IgM response is a prognostic biomarker of primary biliary cholangitis treated with ursodeoxycholic acid and bezafibrate.

BACKGROUND AND AIM: Primary biliary cholangitis (PBC) patients who are refractory to ursodeoxycholic acid (UDCA) are at risk for progression to cirrhosis and liver failure. Bezafibrate could be an alternative second-line therapeutic option in these patients. This study aimed to evaluate the long-term outcome(s) of combined UDCA and bezafibrate therapy in UDCA-refractory PBC patients and identify prognostic factors. METHODS: Among 445 patients treated with UDCA, 150 patients inadequately responded to UDCA monotherapy and received long-term UDCA plus bezafibrate (median, 15 years). Data from these patients were used for this retrospective analysis. RESULTS: Combination therapy resulted in significant improvements in serum biochemistry and liver transplantation risk estimated using the UK-PBC-risk and the GLOBE scores. The cumulative normalization rates of alkaline phosphatase, gamma-glutamyltransferase, and immunoglobulin M (IgM) were significantly higher in patients without cirrhosis-related symptoms or liver-related events than in those with them. Overall, IgM constantly emerged as a significant factor associated with cirrhosis-related symptoms and liver-related events at all time points. Cumulative survival rates were significantly lower in patients with IgM ≥ 240 mg/dL than in patients with IgM < 240 mg/dL. Thus, normalization of IgM levels was a good surrogate predictor of long-term prognosis. None of the patients discontinued combination therapy due to any adverse events during the follow-up period. CONCLUSIONS: Our findings point to the beneficial effects of long-term UDCA plus bezafibrate combination therapy for UDCA-refractory PBC patients, and IgM response can be a useful predictive biomarker of long-term clinical outcomes.

Efficacy and safety of pemetrexed plus cisplatin as first-line chemotherapy in advanced malignant peritoneal mesothelioma.

BACKGROUND: Malignant peritoneal mesothelioma (MPeM) is a rare cancer for which no standard systemic chemotherapy has been established. While cisplatin plus pemetrexed, the standard treatment for malignant pleural mesothelioma (MPlM), is usually used for MPeM, its efficacy remains unclear. METHODS: We retrospectively reviewed the medical charts of MPeM patients who had received cisplatin plus pemetrexed as first-line chemotherapy between January 2001 and July 2016 at the National Cancer Center Hospital. Patients received cisplatin 75 mg/m2 and pemetrexed 500 mg/m2 on day1, repeated every 3 weeks until progressive disease, unacceptable toxicities or patient's refusal to continue. RESULTS: A total of 29 MPeM patients received cisplatin plus pemetrexed. Median progression-free survival and overall survival were 7.1 months (95% CI: 4.8-9.3) and 15.4 months (95% CI: 9.5-21.2), respectively. Among 16 patients with measurable lesions, the response rate was 38%. Incidences of grade 3/4 leukopenia, neutropenia, anemia and thrombocytopenia were 21%, 17%, 14% and 3%, respectively. Non-hematological toxicities were mild, and there were no treatment-related deaths. CONCLUSIONS: Cisplatin plus pemetrexed, showing consistent efficacy with MPlM, can be recommended as first-line treatment for unresectable MPeM patients.

Questionnaire-based analysis of atovaquone-proguanil compared with mefloquine in the chemoprophylaxis of malaria in non-immune Japanese travelers.

Malaria is one of the most common and serious infectious diseases in the tropics and subtropics. For high-risk travelers to endemic regions, malaria chemoprophylaxis is recommended. Internationally, atovaquone-proguanil (A/P), mefloquine (MEF), or doxycycline (DOX) are the prescribed malaria chemoprophylactic drugs. However, A/P and DOX are not approved in Japan. Therefore, the data on A/P for malaria chemoprophylaxis in Japanese travelers are not clear. We analyzed questionnaire survey data obtained in Hibiya Clinic to assess the safety and tolerability of A/P and compare them with those of MEF for non-immune Japanese travelers. A/P was given to 278 travelers and MEF to 38 travelers. The mean duration of each prophylaxis is for 20.0 ± 9.6 and 59.0 ± 15.9 days, respectively. Nine travelers discontinued prophylaxis: 5 in the A/P prescribed group (A/P group) and 4 in the MEF prescribed group (MEF group), and the rate of discontinuation was significantly less in the A/P group. The frequency of adverse events was significantly less in the A/P group than in the MEF group [52 cases (18.8 %) vs. 14 cases (36.8 %), respectively]. In particular, the frequency of psychoneurotic adverse events was significantly less in the A/P group. These results suggest that A/P is better tolerated and has fewer adverse events than MEF in non-immune Japanese travelers.

