Total Serum Complement Research Articles

Growth performance, blood biochemistry profile, and immune response of rainbow trout (Oncorhynchus mykiss) fed dietary Persian shallot (Allium stipitatum) powder

Persian shallot is a member of the Alliaceae family and is known for its efficacy as antibacterial and immunostimulant effects, but its application in aquaculture is scarce. Herein, we evaluated the effects of Persian shallot powder (PSP) on the growth performance, blood biochemistry profile, and immune response of rainbow trout. Fish fed dietary PSP at 0, 0.5, 1, and 2% for 56 days, then the growth, serum, and skin mucus indices were evaluated. The final weight, weight gain, and specific growth rate (SGR) were meaningfully enhanced in fish fed 1 and 2%. The voluntary feed intake and protein efficiency ratio were meaningfully higher, while the feed conversion ratio (FCR) was lower in rainbow trout-fed dietary PSP at 1% than the control. The regression analysis illustrated that the optimum dose of PSP powder according to the FCR and SGR results is 1.27–1.35% for rainbow trout. The protease, amylase, and lipase activities were meaningfully increased in rainbow trout-fed PSP powder in a dose-dependent manner. The blood glucose was significantly reduced in fish fed 1 and 2% of PSP than the control. Further, the lactate dehydrogenase was markedly decreased by dietary PSP regardless of the dose. The total serum protein, lysozyme activity, total immunoglobulin (Ig), and complement component C4 were markedly higher in rainbow trout-fed PSP at 1 and 2% than the control. Additionally, the serum complement component C3 is higher in rainbow trout fed 1% PSP than the other groups. The skin mucus total protein level was significantly higher in fish fed PSP at varying levels than the control, and fish fed 1% PSP levels had higher Ig than fish fed 0.5 and 2% levels. The lysozyme and protease activities in the skin mucus samples were higher in fish fed 1 and 2% levels than fish fed 0 and 0.5% levels. The skin mucus Ig is higher in rainbow trout fed 1% PSP than fish fed 0 and 0.5% without difference with 2%. Overall, we recommend the dietary administration of PSP to bolster the performance and immunity of rainbow trout.

Alterations of IGF-1, complement C3 and superoxide dismutase in patients with moderate-to-severe obstructive sleep apnea hypopnea syndrome.

To evaluate various biomarkers of metabolism, immunity and inflammation in obstructive sleep apnea hypopnea syndrome (OSAHS). After overnight polysomnography, blood was collected from 292 OSAHS patients or healthy volunteers. Serum content of inflammatory, immune, metabolic biomarkers were investigated. In addition, the effects of 1-month continuous positive airway pressure (CPAP) were studied in moderate/severe OSAHS. C3, serum total complement activity, superoxide dismutase, uric acid were significantly higher in moderate/severe OSAHS than that in no/mild OSAHS. In contrast, IGF-1 in moderate/severe OSAHS was lower than it in no/mild OSAHS, which was negative correlated with apnea-hypopnea index. Moreover, CPAP significantly decreased C3, meanwhile elevated IGF-1. C3, serum total complement activity and superoxide dismutase were higher in moderate/severe OSAHS, while IGF-1 decreased. Elevated C3 and reduced IGF-1 in moderate/severe OSAHS may be reversed by CPAP.

Health Care Quality - An Urgent Issue for Bangladesh

Thirty-four patients undergoing bone marrow transplantation or remission induction for acute non-lymphocytic leukemia were the subjects of a study to determine whether outcome of infection (survival, death) could be related to total complement (TC), complement components, or C-reactive protein (CRP). Serum samples were obtained when the neutropenic patients became febrile, and at intervals thereafter. Significant differences were found between final total serum complement levels, the C3 component of complement, and the C-reactive protein. Multivariate logistic regression demonstrated a significant relationship between the final C3 complement and C-reactive protein levels and the outcome of infection. Changes between initial and final values were also predictive of outcome, suggesting that the magnitude and direction of changes in these measurements may assist the clinician in assessing the success of his prescribed antibiotic therapy. Our data suggest that a test battery comprising serial TC, C3, and CRP measurements may have more predictive potential than each test performed independently.

