Absorption, Distribution, Metabolism, and Excretion of [14C]iptacopan in Healthy Male Volunteers and in In Vivo and In Vitro Studies.

Iptacopan (LNP023) is an oral, small-molecule, first-in-class, highly potent proximal complement inhibitor that specifically binds factor B and inhibits the alternative complement pathway. Iptacopan is currently in development as a targeted treatment of paroxysmal nocturnal hemoglobinuria and multiple other complement-mediated diseases. In this study, the absorption, distribution, metabolism, and excretion (ADME) of iptacopan was characterized in six healthy volunteers after a single 100 mg oral dose of [14C]iptacopan. This was supplemented with an in vivo rat ADME study and metabolite exposure comparisons between human, rat, and dog, in addition to in vitro assays, to better understand the clearance pathways and enzymes involved in the metabolism of iptacopan. The fraction of [14C]iptacopan absorbed was estimated to be about 71%, with a time to maximum concentration of 1.5 hours and elimination half-life from plasma of 12.3 hours. Following a single dose of [14C]iptacopan, 71.5% of the radioactivity was recovered in feces and 24.8% in urine. [14C]iptacopan was primarily eliminated by hepatic metabolism. The main biotransformation pathways were oxidative metabolism via CYP2C8, with M2 being the major oxidative metabolite, and acyl glucuronidation via UGT1A1. The two acyl glucuronide metabolites in human plasma, M8 and M9, each accounted for ≤ 10% of the total circulating drug-related material; systemic exposure was also observed in toxicology studies in rat and dog, suggesting a low risk associated with these metabolites. Binding of iptacopan to its target, factor B, in the bloodstream led to a concentration-dependent blood:plasma distribution and plasma protein binding of [14C]iptacopan. SIGNIFICANCE STATEMENT: We characterized the pharmacokinetics, excretion, metabolism and elimination of [14C]iptacopan (an oral, selective small-molecule inhibitor of factor B) in healthy human subjects. [14C]iptacopan was primarily eliminated by metabolism. The primary biotransformation pathways were oxidative metabolism via CYP2C8 and acyl glucuronidation via UGT1A1. Direct secretion of iptacopan into urine and potentially bile represented additional elimination mechanisms. Binding of iptacopan to its target, factor B, in the bloodstream led to a concentration-dependent blood:plasma distribution and plasma protein binding of [14C]iptacopan.

Predictive value of the complement factors B and H for women with gestational diabetes mellitus who are at risk of preeclampsia.

OBJECTIVES: We aimed to define the relationships between the serum concentrations of complement factors B and H in mid-pregnancy and the risk of preeclampsia (PE) in patients with gestational diabetes mellitus (GDM). STUDY DESIGN: We performed a prospective nested case-control study of 503 patients with GDM who attended Peking University Third Hospital between March 2018 and December 2018. 456 patients were followed until delivery and blood samples were collected between gestational weeks 24 and 28. Thirty patients developed PE, 12 developed gestational hypertension (GH), and 42 matched cases were selected as a control group. RESULTS: The incidence of PE was 5.96 %. The serum concentrations of triacylglycerol (TG), FB, and FH of women with GDM who developed PE (GDM-PE group) in mid-pregnancy were significantly higher than those of the GDM group [TG: 3.60 (2.94-4.63) vs 2.54 (2.14-3.01) mmol/L, p < 0.001; FB: 346 (314-378) vs 284 (263-323) mg/L, p < 0.001; FH: 417 ± 45 vs 379 ± 47 mg/L, p = 0.003]. Multivariate regression analysis showed that high serum concentrations of TG and FB in mid-pregnancy were related to the risk of patients with GDM developing PE [TG: odds ratio (OR) 2.035 (95 % confidence interval (CI) 1.032-4.013); FB: OR 1.018 (95 % CI 1.001-1.035)]. The area under the curve (AUC) of FB for the prediction of PE was 0.821 (95 % CI 0.722-0.921) and that for a combination of TG, FB, and FH was 0.857 (95 % CI 0.770-0.944). CONCLUSIONS: High serum FB concentration during mid-pregnancy is a potential predictor of the risk of PE in patients with GDM, and the combination of FB, FH, and TG increased this predictive value.

