Yakovleva Oksana, Pilant Teresa, Kaldhone Pravin, Jackson Joseph, Rotstein David, Stewart Caitlin, Anderson John, MacGregor Scott, Maclean Michelle, Gregori Luisa, Atreya Chintamani
Division of Emerging Transfusion-Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, FDA, 10903 New Hampshire Avenue, Silver Spring, MD, 20993, USA.
Division of Blood Components and Devices, Office of Blood Research and Review, Center for Biologics Evaluation and Research, FDA, Silver Spring, MD, 20993, USA.
Sci Rep. 2025 Jun 6;15(1):19893. doi: 10.1038/s41598-025-03230-1.
Pathogen reduction technologies using chemicals and or UV light have been demonstrated to improve the safety of ex vivo platelets from infectious diseases. However, UV light exposure also may affect the treated products, depending on wavelength and exposure. Alternatively, visible spectra 405 nm violet-blue light has broad-spectrum microbicidal activity. Here we tested the effect of 405 nm light on Treponema pallidum, the bacterium that causes syphilis. We contaminated platelets stored in plasma with two treponemal concentrations (low and high titers) and treated an aliquot with 270 J/cm dose (irradiance = 15 mW/cm) of 405 nm light while another aliquot remained untreated. Next, we inoculated intradermally an aliquot of both samples into rabbits. Rabbits inoculated with untreated samples developed syphilis while animals inoculated with light-treated samples did not. Thus, inactivation was demonstrated to the limit of detection of the bioassay. We estimated > 2 log and > 4 log reduction in the low and high dose studies, respectively. These results provide proof-of-concept that 405 nm light is effective in reducing syphilis risk in ex vivo platelets.
使用化学物质和/或紫外线的病原体灭活技术已被证明可提高体外血小板免受传染病感染的安全性。然而，紫外线照射也可能会影响处理后的产品，这取决于波长和照射时间。另外，可见光谱405纳米的紫蓝光具有广谱杀菌活性。在此，我们测试了405纳米光对引起梅毒的苍白密螺旋体的作用。我们用两种梅毒螺旋体浓度（低滴度和高滴度）污染储存在血浆中的血小板，并用270 J/cm²剂量（辐照度 = 15 mW/cm²）的405纳米光处理其中一份等分试样，而另一份等分试样不做处理。接下来，我们将两份样品的等分试样皮内接种到兔子体内。接种未处理样品的兔子患上了梅毒，而接种光处理样品的动物则没有。因此，在生物测定的检测极限内证明了灭活效果。我们估计在低剂量和高剂量研究中分别减少了>2个对数和>4个对数。这些结果提供了概念验证，即405纳米光可有效降低体外血小板中的梅毒风险。
