Cocks R A, Chan T Y
Accident and Emergency Medicine Academic Unit, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong.
Eur J Emerg Med. 1997 Dec;4(4):193-5. doi: 10.1097/00063110-199712000-00003.
An understanding of the mechanisms of post-injury leukocyte trafficking is essential to the development of future therapeutic interventions aimed at preventing infection and multiple organ failure in trauma patients, yet very little is known about the cellular and molecular events resulting in mobilization of members of the leukocyte family following trauma. We have studied the post-injury expression of the lymphocyte, monocyte and neutrophil adhesion molecules CD11a (LFA-1), CD11b, CD11c, CD29 (beta-1 integrin) and CD62L (L-selectin) in a group of 36 trauma patients, 13 of whom had suffered major trauma (ISS > or = 16), 15 moderate trauma (ISS = 9-15) and eight minor trauma (ISS < 9). Three ml blood samples were taken within 2.5 h of injury (mean sample time = 1.2 h, median = 1 h) into EDTA anticoagulant. Fifty-three normal control subjects were also studied for comparison. Leukocytes were stained using fluorescent-labelled monoclonal antibodies specific for each adhesion molecule, and the mean receptor density per cell measured using flow cytometry. Monocytes, neutrophils and lymphocytes in the trauma patients showed significantly increased mean-receptor density of L-selectin (p < 0.0001, 0.0001 and 0.004 respectively). Neutrophils and monocytes showed a significantly decreased level of expression of CD11a, and neutrophils showed a significant decrease in expression of CD11c. Our results indicate that there is a reduction in CD11a expression after trauma which may play an important role in the demargination of neutrophils and monocytes. The strong increase in L-selectin expression in all cell populations was unexpected, and is potentially important because this molecule supports rolling behaviour in all members of the leukocyte family, and would promote close contact between leukocytes and the endothelium at the site of injury without firm adhesion taking place. These events may be of significance in planning future strategies to combat post-trauma complications.
了解损伤后白细胞运输机制对于开发旨在预防创伤患者感染和多器官功能衰竭的未来治疗干预措施至关重要，但对于创伤后导致白细胞家族成员动员的细胞和分子事件却知之甚少。我们研究了一组36名创伤患者损伤后淋巴细胞、单核细胞和中性粒细胞黏附分子CD11a（淋巴细胞功能相关抗原-1）、CD11b、CD11c、CD29（β-1整合素）和CD62L（L-选择素）的表达情况，其中13名患者遭受严重创伤（损伤严重度评分[ISS]≥16），15名患者为中度创伤（ISS=9-15），8名患者为轻度创伤（ISS<9）。在受伤后2.5小时内（平均采样时间=1.2小时，中位数=1小时）采集3ml血液样本，置于乙二胺四乙酸抗凝剂中。还研究了53名正常对照受试者以作比较。使用针对每种黏附分子的荧光标记单克隆抗体对白细胞进行染色，并使用流式细胞术测量每个细胞的平均受体密度。创伤患者的单核细胞、中性粒细胞和淋巴细胞显示L-选择素的平均受体密度显著增加（分别为p<0.0001、0.0001和0.004）。中性粒细胞和单核细胞显示CD11a表达水平显著降低，中性粒细胞显示CD11c表达显著降低。我们的结果表明，创伤后CD11a表达降低，这可能在中性粒细胞和单核细胞的边缘白细胞脱离中起重要作用。所有细胞群体中L-选择素表达的强烈增加出乎意料，并且可能具有重要意义，因为该分子支持白细胞家族所有成员的滚动行为，并且会促进损伤部位白细胞与内皮细胞之间的密切接触而不发生牢固黏附。这些事件对于规划未来对抗创伤后并发症的策略可能具有重要意义。
