Granulocyte extravasation and recruitment to sites of interstitial inflammation in patients with renal failure

BACKGROUND: We have shown that leukocytes collected from sites of interstitial inflammation in patients on hemodialysis have a disturbed expression of CD11b compared to cells from healthy subjects. The aim of the present study was to study adhesion molecule expression on granulocytes in the peripheral circulation and at sites of interstitial inflammation in patients with renal failure. METHODS: Two skin blisters were raised in 10 patients and 19 healthy subjects and interstitial exudates collected (0 h). Skin chambers were applied and exposed to buffer or serum for 10 h in order to induce an intermediate and an intense interstitial inflammation. Cells and blister fluid were collected for determination of leukocyte count, CD11b/CD62L expression, interleukin-8 (IL-8) concentration in the interstitium and blister activity in terms of CD11b up-regulation. RESULTS: At the sites of intermediate and intense inflammation, granulocytes from patients with renal failure showed significantly higher expression of CD62L (p < 0.01 and p < 0.001, respectively) and significantly lower expression of CD11b (p < 0.0001 and p < 0.0001, respectively) compared to corresponding cells from healthy subjects. The interstitial concentration of IL-8 was significantly lower at the sites of intermediate (p < 0.005) and intense inflammation (p < 0.05) in patients with renal failure compared to in healthy subjects. In order to explore whether the decreased CD11b expression observed in patients is due to the interstitial milieu, blister exudates from patients and healthy subjects were incubated with leukocytes from healthy blood donors. Blister exudates from patients had a similar capacity to mobilize CD11b on granulocytes in vitro compared with blister exudates from healthy subjects. There was no consistent correlation between the expression of adhesion molecules on granulocytes in the interstitium and the concentration of IL-8 or the total interstitial concentration of chemotactic mediators. CONCLUSION: Constitutive cellular determinants are probably involved in the disturbed expression of adhesion molecules on granulocytes at sites of interstitial inflammation in patients with renal failure.     

Impaired monocyte CD11b expression in interstitial inflammation in hemodialysis patients

BACKGROUND: It is not known to what extent intravascular phenotypic alterations in adhesion molecule expression induced by hemodialysis influence the recruitment of monocytes and their ability to up-regulate CD11b at the local site of inflammation in the interstitium. Using a skin suction chamber technique, we addressed these issues in eight hemodialysis patients and in eight healthy subjects. METHODS: Two skin blisters were raised on the forearm of each individual and blister exudate collected. The blisters were then stimulated with autologous serum (active blister, intense inflammation) or buffer (control blister, intermediate inflammation), respectively. Thereafter the patients were treated with Cuprophan hemodialysis for four hours. After 10 hours, the exudate was aspirated from each chamber in all subjects. Monocyte count and expression of CD11b were analyzed in serum and blister fluid by flow cytometry. Then, monocytes from healthy blood donors were incubated in blister fluid from patients and healthy subjects in order to determine the local chemotactic activity in terms of CD11b up-regulation. Monocyte chemotactic protein-1 (MCP-1), a marker of systemic monocyte chemotactic activity, was also analyzed in serum at 0 and 10 hours in all individuals. RESULTS: The number of monocytes at the site of inflammation in the interstitium in hemodialysis patients correlated with the expression of CD11b on transmigrated cells (r = 0.78, P < 0.001). Monocytes collected in the active blister fluid of dialysis patients expressed equal levels of CD11b as cells collected from healthy subjects. By contrast, monocytes collected from the control blisters of patients expressed lower levels of CD11b than cells from healthy subjects (P < 0.01), despite equal interstitial biological activity of CD11b-mobilizing factors in blister fluid from patients and healthy subjects and the fact that patients had higher systemic chemotactic activity in terms of MCP-1 concentration in serum (P < 0.001). CONCLUSION: Monocytes from hemodialysis patients have the capacity to mobilize CD11b to the same extent as cells from healthy individuals at the inflammatory spot, but more intense stimuli are required for such actions, probably because of a transient refractoriness.     

