Viander M, Jansén C T, Eskola J
Photodermatol. 1984 Feb;1(1):23-9.
Recent animal studies have demonstrated the importance of cancer surveillance in determining susceptibility to UV-induced cancers. On the other hand, even subcarcinogenic UV doses have been shown to suppress cancer surveillance immune mechanisms in experimental animals. To find out if photochemotherapy may compromise human cancer surveillance mechanisms, natural killer (NK) cell activity was monitored during PUVA treatment for up to 38 irradiations in dermatological patients. A significant depression of basal NK activity was seen during the first 4 to 24 irradiations in psoriatic patients. Thereafter, an increase toward starting values was seen in assays performed at high effector to target (E:T) ratios, but not at low ones. The maximal (interferon-boosted) NK activity, however, remained unchanged during the therapy, due to an increased sensitivity to IFN augmentation. The results are interpreted as a redistribution in the proportions of immature and mature NK cells. Thus, no serious effects of PUVA treatment on human natural resistance against cancer could be demonstrated, but longer follow up studies are recommended.
近期的动物研究已证明癌症监测在确定对紫外线诱导癌症易感性方面的重要性。另一方面，即使是亚致癌剂量的紫外线也已显示会抑制实验动物的癌症监测免疫机制。为了弄清楚光化学疗法是否会损害人类癌症监测机制，在皮肤科患者接受补骨脂素加长波紫外线（PUVA）治疗长达38次照射期间，对自然杀伤（NK）细胞活性进行了监测。在银屑病患者接受最初4至24次照射期间，观察到基础NK活性显著降低。此后，在以高效应细胞与靶细胞（E:T）比例进行的检测中，NK活性朝着起始值增加，但在低比例时未出现这种情况。然而，由于对干扰素增强的敏感性增加，治疗期间最大（干扰素增强的）NK活性保持不变。这些结果被解释为未成熟和成熟NK细胞比例的重新分布。因此，未证明PUVA治疗对人类抗癌天然抵抗力有严重影响，但建议进行更长时间的随访研究。
