C3a Receptor Inhibition Protects Brain Endothelial Cells Against Oxygen-glucose Deprivation/Reperfusion

The complement cascade is a central component of innate immunity which plays a critical role in brain inflammation. Complement C3a receptor (C3aR) is a key mediator of post-ischemic cerebral injury, and pharmacological antagonism of the C3a receptor is neuroprotective in stroke. Cerebral ischemia injures brain endothelial cells, causing blood brain barrier (BBB) disruption which further exacerbates ischemic neuronal injury. In this study, we used an in vitro model of ischemia (oxygen glucose deprivation; OGD) to investigate the protective effect of a C3aR antagonist (C3aRA, SB290157) on brain endothelial cells (bEnd.3). Following 24 hours of reperfusion, OGD-induced cell death was assessed by TUNEL and Caspase-3 staining. Western blot and immunocytochemistry were utilized to demonstrate that OGD upregulates inflammatory, oxidative stress and antioxidant markers (ICAM-1, Cox-2, Nox-2 and MnSOD) in endothelial cells and that C3aRA treatment significantly attenuate these markers. We also found that C3aRA administration restored the expression level of the tight junction protein occludin in endothelial cells following OGD. Interestingly, OGD/reperfusion injury increased the phosphorylation of ERK1/2 and C3aR inhibition significantly reduced the activation of ERK suggesting that endothelial C3aR may act via ERK signaling. Furthermore, exogenous C3a administration stimulates these same inflammatory mechanisms both with and without OGD, and C3aRA suppresses these C3a-mediated responses, supporting an antagonist role for C3aRA. Based on these results, we conclude that C3aRA administration attenuates inflammation, oxidative stress, ERK activation, and protects brain endothelial cells following experimental brain ischemia.

Complement C3a, But Not C5a, Levels in Amniotic Fluid Are Associated with Intra-amniotic Infection and/or Inflammation and Preterm Delivery in Women with Cervical Insufficiency or an Asymptomatic Short Cervix (≤ 25 mm)

BACKGROUND: We aimed to estimate whether elevated levels of complement C3a and C5a in amniotic fluid (AF) are independently associated with increased risks of intra-amniotic infection and/or inflammation (IAI) and spontaneous preterm delivery (SPTD) in women with cervical insufficiency or a short cervix (≤ 25 mm). METHODS: We conducted a retrospective cohort study of 96 consecutive women with cervical insufficiency (n = 62) or a short cervix (n = 34) at 17 to 27 weeks, and who underwent an amniocentesis. AF was cultured and analyzed for C3a and C5a by enzyme-linked immunosorbent assay kits. The primary outcome measures were IAI (defined as a positive AF culture and/or an elevated AF interleukin-6 level [≥ 7.6 ng/mL]) and SPTD at < 32 weeks. RESULTS: In multivariable analysis, AF level of C3a was the only variable significantly associated with IAI, whereas C5a level in AF and serum C-reactive protein level were not associated with IAI. Using SPTD at < 32 weeks as the outcome variable in logistic regression, elevated AF levels of C3a were associated with increased risk of SPTD at < 32 weeks after adjusting for other baseline confounders, whereas elevated AF levels of C5a were not. CONCLUSION: In women with cervical insufficiency or a short cervix, elevated AF level of C3a, but not C5a, is independently associated with increased risks of IAI and SPTD at < 32 weeks. These findings suggest that subclinical IAI or SPTD in the context of cervical insufficiency is related to activation of complement system in AF.

