Increased endoneurial albumin in diabetic polyneuropathy

Area of Science:

• Neurology
• Diabetology
• Vascular Biology

Background:

• Diabetic polyneuropathy is a common complication of diabetes mellitus.
• The integrity of the blood-nerve barrier (BNB) is crucial for nerve function.
• Previous research suggests potential alterations in the BNB in diabetic neuropathy.

Purpose of the Study:

• To investigate the integrity of the blood-nerve barrier in patients with diabetic polyneuropathy.
• To quantify albumin levels within the endoneurium as an indicator of BNB permeability.
• To compare BNB integrity between diabetic patients with polyneuropathy and healthy controls.

Main Methods:

• Fascicular biopsies of sural nerves were obtained from diabetic patients with polyneuropathy and controls.
• Albumin concentration was measured in endoneurial tissue and plasma using solid-phase radioimmunoassay.
• Albumin levels were normalized to total protein to calculate the blood-nerve barrier index (BNB-Index).

Main Results:

• The mean BNB-Index in fifteen diabetic patients with polyneuropathy was 29.7% ± 12.6% SD.
• This value was significantly higher, approximately 3.8 times, than the control group's mean BNB-Index of 7.8% ± 2.0% SD.
• Elevated endoneurial albumin indicates increased permeability of the blood-nerve barrier.

Conclusions:

• The blood-nerve barrier of endoneurial capillaries is impaired in patients suffering from diabetic polyneuropathy.
• Increased BNB permeability may contribute to the pathogenesis of diabetic nerve damage.
• These findings highlight the BNB as a potential therapeutic target in diabetic neuropathy.