Monocyte-related determinants of inflammation in patients on peritoneal dialysis

AIMS: We studied markers of monocyte activation, i.e., the cell surface expression of CD11b and CD62L, and the serum concentrations of monocyte chemotactic protein 1 (MCP-1; a monocyte-specific chemoattractant) and soluble vascular cell adhesion molecule 1 (sVCAM-1; an adhesion molecule involved in monocyte recruitment) in 20 patients on peritoneal dialysis (PD), in 25 patients with chronic renal insufficiency, and in 27 healthy subjects. RESULTS: Monocytes obtained from the peripheral blood of PD patients had a significantly higher expression of CD62L (p = 0.02) as compared with monocytes from healthy subjects and a lower CD11b/CD18 expression as compared with monocytes collected from healthy subjects (p < 0.001) and from patients with renal insufficiency (p < 0.001). Monocytes from PD patients had, however, the capacity to increase the expression of CD11b following stimulation with a potent chemotactic factor. The serum concentrations of MCP-1 and sVCAM-1 were higher in PD patients (575 +/- 51 and 1,517 +/- 89 ng/ml) than in healthy subjects (225 +/- 17 and 668 +/- 64 ng/ml, respectively; p < 0.001 for both comparisons). There was a correlation between the levels of sVCAM-1 and MCP-1 (r = 0.48, p < 0.05) in patients on PD, but neither correlated with the monocyte expression of CD11b/CD18 or CD62L. The concentration of C-reactive protein was higher in patients on PD as compared with healthy subjects and correlated significantly with the concentration of sVCAM-1 (r = 0.63, p < 0.01). CONCLUSIONS: Monocytes in the peripheral circulation of patients on PD have a CD62L(high)/CD11b(low) phenotype, indicating that they have not undergone complete differentiation. Patients also have an increase in the systemic chemotactic activity for monocytes in combination with increased levels of sVCAM-1 and C-reactive protein. These inflammatory aberrations may play a pathophysiological role in the response to inflammatory and infectious diseases in patients on PD.     

Preserved leukocyte CD11b expression at the site of interstitial inflammation in patients with high-flux hemodiafiltration

The impact of high-flux hemodialysis on clinical outcomes remains controversial. We have previously shown that in vivo transmigrated leukocytes from patients with low-flux bioincompatible hemodialysis have an impaired capacity to upregulate CD11b at the site of interstitial inflammation. In the present study, we investigated the in vivo capacity of transmigrated monocytes and granulocytes to express CD11b at the site of interstitial inflammation in 10 patients on biocompatible high-flux hemodiafiltration or high-flux hemodialysis and 12 healthy subjects, and the in vitro response to a bacteria-related peptide (N-formyl-methionyl-leucyl-phenylalanine (fMLP)). Leukocyte formation of hydrogen peroxide (H(2)O(2)) and leukocyte apoptosis were also studied. In patients, both monocytes and granulocytes had a preserved capacity to express CD11b following in vivo transmigration to sites of interstitial inflammation, compared with cells from healthy subjects. Furthermore, monocytes and granulocytes from patients showed a preserved ability to respond to challenge with fMLP in the extravascular milieu. The intracellular killing capacity of leukocytes (H(2)O(2) production) in the interstitium was similar as of cells from healthy subjects both before and after stimulation with fMLP. Following maximal receptor independent stimulation (phorbol 12-myristate 13-acetate), leukocytes from patients showed lower H(2)O(2) production at the site of intense inflammation, compared with cells from healthy subjects. Finally, leukocyte apoptosis in interstitial inflammation was similar in patients and healthy subjects. We conclude that in vivo transmigrated leukocytes from patients on biocompatible high-flux hemodiafiltration or high-flux hemodialysis have a preserved capacity to express CD11b at the site of interstitial inflammation. This may have important biological implications.     

Three monocyte-related determinants of atherosclerosis in haemodialysis.