Circulating C3 and glucose metabolism abnormalities in patients with OSAHS.

Obstructive sleep apnea hypopnea syndrome (OSAHS) is a common breathing disorder during sleep characterized by multiple disease roots, including disorders of complement and glycometabolism. And the main purpose of the present study is to make clear the effect of complement C3 on glucose metabolism abnormalities in patients with OSAHS. This was a cross-sectional study. Two hundred six patients, mean age 44.58±11.84years and 26 female patients (26/206), had been suspected with OSAHS and underwent overnight polysomnography. The assessment of complement levels included complement 3 (C3), complement 4 (C4), and serum total complement (TC). The measured indicators of glucose metabolism were fasting blood glucose (FPG), fasting insulin (FINS), and 75g oral glucose tolerance test-derived glucose. A multivariate linear regression was used to determine relevant factors with 2-h postprandial blood glucose (2hPG) and C3. The patients were classified according to apnea-hypopnea index (AHI) into four groups: simple snore (n=21), mild OSAHS (n=43), moderate OSAHS (n=35), and severe OSAHS (n=107). The level of C3 in the severe OSAHS was higher than other groups (simple snore: 1.16±0.18g/L VS 1.00±0.18g/L, p<0.001; mild OSAHS: 1.16±0.18g/L VS 1.04±0.17g/L, p<0.001; moderate OSAHS: 1.16±0.18g/L VS 1.06±0.14g/L, p=0.003) and no-severe OSAHS group (1.16±0.18g/L VS 1.04±0.16g/L, p<0.001). And C3 was associated with AHI, average pulse oxygen saturation (A-spo2), homeostasis model assessment-insulin resistance (HOMA-IR), 2hPG, age, sleep stage (I + II)/TST, and sleep stage (III)/TST, respectively. HOMA-IR was correlated to AHI after adjustment with age and BMI. OSAHS was an independent risk of C3 regardless of obesity and sleep parameters (p=0.002). After adjustment with neck circumference (NC), BMI, AHI, sleep stage (I + II)/TST, and sleep stage (III)/TST,C3 level was associated with 2hPG (p<0.001). A high level in C3 is correlated with the occurrence of OSAHS and C3 alterations in OSAHS patients seem to contribute to disorders of glucose metabolism. And targeting OSAHS to improve glucose metabolism and immune function could be useful.

Antipyretic Effects of Liposoluble Fractions of Viola yedoensis

ObjectiveTo clarify the antipyretic effect of the Chinese materia medica, Violae Herba (Viola yedoensis), and its active fractions by examining the effects of V. yedoensis extracts with differing polarities on body temperature, total white blood cell (WBC) count, WBC differential count, and total serum complement of rabbits with lipopolysaccharide (LPS)-induced fever. MethodsThe rabbits were treated with water and ethanolic extracts of V. yedoensis, as well as petroleum ether, ethyl acetate, and n-butanol fractions of the ethanolic extract at low-, mid- and high- doses. The LPS was injected via the ear vein of rabbits in model and treatment groups 30 min post-gavage. Their body temperature was measured at 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, and 6.0 h after the LPS challenge to calculate the temperature changes and thermal response index. After the last temperature measurement, blood samples were collected to determine the blood cell counts and total serum complement (CH50) level. ResultsCompared with the model group, body temperature was significantly lower in the low-dose ethanolic extract group, low- and mid-dose petroleum ether fraction groups, and all three ethyl acetate fraction groups. Serum CH50 levels were lower in all treatment groups, except the ethanolic extract groups, than that in the model group, with no significant difference. V. yedoensis had no significant effect on the blood cells of febrile rabbits challenged with LPS for 6 h. ConclusionsThe antipyretic effects of V. yedoensis are strong, and its active fractions are the petroleum ether and ethyl acetate fractions of ethanolic extract.

