摘要目的：探讨慢性光线性皮炎（CAD）患者与健康志愿者光试验、光斑贴试验、皮肤颜色相关参数的差异以及与Arg163Gln基因型特征分布关系。方法用日光模拟仪SUN1000、瑞敏牌光斑贴抗原、紫外线光疗仪SS?03A和窄波反射分光光度仪对25例CAD患者和25例健康志愿者进行光试验、皮肤色素测定，同时用PCR法行Arg163Gln基因型检测。其中25例CAD患者和5例健康志愿者进行光斑贴试验。结果光试验：CAD患者UVA最小持续性黑化量和UVB最小红斑量均显著低于健康志愿者（P<0.05），其中UVB最小红斑量更明显（P<0.01）。光斑贴试验出现阳性反应16例（64%），其中光变态反应13例（52%）。对于4处不同皮肤颜色相关参数的检测，CAD患者面颊部、前额、上臂内侧、手背皮肤的血红蛋白含量均显著高于健康志愿者，而面颊、前额、上臂内侧皮肤的黑素含量差异无统计学意义，仅手背皮肤黑素含量显著高于健康志愿者（P<0.01），CAD患者曝光部位皮肤黑素和血红蛋白含量均显著高于上臂内侧（P<0.05）。CAD在Arg163Gln位点突变为CGA比例与健康志愿者相比，差异无统计学意义（P>0.05）；CAD在Arg163Gln位点突变为CAA比例与健康志愿者相比，差异有统计学意义（P<0.01）。比较Arg163Gln突变为CAA阳性者和CAA阴性者对UVA和UVB的反应性差异，发现Arg163Gln突变为CAA阳性者的UVA最小持续性黑化量（P=0.055）和UVB最小红斑量（P=0.325）均明显低于CAA阴性者。结论皮肤光生物学检查方法在CAD的诊断中具有一定价值。Arg163Gln突变为CAA基因型特征在CAD诊断和防治中有一定的提示作用。

abstractsObjective To explore differences in phototest and photopatch test results, and in skin color?related parameters between healthy subjects and patients with chronic actinic dermatitis (CAD), and to examine their relationship with the melanocortin?1 receptor gene(MC1R)Arg163Gln variant. Methods Phototests were performed by using a sun simulator SUN1000, and skin color was analyzed by using Hexameter MX18 in 25 patients with CAD and 25 healthy subjects. The MC1R genotype at position?163 was determined by PCR. Photopatch tests were performed on 25 patients with CAD and 5 healthy subjects using a standard series of photoallergens(RuiMin)and an ultraviolet (UV)phototherapy equipment, SS?03A. Results Regarding phototest results, both UVA?minimal persistent pigment darkening dose(MPPD)and UVB?minimal erythema dose(MED)were significantly lower in CAD patients compared with healthy controls (both P < 0.05), with the reduction in UVB?MED being particularly notable. Sixteen patients (64%)in the CAD group had positive photopatch reactions, including 13(52%)cases of photoallergy. Skin color?related parameters were measured at four sites. Skin hemoglobin levels on the cheek, forehead, back of hands, inner upper arms were all significantly higher in CAD patients than in healthy controls(all P<0.05). However, skin melanin levels on the cheek, forehead and inner upper arms were similar between the two groups, and only those on the back of hands were significantly higher in CAD patients than in controls(P<0.01). Skin melanin and hemoglobin levels were significantly higher in exposed than in unexposed (inner upper arms) areas in CAD patients (all P < 0.05). The frequency of the CGA genotype at position?163 in the MC1R gene was similar between CAD patients and controls(P>0.05), but that of the CAA genotype differed significantly between the two groups(P<0.01). UVA?MPPD and UVB?MED were both significantly lower in CAD patients with the CAA genotype at position?163 in the MC1R gene than in those without the genotype(P=0.055, 0.325, respectively). Conclusions Skin photobiological testing plays a critical&nbsp;role in the diagnosis of CAD. Further studies are needed to clarify the role of the CAA genotype at position?163 in the MC1R gene in the diagnosis, prevention and treatment of CAD.