High blood levels of soluble OX40 (CD134), an immune costimulatory molecule, indicate reduced survival in patients with advanced colorectal cancer.

The interaction between tumor necrosis factor receptor superfamily, member 4 (OX40) on T cells and the OX40 ligand (OX40L) on antigen­presenting cells (APCs) is a pivotal step for T­cell activation and the promotion of antitumor immunity. However, it is hypothesized that soluble OX40 (sOX40) in blood suppresses T­cell activation by blocking the OX40/OX40L interaction. In the present study, the association between blood sOX40 levels and the clinical characteristics of advanced colorectal cancer (CRC) patients was investigated. Blood was collected from 22 patients with advanced CRC. Blood sOX40 levels were determined by enzyme­linked immunosorbent assay (ELISA). Messenger RNA (mRNA) expression encoding OX40 or cytokines was analyzed by quantitative RT­PCR. Blood sOX40 levels were positively correlated with the blood levels of carbohydrate antigen (CA) 19­9, carcinoembryonic antigen (CEA), C­reactive protein (CRP) and soluble programmed cell death ligand­1 (PD­L1) in patients but negatively correlated with the blood levels of albumin. Blood sOX40 levels were not correlated with the mRNA expression of interferon (IFN)­gamma, interleukin (IL)­6, IL­10 and IL­4 in the peripheral blood mononuclear cells (PBMCs) of the patients and were not correlated with the frequency of programmed cell death­1 (PD­1) expressing CD4+, CD8+ and CD56+ cells. Notably, according to both univariate and multivariate analyses, high blood sOX40 levels were significantly correlated with a reduced survival time in patients. Although activated Jurkat cells (a human T cell line) exhibited an upregulation of sOX40 production and OX40 mRNA expression, the OX40 mRNA expression of the PBMCs of patients was not correlated with blood sOX40 levels. High blood levels of sOX40 were correlated with a reduced survival time in patients with advanced CRC, possibly associated with the suppression of antitumor immunity by sOX40.

Oxidative stress markers, secondary bile acids and sulfated bile acids classify the clinical liver injury type: Promising diagnostic biomarkers for cholestasis.

Clinicians sometimes encounter difficulty in choosing a therapeutic strategy due to the uncertainty regarding the type of liver injury. In particular, cholestasis is difficult to diagnose by conventional markers at an early stage of disease. The aim of this study was to identify promising biomarkers for distinguishing the symptom-based types of liver injury (e.g. hepatocellular injury, cholestasis), which was derived from a rigorously statistical perspective. The associations between diagnostic biomarkers (e.g. bile acid components, oxidative stress markers and liver fibrosis markers) and the liver injury types were assessed by a multiple logistic regression analysis using 304 blood samples from patients with liver disease. As a result, reductions in the lithocholic acid (LCA) and deoxycholic acid (DCA) levels, and elevation of the serum sulfated bile acid (SSBA), liver fibrosis marker IV collagen (type IV collagen), hyaluronic acid (HA) and reactive oxygen species (ROS) levels were all significantly associated with cholestasis. On the other hand, elevations in the LCA and type IV collagen levels, and a reduction in the ursodeoxy cholic acid (UDCA) level, were significantly associated with hepatocellular injury. The receiver operating characteristic (ROC) analyses showed that the largest area under the ROC curve (AUC) was found for ROS, followed by DCA, HA, LCA, SSBA and type IV collagen in the cholestatic-type cases. These results indicated that ROS, the secondary bile acid levels such as DCA and LCA, and SSBA are promising biomarkers for cholestasis and for classifying the type of liver injuries. This comprehensive approach will allow for an accurate diagnosis, which will facilitate the selection of an appropriate therapy at the onset of disease.

