多形性日光疹皮损中板层小体分布、神经酰胺酶表达与皮肤屏障功能

目的 探讨多形性日光疹（PLE）表皮中板层小体的分布、神经酰胺酶的表达与皮肤屏障受损的相关性。方法 选取PLE患者47例及正常人对照40例，通过电镜观察两组皮损处颗粒层、棘层板层小体的数量及分布情况，运用免疫组化测定皮损处神经酰胺酶的表达，采用无创性皮肤测试仪测量皮损处经皮水分丢失（TEWL）、角质层含水量及皮脂含量。结果 透射电镜结果显示：与对照组相比，PLE患者颗粒层、棘层板层小体数量明显少于正常人对照组，分布较正常人对照组紊乱。免疫组化结果显示：PLE患者皮损处神经酰胺酶表达20例阳性、21例弱阳性、6例阴性；正常人对照组中36例阳性、4例弱阳性，差异有统计学意义（P < 0.01）；皮损处TEWL（34.2191 ± 12.70）较正常人对照组（16.8350 ± 6.50）高，角质层含水量（22.7319 ± 8.71）较正常人对照组（29.4250 ± 5.08）低，差异有统计学意义（P < 0.01）；皮脂含量两者之间差异无统计学意义。结论 PLE患者存在神经酰胺合成障碍，可能是皮肤屏障受损的原因之一。

Lamellar body distribution, ceramidase expression and skin barrier function in lesions of polymorphous light eruption

Objective To investigate the correlation of epidermal distribution of lamellar bodies and expression of ceramidase with skin barrier dysfunction in polymorphous light eruption.Methods Forty-seven patients with polymorphous light eruption and 40 healthy volunteers were recruited into this study.Noninvasive instruments were used to measure skin sebum content,transepidermal water loss(TEWL)and water content in stratum corneum in all of the subjects.Then,tissue specimens were obtained from the lesions at sunexposed sites in the patients and normal skin of the healthy volunteers.The ultrastructure and distribution of lamellar bodies were observed with transmission electron microscopy in five lesion and control specimens.Immunohistochemistry was performed to detect the expression of ceramidase in the tissue specimens.Results Compared with the normal skin from healthy volunteers,the lesions from patients showed decreased number of lamellar bodies in the granular layer and prick cell layer with a disorganized arrangement.Ceramidase was positively expressed in 20 lesion specimens and 36 normal control specimens,weakly expressed in 21 lesion specimens and 4 normal control specimens,and negative in 6 lesion specimens; there was a significant difference in the expression of ceramidase between the lesion specimens and normal control specimens(P ＜ 0.01).The lesions also showed high TEWL(34.2191 ± 12.70 vs.16.8350 ± 6.50,P ＜ 0.01),lower water content in stratum corneum(22.7319 ± 8.71 vs.29.4250 ± 5.08,P ＜ 0.01)and similar skin sebum content compared with the normal skin.Conclusions There is a disturbance in the synthesis of ceramide in patients with polymorphous light eruption,which may contribute to the impairment of skin barrier.