Hegde Vishal, Dworsky Erik M, Stavrakis Alexandra I, Loftin Amanda H, Zoller Stephen D, Park Howard Y, Richman Sherif, Johansen Daniel, Hu Yan, Taylor Julie A, Hamad Christopher D, Chun Rene F, Xi Weixian, Adams John S, Bernthal Nicholas M
1Department of Orthopaedic Surgery, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, California.
J Bone Joint Surg Am. 2017 Oct 18;99(20):1737-1744. doi: 10.2106/JBJS.16.01598.
Despite recent advances, infection remains the most common etiology of arthroplasty failure. Recent work suggests that 25-hydroxyvitamin D (25D) deficiency correlates with the frequency of periprosthetic joint infection (PJI). We endeavored to examine whether 25D3 deficiency leads to increased bacterial burden in vivo in an established mouse model of PJI and, if so, whether this effect can be reversed by preoperative 25D3 supplementation.
Mice (lys-EGFP) possessing fluorescent neutrophils were fed a vitamin D3-sufficient (n = 20) or deficient (n = 40) diet for 6 weeks. A group of 25D3-deficient mice (n = 20) were "rescued" with 1 intraperitoneal dose of 25D3 at 3 days before surgery. A stainless steel implant was inserted into the knee joint and the joint space was inoculated with bioluminescent Staphylococcus aureus (1 × 10 colony forming units [CFUs]). In vivo imaging was used to monitor bacterial burden and neutrophil infiltration. Blood was drawn to confirm 25D3 levels 3 days before surgery and on postoperative days (PODs) 0 and 14. Mice were killed at POD 21, and CFUs were quantified after culture. Myeloperoxidase (MPO) and β-N-acetylglucosaminidase (NAG) were assayed to look at neutrophil infiltration and activated tissue macrophage recruitment, respectively.
Serum values confirmed 25D3 deficiency and repletion of the 25D3-rescued group. Bacterial bioluminescence and neutrophil fluorescence were significantly greater (p < 0.05) in the 25D3-deficient group. CFU counts from the joint tissue and implant were also significantly greater in this group (p < 0.05). Rescue treatment significantly decreased bacterial burden and neutrophil infiltration (p < 0.05). Compared with the 25D3-sufficient and 25D3-rescued groups, MPO activity was higher (p < 0.02) and NAG activity was lower (p < 0.03) in the 25D3-deficient group.
This study demonstrated in vivo in a mouse model of PJI that (1) 25D3 deficiency results in increased bacterial burden and neutrophil infiltration, and (2) this effect can be reversed with preoperative repletion of 25D3.
Considering that >65% of patients undergoing arthroplasty have insufficient or low levels of total 25D and that 25D levels can be replenished with ease using a U.S. Food and Drug Administration (FDA)-approved, oral 25D3 product, 25D deficiency may be an important modifiable risk factor in humans undergoing joint replacement.
尽管近年来取得了进展,但感染仍是关节置换失败最常见的病因。最近的研究表明,25-羟基维生素D(25D)缺乏与假体周围关节感染(PJI)的发生率相关。我们试图研究在已建立的PJI小鼠模型中,25D3缺乏是否会导致体内细菌负荷增加,如果是,术前补充25D3是否可以逆转这种影响。
将具有荧光中性粒细胞的小鼠(lys-EGFP)分为两组,一组给予维生素D3充足(n = 20)的饮食,另一组给予维生素D3缺乏(n = 40)的饮食,持续6周。一组25D3缺乏的小鼠(n = 20)在手术前3天腹腔注射一剂25D3进行“挽救”。将不锈钢植入物插入膝关节,并向关节间隙接种生物发光金黄色葡萄球菌(1×10菌落形成单位[CFU])。使用体内成像监测细菌负荷和中性粒细胞浸润。在手术前3天、术后第0天和第14天采集血液以确认25D3水平。在术后第21天处死小鼠,培养后对CFU进行定量。分别检测髓过氧化物酶(MPO)和β-N-乙酰氨基葡萄糖苷酶(NAG),以观察中性粒细胞浸润和活化组织巨噬细胞募集情况。
血清值证实了25D3缺乏以及25D3挽救组的补充情况。25D3缺乏组的细菌生物发光和中性粒细胞荧光明显更高(p < 0.05)。该组关节组织和植入物的CFU计数也明显更高(p < 0.05)。挽救治疗显著降低了细菌负荷和中性粒细胞浸润(p < 0.05)。与25D3充足组和25D3挽救组相比,25D3缺乏组的MPO活性更高(p < 0.02),NAG活性更低(p < 0.03)。
本研究在PJI小鼠模型中证实,(1)25D3缺乏导致细菌负荷增加和中性粒细胞浸润增加,(2)术前补充25D3可逆转这种影响。
考虑到>65%接受关节置换术的患者总25D水平不足或较低,且使用美国食品药品监督管理局(FDA)批准的口服25D3产品可轻松补充25D水平,25D缺乏可能是接受关节置换术患者中一个重要的可改变风险因素。