Diagnostic and Prognostic Significance of Complement in Patients With Alcohol-Associated Hepatitis.

BACKGROUND AND AIMS: Given the lack of effective therapies and high mortality in acute alcohol-associated hepatitis (AH), it is important to develop rationally designed biomarkers for effective disease management. Complement, a critical component of the innate immune system, contributes to uncontrolled inflammatory responses leading to liver injury, but is also involved in hepatic regeneration. Here, we investigated whether a panel of complement proteins and activation products would provide useful biomarkers for severity of AH and aid in predicting 90-day mortality. APPROACH AND RESULTS: Plasma samples collected at time of diagnosis from 254 patients with moderate and severe AH recruited from four medical centers and 31 healthy persons were used to quantify complement proteins by enzyme-linked immunosorbent assay and Luminex arrays. Components of the classical and lectin pathways, including complement factors C2, C4b, and C4d, as well as complement factor I (CFI) and C5, were reduced in AH patients compared to healthy persons. In contrast, components of the alternative pathway, including complement factor Ba (CFBa) and factor D (CFD), were increased. Markers of complement activation were also differentially evident, with C5a increased and the soluble terminal complement complex (sC5b9) decreased in AH. Mannose-binding lectin, C4b, CFI, C5, and sC5b9 were negatively correlated with Model for End-Stage Liver Disease score, whereas CFBa and CFD were positively associated with disease severity. Lower CFI and sC5b9 were associated with increased 90-day mortality in AH. CONCLUSIONS: Taken together, these data indicate that AH is associated with a profound disruption of complement. Inclusion of complement, especially CFI and sC5b9, along with other laboratory indicators, could improve diagnostic and prognostic indications of disease severity and risk of mortality for AH patients.

Deciphering biomarkers of endometriosis by proteomic analysis of eutopic endometrium in infertile patients.

AIM: Endometriosis is associated with infertility. The aim of this study was to examine the overall proteomic changes of eutopic endometrium in infertile women with endometriosis. METHODS: Tandem mass tags combined with multidimensional liquid chromatography and mass spectrometry analyses were used to screen the proteomic profiles of eutopic endometrium from infertile patients with endometriosis (N = 4), compared with that from patients without endometriosis (N = 4). Quantitative proteomic analysis, functional categories and significant pathway analysis were investigated subsequently. RESULTS: In total, 6.698 proteins were identified, among which 5,812 proteins were quantified. Compared with controls, proteomic analysis showed some differentially expressed proteins: 16 up-regulated proteins and 23 down-regulated proteins. Bioinformatics analysis indicated that differentially expressed proteins were involved in humoral immune response pathways, antimicrobial humoral response and regulation of nitric oxide biosynthetic process. Besides, our results showed that alpha-1-acid glycoprotein 2, complement factor B and zinc transporter Zip14 were important resources for investigating potential mechanism of infertility in infertile women with endometriosis. CONCLUSIONS: This study provided a reference proteome map of eutopic endometrium from infertile women with endometriosis. The long-term benefits of using those markers to stratify clinical treatment warrant further investigation.

Complement activation is associated with crescent formation in IgA nephropathy.

IgA nephropathy (IgAN) is common chronic glomerulonephritis with variable prognosis, ranging from minor urinary abnormalities to end-stage renal disease. The revised Oxford classification of IgAN explains that cellular/fibrocellular crescents are associated with poor renal prognosis, proposing an extension to the MEST-C score. C3 immunofluorescent staining follows a distribution similar to IgA staining. Therefore, complement activation was reported to play a pivotal role in IgAN pathogenesis. This study included 132 IgAN patients diagnosed by renal biopsies. The clinical parameters at the time of the biopsies were obtained from patient data records. We classified the patients into C ≥ 1 and C0 groups, and compared clinical, light microscopic, and immunofluorescent features. In the C ≥ 1 group, 2 (1.5%) and 31 (23.5%) patients were assigned to C2 and C1, respectively. The remaining 99 patients (75%) were classified as C0. The C ≥ 1 group had lower average age and rate of hypertension, and higher score of urinary occult blood and E score. The C ≥ 1 group had significantly higher average immunofluorescence scores for IgA, C5b-9, mannose-associated serine protease (MASP) 1/3, MASP2, properdin, factor B, and kappa. The steroid use rate was significantly higher in the C ≥ 1 group. During the follow-up period of 2.90 years on average, the rate of renal dysfunction was not significantly different between groups. Crescent formation in IgAN was associated with activation of the lectin and alternative pathways. The C ≥ 1 group had significantly increased use of steroids, which probably caused comparable renal function during the follow-up period.