Association between protective effect of Liuwei Wuling tablets against acute liver injury and its inhibitory effect on cytoplasmic translocation of high-mobility group box-1 in hepatocytes in mice / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effect of Liuwei Wuling tablets on the cytoplasmic translocation and release of high-mobility group box-1 (HMGB1) in hepatocytes in mice with acute live injury induced by D-galactosamine (D-GalN) and lipopolysaccharide (LPS).</p><p><b>METHODS</b>A Balb/c mouse model of acute liver injury was established by intraperitoneal injection of D-GalN (400 mg/kg) and LPS (5 ug/kg). A total of 24 healthy mice were randomly and equally divided into acute liver injury control group and Liuwei Wuling tablet treatment group. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured in both groups at each time point within one week. Liver tissues were collected at 36 hours to perform pathological examination. The serum levels of HMGB1, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), complement 3a (C3a), and complement 5a (C5a) were measured. Immunohistochemistry was used to determine the expression and cytoplasmic translocation of HMGB1 in hepatocytes.</p><p><b>RESULTS</b>At 6, 12, and 24 hours, the Liuwei Wuling tablet treatment group had significantly lower serum levels of ALT than the control group (225.33±181.64 U/L vs 471.17±174.72 U/L, t = 3.38, P < 0.01; 1509.53±182.51 U/L vs 7149.52±734.25 U/L, t = 25.82, P < 0.01; 162.89±86.51 U/L vs 1318.16±557.71 U/L, t = 7.09, P < 0.01), as well as significantly lower serum levels of AST than the control group (179.22±94.57 U/L vs 561.91±209.6 U/L, t = 5.76, P < 0.01; 590.92±190.92 U/L vs 2266.48±705.64 U/L, t = 7.94, P < 0.01; 231.24±87.7 U/L vs 444.32±117.01 U/L, t = 5.05, P < 0.01). The treatment group had significantly lower levels of HMGB1 than the control group at 6 and 12 hours (54.21±11.89 ng/ml vs 72.07±13.65 ng/ml, t = 3.41, P < 0.01; 49.23±5.97 ng/ml vs 68.71±13.07 ng/ml, t = 4.70, P < 0.01). The treatment group had significantly lower levels of TNF-α, IL-1β, and IL-6 than the control group at 12 hours (163.62±9.12 pg/ml vs 237.09±51.47 pg/ml, t = 4.86, P < 0.01; 15.66±13.13 pg/ml vs 37.43±18.68 pg/ml, t = 3.30, P < 0.01; 7.10±3.06 pg/ml vs 21.42±8.23 pg/ml, t = 5.65, P < 0.01). The treatment group had significantly lower levels of C3a and C5a than the control group at 12 hours (2.52±1.27 pg/ml vs 9.83±2.96 ng/ml, t = 7.86, P < 0.01; 2.16±1.03 ng/ml vs 7.23±1.55 ng/ml, t = 9.67, P < 0.01). Compared with the control group, the treatment group had significantly reduced liver inflammation and necrosis, and a significantly lower cytoplasmic translocation rate of HMGB1 in hepatocytes (38.76%±7.37% vs 8.15%±2.11%, P < 0.01).</p><p><b>CONCLUSION</b>Liuwei Wuling tablets can reduce the cytoplasmic translocation of HMGB1 in hepatocytes and relieve liver inflammation in mice with acute liver injury.</p>

Changes of C3a in induced sputum in patients with asthma / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the clinical significance of anaphylatoxin C3a in induced sputum in patients with asthma.</p><p><b>METHODS</b>The patients with acute exacerbation of asthma treated at our department between September, 2006 and February, 2007 were included in the study. The demographic data, medical history, levels of lung function and C3a levels in induced sputum were assessed.</p><p><b>RESULTS</b>A total of 33 patients were included in the study. The level of C3a in induced sputum was significantly higher in patients with acute exacerbation of asthma (2.24 ng/ml, range 1.68-5.58 ng/ml) than that in patients with asthma remission (0.7 ng/ml, range 0.24-2.31 ng/ml, P<0.05). Sputum C3a levels in the remission patients were significantly higher than those in the healthy controls (0.12 ng/ml, range 0.07-0.39 ng/ml, P<0.05). The levels of C3a in patients with severe exacerbation (4.69 ng/ml, range 2.69-6.59 ng/ml) were significantly higher than those in patients with mild exacerbation (0.25 ng/ml, range 0.09-0.40 ng/ml) and moderate exacerbation (2.21 ng/ml, range 1.16-3.41 ng/ml) (P<0.01), and were significantly higher in patients with moderate exacerbation than in those in mild exacerbation (P<0.01). The level of C3a in induced sputum was positively correlated with the number of total cell count (r=0.718, P<0.05), eosinophils (r=0.495, P<0.05) and macrophages (r=0.600, P<0.05) in patients with acute exacerbation of asthma.</p><p><b>CONCLUSION</b>Induced sputum C3a level can serve as an important clinical biomarker for clinical asthma management.</p>