BACKGROUND: It has been suggested that monocyte-related inflammatory mediators play a role in atherosclerosis. Haemodialysis induces phenotypic changes in adhesion molecule expression on monocytes. Soluble vascular cell adhesion molecule-1 (sVCAM-1), an adhesion molecule involved in monocyte recruitment, has been proposed to correlate with the extent of atherosclerosis in humans. Monocyte chemotactic protein-1 (MCP-1) functions as a monocyte-specific chemoattractant. METHODS: We studied monocyte count, CD11b/CD18 expression on monocytes, MCP-1, and sVCAM-1 in nine patients on either cuprophane or polysulphone haemodialysis (n=18 treatments) at times 0 (before haemodialysis), 3 h (end of haemodialysis), 4, 6, 8 and 24 h after start of treatment, as well as in 18 healthy subjects. RESULTS: Monocyte CD11b/CD18 expression increased with both membranes (P:<0.001) during and after dialysis compared to before treatment. The concentrations of sVCAM-1 and MCP-1 were higher in patients compared to those in controls both before, during and after haemodialysis (P:<0.001 at all time points). There were correlations between the expression of CD11b/CD18 on monocytes and the interdialytic concentrations of sVCAM-1 (r=0.76, P:<0.001) and MCP-1 (r=0.54, P:<0.05) and between MCP-1 and sVCAM-1 before and after haemodialysis (P:<0.05). CONCLUSION: Patients on haemodialysis have an increased systemic chemotactic activity for monocytes, unphysiological phenotypic alterations in CD11b/ CD18 expression during and after dialysis, and increased sVCAM-1 and MCP-1 concentrations. Prospective studies are needed to establish the role of these abnormalities in the pathogenesis of atherosclerosis in haemodialysis patients.     

Monocyte activation and relationship to anti-proteinase 3 in acute vasculitis.

BACKGROUND: Monocytes have been suggested to play a role in antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis, but their state of activation in vivo in patients is still unknown. METHODS: Twelve consecutive patients with acute anti-proteinase 3 (PR3)-positive vasculitis were included prospectively, and blood samples were drawn at diagnosis. As controls, peripheral blood was obtained from a group of patients with acute infection (n = 12) and from healthy controls (n = 12). Monocyte activation was estimated from the expression of adhesion molecules (CD62L and CD11b), production of oxygen radicals and serum concentrations of soluble inflammation markers and adhesion molecules [intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1)]. RESULTS: Compared with monocytes from healthy subjects, monocytes from patients with acute vasculitis expressed upregulated CD11b (P < 0.05) but had reduced production of oxygen radicals (P < 0.01). A high concentration of anti-PR3 correlated with decreased expression of CD62L (r = 0.71, P = 0.009) and increased expression of CD11b (r = 0.63, P = 0.02). The serum concentrations of soluble inflammation markers [soluble CD14, interleukin (IL)-6, tumour necrosis factor receptor 1 (TNFR1), IL-10 and IL-8] as well as soluble adhesion molecules (sVCAM-1 and sICAM-1) were increased. Monocytes in patients with acute vasculitis displayed a reduced production of oxygen free radicals (P < 0.01) but similar serum concentrations of soluble inflammation markers and adhesion molecules, as compared with the control group of patients with acute infection and negative PR3-ANCA. CONCLUSIONS: High anti-PR3 concentration in patients with acute vasculitis correlated with an activated adhesion molecule phenotype (CD62L(low)/CD11b(high)) in circulating monocytes, indicating a potential pathophysiological role for anti-PR3. An impaired production of oxygen radicals in monocytes in patients with vasculitis compared with those with acute infection may mirror the longer time interval from onset of first symptoms to admission, in patients with vasculitis.     

Peripheral blood monocyte activation during coronary artery bypass grafting with or without cardiopulmonary bypass