Association between antiphospholipid antibodies and factor Bb in lupus nephritis patients with glomerular microthrombosis.

BACKGROUND AND PURPOSE: The mechanism of glomerular microthrombosis (GMT) in patients with lupus nephritis (LN) is largely unknown. The aim of this study is to investigate the association between antiphospholipid antibodies (aPLs) and factor Bb in LN patients with GMT. METHODS: Patients with biopsy-proven LN hospitalized from July 2015 to July 2018 in our hospital were selected for this study. Levels of lupus anticoagulant (LAC), anticardiolipin antibodies (aCLs), anti-ß2-glycoprotein I (anti-ß2-GPI) antibodies and factor Bb were measured, and other clinical and pathological data were also obtained during the same period before renal biopsy. RESULTS: A total of 25 LN patients with GMT and 76 LN patients without GMT were included in this study. In LN patients with GMT, the presence of anti-ß2GPI and LAC were both significantly higher than in those without GMT (P < .001 and P = .039, respectively). The level of factor Bb was also higher in LN patients with GMT than in those without GMT (P = .021). In the correlation analysis, Bb level was positively correlated with serum creatinine (r = 0.28, P = .014), activity index (r = 0.24, P = .021) GMT (r = 0.65, P < .001) and IgG-anti-ß2GPI (r = 0.771, P < .001). CONCLUSIONS: Our work suggests that aPLs, especially IgG-anti-ß2GPI, may play a role in the progress of GMT, and this process might involve alternative complement activation.

Complement activation products in the circulation and urine of primary membranous nephropathy.

BACKGROUND: Complement activation plays a substantial role in the pathogenesis of primary membranous nephropathy (pMN). C5b-9, C3c, MBL, and factor B have been documented in the subepithelial immune deposits. However, the changing of complement activation products in circulation and urine is not clear. METHODS: We measured the circulating and urinary levels of C1q, MBL, C4d, Bb, properdin, C3a, C5a, and sC5b-9, in 134 patients with biopsy-proven pMN, by enzyme-linked immunosorbent assay. All the plasma values were corrected by eGFR and all the urinary values were corrected by urinary creatinine and urinary protein excretion. Anti-PLA2R antibodies were measured in all patients. RESULTS: The plasma complement activation products were elevated both in the patients with and without anti-PLA2R antibodies. C3a levels were remarkably increased in the circulation and urine, much higher than the elevated levels of C5a. C5b-9 was in normal range in plasma, but significantly higher in urine. The urinary C5a had a positive correlation with anti-PLA2R antibody levels and urinary protein. The plasma level of C4d was elevated, but C1q and MBL were comparable to healthy controls. Positive correlations were observed between plasma C4d/MBL and urinary protein, only in the patients with positive anti-PLA2R antibodies but not in those without. The plasma level of Bb was elevated and had positive correlation with urinary protein only in the patients without anti-PLA2R antibodies. CONCLUSION: Complement activation products were remarkable increased in pMN and may serve as sensitive biomarkers of disease activity. The complement may be activated through lectin pathway with the existence of anti-PLA2R antibodies, while through alternative pathway in the absence of antibody.

Magnetized Carbon Nanotube Based Lateral Flow Immunoassay for Visual Detection of Complement Factor B.