Levels of complement components C3a and C5a in renal injury among trichloroethylene-sensitized BALB/c mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To determine the levels of complement components C3a and C5a in the kidneys of trichloroethylene (TCE)-sensitized BALB/c mice, and to investigate the role of complement components in TCE-induced renal injury among BALB/c mice.</p><p><b>METHODS</b>Sixty-two female BALB/c mice were randomly divided into blank control group, vehicle control group, and TCE sensitization group. The mice in TCE sensitization group were sensitized by one intracutaneous injection and one abdominal smear of TCE. At 24 h, 48 h, 72 h, and 7 d after the second sensitization, mice were sacrificed, and the blood and kidneys were collected. An automatic biochemical analyzer was used in the determination of serum blood urea nitrogen (BUN) and creatinine (Cr). The levels of C3a and C5a in the kidneys were determined by immunohistochemistry.</p><p><b>RESULTS</b>The sensitization rate of TCE sensitization group was 42.0%. Kidney coefficient and serum levels of BUN and Cr were significantly increased in the TCE sensitization group as compared with the vehicle control group at 48 h and 72 h after sensitization (P < 0.05). The kidney coefficients of the TCE sensitization group at 48 h and 72 h were significantly higher than those of the control groups (P < 0.05). In comparison with the vehicle control group, however, no significant change was found in kidney coefficient, serum BUN, or serum Cr at 7 d after TCE sensitization (P > 0.05). Levels of C3a and C5a at 48 h (3.80±0.84 and 4.00±1.00, respectively) and 72 h (4.40 ± 1.14 and 4.40 ± 1.14, respectively) after sensitization were all significantly higher than those of the vehicle control group (P < 0.05), but no significant difference was found in level of C3a (1.80±0.45) or C5a (2.00 ± 0.71) at 7 d (P > 0.05).</p><p><b>CONCLUSION</b>TCE sensitization can induce renal injury in mice. Levels of complement components C3a and C5a are elevated in the kidneys of sensitized mice, indicating that C3a and C5a may be involved in the renal injury induced by TCE sensitization.</p>

Alisol B inhibited complement 3a-induced human renal tubular epithelial to mesenchymal transition / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study whether alisol B could inhibit complement 3a (C3a) induced renal tubular epithelial-mesenchymal transition (EMT).</p><p><b>METHODS</b>The in vitro cultured human renal tubular epithelial HK-2 cells were intervened with 5 ng/mL transforming growth factor-beta (TGF-beta), 0.1 micromol C3a, and 0.1 micromol C3a + 10 micromol alisol B, respectively. The mRNA and protein expressions of alpha-SMA, E-cadherin, and C3 were detected using RT-PCR, Western blot, and immunofluorescence, respectively.</p><p><b>RESULTS</b>The mRNA and protein expressions of C3 in HK-2 cells were up-regulated after intervention of C3a (P < 0.01), the mRNA and protein expressions of alpha-SMA in HK-2 cells were obviously enhanced (P < 0.01), the mRNA and protein expressions of E-cadherin obviously decreased (P < 0.01). When compared with the group intervened by exogenous C3a, after intervention of alisol B, the mRNA and protein expressions of alpha-SMA in HK-2 cells were obviously reduced (P < 0.01), the mRNA and protein expressions of E-cadherin obviously increased (P < 0.05).</p><p><b>CONCLUSIONS</b>Exogenous C3a could induce renal tubular EMT. Alisol B was capable of suppressing C3a induced EMT.</p>