OBJECTIVE: The aim of this prospective, randomized study was to investigate the impact of coronary artery bypass grafting (CABG) on peripheral monocytes and to evaluate the additional effect of cardiopulmonary bypass (CPB). DESIGN: Twenty patients admitted for elective CABG were randomized to either on-pump (ONCAB, n = 9) or off-pump (OFFCAB, n = 11) surgery and blood samples were drawn before, during and 24 h after the operation. The total number of monocytes and the proportion of the more mature CD16+/CD14+ monocytes were measured. Expression of activation markers (CD11b, CD35 and CD62L) and oxidative burst were determined using flow cytometry on both resting and in vitro stimulated cells. Serum concentrations of soluble CD14 and monocytes/macrophage chemotactic protein 1 (MCP-1) were analysed. RESULTS: During surgery there was a selective decrease in the proportion of CD16+/CD14+ monocytes compared to total monocytes. These had returned to preoperative values 24 h after surgery while the total number of monocytes had increased more than 100%. Intracellular production of oxygen free radical H2O2 was increased in the ONCAB group during surgery compared to OFFCAB. Monocyte expression and in vitro mobilization of complement receptors, CD11b and CD35, were similar in both study groups during and after surgery as was the expression of CD62L. Serum levels of MCP-1 decreased during surgery as did soluble CD14, both with increased levels again the day after surgery. CONCLUSION: It is concluded that the circulating monocyte population is activated during and as a consequence of CABG. There were few apparent additional effects of CPB found in this study. In this setting the inflammation caused by the surgery procedure per se probably surpasses the impact of the CPB on circulating blood monocytes.     

Increased serum levels of MRP-8/14 in type 1 diabetes induce an increased expression of CD11b and an enhanced adhesion of circulating monocytes to fibronectin

The recruitment of monocytes from the bloodstream is crucial in the accumulation of macrophages and dendritic cells in type 1 diabetic pancreases. Adhesion via integrins to endothelium and extracellular matrix proteins, such as fibronectin (FN), and the production of myeloid-related protein (MRP)-8, -14, and -8/14 by recently transmigrated monocytes are thought to be instrumental in such recruitment. We determined the FN-adhesive capacity and integrin expression of monocytes of type 1 and type 2 diabetic patients and related them to the subjects' serum levels of MRP-8, -14 and -8/14. Monocytes of type 1 diabetic patients displayed an increased adhesion to fibronectin in comparison with type 2 patients and healthy control subjects but had a normal expression of the FN binding integrins CD29, CD49a, CD49d, and CD49e (although CD11b and CD18 expression was increased). MRP-8/14, which was increased in the sera of type 1 diabetic patients, induced healthy donor monocytes to adhere to FN and upregulate CD11b expression in a dosage-dependent manner. The observed MRP-induced increased adhesion of monocytes to FN and upregulation of CD11b most likely contributed to a facilitated accumulation of monocytes and monocyte-derived cells at the site of inflammation, in this case the pancreatic islets.     

Peripheral blood monocyte activation during coronary artery bypass grafting with or without cardiopulmonary bypass

Objective. The aim of this prospective, randomized study was to investigate the impact of coronary artery bypass grafting (CABG) on peripheral monocytes and to evaluate the additional effect of cardiopulmonary bypass (CPB).

Design. Twenty patients admitted for elective CABG were randomized to either on-pump (ONCAB, n=9) or off-pump (OFFCAB, n=11) surgery and blood samples were drawn before, during and 24 h after the operation. The total number of monocytes and the proportion of the more mature CD16⁺/CD14⁺ monocytes were measured. Expression of activation markers (CD11b, CD35 and CD62L) and oxidative burst were determined using flow cytometry on both resting and in vitro stimulated cells. Serum concentrations of soluble CD14 and monocytes/macrophage chemotactic protein 1 (MCP-1) were analysed.

Results. During surgery there was a selective decrease in the proportion of CD16⁺/CD14⁺ monocytes compared to total monocytes. These had returned to preoperative values 24 h after surgery while the total number of monocytes had increased more than 100%. Intracellular production of oxygen free radical H₂O₂ was increased in the ONCAB group during surgery compared to OFFCAB. Monocyte expression and in vitro mobilization of complement receptors, CD11b and CD35, were similar in both study groups during and after surgery as was the expression of CD62L. Serum levels of MCP-1 decreased during surgery as did soluble CD14, both with increased levels again the day after surgery.

Conclusion. It is concluded that the circulating monocyte population is activated during and as a consequence of CABG. There were few apparent additional effects of CPB found in this study. In this setting the inflammation caused by the surgery procedure per se probably surpasses the impact of the CPB on circulating blood monocytes.     