Non-Clinical Safety Studies of IMT504, a Unique Non-CpG Oligonucleotide

IMT504 is a non-CpG 24-mer oligodeoxynucleotide (ODN) with immunomodulatory as well as tissue repair activity. IMT504 has been previously proven to be effective in animal models of vaccine potency, chronic lymphocytic leukemia, tissue regeneration, and sepsis. Here, we assessed the safety, including pharmacokinetics and toxicity studies in rats and monkeys, of IMT504 in a single- or repeated-dose administration by the subcutaneous (SC) or intravenous (IV) routes. In rats, the maximum tolerated dose was determined to be 50 mg/kg when administered SC. Adverse effects at 50 mg/kg were mild and reversible liver injury, revealed as lobular inflammation, focal necrosis, and small changes in the transaminase profile. Dose-dependent splenomegaly and lymphoid hyperplasia, most probably associated with immune stimulation, were commonly observed. Rats and monkeys were also IV injected with a single dose of 10 or 3.5 mg/kg, and no adverse effects were observed. Rats injected IV with 10 mg/kg showed a transient increase in spleen weight, together with a slight increase in the marginal zone of the white pulp and in leukocyte count 2 days post-administration. In monkeys, this dosage caused slight changes in total serum complement and leukocyte count on day 14. No adverse effects were observed at 3.5 mg/kg IV in rats or monkeys. Therefore, this dose was defined as the "no observed adverse effect level" for this route. Furthermore, repeated-dose toxicity studies were performed in these species using 3.5 or 0.35 mg/kg/day IV for 6 weeks. A transient increase in the spleen and liver weight was observed at 3.5 mg/kg/day only in female rats. No changes in clotting time and activation of the alternative complement pathway were observed. The toxicity profile of IMT504 herein reported suggests a dose range in which IMT504 can be used safely in clinical trials.

Ham Test For Therapeutic Monitoring Of Eculizumab In Paroxysmal Nocturnal Hemoglobinuria