Analysis of the serum bile Acid composition for differential diagnosis in patients with liver disease.

Objectives. We determined the serum bile acid (BA) composition in patients with liver diseases and healthy volunteers to investigate the relationship between the etiologies of liver disease and BA metabolism. Material and Methods. Sera from 150 patients with liver diseases and 46 healthy volunteers were obtained. The serum concentrations of the 16 different BAs were determined according to the LC-MS/MS method and were compared between the different liver diseases. Results. A total of 150 subjects, including patients with hepatitis C virus (HCV) (n = 44), hepatitis B virus (HBV) (n = 23), alcoholic liver disease (ALD) (n = 21), biliary tract disease (n = 20), nonalcoholic fatty liver disease (NAFLD) (n = 13), and other liver diseases (n = 29), were recruited. The levels of UDCA and GUDCA were significantly higher in the ALD group, and the levels of DCA and UDCA were significantly lower in the biliary tract diseases group than in viral hepatitis group. In the UDCA therapy (-) subgroup, a significantly lower level of TLCA was observed in the ALD group, with lower levels of CDCA, DCA, and GLCA noted in biliary tract diseases group compared to viral hepatitis group. Conclusions. Analysis of the BA composition may be useful for differential diagnosis in liver disease.

Chemical xenobiotics and mitochondrial autoantigens in primary biliary cirrhosis: identification of antibodies against a common environmental, cosmetic, and food additive, 2-octynoic acid.

Emerging evidence has suggested environmental factors as causative agents in the pathogenesis of primary biliary cirrhosis (PBC). We have hypothesized that in PBC the lipoyl domain of the immunodominant E2 component of pyruvate dehydrogenase (PDC-E2) is replaced by a chemical xenobiotic mimic, which is sufficient to break self-tolerance. To address this hypothesis, based upon our quantitative structure-activity relationship data, a total of 107 potential xenobiotic mimics were coupled to the lysine residue of the immunodominant 15 amino acid peptide of the PDC-E2 inner lipoyl domain and spotted on microarray slides. Sera from patients with PBC (n = 47), primary sclerosing cholangitis (n = 15), and healthy volunteers (n = 20) were assayed for Ig reactivity. PBC sera were subsequently absorbed with native lipoylated PDC-E2 peptide or a xenobiotically modified PDC-E2 peptide, and the remaining reactivity analyzed. Of the 107 xenobiotics, 33 had a significantly higher IgG reactivity against PBC sera compared with control sera. In addition, 9 of those 33 compounds were more reactive than the native lipoylated peptide. Following absorption, 8 of the 9 compounds demonstrated cross-reactivity with lipoic acid. One compound, 2-octynoic acid, was unique in both its quantitative structure-activity relationship analysis and reactivity. PBC patient sera demonstrated high Ig reactivity against 2-octynoic acid-PDC-E2 peptide. Not only does 2-octynoic acid have the potential to modify PDC-E2 in vivo but importantly it was/is widely used in the environment including perfumes, lipstick, and many common food flavorings.

Antimitochondrial antibodies and reactivity to N. aromaticivorans proteins in Icelandic patients with primary biliary cirrhosis and their relatives.

