of diabetic microcirculatory disorders.