IntroductionParoxysmal nocturnal hemoglobinuria (PNH) is a rare acquired clonal disease, caused by an inactivating mutation in the PIG-A gene in a hematopoietic stem cell. The PIG-A gene encodes an enzyme required for glycosylphosphatidylinositol (GPI) anchor synthesis. Its inactivation results in a deficiency of many plasma membrane GPI-anchored proteins -including CD55 and CD59, natural inhibitors of the complement cascade- in the involved stem cell and all its progeny (the PNH clone). Intravascular hemolysis, anemia, thrombosis, acute and chronic renal damage, pulmonary hypertension, abdominal pain, esophagic spasm, erectile dysfunction -among others manifestations- are consequences of complement mediated damage of the sensitive PNH blood cells. In 2007 both the FDA and the EMA approved eculizumab, a monoclonal chimeric antibody targeted against C5 fraction of complement, as the first specific treatment of complement mediated PNH manifestations.Flow cytometry (FC) is the gold standard method for diagnosis. The former diagnostic test -the Ham test- is based on the susceptibility of PHN red blood cells (RBC), when they are incubated with both normal and patient sera to lysis mediated by the alternative pathway of complement (APC). APC is activated, in the Ham test, through sera acidification. Despite its physiopathological value, Ham test has been replaced with flow cytometry to diagnose PNH due to a much higher sensitivity and reproducibility. AimsTo evaluate the Ham test in PNH treated patients, to monitor the eculizumab-mediated blockade of APC. Patients and methodsHam test was used to monitor APC blockade in the patient serum, testing the ability of the acidified patient serum to lyse his or her own PNH-RBC. Eight patients were diagnosed as PNH by FC and were treated with eculizumab. Six had a good therapeutic response, with decreased levels of both, LDH and the serum total complement hemolytic capacity (CH50). Ham test, in these six patients, showed hemolysis when PNH-RBC were mixed with normal acidified serum but absence of hemolysis when the acidified serum of eculizumab treated patient was added to the PNH-RBC. This result was called “blockade profile” and shows the “ex vivo” APC blockade, confirming thus the eculizumab success. The remaining two patients showed a persistent positivity of the Ham test at day 14 of eculizumab administration (as PNH-RBC lysis continued taking place with both normal and patient acidified sera). One patient demonstrated break through hemolysis occurring near the end of eculizumab dosing period as indicated by increase in LDH. As LDH may increase due to other possible factors (ie hepatic lesions) the positive Ham test confirmed that intravascular hemolysis was taking place, possibly due to a shorter eculizumab half life. An increase of the eculizumab dose to 1,200 mg/14 days reinstated lower LDH levels and the blockade profile in the Ham test (Table). There has been a single patient treated with eculizumab where LDH did not reduce. There was a persistently positive Ham test, elevated LDH and free hemoglobin levels and normal CH50 values despite a dose of 1,200 mg of eculizumab every 14 days (Table). A genetic study found in this case a C5 mutation, which seems responsible of the lack of response to eculizumab. ConclusionsIn our experience, the Ham test has proved to be a useful and economic method to monitor the effectiveness of eculizumab treatment in cases with high LDH levels due to either a) other causes than intravascular hemolysis, or b) no responsive patients due to pharmacokinetic (inadequate eculizumab concentration) or pharmacodynamic causes.TableCorrelation between intravascular hemolysis markers (LDH, free hemoglobin), total serum hemolytic capacity (CH50) and Ham test in non responding patientsPatientDay of last dose of eculizumab (mg)LDH (U/L) (ULN: 480 U/L)Free Hb (mg/dL)CH50 (hemolytic units)Ham testPatient 1-136,1612034++14 (900 mg)1,84931--++7 (900 mg)88610.41Blocked+9 (900 mg)8565.81Blocked+12 (900 mg)1,1599.716Blocked+14 (900 mg)3,2757031++1 (1,200 mg)6162.51Blocked+7 (1,200 mg)5541.71Blocked+14 (1,200 mg)6393.05BlockedPatient 2+06,2197326++14 (1,200 mg)4,8492936+ Disclosures:Brodsky:Alexion Pharmaceuticals: Consultancy, Speakers Bureau. Colin:Alexion Pharmaceuticals: Consultancy.

Preclinical evaluation of the neuroprotective effect of soluble complement receptor Type 1 in a nonhuman primate model of reperfused stroke

Postischemic cerebral inflammatory injury has been extensively investigated in an effort to develop effective neuroprotective agents. The complement cascade has emerged as an important contributor to postischemic neuronal injury. Soluble complement receptor Type 1 (sCR1), a potent inhibitor of complement activation, has been shown to reduce infarct volume and improve functional outcome after murine stroke. Given numerous high-profile failures to translate promising antiinflammatory strategies from the laboratory to the clinic and given the known species-specificity of the complement cascade, the authors sought to evaluate the neuroprotective effect of sCR1 in a nonhuman primate model of stroke. A total of 48 adult male baboons (Papio anubis) were randomly assigned to receive 15 mg/kg of sCR1 or vehicle. The animals were subjected to 75 minutes of middle cerebral artery occlusion/reperfusion. Perioperative blood samples were analyzed for total complement activity by using a CH50 assay. Infarct volume and neurological scores were assessed at the time the animals were killed, and immunohistochemistry was used to determine cerebral drug penetration and C1q deposition. An interim futility analysis led to termination of the trial after study of 12 animals. Total serum complement activity was significantly depressed in the sCR1-treated animals compared with the controls. Immunostaining also demonstrated sCR1 deposition in the ischemic hemispheres of treated animals. Despite these findings, there were no significant differences in infarct volume or neurological score between the sCR1--and vehicle-treated cohorts. A preischemic bolus infusion of sCR1, the most effective means of administration in mice, was not neuroprotective in a primate model. This study illustrates the utility of a translational primate model of stroke in the assessment of promising antiischemic agents prior to implementation of large-scale clinical trials.