The authors describe a magnetized carbon nanotube (MCNT) based lateral flow immunoassay (LFI) for visual detection of complement factor B (CFB) in blood. MCNT was prepared by decorating magnetic Fe3O4 nanoparticles on multi-walled CNT surface and used as a colored tag for LFI. Monoclonal antibody (mAb, Ab1) of CFB was covalently immobilized on the MCNT surface via diimide-activated conjugation between the carboxyl groups on the MCNT surface and amino groups of antibodies. Polyclonal antibody of CFB (Ab2) and the secondary antibody were used to prepare the lateral flow test strips. The assay involved: (1) the capture of CFB in blood with the mAb-functionalized MCNT; (2) magnetic separation of the formed CFB-mAb-MCNT and excess of mAb-MCNT from the blood with an external magnet; (3) lateral flow test to capture the CFB-mAb-MCNT complex on the test zone and the excess of mAb-MCNT on the control zone; (4) Recording the intensities of the produced the characteristic brown bands with a portable strip reader and quantitating the concentration of CFB. The proof-of-concept was demonstrated by testing CFB in the buffer, and the detection limit was 5 ng mL-1 under the optimized analytical parameters. CFB in 1 µL of human blood was detected successfully in 30 min with this LFI and the results had a high correlation with commercial ELISA kit. Thence, the MCNT-based LFI offers a rapid and low-cost tool for detecting CFB in human blood directly.

Biomarker panel for early detection of endometrial cancer in the Prostate, Lung, Colorectal, and Ovarian cancer screening trial.

BACKGROUND: Endometrial cancer is the most common gynecological cancer in the United States. However, no early detection test exists for asymptomatic women at average risk for endometrial cancer. OBJECTIVE: We sought to identify early detection biomarkers for endometrial cancer using prediagnostic serum. STUDY DESIGN: We performed a nested case-control study of postmenopausal women in the Prostate, Lung, Colorectal, and Ovarian cancer screening trial (n = 78,216), including 112 incident endometrial cancer cases and 112 controls. Prediagnostic serum was immunodepleted of high-abundance proteins and digested with sequencing grade porcine trypsin via pressure cycling technology. Quantitative proteomics and phosphoproteomics was performed using high-resolution liquid chromatography-tandem mass spectrometry and highly multiplexed isobaric mass tag combined with basic reversed-phase liquid chromatography. A set of proteins able to predict cancer status was identified with an integrated score assessed by receiver-operator curve analysis. RESULTS: Mean time from blood draw to endometrial cancer diagnosis was 3.5 years (SD, 1.9 years). There were 47 differentially abundant proteins between cases and controls (P < .05). Protein alterations with high predictive potential were selected by regression analysis and compiled into an aggregate score to determine the ability to predict endometrial cancer. An integrated risk score of 6 proteins was directly related to disease incidence in cases with blood draw ≤2 years, >2 years to ≤5 years or >5 years prior to cancer diagnosis. The integrated score distinguished cases from controls with an area under the curve of 0.80 (95% confidence interval, 0.72-0.88). CONCLUSION: An integrated score of 6 proteins using prediagnostic serum from the Prostate, Lung, Colorectal, and Ovarian cancer screening trial distinguishes postmenopausal endometrial cancer cases from controls. Validation is needed to evaluate whether this test can improve prediction or detection of endometrial cancer among postmenopausal women.

Mass spectrometry-based analysis of cerebrospinal fluid from arthritis patients-immune-related candidate proteins affected by TNF blocking treatment.