Effect of uremia and hemodialysis on soluble L-selectin and leukocyte surface CD11b and L-selectin

Leukocyte Mac-1 (CD11b/CD18) and L-selectin (CD62L) are implicated in leukocyte adhesion to endothelial cells. In this study, L-selectin and CD11b expression on leukocytes and soluble L-selectin (sL-selectin) serum levels were investigated in 17 nondialyzed patients with chronic renal failure (CRF), in 28 chronic hemodialysis patients before hemodialysis (basal state), and in 32 healthy subjects. These parameters were also monitored during hemodialysis with cuprophane and cellulose diacetate membranes in a crossover study in five patients. Granulocytes from CRF patients displayed lower expression of L-selectin and higher expression of CD11b than granulocytes from healthy subjects. On the other hand, baseline expression of L-selectin and CD11b on leukocytes from hemodialysis patients did not differ from that of healthy subjects. In CRF and hemodialysis patients, sL-selectin levels were significantly lower than in healthy subjects. During hemodialysis, cuprophane membrane induced an upregulation of granulocyte CD11b, a decrease in granulocyte L-selectin, and an increase in sL-selectin serum levels. Conversely, cellulose diacetate caused only a transient increase in granulocyte CD11b and did not modify granulocyte L-selectin and sL-selectin serum levels. High CD11b and low L-selectin expression on granulocytes in CRF patients suggests an activation state, which was not found in hemodialysis patients at the basal state. The lack of activation in hemodialysis patients could reflect the elimination of a uremic toxin by dialysis or a loss of granulocyte responsiveness because of the repetitive stimulation by hemodialysis treatment. The low serum levels of sL-selectin in CRF and hemodialysis patients also suggest granulocyte dysfunction.     

Effect of Surgically-Induced Weight Loss on Leukocyte Indicators of Chronic Inflammation in Morbid Obesity

Background: Recent evidence suggests that morbid obesity is a chronic inflammatory condition that may be associated with immune dysfunction.To test this hypothesis, we investigated several leukocyte cell surface markers of chronic inflammation and followed their response to surgically-induced weight loss. Methods: 26 patients having Roux-en-Y gastric bypass (RYGBP) for morbid obesity (BMI>40) were compared to 10 normal controls (BMI<25). Relative monocyte and neutrophil frequencies and expression of the activation antigens CD11b (adhesion molecule), CD16 (Fc receptor), and CD62L (Lselectin), were evaluated by flow cytometry preoperatively and at 1, 3, 6 and 12 months after RYGBP. Cases served as their own controls but were also compared to non-obese controls. The results were statistically analyzed using Student's t-test and ANOVA for parametric values and Mann-Whitney along with Kruskal-Wallis ANOVA for nonparametric values Results: The control group had mean age 37 ± 7.6 with mean 23 ± 2.5 and no comorbidities. The mean age of the sample group was 40.36 ± 13.7 with mean BMI 52 ± 8.2. The neutrophil and monocyte relative frequencies of CD11b (monocytes and neutrophils), and CD16 (neutrophils only) were comparable to controls at baseline and did not change significantly with weight loss throughout the study period. However, a significant reduction of CD62L (Lselectin) expression was noted in monocytes and neutrophils at baseline (neutrophils 103 vs 240 gmf, p<0.001) (monocytes104 vs 246 gmf, P<0.001) when compared to normal controls. Levels of L-selectin normalized by 6 months in both monocytes and neutrophils, and by 12 months had become abnormally elevated in monocytes (monocytes 391 gmf, P=0.007); in neutrophils, there was an upward trend that did not reach significance.The expression of the LPS receptor CD14 in the study group was elevated significantly compared to controls at baseline (1129 vs 719 gmf, P=0.004); this marker appeared to return to normal by 3 months. Monocyte CD14+/CD16+ subset percentage were also elevated significantly at baseline (14.3% vs 5.25%, P <0.001), declined throughout the time period but was still significant at 1 year (8.8%, P<0.001). Eosinophil percentages were elevated at baseline (3.3% obese vs 1.8% controls, P=0.003) and remained so throughout the time period. Conclusion: Deficiencies in the immune system of morbidly obese individuals include elevated levels of eosinophils, monocyte CD14, and monocyte CD14+/CD16+ subsets, with depression of monocyte and neutrophil CD62L. These abnormal levels reverse rapidly with surgically-induced weight loss. RYGBP is not only a weight loss operation but also appears to be an immune restorative procedure.     