Infections in systemic lupus erythematosus: a prospective and controlled study of 110 patients

We decided to analyse the incidence and characteristics of infection in systemic lupus erythematosus (SLE) and determine the related risks factors. One-hundred and ten SLE patients and 220 controls were prospectively followed up over three years and all the infectious episodes were recorded. A case-control design was established to identify risk factors of infection. Thirty-nine SLE patients suffered at least one infection (36%) versus 53 controls (22%), RR = 1.63 (P < 0.05). The incidence of urinary infections, pneumonia and bacteraemia without known focus was significantly greater in SLE. E. coli was the chief isolated microorganism (21.3%). In the univariate analysis, nephritis, SLE activity, leucopenia, anti-dsDNA levels above 20 IU/mL, CH50 levels under 300 IU/mL, ever use of steroids, daily dose of prednisone higher than 10 mg and ever use of cyclophosphamide were significantly associated with infection. In the multivariate analysis, total serum complement levels below 300 UU/mL and a daily dose of prednisone above 20 mg during at least one month plus ever use of cyclophosphamide were found to be significant (P < 0.0001). We conclude that patients with SLE have an increased overall risk for infection and they are especially prone to develop urinary infection, pneumonia and bacteraemia without focus. Hypocomplementaemia represents an independent predictive factor for infection. It seems mandatory to closely follow up SLE patients with low complement levels and instruct them to report any suspicious sign of infection, especially in those receiving more than 20 mg/day of prednisone who have also been administered cyclophosphamide.

Effect of Yunnan-cobra venom factor in overcoming acute humoral rejection after allograft cardiac transplantation in presensitized recipients: experiment with rats

To investigate the effect of Yunnan-cobra venom factor (Y-CVF) in overcoming acute humoral rejection after allograft cardiac transplantation in presensitized recipients. Fifteen Lewis rats received the transplantation of full-thickness skin graft of BN rats three times so as to be presensitized. Fifteen pairs of Lewis rat, as recipients of heart, and BN rat, as heart donors, were randomly divided into 2 groups: experimental group (n = 8), and control group (n = 7). The Lewis rats in the experimental group received heart transplantation of the heart of the BN rat 7 approximately 10 days after the third skin transplantation, and were injected with Y-CVF 80 microg/kg 24 hours before the heart transplantation. The Lewis rat in the control group received only the heart transplantation without Y-CVF injection. Blood samples were collected from all rats before pre-sensitization and 7 days after the third skin transplantation so as to determine the titer of anti-BN rat lymphocyte antibody. 0 and 24 hours, and 6 and 8 days after Y-CVF injection blood samples were collected from the Lewis rats to determine the total complement activity with the complement activity before Y-CVF injection defined as 100%. The survival time of the transplanted heart was observed. After the transplanted hearts stopped to beat, they were resected and underwent HE staining and microscopy. Immunohistochemistry was used to examine the deposition of IgG and complement 3 (C3). The titer of anti-BN rat lymphocyte antibody was 0 before the pre-sensitization, and increased to 1:1028 - 1:2056 7 days after the third skin pre-sensitization. The serum total complement activity of the Lewis rats decreased to 0 twenty-four hours after the Y-CVF injection, recovered to 2.01% - 15.41% 6 days after, and returned to the normal level (89.61% - 109.46%) 8 days after. The mean survival time of the transplanted hearts of the control group was 12.71 +/- 13.94 hours (with a range of 1.5 - 15 hours), significantly shorter than that of the experimental group (99.50 +/- 38.72 hours, with a range of 23 - 153 hours, P < 0.01). Pathological examination showed that the acute humoral rejection in the control group was mainly complement-dependent antibody-mediated humoral rejection characterized by intravascular thrombosis, and that in the experimental group was mainly cellular rejection, characterized by extensive infiltration of mononuclear cells. Immunohistochemistry showed that remarkable IgG deposition was seen in the cardiac muscle cells and vascular endothelial cells in both groups; however, C3 deposition in vascular endothelial cells could be seen only in the control group. Administration of CVF is effective in overcoming the acute humoral rejection after allograft cardiac transplantation in presensitized recipients.