BACKGROUND: Signs of inflammation in cerebrospinal fluid (CSF) of rheumatoid arthritis patients correlate positively with fatigue, a central nervous system (CNS)-related symptom that can be partially suppressed by TNF blockade. This suggests a possible role for CNS inflammation in arthritis that may be affected by TNF blockade. We therefore investigated the effects of TNF blockade on the arthritis CSF proteome and how candidate proteins related to clinical measures of disease activity and inflammation. METHODS: Mass spectrometry-based quantitative proteomic analysis was performed on CSF from seven polyarthritis patients before and during infliximab treatment. Treatment-associated proteins were identified using univariate (Wilcoxon signed rank test) and multivariate (partial least squares discriminant analysis (PLS-DA)) strategies. Relations between selected candidate proteins and clinical measures were investigated using the Spearman correlations. Additionally, selected proteins were cross-referenced to other studies investigating human CSF in a thorough literature search to ensure feasibility of our results. RESULTS: Univariate analysis of arthritis CSF proteome revealed a decrease of 35 proteins, predominantly involved in inflammatory processes, following TNF blockade. Seven candidate proteins, Contactin-1 (CNTN1), fibrinogen gamma chain (FGG), hemopexin (HPX), cell adhesion molecule-3 (CADM3), alpha-1B-glycoprotein (A1BG), complement factor B (CFB), and beta-2-microglobulin (B2M), were selected for further studies based on identification by both univariate and multivariate analyses and reported detection in human CSF and known associations to arthritis. Decreased levels of FGG and CFB in CSF after treatment showed strong correlations with both erythrocyte sedimentation rate and disability scores, while CNTN1 and CADM3 were associated with pain. CONCLUSION: Several immune-related proteins in the CSF of arthritis patients decreased during TNF blockade, including FGG and CFB that both correlated strongly with systemic inflammation. Our findings stress that also intrathecal inflammatory pathways are related to arthritis symptoms and may be affected by TNF blockade.

Viral mimic polyinosine-polycytidylic acid potentiates liver injury in trichloroethylene-sensitized mice - Viral-chemical interaction as a novel mechanism.

Occupational trichloroethylene (TCE) exposure can induce hypersensitivity dermatitis and severe liver injury. Recently, several clinical investigations indicate that viral infection, such as human herpesvirus-6, is associated with hepatic dysfunction in patients with TCE-related generalized skin disorders. However, whether viral infection potentiates TCE-induced liver injury remains unknown. This study aimed to explore the contribution of viral infection to the development of TCE-sensitization-induced liver injury in BALB/c mice. Female BALB/c mice were randomly assigned into four groups: solvent control group (n = 20), TCE group (n = 80), poly(I:C) group (n = 20) and combination of TCE and poly(I:C) (poly(I:C)+TCE) group (n = 80). Poly(I:C) (50 µg) was i.p. administrated. TCE and poly(I:C)+TCE groups were further divided into sensitization and non-sensitization subgroup. Complement 3 and C3a protein levels, and complement factors were measured. Combination treatment significantly enhanced TCE-induced liver injury, decreased complement 3, but increased C3a in serum and liver tissues in sensitization group. These changes were not correlated with the hepatic complement 3 transcription. Moreover, combination treatment specifically promoted complement factor B, but not factor D and factor H expressions. These data provide first evidence that poly(I:C) potentiates liver injury in BALB/c mouse model of TCE-sensitization. Upregulated C3a and factor B contributes to the poly(I:C) action in TCE-induced liver injury. This new mode of action may explain increased risk of chemical-sensitization induced tissue damage by viral infection.

Complement activation predicts adverse pregnancy outcome in patients with systemic lupus erythematosus and/or antiphospholipid antibodies.

OBJECTIVE: Studies in mouse models implicate complement activation as a causative factor in adverse pregnancy outcomes (APOs). We investigated whether activation of complement early in pregnancy predicts APOs in women with systemic lupus erythematosus (SLE) and/or antiphospholipid (aPL) antibodies. METHODS: The PROMISSE Study enrolled pregnant women with SLE and/or aPL antibodies (n=487) and pregnant healthy controls (n=204) at <12 weeks gestation and evaluated them monthly. APOs were: fetal/neonatal death, preterm delivery <36 weeks because of placental insufficiency or preeclampsia and/or growth restriction <5th percentile. Complement activation products were measured on serial blood samples obtained at each monthly visit. RESULTS: APO occurred in 20.5% of SLE and/or aPL pregnancies. As early as 12-15 weeks, levels of Bb and sC5b-9 were significantly higher in patients with APOs and remained elevated through 31 weeks compared with those with normal outcomes. Moreover, Bb and sC5b-9 were significantly higher in patients with SLE and/or aPL without APOs compared with healthy controls. In logistic regression analyses, Bb and sC5b-9 at 12-15 weeks remained significantly associated with APO (ORadj=1.41 per SD increase; 95% CI 1.06 to 1.89; P=0.019 and ORadj=1.37 per SD increase; 95% CI 1.05 to 1.80; P=0.022, respectively) after controlling for demographic and clinical risk factors for APOs in PROMISSE. When analyses were restricted to patients with aPL (n=161), associations between Bb at 12-15 weeks and APOs became stronger (ORadj=2.01 per SD increase; 95% CI 1.16 to 3.49; P=0.013). CONCLUSION: In pregnant patients with SLE and/or aPL, increased Bb and sC5b-9 detectable early in pregnancy are strongly predictive of APOs and support activation of complement, particularly the alternative pathway, as a contributor to APOs.

