Department of Orthopedics, Institute of Surgical Sciences, Uppsala University Hospital, Sweden.
Acta Orthop. 2011 Feb;82(1):6-12. doi: 10.3109/17453674.2010.548028. Epub 2010 Dec 29.
Following metal-on-metal hip arthroplasty (THA), immunological reactions including changes in lymphocyte populations, aseptic loosening, and lymphocytic pseudotumors occur. We hypothesized that changes in lymphocyte subpopulations would be associated with elevated metal ion concentrations.
A randomized trial involving 85 patients matched for age and sex and randomized to receiving metal-on-metal (n = 41) or metal-on-polyethylene total hip arthroplasty (n = 44) was conducted. 36 patients were eligible for follow-up after mean 7 (6-8) years. Concentrations of chromium and cobalt were analyzed by high-resolution inductively coupled plasma mass spectrometry. Leukocyte subpopulations and immunoglobulins in patient blood were measured using standard laboratory methods.
Patients with a metal-on-metal hip had higher serum concentrations of chromium (1.05 vs. 0.36 μg/L; p < 0.001) and cobalt (0.86 vs. 0.24 μg/L; p < 0.001) than those with metal-on-polyethylene. The percentage of HLA DR(+) CD8(+) T-cells was higher in the metal-on-metal group (10.6 vs. 6.7%; p = 0.03) and correlated positively with chromium and cobalt concentrations in patient blood (Pearson's correlation coefficient: 0.39, p = 0.02; 0.36, p = 0.03, respectively). The percentage of B-cells was lower in the metal-on-metal group (p = 0.01). The two groups were similar with respect to immunoglobulin concentrations and Harris hip scores, and there were no radiographic signs of loosening.
We conclude that immunological alterations appear to be associated with increased cobalt and chromium concentrations. It is tempting to speculate that HLA DR(+) CD8(+) T-cells are involved in the pathogenesis of allergic reactions, implant loosening, and lymphocytic pseudotumors.
在金属对金属髋关节置换术后（THA），会发生包括淋巴细胞群变化、无菌性松动和淋巴细胞假瘤在内的免疫反应。我们假设淋巴细胞亚群的变化与金属离子浓度升高有关。
进行了一项涉及 85 名年龄和性别匹配的患者的随机试验，并随机分为接受金属对金属（n=41）或金属对聚乙烯全髋关节置换术（n=44）的两组。平均 7（6-8）年后，有 36 名患者符合随访条件。采用高分辨率电感耦合等离子体质谱法分析铬和钴的浓度。采用标准实验室方法测量患者血液中的白细胞亚群和免疫球蛋白。
金属对金属髋关节患者的血清铬浓度（1.05 vs. 0.36 μg/L；p<0.001）和钴浓度（0.86 vs. 0.24 μg/L；p<0.001）高于金属对聚乙烯组。金属对金属组 HLA DR(+) CD8(+) T 细胞的百分比更高（10.6 vs. 6.7%；p=0.03），且与患者血液中的铬和钴浓度呈正相关（Pearson 相关系数：0.39，p=0.02；0.36，p=0.03）。金属对金属组 B 细胞的百分比较低（p=0.01）。两组在免疫球蛋白浓度和 Harris 髋关节评分方面相似，且均无松动的影像学迹象。
我们的结论是，免疫改变似乎与钴和铬浓度的增加有关。令人不禁联想到 HLA DR(+) CD8(+) T 细胞可能参与了过敏反应、植入物松动和淋巴细胞假瘤的发病机制。
