通过皮肤活检评估健康成年人表皮神经纤维分布的数量特点

Quantitative characteristics of intraepidermal nerve fibers by skin biopsy in healthy Chinese

目的通过皮肤活检对健康成年人的表皮神经纤维进行大样本的系统定量研究，确立中国人正常皮肤神经的量化标准，为周围神经疾病的早期诊断提供参考依据。方法共收集健康成年人皮肤标本192例（来源于自2009年5月至2013年7月在河北大学附属医院接受皮肤活检的受试者），将其按不同解剖部位分为手背、前臂（前臂远端）、上臂（上臂远端）、足背、小腿（小腿端）、大腿（大腿近端）6个部位组，将其以20岁为1个年龄段分为20岁以下、21～40岁、41～60岁、61岁以上4个年龄组，均男女各半，通过皮肤活检结合免疫组化染色技术对其进行表皮神经纤维的定量观察。结果（1）大腿、小腿、足背各组之间表皮神经纤维密度（IENFD）两两比较，上臂、前臂、手背各组之间IENFD两两比较，足背与手背之间、小腿与前臂之间、大腿与上臂之间IENFD比较，差异均有统计学意义（P〈0．05），且随着肢体取材部位的由近及远，IENFD呈现逐渐递减的趋势。各解剖部位正常参考值范围分别为：上臂〉320．00纤维数／mm^2，前臂〉190．57纤维数／mm^2，手背〉184.37纤维数／mm^2，大腿〉418．36纤维数／mm^2，小腿〉157．35纤维数／mm^2，足背〉140．00纤维数／mm^2。（2）20岁以下组与21～40岁组、21～40岁组与41～60岁组、41～60岁组与61岁以上组IENFD比较差异均无统计学意义（P〉0．05）：20岁以下组与61岁以上组IENFD比较差异具有统计学意义（P〈0．05）。（3）在排除年龄影响的情况下，不同性别间IENFD值比较差异无统计学意义（P〉0．05）。结论解剖部位对IENFD具有明显的影响，体现出神经轴突“长度依赖性”的特点；年龄对IENFD影响程度较小；性别对IENFD无明显影响。

Objective To establish the quantitative standard of intraepidermal nerve fibers in healthy Chinese and provide reference basis for the early diagnosis of peripheral neuropathy through the large sample system of quantitative research by skin biopsy. Methods Adult skin samples of different anatomical locations, age and gender were obtained from 192 healthy volunteers who performed skin biopsies in our hospital from May 2009 to July 2013; they were divided into 6 groups according to different anatomic sites （distal upper arm, distal forearm, opisthenar, proximal thigh, distal crus and acrotarsium） and 4 groups according to the ages （patients under 20 years old, patients of 21-40 years old, patients of 41-60 years old and patients older than 61 years）. Quantitative observation of the intraepidermal nerve fibers was performed by skin biopsy and immunohistochemical technique. Half males and half females were chosen. Results The comparison of intra epidermal nerve fiber density （IENFD） among thigh, leg, dorsum of foot and the comparison among upper arm, forearm, dorsum of hand showed statistical significance （P〈0.05）. Along with the limbs part from proximal to distal, the IENFD in the upper and lower limbs both manifested a degressive tendency by degrees （normal reference value ranges of each anatomic site： upper arm〉320.00 fibers/mm^2, forearm〉190.57 fibers/mm^2, opisthenar〉184.37 fibers/mm^2, thigh〉418.36 fibers/mm^2, crus〉157.35 fibers/mm^2, and acrotarsium〉 140.00 fibers/mm^2）. The IENFD among patients under 20 years old, patients of 21-40 years old, patients of 41-60 years old and patients older than 61 years did not show statistically significant differences （P〉0.05）. The IENFD between patients under 20 years old and patients older than 61 years showed statistical significance （P〈0.05）. The IENFD in male and female adults did not show statistical significance （P〉0.05）. Conclusions A significant difference oflENFD is observed among different anatomic sites. Ages has small effect on IENFD, and gender has no effect on IENFD.