The role of complement in the early phase of Leishmania (Leishmania) amazonensis infection in BALB/c mice.

Complement-depleted and -non-depleted BALB/c mice were inoculated with Leishmania (Leishmania) amazonensis promastigotes into the hind footpad to study the role of the complement system in cutaneous leishmaniasis. Total serum complement activity was measured by hemolytic assay and C3 fragment deposit at the inoculation site was determined by direct immunofluorescence in the early period of infection, i.e., at 3, 24, 48 h and 7 days post-infection. The inflammatory reaction and the parasite burden were evaluated in the skin lesion at 7 and 30 days post-infection. Total serum complement activity decreased in the early phase of infection, from 3 to 24 h, in non-depleted mice compared to non-infected and non-depleted mice. C3 fragment deposit at the site of parasite inoculation was present throughout the period of infection in non-depleted mice. In contrast, no C3 fragment deposit was observed at the inoculation site in complement-depleted mice. Complement-depleted mice showed a significant decrease in the inflammatory response and a significant increase in the number of parasites (70.0 +/- 5.3 vs 5.3 +/- 1.5) at 7 days of infection (P<0.05). A higher number of parasites were also present at 30 days of infection at the inoculation site of complement-depleted mice (78.5 +/- 24.9 vs 6.3 +/- 5.7). These experiments indicate that complement has an important role at the beginning of experimental cutaneous leishmaniasis caused by L. (L.) amazonensis by controlling the number of parasites in the lesion.

ACUTE Q FEVER PERICARDITIS FOLLOWED BY CHRONIC HEPATITIS IN A TWO-YEAR-OLD GIRL

Acute Coxiella burnetii infection is most commonly a mild and self-limiting disease with fever, pneumonia and hepatitis. Endocarditis is the most frequent clinical presentation of chronic infection. We report a 2-year-old child with Q fever who presented with acute pericarditis and cardiac tamponade and who developed a chronic hepatic infection.

The significance of stress hormones (glucocorticoids, catecholamines) for eruptions and spontaneous remission phases in psoriasis.

In an earlier paper, it was described how acute eruptions of psoriasis may be produced in phases of immune deficiency and in the presence of bacterial antigen-releasing inflammatory foci, whereas clinical spontaneous remissions are produced in phases of immunologic activity. Therefore, it was of interest to investigate whether the stress hormones cortisol/epinephrine are involved in triggering such deficiency and activity phases. During a series of investigations lasting up to 3 years in 95 patients, the following were determined: cortisol/epinephrine levels, polyclonal serum immunoglobulins IgM, IgG, and IgA, total serum IgE, complement C3 and C4 proteins, T cells and subpopulations, as well as streptococcal titers ASO/ADNase B, severity index (PASI) RESULTS: Phases of clinical inactivity are associated with the mechanism, "immunologic regulation," where antibacterial titers are elevated, but all other parameters are unremarkable. Eruption phases (in 32 of 95 patients) showed absolute increases in serum cortisol levels and antibacterial titers, and decreases in serum epinephrine (adrenaline) levels. Phases of spontaneous remission (in 25 of 32 patients) showed, in contrast to the eruption phases, absolute increases in serum epinephrine levels, and significant falls in serum cortisol levels and bacterial titers. On the basis of these results, the participation of the immune system is confirmed in the pathogenesis of psoriasis, which is subject to control by higher neurohormonal systems. Cortisol may be involved in the clinical eruption phase, and epinephrine in the remission phase. Both hormones are true antagonists and have important effects on the human immune system if produced in excess via the pituitary-adrenal axis. Infection with Streptococcus pyogenes is an additional trigger for the dermatosis.