A novel CFHR1-CFHR5 hybrid leads to a familial dominant C3 glomerulopathy.

The intrinsic similarity shared between the members of the complement factor H family, which comprises complement factor H and five complement factor H-related (CFHR) genes, leads to various recombination events. In turn these events lead to deletions of some genes or abnormal proteins, which are found in patients with atypical hemolytic uremic syndrome or C3 glomerulopathies. Here we describe a novel genetic rearrangement generated from a heterozygous deletion spanning 146 Kbp involving multiple CFHR genes leading to a CFHR1-R5 hybrid protein. This deletion was found in four family members presenting with a familial dominant glomerulopathy histologically classified as an overlap of dense deposit disease and C3 glomerulonephritis. Affected patients exhibited permanently low C3 and factor B levels and high amounts of activation fragments sC5b9 and Bb, indicating a systemic alternative pathway dysregulation. The abnormal protein, characterized by Western blot and immunoprecipitation, was shown to circulate in association with CFHR1 and CFHR2, attributable to its two N-terminal dimerization motifs. The presence of this protein is associated with a perturbation of Factor H activity on the C3 convertase decay. Thus, our study highlights the role of CFHRs in the physiopathology of C3 glomerulopathies and stresses the importance of screening CFHRs in all familial C3 glomerulopathies. Such hybrids described till now were always associated with familial forms.

Human neutrophil peptides and complement factor Bb in pathogenesis of acquired thrombotic thrombocytopenic purpura.

Acquired thrombotic thrombocytopenic purpura is primarily caused by the deficiency of plasma ADAMTS13 activity resulting from autoantibodies against ADAMTS13. However, ADAMTS13 deficiency alone is often not sufficient to cause acute thrombotic thrombocytopenic purpura. Infections or systemic inflammation may precede acute bursts of the disease, but the underlying mechanisms are not fully understood. Herein, 52 patients with acquired autoimmune thrombotic thrombocytopenic purpura and 30 blood donor controls were recruited for the study. The plasma levels of human neutrophil peptides 1-3 and complement activation fragments (i.e. Bb, iC3b, C4d, and sC5b-9) were determined by enzyme-linked immunosorbent assays. Univariate analyses were performed to determine the correlation between each biomarker and clinical outcomes. We found that the plasma levels of human neutrophil peptides 1-3 and Bb in patients with acute thrombotic thrombocytopenic purpura were significantly higher than those in the control (P<0.0001). The plasma levels of HNP1-3 correlated with the levels of plasma complement fragment Bb (rho=0.48, P=0.0004) and serum lactate dehydrogenase (rho=0.28, P=0.04); in addition, the plasma levels of Bb correlated with iC3b (rho=0.55, P<0.0001), sC5b-9 (rho=0.63, P<0.0001), serum creatinine (rho=0.42, p=0.0011), and lactate dehydrogenase (rho=0.40, P=0.0034), respectively. Moreover, the plasma levels of iC3b and sC5b-9 were correlated (rho=0.72, P<0.0001), despite no statistically significant difference of the two markers between thrombotic thrombocytopenic purpura patients and the control. We conclude that innate immunity, i.e. neutrophil and complement activation via the alternative pathway, may play a role in the pathogenesis of acute autoimmune thrombotic thrombocytopenic purpura, and a therapy targeted at these pathways may be considered in a subset of these patients.

The Relationship of Longitudinal Levels of Complement Bb During Pregnancy with Preeclampsia.