Effect of anaphylatoxin C3a, C5a on the tubular epithelial-myofibroblast transdifferentiation in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Tubulointerstitial renal fibrosis is the common end point of progressive kidney diseases, and tubular epithelial-myofibroblast transdifferentiation (TEMT) plays a key role in the progress of tubulointerstitial renal fibrosis. Anaphylatoxin C3a and C5a are identified as novel profibrotic factors in renal disease and as potential new therapeutic targets. The aim of this study was to investigate whether C3a, C5a can regulate TEMT by transforming growth factor-β1 (TGF-β)/connective tissue growth factor (CTGF) signaling pathway and the effects of C3a and C5a receptor antagonists (C3aRA and C5aRA) on C3a- and C5a-induced TEMT.</p><p><b>METHODS</b>HK-2 cells were divided into C3a and C5a groups which were subdivided into four subgroups: control group, 10 ng/ml TGF-β1 group, 50 nmol/L C3a group, 50 nmol/L C3a plus 1 µmol/L C3aRA group; control group, 10 ng/ml TGF-β1 group, 50 nmol/L C5a group, 50 nmol/L C5a plus 2.5 µmol/L C5aRA group. TGF-β1 receptor antagonist (TGF-β1RA) 10 µg/ml was used to investigate the mechanism of C3a- and C5a-induced TEMT. Electron microscopy was used to observe the morphological changes. Immunocytochemistry staining, real-time PCR and Western blotting were used to detect the expressions of a smooth muscle actin (α-SMA), E-cadherin, Col-I, C3a receptor (C3aR), C5aR, CTGF and TGF-β1.</p><p><b>RESULTS</b>HK-2 cells cultured with C3a and C5a for 72 hours exhibited strong staining of α-SMA, lost the positive staining of E-cadherin, and showed a slightly spindle-like shape and loss of microvilli on the cell surface. The expressions of α-SMA, E-cadherin, Col-I, C3aR, C5aR, TGF-β1 and CTGF in C3a- and C5a-treated groups were higher than normal control group (P < 0.05). C3aRA and C5aRA inhibited the expressions of α-SMA, Col-I, C3aR, C5aR, and up-regulated the expression of E-cadherin (P < 0.05). TGF-β1 and CTGF mRNA expressions induced by C3a and C5a were partly blocked by TGF-β1RA (P < 0.05).</p><p><b>CONCLUSION</b>C3a and C5a can induce TEMT via the up-regulations of C3aR and C5aR mRNA and the activation of TGF-β1/CTGF signaling pathway in vitro.</p>

Effect of acylation stimulating protein on the perilipin and adipophilin expression during 3T3-L1 preadipocyte differentiation / 生理学报