OBJECTIVES: Primary biliary cirrhosis (PBC) is a chronic, progressive cholestatic disease of unknown etiology characterized by serum antimitochondrial antibodies (AMA) directed against a functionally related family of mitochondrial enzymes. We recently suggested that N. aromaticivorans might be the trigger of autoimmunity in PBC. No data are available on the specificity and crossreactivity of AMA in a genetically homogenous group of patients, such as the Icelandic population. METHODS: To address these issues and to confirm previous findings in a unique population, we obtained sera from 14 PBC patients and 85 first-degree relatives, all of Icelandic descent. We analyzed such sera for AMA specificity using recombinant mitochondrial antigens and for reactivity against N. aromaticivorans proteins. RESULTS: Thirteen of the 14 Icelandic patients with PBC (93%) were found AMA positive. We found that 5/13 AMA positive sera (38%) reacted against PDC-E2 only; 5/13 (or 38%) reacted against BCOADC-E2; and 2/13 (15%) reacted against all three antigens. There was no reactivity against OGDC-E2. Reactivities of patients' sera against N. aromaticivorans were consistent with the AMA status. One serum among the 85 first-degree relatives (1.2%) was found to be AMA-positive, as well as reactive against N. aromaticivorans. CONCLUSIONS: Interestingly, despite the homogenous genetic background, the group of Icelandic patients with PBC was heterogeneous in their AMA reactive patterns and also reacted with N. aromaticivorans proteins.

Xenobiotic-induced loss of tolerance in rabbits to the mitochondrial autoantigen of primary biliary cirrhosis is reversible.

Previous work has demonstrated that immunization of rabbits with the xenobiotic 6-bromohexanoate coupled to BSA breaks tolerance and induces autoantibodies to mitochondria in rabbits. Such immunized rabbits develop high-titer Abs to pyruvate dehydrogenase complex (PDC)-E2, the major autoantigen of primary biliary cirrhosis. In efforts to map the fine specificity of these autoantibodies, rabbits were immunized biweekly with 6-bromohexanoate-BSA and screened for reactivity using a unique xenobiotic-peptide-agarose microarray platform with an emphasis on identifying potential structures that mimic the molecular image formed by the association of lipoic acid with the immunodominant PDC-E2 peptide. Essentially, a total of 23 xenobiotics and lipoic acid were coupled to the 12-mer peptide backbones, PDC, a mutant PDC, and albumin. As expected, we succeeded in breaking tolerance using this small organic molecule coupled to BSA. However, unlike multiple experimental methods of breaking tolerance, we report in this study that, following continued immunization, the rabbits recover tolerance. With repeated immunization, the response to the rPDC-E2 protein increased with a gradual reduction in autoantibodies against the lipoic acid-peptide, i.e., the primary tolerance-breaking autoantigen. Detailed analysis of this system may provide strategies on how to restore tolerance in patients with autoimmune disease.

Autoreactivity to lipoate and a conjugated form of lipoate in primary biliary cirrhosis.

BACKGROUND & AIMS: Although considerable effort has been directed toward the mapping of peptide epitopes by autoantibodies, the role of nonprotein molecules has been less well studied. The immunodominant autoantigen in primary biliary cirrhosis (PBC), E2 components of pyruvate dehydrogenase complexes (PDC-E2), has a lipoate molecule bonded to the domain to which autoantibodies are directed. METHODS: We examined sera from patients with PBC (n = 105), primary sclerosing cholangitis (n = 70), and rheumatoid arthritis (n = 28) as well as healthy volunteers (n = 43) for reactivity against lipoic acid. The lipoic acid hapten specificity of the reactive antibodies in PBC sera was determined following incubation of aliquots of the sera with human serum albumin (HSA), lipoylated HSA (HSA-LA), PDC-E2, lipoylated PDC-E2, polyethylene glycol (PEG), lipoylated PEG, free lipoic acid, and synthetic molecular mimics of lipoic acid. RESULTS: Anti-lipoic acid specific antibodies were detected in 81% (79 of 97) of antimitochondrial antibody (AMA)-positive patients with PBC but not in controls. Two previously unreported specificities in AMA-positive sera that recognize free lipoic acid and a carrier-conjugated form of lipoic acid were also identified. CONCLUSIONS: We hypothesize that conjugated form(s) of native or xenobiotic lipoic acid mimics contribute to the initiation and perpetuation of autoimmunity by at first breaking self-tolerance and participating in subsequent determinant spreading. The variability in the immunoreactive carrier/lipoate conjugates provides an experimental framework on which potential mechanisms for the breakdown of self-tolerance following exposure to xenobiotics can be investigated. The data have implications for patients taking lipoic acid as a dietary supplement.