Martin C, Viviand X, Bongrand P, Papazian L, Saux P, Gouin F
Department of Anesthesia and Intensive Care, Sainte-Marguerite Hospital, Marseille, France.
J Crit Care. 1997 Dec;12(4):193-9. doi: 10.1016/s0883-9441(97)90032-0.
Phagocytosis is a major mechanism of defense against bacterial infections. The ingestion of bacteria by phagocytes involves a variety of cell membrane recognition structures and, among them, immunoglobulin receptors. The aim of this study was to test the phagocytic activity of granulocytes and monocytes of intensive care unit (ICU) patients, and to evaluate the effects of intravenous polyvalent immunoglobulins (IVIG) used as adjunct treatment of nosocomial pneumonia on some phagocyte membrane receptors of these patients.
The phagocytic activity of granulocytes and monocytes of 41 mechanically ventilated patients with nosocomial bacterial pneumonia was studied during the acute phase of infection. These ICU patients were compared with 21 hospitalized, noninfected volunteer patients hospitalized in a medical ward. Peripheral blood granulocytes and monocytes were studied. Of the 41 ICU patients, after randomization, 21 received IVIG at a dose of 1 g/kg for 3 days. The 41 ICU patients were compared with the 21 non-ICU, noninfected hospitalized controls. The 21 ICU patients who received 3 days of IVIG were also compared with the 20 ICU patients not receiving IVIG. Cells were tested in standard immunoglobulin-free medium (fetal calf serum) and in the presence of patients' serum. Blood granulocytes and monocytes were purified and separately exposed to three types of particles: antibody-coated erythrocytes (to test immunoglobulin receptors), opsonized zymosan (to test C3 receptors), and glutaraldehyde-treated erythrocytes (to test lectinlike or other nonspecific binding sites). Phagocytosis and superoxide anion production (oxidative burst) were measured.
Granulocytes of ICU patients compared with those of non-ICU, noninfected patients exhibited a substantial decrease of zymosan ingestion (P < .05), whereas phagocytosis of other particles was normal. Monocytes from the ICU patients, compared with those of the non-ICU, noninfected patients, displayed an unselective overall decrease of phagocytic ability for the three particle types (P < .05). The phagocytosis activity of the three membrane receptor species of blood monocytes and granulocytes of ICU patients was not significantly modified by the IVIG infusion. For both monocytes and granulocytes, no significant improvement was observed in the fraction of cells that ingested at least one foreign particle and the mean number of particles per cell having phagocytized at least one foreign particle. Granulocyte and monocyte functions were also tested by the production of reduced ferricytochrome and no significant improvement in the oxidative burst was observed after infusion of IVIG.
Infected ICU patients display a deficiency of phagocytosis membrane receptors of blood granulocytes and monocytes. The addition of IVIG to standard therapy does not improve the phagocytic activity of ICU patients with nosocomial pneumonia.
吞噬作用是抵御细菌感染的主要机制。吞噬细胞摄取细菌涉及多种细胞膜识别结构，其中包括免疫球蛋白受体。本研究的目的是检测重症监护病房（ICU）患者粒细胞和单核细胞的吞噬活性，并评估静脉注射多价免疫球蛋白（IVIG）作为医院获得性肺炎辅助治疗对这些患者某些吞噬细胞膜受体的影响。
在感染急性期，对41例机械通气的医院获得性细菌性肺炎患者的粒细胞和单核细胞的吞噬活性进行了研究。将这些ICU患者与21例在普通内科病房住院的非感染志愿者患者进行比较。研究外周血粒细胞和单核细胞。在41例ICU患者中，随机分组后，21例接受剂量为1 g/kg的IVIG治疗，持续3天。将41例ICU患者与21例非ICU的非感染住院对照患者进行比较。还将接受3天IVIG治疗的21例ICU患者与未接受IVIG治疗的20例ICU患者进行比较。细胞在标准无免疫球蛋白培养基（胎牛血清）中以及在患者血清存在的情况下进行检测。纯化血液中的粒细胞和单核细胞，并分别使其接触三种类型的颗粒：抗体包被的红细胞（用于检测免疫球蛋白受体）、调理酵母聚糖（用于检测C3受体）和戊二醛处理的红细胞（用于检测凝集素样或其他非特异性结合位点）。测量吞噬作用和超氧阴离子产生（氧化爆发）。
与非ICU的非感染患者相比，ICU患者的粒细胞对酵母聚糖的摄取显著减少（P < 0.05），而对其他颗粒的吞噬作用正常。与非ICU的非感染患者相比，ICU患者的单核细胞对三种颗粒类型的吞噬能力总体上呈现非选择性下降（P < 0.05）。IVIG输注并未显著改变ICU患者血液单核细胞和粒细胞的三种膜受体类型的吞噬作用活性。对于单核细胞和粒细胞，摄取至少一个外来颗粒的细胞比例以及每个吞噬了至少一个外来颗粒的细胞的平均颗粒数均未观察到显著改善。通过还原型细胞色素c的产生来测试粒细胞和单核细胞的功能，IVIG输注后氧化爆发也未观察到显著改善。
感染的ICU患者血液粒细胞和单核细胞的吞噬细胞膜受体存在缺陷。在标准治疗中添加IVIG并不能改善医院获得性肺炎ICU患者的吞噬活性。