Perilipin and adipophilin, two significant lipid droplet (LD)-specific proteins, participate in storing fat or ectopic lipid deposition and fat mobilization in many types of mammalian cells. Acylation stimulating protein (ASP) is a novel adipocyte-derived hormone known for a major determinant for triglyceride synthesis (TGS) and lipid metabolism. The present study was aimed to investigate: (1) whether ASP, rather than insulin, is a powerful potentiator which could physiologically and directly influence TGS during 3T3-L1 preadipocyte differentiation; (2) whether ASP exposure at indicated time points during 3T3-L1 preadipocyte differentiation could influence the gene/protein expression of adipophilin and perilipin. 3T3-L1 preadipocytes were differentiated by traditional hormone cocktail and divided into control, ASP and insulin groups according to the treatment of ASP (1 mmol/L) or insulin (100 nmol/L). ASP-stimulated and insulin-stimulated TGS rate at indicated time points (0 d, 3 d, 6 d, 9 d) were assayed by measuring the incorporation of [(3)H]-oleic acid into TG, and the corresponding glucose transport was assayed by [(3)H]-2-DG uptake. The effects of ASP or insulin on gene/protein expression of adipophilin and perilipin at indicated time points were evaluated by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The results obtained were as follows: (1) on the 3rd and 6th day of differentiation, ASP dramatically enhanced TGS rate compared with control group (P<0.05, P<0.01); There was no significant difference in TGS rate between insulin group and control group; (2) on the 6th and 9th day of differentiation, both ASP and insulin promoted glucose uptake (P<0.05, P<0.01), and the promoting effect in ASP group was greater than that in insulin group; (3) ASP elevated adipophilin gene and protein expression at the very early stage of differentiation (P<0.05, P<0.001) and had no significant effect from the 4th day of differentiation. Perilipin gene and protein expression increased throughout preadipocyte differentiation and its expression was up-regulated following ASP stimulation from the 3rd day of differentiation (P<0.05, P<0.001) to the end of differentiation (P<0.05); (4) Insulin did not affect gene and protein variation pattern of adipophilin and perilipin. Taken together, this study provides evidence that ASP-evoked changes in gene and protein expression of adipophilin and perilipin correlate with ASP-stimulated TGS acceleration, and adipophilin and perilipin are involved in the molecular mechanism of ASP-induced adipogenesis and LD formation.

Regulation of tyrosylprotein sulfotransferases activity by sulfotyrosine / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the role of sulfated tyrosine in regulating the activity of tyrosylprotein sulfotransferases (TPST) 1 and TPST2.</p><p><b>METHODS</b>Constructs of TPST 1 and TPST2 were amplified by polymerase chain reaction (PCR), then fused into immunoglobulin G1 Fc region. All the variants in which sulfated tyrosines were mutated to phenylalanine were made by the PCR-based Quick Change method and confirmed by sequencing the entire reading frame. Small hairpin RNA (shRNA) constructs-targeting nucleotides 259-275 of TPST1 and nucleotides 73-94 of TPST2 were generated and subcloned into pBluescript. Human embryonic kidney (HEK) 293T cells were transfected with these plasmids. One day later, cells were split: one part was labeled with 35S-cysteine and methionine or 35S-Na2SO3 overnight, the second part was used for 125I labeled binding experiment, and the third part was retained for binding and flow cytometry.</p><p><b>RESULTS</b>Tyrosines at position 326 of TPST1 and position 325 of TPST2 were sulfated posttranslationally. Tyrosine sulfation of TPSTs was effectively inhibited by sulfation inhibitors, including specific shRNAs and non-specific NaCIO3. shRNAs reduced the sulfation of C3a receptor and C5a receptor, and partially blocked the binding of these two receptors to their respective ligands.</p><p><b>CONCLUSIONS</b>The activities of TPSTs were regulated by tyrosine sulfation. Inhibition of sulfotyrosine decreases the binding ability of C3a receptor and C5a receptor to their respective ligands.</p>

Hemocompatibility of bovine pericardium with additional sodium bisulfite treatment / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the hemocompatibility of glutaraldehyde (GA)-tanned bovine pericardium additionally treated by sodium bisulfite (SOB) solution.</p><p><b>METHODS</b>The hemocompatibility of GA-tanned bovine pericardium treated by SOB solution is evaluated by using dynamic clotting time test, blood platelet adhension test, D-dimeride determination, and complement activation test. The GA-tanned bovine pericardium was used as control.</p><p><b>RESULTS</b>The curve of absorbance-clotting time of two kinds of bovine pericardium was similar in dynamic clotting time test. There was no significant difference between SOB-treated and control groups in blood platelet adhension test. The D-dimeride contents of all bioprostheses were at normal level, and the D-dimeride content of GA-tanned bovine pericardium treated by SOB solution was significantly lower than that of control group (P < 0.05). In complement activation test, the level of complement C3a in SOB-treated group was significantly lower than that in control group (P < 0.05).</p><p><b>CONCLUSION</b>GA-tanned bovine pericardium treated by SOB solution meets the demands of cardiac interstitial implanted materials in hemocompatibility.</p>