急性脊髓损伤患者血清中单核趋化蛋白-1的表达

目的:观察急性不完全性脊髓损伤患者血清中单核细胞趋化蛋白-1(MCP-1)的表达,探讨继发性脊髓损伤的可能机制。方法:收集急性不完全性脊髓损伤患者和单纯脊柱压缩骨折患者及正常对照者的血清,ELISA方法检测其中MCP-1的水平。结果:与健康对照组相比,急性不完全性脊髓损伤患者血清中MCP-1的浓度明显增高(P<0.01)。结论:MCP-1可能通过向脊髓损伤部位募集炎症细胞而参与脊髓损伤部位的继发性炎症反应。     

Urinary monocyte chemoattractant protein-1 (MCP-1) is a marker of active renal vasculitis.

BACKGROUND: Macrophage infiltration and cytokine production are important in the pathogenesis of crescentic glomerulonephritis in anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis. The aim of this study was to investigate whether urinary levels of chemokines, monocyte chemoattractant protein-1 (MCP-1) and fractalkine, were useful tools for non-invasive assessment of renal vasculitis. METHODS: In a prospective study, concentrations of chemokines were measured in urine and serum samples using specific enzyme-linked immunosorbent assays, and related to the patients' clinical status. Renal expression of MCP-1 was studied by immunohistochemical staining of renal biopsies. RESULTS: Urinary levels of MCP-1 were significantly higher in patients with active (P<0.01) or persistent (P<0.05) renal vasculitis, in comparison with healthy volunteers, control patients, patients with inactive vasculitis and patients with extra-renal disease only. There were no differences in serum concentrations of MCP-1 between these groups. Reduction in urinary MCP-1 levels following treatment preceded the improvement of renal function by a median of 2 weeks. In one patient, rising urinary levels of MCP-1, despite immunosuppressive therapy, was associated with progression to severe renal failure. There were no differences in urinary fractalkine levels between the different groups of patients and controls. Immunohistology of renal biopsies from patients with crescentic glomerulonephritis showed increased staining for MCP-1 in glomerular and interstitial cells. Urinary MCP-1 levels correlated with glomerular, but not tubulointerstitial, macrophage infiltration (P<0.05). CONCLUSIONS: This study shows that measurement of urinary MCP-1, but not fractalkine, is a useful non-invasive technique for the assessment of renal involvement and monitoring the response to therapy in ANCA-associated vasculitis.     

Reduction of CD47 on monocytes correlates with MODS in burn patients

Alternation of surface markers on monocytes is associated with the development of inflammation. The goals of the present study were to detect CD47 expression on monocytes by flow cytometry and explore its relationship with disease severity and MODS in burned patients. The results show CD47 expression on monocytes from all burned patients (n = 21) was lower than that from the healthy population (n = 21) for 24 days after burn. There was a significant difference in CD47 expression on monocytes between the patients with differing burn severity in the first 7 days after injury (P < 0.05). Considering the relationship between CD47 expression and MODS, we found the CD47 expression on monocytes from patients with MODS was lower (P < 0.05) in the first 3 days after injury than that from patients without MODS. In conclusion, diminished CD47 expression on monocytes is associated with burn severity and the occurrence of MODS in burn patients.     