Immunological Characteristics and Skin Structure of the Meishan Pig: Serum Complement Activity, Serum C3 Level and Immune Response

We examined several immunological characteristics of Meishan pigs to determine the cause of their high susceptibility to skin disease. The total serum complement activity (CH 50) and the third complement component (C3) levels of Meishan pigs were, respectively, two-fold and 1.2-1.3 fold those of the levels of the European pig breeds at 26 weeks of age. We compared changes in total serum immunoglobulin G (IgG) levels in Meishan and Duroc pig breeds after Alum-BSA immunization. The IgG levels of the immunized Meishan pigs at 16 weeks of age were remarkably higher than those of the Duroc and non-immunized control Meishan pigs (2.9-fold and 2.6-fold, respectively). Meishan pigs were also found to have different SLA class II genotypes, thicker epidermises, and clearer increases in eosinophil infiltration with age than their Duroc counterparts. Furthermore, a severe eosinophil infiltration was found around blood capillaries in the dermis and hypodermis of Meishan pigs at 153 days of age. These histopathological findings appear to reflect characteristics of the allergic dermatitis. Collectively, these results suggest that the Meishan pig has a high tendency toward type I allergic reaction, a tendency which may be due to the breed's high CH 50 and C 3 levels and high humoral immune responsiveness.

Early complement system activation and neutrophil priming in acute pancreatitis: Participation of trypsin

Background . It is known that the pancreatic enzyme trypsin can cleave components of the complement system, producing the chemokines C3a and C5a. In the setting of experimental acute pancreatitis, we analyzed the contribution of serum trypsin to systemic complement activation and its importance in neutrophil lung sequestration, an early event in acute pancreatitis. Methods . Cerulein was infused into Lewis rats to produce mild edematous acute pancreatitis. Soluble complement receptor, sCR1, was used to block complement activation. Results . Induction of acute pancreatitis was confirmed by the serum levels of amylase and trypsin and by histologic studies. A correlation was found between serum total complement activity and the trypsin level (r = −0.884). Whole lung tissue myeloperoxidase activity was high in rat lungs at t = 4 hours, indicating accumulation of neutrophils. The sCR-1-treated group showed significantly lower levels. Flow cytometry of neutrophils incubated with serum from rats with pancreatitis showed significantly higher CD11b/CD18 expression than that after incubation with serum from control or sCR-1-treated rats. Until t = 12 hours, no change in the lung wet to dry weight ratio or bronchoalveolar fluid cytology was observed, indicating no functional enhancement of neutrophils that had accumulated in the lungs. Conclusions . The present results demonstrate the important role of trypsin in systemic complement activation early in the course of acute pancreatitis. The resulting central production of chemotaxins causes priming of circulating neutrophils and subsequent lung sequestration. These events can be at least partially reversed by sCR-1 treatment.

Additive effect of diabetes and systemic hypertension on the immune mechanisms of atherosclerosis

In order to evaluate the changes in humoral immunity due to one and two atherogenic factors (systemic hypertension and/or diabetes mellitus), we investigated 350 women divided into four groups: (1) 65 insulin-dependent (type I) non-hypertensive diabetics; (2) 92 systemic hypertensive non-diabetic subjects; (3) 64 hypertensive insulin-dependent diabetics; and (4) 129 non-hypertensive and non-diabetic women as a control group. All subjects had no coronary artery disease. The humoral immunity was evaluated by (1) circulating immune complexes, (2) total serum complement, (3) C3 fraction of complement, and (4) circulating antitissue antibodies (antivascular and antisclerotic-vascular). The patients with atherosclerotic risk factors (diabetes and/or hypertension) had significantly ( P < 0.001) elevated levels of total complement, C3 fraction and circulating complexes compared with the control group. Total complement and circulating complexes levels were most elevated in patients with a combination of diabetes and hypertension. Similarly, these patients had the highest frequency of antitissue antibodies. In summary, the parameters of humural immunity were more changed in patients with two risk factors (diabetes and hypertension) compared to patients with only one risk factor. It is possible that these immunological changes appeared earlier than clinical symptoms of atherosclerosis and they could be used as an early prognostic test for predisposition to atherosclerotic vascular complications.