Expression of Complement C3a Receptor and C5a Receptor by A(beta)(1-42) Stimulated Human Neuroblastoma Cell Line

BACKGROUND: Complementary receptors have been suggested to play causative roles in the neuroinflammatory process of Alzheimer's disease (AD). The genetic expressions of the C3a receptor (C3aR), C5a receptor (C5aR) and the protein expressions of the C3aR and C5aR were examined in the human neuroblastoma cell line, SK-N-SH, after the administration of amyloid peptide (A1-42). METHODS: SK-N-SH cells were incubated overnight with a single dose of 20 M of aggregated A (A1-42). An inhibition study was done with actinomycin D (ActD, 2.5 M) or with the administration of cycloheximide (CHX, 2.5 M) to the cell suspension. Messenger RNA expressions of C3aR and C5aR were detected by RT-PCR. The intensity of bands from 6% polyacrylamide electrophoretic gel was analyzed by a bioimage analyzer. The protein production of C3aR and C5aR in the A-treated cells was also measured by flow cytometry. NFB activation after treatment of A in the cells was detected by an electrophoretic mobility-shift assay. RESULTS: A1-42 increased the expression of C3aR and C5aR. ActD inhibited the expression of both anaphylatoxin receptors but CHX only suppressed C5aR mRNA expression. Activated NFB was demonstrated in the A-stimulated cells. CONCLUSIONS: C3aR and C5aR were constitutively expressed in the human neuroblastoma SK-N-SH cell. Expression of these anaphylatoxin receptors was upregulated after A1-42 stimulation, which as a result, may contribute to the complement-mediated neuroinflammation of AD.

CD59 prevents human complement-mediated injuries in isolated guinea pig hearts / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To assess complement-mediated myocardial injury on isolated guinea pig working hearts and cardioprotective effects of CD59.</p><p><b>METHODS</b>Using a modified Langendorff apparatus, isolated guinea-pig working hearts were perfused with a modified Krebs Henseleit buffer containing 3% heat-inactivated human plasma and zymosan (IPZ) (control) (n = 10), 3% normal human plasma and zymosan (NPZ) (n = 10), or 3% normal human plasma and zymosan and 1.5 microg/ml CD59 (NPZC) (n = 10), respectively. Epicardial electrocardiogram (ECG), cardiac output (CO), coronary arterial flow (CF), maximum left ventricular developed pressure (LVP(max)), maximum left ventricular developed pressure increase rate (+ dp/dt(max)), maximum left ventricular developed pressure decrease rate (- dp/dt(max)) and heart rate (HR) were recorded at 0, 15, 30, 45 and 60 min of treatment. After the experiment, immunohistochemical examination was performed to detect the presence of C3a or C5b-9 in the myocardium of the isolated hearts.</p><p><b>RESULTS</b>Compared the IPZ group, hearts treated with NPZ showed a slight depression on ST segments of epicardial ECG at 15 min, a significant elevation between 30 min to 60 min, a decrease in CF, CO, LVP(max), + dp/dt(max) and - dp/dt(max), and an increase in HR at 15 min. The observed alterations in CF, CO, LVP(max), + dp/dt(max) and - dp/dt(max) remained decreased, while the HR remained increased until the end of the protocol. The all above parameters of hearts treated with NPZC were similar to the control group (IPZ) at any given time. Immunohistochemical examination showed positive signals of C3a and C5b-9 in the myocardium of hearts treated with NPZ. C3a was positive in NPZC, and C3a and C5b-9 were negative in IPZ.</p><p><b>CONCLUSIONS</b>Activated human complements directly damage isolated guinea pig working hearts, and CD59 offers a significant protection against the injuries.</p>