PROBLEM: To determine the understudied relationship between complement Bb during pregnancy in subjects with preeclampsia compared with normotensive controls. METHOD OF STUDY: Nested case-control study. RESULTS: Average Bb levels significantly decreased over time in pregnancy [weekly slope (S.E.): -0.0094 (0.0005), P < 0.01]. Cross-sectionally, at less than 10 weeks, Bb levels decreased with increasing gestational age in women who remained normotensive [weekly slope (S.E.): -0.007 (0.02) and for women who developed preeclampsia (weekly slope (S.E.): -0.059 (0.03) P = 0.12]. Among women who developed preeclampsia, Bb levels were greatest when samples were drawn in the gestational window of 15-20 weeks [(weekly slope (S.E.): 0.06 (0.02)], while levels among normotensive women were inversely related with gestational age [weekly slope (S.E.): -0.02 (0.01)]. The differences in slopes between cases and controls between 10 and 21 weeks' gestation were statistically significant (P = 0.003). CONCLUSIONS: We suggest dysregulation of Bb activation between 10 and 20 weeks' gestation in women who develop preeclampsia.

A phase II and pharmacodynamic study of sunitinib in relapsed/refractory oesophageal and gastro-oesophageal cancers.

BACKGROUND: Blockade of the vascular endothelial growth factor (VEGF) pathway shows evidence of activity in gastro-oesophageal (GE) and oesophageal cancer. We investigated the efficacy of sunitinib, a multikinase VEGF inhibitor, in patients with relapsed/refractory GE/oesophageal cancer. METHODS: This was a single-stage Fleming phase II study. The primary end point was progression-free survival (PFS) at 24 weeks. If five or more patients out of a total of 25 were free of progressive disease at 24 weeks, sunitinib would be recommended for further study. Patients received sunitinib 37.5 mg orally daily and imaged every 6 weeks. Exploratory correlative analysis included serum growth factors, tumour gene expression and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). RESULTS: Twenty-five evaluable patients participated in the study. Progression-free survival at 24 weeks was 8% (n=2 patients; confidence interval (CI): 95% 1.4-22.5%), and the duration of best response for the patients was 23 and 72 weeks. Ten patients (42%) had stable disease (SD) for >10 weeks. Overall response rate is 13%. Median PFS is 7 weeks (95% CI: 5.6-11.4 weeks) and the median overall survival is 17 weeks (95% CI: 8.9-25.3 weeks). Most common grade 3/4 toxicities included fatigue (24%), anaemia (20%) thrombocytopenia (16%), and leucopenia (16%). No patients discontinued therapy due to toxicity. Serum VEGF-A and -C levels, tumour complement factor B (CFB) gene expression, and DCE-MRI correlated with clinical benefit, defined as SD or better as best response. CONCLUSION: Sunitinib is well tolerated but only a select subgroup of patients benefited. Serum VEGF-A and -C may be early predictors of benefit. On this study, patients with clinical benefit from sunitinib had higher tumour CFB expression, and thus has identified CFB as a potential predictor for efficacy of anti-angiogenic therapy. These findings need validation from future prospective trials.

A method to determine the kinetics of multiple proteins in human infants with respiratory distress syndrome.

We report a method to measure in vivo turnover of four proteins from sequential tracheal aspirates obtained from human newborn infants with respiratory distress syndrome using targeted proteomics. We detected enrichment for all targeted proteins approximately 3 h from the start of infusion of [5,5,5-(2)H(3)] leucine, secretion times that varied from 1.2 to 2.5 h, and half lives that ranged between 10 and 21 h. Complement factor B, a component of the alternative pathway of complement activation, had an approximately twofold-longer half-life than the other three proteins. In addition, the kinetics of mature and carboxy-terminal tryptic peptides from the same protein (surfactant protein B) were not statistically different (p = 0.49).

Circulating glucagon is associated with inflammatory mediators in metabolically compromised subjects.