Time Course of β2-Integrin CD11b/CD18 (Mac-1, αMβ2) Upregulation on Neutrophils and Monocytes after Coronary Artery Bypass Grafting: CD11b upregulation after CABG surgery

Although upregulation of CD11b/CD18 receptor, i.e. activation of neutrophils and monocytes, during cardiopulmonary bypass is well documented, the duration of the active state after uncomplicated operation is less understood. We therefore investigated CD11b expression of phagocytes in blood samples collected 2-4, 24, 48 and 72 h after coronary artery bypass grafting. CD11b expression on neutrophils was significantly elevated at 2-4 and 24 hours after operation as compared with baseline. On monocytes, expression peaked at 24 h and returned to baseline by 72 h. Because CD11b is a sensitive marker, effects of different sampling techniques on its expression were also studied. CD11b expression was similar in samples collected with a syringe from arterial or central venous catheter or with open technique from cubital vein. On neutrophils from healthy subjects, sampling with syringe caused small (10%) but statistically significant increase of expression. We conclude that activated neutrophils disappear from circulation within hours after CABG surgery while activated monocytes may continue circulating for 2-3 days, and that CD11b sampling can be done with a syringe.     

尿毒症患者桡动脉上炎症因子表达和氧化脂质沉积对内瘘寿命影响的COX分析

目的 研究氧化低密度脂蛋白(ox-LDL、单核细胞趋化因子1(MCP-1)及巨噬细胞表面抗原(CD68)在尿毒症患者桡动脉壁上的沉积和表达对内瘘使用寿命的影响。 方法 对23例年龄为29~68岁尿毒症患者在初次手术行桡动脉-头静脉端端吻合建立动静脉内瘘时，保留其手术中因修剪而去除的桡动脉组织。采用免疫组化法测定桡动脉血管壁ox-LDL、MCP-1及CD68的表达。随访内瘘使用寿命，进行内瘘生存分析。失效事件定义为动静脉内瘘非外伤原因引起的堵塞。失访、终止观察为截尾事件。 结果 用ox-LDL、MCP-1及CD68分别建立COX风险比例模型时，3者的表达每增加1个单位，内瘘寿命缩短的风险比将分别增加1.008(P = 0.008，95% CI:1.002064~1.014104)、1.007(P=0.000， 95% CI:1.003853~1.010966)及 1.098 (P=0.000， 95% CI: 1.047909~1.151526)。若3者同时进入COX风险比例模型，整个模型成立(决定系数为52.7，P=0.000)。整个模型中，ox-LDL、MCP-1及CD68 3者缩短内瘘寿命的风险比分别为0.997(P=0.414)、1.006(P=0.025)及1.113(P=0.001)。 结论 ox-LDL、MCP-1及CD68在尿毒症患者桡动脉壁上的表达增加将缩短内瘘使用寿命，尤其是尿毒症患者炎症因素的影响更大。     

IGG and complement receptor expression on peripheral white blood cells in uraemic children.

BACKGROUND: Phagocytosis of IgG- or complement-opsonized bacteria and antibody production by lymphocytes are regulated by cell surface receptors for IgG (FcgammaRI, FcgammaRII and FcgammaRIII) and complement (CR1 and CR3). We measured the effect of uraemia and dialysis treatment on FcgammaR and CR expression on leukocytes in blood. METHODS: Blood samples were obtained from children: 40 treated with peritoneal dialysis (PD), 23 with haemodialysis (HD), 46 not yet dialysed (CRF) and 33 healthy (HC). White blood cells, isolated from EDTA-blood by centrifugation after cell fixation with paraformaldehyde, were labelled with FITC-conjugated CD16 (FcgammaRIII), CD32 (FcgammaRII), CD64 (FcgammaRI), CD11b (CR3) and CD35 (CR1) monoclonal antibodies and analysed by flow cytometry. RESULTS: In PD, HD, CRF and HC, monocytes and neutrophils were all positive for FcgammaR and CR, except for CD16 on monocytes (20% positive). Lymphocytes expressed CD16 and CD32 but not CD64. PD, HD and CRF children had lower percentages of CD16(+) and CD32(+) lymphocytes compared with HC. The percentage of CD11b(+) lymphocytes was lower only in PD and the percentage of CD35(+) lymphocytes was lower in HD and CRF compared with HC. The median CD32 mean fluorescense intensity (MFI) on lymphocytes, monocytes and neutrophils was lower in PD, HD and CRF compared with HC. On the other hand, CD11b MFI on lymphocytes, monocytes and neutrophils was higher in PD, HD and CRF children compared with HC. CD16 and CD64 MFI were not different among the groups and CD35 MFI was only lower on lymphocytes from PD, HD and CRF compared with HC. CONCLUSIONS: In children with chronic renal failure, whether dialysed or not, FcgammaRII expression on lymphocytes, monocytes and neutrophils was reduced and CR3 expression was increased. Furthermore, CR1 expression on lymphocytes, important for the humoral response, was lower in children with renal failure. Age and uraemia are associated with these abnormalities and might contribute to impaired immune function in children with chronic renal failure.     