Efficacies of the Modified Ultrafiltration and Peritoneal Dialysis in Removing Inflammatory Mediators After Pediatric Cardiac Surgery / 대한흉부외과학회지

BACKGROUND: Cardiopulmonary bypass induces an acute systemic inflammatory response mediated by complement activation and cytokine release. This response is likely to cause capillary leak syndrome and organ dysfunction in infants. Removing harmful cytokines and complement anaphylatoxins after cardiopulmonary bypass may attenuate this response. This study was conducted to see if the modified ultrafiltration and postoperative peritoneal dialysis can reduce plasma inflammatory mediators in pediatric cardiac surgery. MATERIAL AND METHOD: 30 infants (age 1.1 to 12.6 months) who underwent closures of ventricular septal defect using cardiopulmonary bypass (CPB) were enrolled in this study. These patients were divided into three groups; 10 patients selected randomly underwent modified ultrafiltration (Group U), 10 with small body weights (

Comparison between Cuprophane and Polysulfone Membrane in Biocompatibility / 대한신장학회잡지

OBJECTIVE: It has been proposed that the contact between blood and dialysis membrane during hemodialysis therapy induces harmful reactions to patients. Membrane biocompatibility is the characteristic that makes less adverse reaction. We tried to compare the biocompatibility between Cuprophane and Polysulfone membranes. MRTHODS: Nine chronic renal failure patients who have undergone maintenance hemrodialysis therapy with Hemophan membrane three times per week were included in this study. Cuprophane membranes were used in the first week: Hemophan membranes in the second week; Polysulfone membranes in the third week. Each membrane was used three times a week. On the day of third dialysis with the Cuprophane membrane(first week) and Polysulfone membrane(third week), serial blood sampling was obtained from the afferent line at hemodialysis initiation, 15 minutes, 30 minutes, 60 minutes, 120 minutes and 30 minutes to measure serum complement activity(C3a, C5a), blood polymorphonuclear leukocyte and platelet count, and arterial oxygen pressure which have been regarded as biocompatibility parameters. The parameters measured during the first week(Cuprophane) and the third week(Polysulfone) were compared to evaluate the difference in biocompatibility of both membranes. RESULTS: 1) C3a desArg In both groups, the level of C3a desArg increased significantly from basal level and the Cuprophane group showed significantly higher level of C3a desArg than that of Polysulfone group. 2) C5a desArg : In both groups, the level of C5a desArg did not increased sigpificantly from basal level. Only at 30 minute after hemodialysis, Cuprophane group showed significantly higher level of C5a desArg than that of Polysulfone group(p=0.037). 3) Polymorphonuclear leukocyte : In both groups, the polymorphonuclear leukocyte counts decreased significantly at 15 minutes and 30 minutes from basal level. The polymorphonuclear leukocyte count was lower in Cuprophane group than that of Polysulfone group at 15 minute after hemodialysis(p=0.001). 4) Platelet: In Cuprophane group, the platelet count was decreased significantly at 15 minute(p=0.004) but there were no difference in platelet counts between the two groups. 5) Arterial oxygen pressure Both group showed no consistent pattern of variation of oxygen pressure and there was no significant difference between the two groups. CONCLUSION: The biocompatibility of Polysulfone membrane was superior to the Cuprophane membrane with respect to the increased activation of complement C3a. decrease of polymorphonuclear leukocyte and decrease of platelet count.

Complement and dengue haemorrhagic fever/shock syndrome.

The complement system is activated in DHF/DSS. The peak of activation and the presence of C3a and C5a anaphylatoxins coincided with the onset of shock and leakage. The levels of C3a correlated well with disease severity. This indicated an important role of the complement system in the pathogenesis of shock. Circulating immune complexes as assayed by two standard techniques were not detected in the majority of patients, and if detected were found in small amount. The role of circulating immune complexes in the activation of complement in DHF/DSS needs to be reinvestigated, and other possible mechanisms leading to complement activation should be sought.