BACKGROUND: Acute phase mediators promote metabolic changes by modifying circulating hormones. However, there is virtually no data about the link between glucagon and inflammatory parameters in obesity-related chronic low-grade inflammation. STUDY DESIGN: We performed both cross-sectional and longitudinal (diet-induced weight loss) studies. METHODS: Circulating glucagon concentrations (ELISA), parameters of glucose and lipid metabolism, interleukin 6 (IL6), and complement factor B (CFB) were analyzed in 316 subjects (250 men and 66 women). The effects of weight loss were investigated in an independent cohort of 20 subjects. RESULTS: Circulating glucagon significantly correlated with glucose (r=0.407, P<0.0001), HbAlc (r=0.426, P<0.0001), fasting triglycerides (r=0.356, P=0.001), and parameters of innate immune response system such as IL6 (r=0.342, P=0.050) and CFB (r=0.404, P=0.002) in obese subjects with altered glucose tolerance, but not in individuals with normal glucose tolerance (NGT). In obese and NGT subjects, glucagon was associated with fasting triglycerides (r=0.475, P=0.003) and CFB (r=0.624, P=0.001). In obese subjects, glucagon (P=0.019) and CFB (P=0.002) independently contributed to 26% of fasting triglyceride variance (P<0.0001) after controlling for the effects of age and fasting serum glucose concentration in multiple lineal regression models. Moreover, concomitant with fat mass, fasting triglycerides, and CFB, weight loss led to significantly decreased circulating glucagon (-23.1%, P=0.004). CONCLUSIONS: According to the current results, acute phase reactants such as IL6 and CFB are associated with fasting glucagon in metabolically compromised subjects. This suggests that glucagon may be behind the association between inflammatory and metabolic parameters in obesity-associated chronic low-grade inflammation.

Diagnosis and classification of hemolytic uremic syndrome: the Hungarian experience.

BACKGROUND: Hemolytic uremic syndrome (HUS) is a rare disease with various etiologies, making the identification of the specific forms and appropriate treatment difficult. Therefore, clinical and laboratory data from these patients need to be analyzed in national and international registries. Herein we have described 47 Hungarian HUS patients with detailed laboratory and clinical data obtained between 2008 and 2010. METHODS: Blood samples and clinical data of 47 patients with HUS diagnosed according to characteristic clinical signs were submitted for diagnostic evaluation, including complement protein and genetic analysis, measurement of ADAMTS13 activity and antibody analysis against O157LPS and factor H. RESULTS: There were 8 patients with typical diarrhea-positive HUS; 13 with atypical HUS (aHUS) and 26 with secondary HUS/thrombotic thrombocytopenic purpura group characterized by signs of complement consumption and decreased ADAMTS13 activity. Thus, decreased total alternative pathway activity is a promising diagnostic parameter with good sensitivity for aHUS. CONCLUSIONS: These observations highlight the requirement for multiple diagnostic tests together with clinical data to identify the specific cause of HUS. Because the long-term prognosis of aHUS, eg, graft survival after renal transplantation, may vary according to the molecular etiology, it is important for all affected patients to undergo a detailed molecular diagnosis of the disease. There is a clear clinical need for the development and application of novel assay in this field to allow more rapid efficient diagnosis of patients who undergo a first episode of HUS.

Specificity of EIA immunoassay for complement factor Bb testing.

BACKGROUND: During the alternative complement pathway activation, factor B is cleaved in two fragments, Ba and Bb. Concentration of those fragments is about 2 logs lower than of factor B present in the blood, which makes fragment detection challenging because of potential cross-reactivity. Lack of information on Bb assay cross-reactivity stimulated the authors to investigate this issue. METHODS: We ran 109 healthy donor EDTA plasmas and 80 sera samples with both factor B immunodiffusion (The Binding Site) and Quidel Bb EIA assays. RESULTS: During the study it was shown that physiological concentrations of gently purified factor B demonstrated approximately 0.15% cross-reactivity in the Quidel Bb EIA assay. We also observed that Bb concentration in serum is higher than in plasma due to complement activation during clot formation which let us use sera as samples representing complement activated state. CONCLUSIONS: Our study demonstrated that despite the potential 0.15% cross-reactivity between endogenous factor B and cleaved Bb molecule, measuring plasma concentrations of factor Bb is adequate to evaluate the activation of the alternative complement pathway.