Nonenzymatic Glycosylation of Immunoglobulin G Impairs Complement Fixation

Transient hyperglycemia in patients receiving total parenteral nutrition may be associated with impaired immune function. The effects of short-term hyperglycemia on one aspect of antimicrobial immune function, ie, the ability of IgG to fix complement, were investigated. Aliquots of anti-human albumin, anti-horse ferritin, and anti-alkaline phosphatase were incubated for 0, 8, 16, 24, 48, and 96 hr with either 0 or 240 mg of glucose per deciliter of buffer. All samples were analyzed for the degree of glycation using a thiobarbituric acid assay, and for complement fixation ability using a microcomplement fixation assay. Significant increases in glycation over control samples were observed after only 16 hr (31 vs 15 mmol 5-hydroxymethylfurfural/mol IgG, p less than 0.01). Complement fixation was significantly altered after 48 hr of incubation (76 +/- 5% vs 90 +/- 8% total serum complement fixed by albumin/anti-albumin complex, p less than 0.03) when four of the 84 (4.7%) IgG lysine residues were glycated. It is demonstrated that a significant reduction in complement fixation by immunoglobulin occurs with elevated glucose concentrations and that this may play a clinically significant role in transiently hyperglycemic patients.

Complement levels in patients with hepatic dysfunction

Total hemolytic complement activity and serum complement protein concentrations were compared in 17 hospitalized patients with normal hepatic function and 16 patients with liver disease due to alcohol (15 patients) or acetaminophen toxicity (one patient). In contrast to the control patients, individuals with hepatic dysfunction had decreased total CH50 levels and low concentrations of total C3, C4, C5, factor B, and the regulatory proteins factor I and beta-1H. These patients also had increased C4d/C4 ratios, indicating classical pathway activation. The level of complement deficiency appears to correlate with either prolongation of the prothrombin time or depression of serum albumin concentration. These results indicate that patients with hepatic disease have severe complement depletion that is probably multifactorial in origin. This impairment in complement function will contribute to the impaired antibacterial host defense of the patient with chronic hepatic disease.

A hemolytic assay for the measurement of equine complement

A hemolytic assay was developed for the measurement of functional equine complement activity. The assay utilizes antibody sensitized chicken erythrocytes as the target cell and was specific for classical pathway (antibody dependent) complement activity. The assay was found to be reproducible and more sensitive than previous reports using other species of target cells. Total serum complement (CH 50) values were determined for five mares and their foals and followed over a period of 3 months.

Inhibition of acute passive transfer experimental autoimmune myasthenia gravis with Fab antibody to complement C6.

The role of the lytic complement C5b-9 membrane attack complex (MAC) in acute passive transfer experimental autoimmune myasthenia gravis (EAMG) produced in rats was investigated by in vivo inhibition of MAC formation with anti-C6 Fab. Anti-C6 Fab totally inhibited in vitro serum hemolytic activity, but did not consume or inhibit early complement pathways. Injection of rats with 0.12 mg/ml anti-C6 Fab reduced serum C6 to 8% and inhibited the muscle weakness, electrophysiologic abnormalities and loss of acetylcholine receptor (AChR) associated with acute EAMG. This level of C6 inhibition reduced the total serum complement hemolytic activity to 29% of normal but did not reduce the serum levels of complement components C3, C5, or C7. Treatment of rats with lower amounts of anti-C6 Fab (0.08 mg/ml) also inhibited clinical and electrophysiologic signs of EAMG, however, the lower amount of anti-C6 did not prevent the loss of muscle AChR. Both the higher and the lower amount of anti-C6 Fab inhibited the accumulation of macrophages at muscle motor end-plates. The inhibition by anti-C6 indicates that muscle weakness and electrophysiologic abnormalities associated with EAMG are dependent on the complement MAC, and that muscle weakness results from tissue injury in addition to loss of muscle membrane and AChR.