评价异体富血小板血浆(PRP)在小型猪体内产生的免疫原性反应。

无菌条件下经颈动脉取1只雄性巴马小型猪全血，第1次以1 000×g力离心15 min分离红细胞，第2次以3 000×g力离心10 min获取PRP；剩余9只雄性巴马小型猪，抽签法选取3只，取其耳缘静脉血各1.0 mL。后9只小型猪双侧股部分别注射激活的异体PRP 0.5 mL，按抽签法分为1、2、4周组，每组3只，于异体PRP注射后1、2、4周分别取对应组各小型猪耳缘静脉血1.0 mL，之后处死该小型猪，取注射部位组织。流式细胞仪检测比较CD4^＋/CD8^＋T淋巴细胞亚群比例，生物显微镜下观察组织形态学变化及免疫组织化学分析局部组织免疫原性反应。对数据行单因素方差分析和Dunnett-t检验。

小型猪肌肉注射异体PRP前，CD4^＋/CD8^＋T淋巴细胞亚群比例为0.75±0.04，异体PRP注射后1、2、4周CD4^＋/CD8^＋T淋巴细胞亚群比例分别为0.96±0.02、0.85±0.02、0.79±0.02，比较差异有统计学意义(F＝37.970，P<0.001)。异体PRP注射后1、2周CD4^＋/CD8^＋T淋巴细胞亚群比例与参照组比较，差异均有统计学意义(P<0.001、＝0.004)；异体PRP注射后4周CD4^＋/CD8^＋T淋巴细胞亚群比例与参照组比较，差异无统计学意义(P＝0.201)。病理检查可见，异体PRP注射部位的局部组织于注射后1周有轻微炎性细胞浸润和白细胞介素-2(IL-2)的表达，注射后2、4周炎性细胞浸润逐渐消失，IL-2表达转为阴性。

异体PRP注射仅在小型猪体内产生轻微的局部和全身免疫原性反应，且在注射后4周该免疫原性反应基本消失。

To estimate the immunogenicity of allogeneic platelet-rich plasma(PRP) in mini-pigs.

Blood was drawn from the carotid artery of one Bama mini-pig under the sterile condition, and then centrifuged twice, first at 1 000×g for 15 min to remove red blood cells, and then at 3 000×g for 10 min to obtain PRP. One milliliter of blood was respectively drawn from the ear vein of 3 mini-pigs which were drawn from the remaining 9 mini-pigs. Allogeneic PRP gel was injected into 9 male mini-pigs′ gluteus maximus muscles bilaterally(0.5 mL of PRP in each injection site). Divided the mini-pigs into 1 week group, 2 weeks group and 4 weeks group by sortition randomization method, 3 pigs in each group. One milliliter of blood was respectively drawn from the ear vein of corresponding group 1, 2, 4 weeks after the injection, and then mini-pigs were sacrificed and the muscle samples from injection site was obtained at each time point. The change of CD4⁺ and CD8⁺ T lymphocyte subpopulation were detected and compared through flow cytometry. Histomorphological changes and immunohistochemical analysis of local tissue immunogenic responses were observed under biological microscope. Data were processed with one-way analysis of variance and Dunnett-t test.

Before the intramuscular injection of allogeneic PRP, the ratio of CD4⁺ and CD8⁺ T lymphocyte subpopulation in peripheral blood was 0.75±0.04, which respectively changed to 0.96±0.02, 0.85±0.02 and 0.79±0.02 at week 1, week 2 and week 4 after injection. The difference was statistically significant (F=37.970, P<0.001). Compared with the CD4⁺ /CD8⁺ cell ratio before the injection, there were significant differences at 1 week group and 2 weeks group respectively(P<0.001, =0.004). There were no obvious difference in CD4⁺ /CD8⁺ cell ratio bettween 4 weeks group and normal physical level. Histopathologic examination revealed that the intramuscular injection of allogeneic PRP only caused subtle inflammation and little expression of IL-2 around the injection site at week 1, which decreased at week 2 and did not persist till week 4.

Allogeneic platelet-rich plasma can cause minor local and systemic immune response in mini-pigs. The responses will get weaker and disappeared after 4 weeks.