HUMAN DIABETIC PERINEURIAL CELL BASEMENT-MEMBRANE THICKENING

Abstract

The perineurium of peripheral nerves is a cellular sleeve which surrounds and isolates the endoneurium with its axons and Schwann cells from the epineurium. Basement membrane covers the inner and outer surfaces of perineurial cells. Ultrastructural thickness measurements were made in human sural nerve perineurial cell basement membranes. Patients (24) with diabetes melitus had a mean SD thickness of 174.1 .+-. 76.2 nm, which was significantly greater than that found in 19 nondiabetics (67.1 .+-. 12.8 nm, pooled variance 2-tailed t-test, P < 0.001). For 13 of the diabetics on insulin, the values were 208.4 .+-. 78.1 nm compared to those not on insulin (133.5 .+-. 51.8 nm, P = 0.01). The P values when comparing males vs. females and source of tissue from autopsy vs. biopsy indicated no significant differences. In diabetes mellitus, in addition to the well known basement membrane thickening of the microvasculature, there is also thickening of the basement membrane covering a nonvascular cell of nerve, the perineurial cell, and this thickening is exaggerated in diabetics treated with insulin. Perineurial cell basement membrane thickness quantitation may be useful in distinguishing diabetic from nondiabetic distal symmetrical neuropathy.