Rose Rebecca F, Batchelor Rebecca J, Turner David, Goulden Victoria
Department of Dermatology at The General Infirmary at Leeds, Great George St, Leeds LS1 3EX, United Kingdom.
J Am Acad Dermatol. 2009 Aug;61(2):259-62. doi: 10.1016/j.jaad.2009.03.011. Epub 2009 Jun 3.
Narrowband ultraviolet (UV) B phototherapy (nbUVB) is a widely used modality in the treatment of psoriasis and is generally accepted to be safe in pregnancy. Previous studies have described photodegradation of serum folate after exposure to UVA radiation but the effect of UVB is not known. Insufficient folate levels predispose to neural tube defects in pregnancy. In addition, folate deficiency may increase the risk of colorectal carcinoma and influence serum homocysteine levels, which are thought to be a risk factor for cardiovascular disease.
We sought to determine whether exposure to nbUVB reduces folate levels.
This single-center, open observational study was conducted in a teaching hospital setting. Serum and red cell folate levels were measured in patients with psoriasis attending for nbUVB at baseline and after a minimum of 18 exposures.
A total of 35 patients completed the study. Mean serum and red cell folate levels at baseline were 6.34 and 410 ng/ml, respectively. After nbUVB, mean serum and red cell folate levels were 6.35 and 423 ng/ml, respectively. This was not significantly different from baseline measurements (P = .99 serum folate and P = .57 red cell folate).
This study examined the effect of a standard course of 18 exposures of nbUVB on folate levels, rather than prolonged treatment. Adult patients with psoriasis only were investigated.
A standard course of nbUVB does not have an effect on serum and red cell folate levels in patients with psoriasis.
窄谱中波紫外线（nbUVB）光疗是治疗银屑病广泛使用的一种方式，并且普遍认为在孕期使用是安全的。既往研究描述了血清叶酸在暴露于UVA辐射后会发生光降解，但UVB的影响尚不清楚。叶酸水平不足会增加孕期神经管缺陷的易感性。此外，叶酸缺乏可能会增加结直肠癌的风险并影响血清同型半胱氨酸水平，而血清同型半胱氨酸水平被认为是心血管疾病的一个危险因素。
我们试图确定暴露于nbUVB是否会降低叶酸水平。
这项单中心、开放性观察性研究在一家教学医院环境中进行。对接受nbUVB治疗的银屑病患者在基线时以及至少18次照射后测量血清和红细胞叶酸水平。
共有35名患者完成了研究。基线时血清和红细胞叶酸水平的平均值分别为6.34和410 ng/ml。nbUVB照射后，血清和红细胞叶酸水平的平均值分别为6.35和423 ng/ml。这与基线测量值无显著差异（血清叶酸P = 0.99，红细胞叶酸P = 0.57）。
本研究考察的是18次nbUVB标准疗程对叶酸水平的影响，而非长期治疗。仅对成年银屑病患者进行了调查。
nbUVB标准疗程对银屑病患者的血清和红细胞叶酸水平没有影响。