Changes in leukocyte subsets: clinical implications for children with chronic renal failure

Increased systemic inflammation and an impaired immune response are features of adult chronic renal failure (CRF). These patients have increased rates of infection, cardiovascular disease, anemia, and malnutrition. We measured inflammatory and immunological markers in a group of children with pre-dialytic CRF. No prior studies have explored these markers even though children with non-dialysed CRF exhibit similar complications to those seen in adults with CRF. Blood was collected from children with mild, moderate, or severe CRF and an age-matched control group. Functional leukocyte subsets were determined using flow cytometry. Circulating levels of interleukin (IL)-1, IL-6, IL-8, IL-12, IL-10, and tumor necrosis factor- were measured using a flow cytometric bead assay. Children with severe CRF showed significantly reduced total white cell count and absolute neutrophil and lymphocyte counts. Absolute numbers of CD3+/CD45RO+ memory T cells and CD3+/CD45RO+/CD62L+ memory Th2 cells were significantly reduced in all CRF groups versus controls. Children with severe CRF showed increased CD11b expression on neutrophils and monocytes. Some patients showed increases in pro-inflammatory cytokines that were not related to their level of residual renal function. As CD11b expression mediates leukocyte adhesion to vascular endothelium, upregulation may contribute to the increased endothelial dysfunction observed in children with CRF. L-selectin mediates extravasation of leukocytes into tissue and homing of peripheral blood lymphocytes to lymph nodes. The reduction in L-selectin may inhibit these actions and predispose patients to increased infection later in life. This is the first study to comprehensively investigate leukocyte functional molecules and inflammatory cytokine profiles in children with pre-dialytic CRF and provides new immunological evidence for the clinical manifestations associated with the disease.     

Human spinal cord injury causes specific increases in surface expression of β integrins on leukocytes

Spinal cord injury (SCI) activates circulating leukocytes that migrate into the injured cord and bystander organs using adhesion molecule-mediated mechanisms. These cells cause oxidative damage, resulting in secondary injury to the spinal cord, as well as injury to bystander organs. This study was designed to examine, over a 6-h to 2-week period, changes in adhesion molecule surface expression on human peripheral leukocytes after SCI (9 subjects), using as controls 10 uninjured subjects and 6 general trauma patients (trauma controls, TC). Both the percentage of cells expressing a given adhesion molecule and the average level of its expression was quantified for both circulating neutrophils and monocytes. The percentage of neutrophils and monocytes expressing the selectin CD62L was unchanged in TC and SCI patients after injury compared to uninjured subjects. Concurrently, the amount of surface CD62L on neutrophils was decreased in SCI and TC subjects, and on monocytes after SCI. The percentage of neutrophils expressing α4 decreased in TC, but not in SCI, subjects. Likewise, the percentage of neutrophils and monocytes expressing CD11d decreased markedly in TC subjects, but not after SCI. In contrast, the mean surface expression of α4 and CD11d by neutrophils and monocytes increased after SCI compared with uninjured and TC subjects. The percentage of cells and surface expression of CD11b were similar in neutrophils of all three groups, whereas CD11b surface expression increased after SCI in monocytes. In summary, unlike changes found after general trauma, the proinflammatory stimulation induced by SCI increases the surface expression of adhesion molecules on circulating neutrophils and monocytes before they infiltrate the injured spinal cord and multiple organs of patients. Integrins may be excellent targets for anti-inflammatory treatment after human SCI.