Haplosufficiency of MHCII in autoreactive germinal center B cells.

Utilizing an autoimmune bone marrow chimera model we determined that B cells depend critically on MHCII expression for participation in the germinal center, but cells displaying a 50% reduction in surface MHCII compete efficiently with their wild-type counterparts. This provides insights into the requirements for germinal center participation.

B cell MHC haplotype affects follicular inclusion, germinal center participation and plasma cell differentiation in a mouse model of lupus.

Introduction: MHC class II molecules are essential for appropriate immune responses against pathogens but are also implicated in pathological responses in autoimmune diseases and transplant rejection. Previous studies have shed light on the systemic contributions of MHC haplotypes to the development and severity of autoimmune diseases. In this study, we addressed the B cell intrinsic MHC haplotype impact on follicular inclusion, germinal center (GC) participation and plasma cell (PC) differentiation in the context of systemic lupus erythematosus (SLE). Methods: We leveraged the 564Igi mouse model which harbors a B cell receptor knock-in from an autoreactive B cell clone recognizing ribonuclear components, including double-stranded DNA (dsDNA). This model recapitulates the central hallmarks of the early stages of SLE. We compared 564Igi heterozygous offspring on either H2b/b, H2b/d, or H2d/d background. Results: This revealed significantly higher germinal center (GC) B cell levels in the spleens of H2b/b and H2b/d as compared to H2d/d (p<0.0001) mice. In agreement with this, anti-dsDNA-antibody levels were higher in H2b/b and H2b/d than in H2d/d (p<0.0001), with H2b/b also being higher compared to H2b/d (p<0.01). Specifically, these differences held true both for autoantibodies derived from the knock-in clone and from wild-type (WT) derived clones. In mixed chimeras where 564Igi H2b/b, H2b/d and H2d/d cells competed head-to-head in the same environment, we observed a significantly higher inclusion of H2b/b cells in GC and PC compartments relative to their representation in the B cell repertoire, compared to H2b/d and H2d/d cells. Furthermore, in mixed chimeras in which WT H2b/b and WT H2d/d cells competed for inclusion in GCs associated with an epitope spreading process, H2b/b cells participated to a greater extent and contributed more robustly to the PC compartment. Finally, immature WT H2b/b cells had a higher baseline of BCRs with an autoreactive idiotype and were subject to more stringent negative selection at the transitional stage. Discussion: Taken together, our findings demonstrate that B cell intrinsic MHC haplotype governs their capacity for participation in the autoreactive response at multiple levels: follicular inclusion, GC participation, and PC output. These findings pinpoint B cells as central contributors to precipitation of autoimmunity.

Antigen presentation by B cells enables epitope spreading across an MHC barrier.

Circumstantial evidence suggests that B cells may instruct T cells to break tolerance. Here, to test this hypothesis, we used a murine model in which a single B cell clone precipitates an autoreactive response resembling systemic lupus erythematosus (SLE). The initiating clone did not need to enter germinal centers to precipitate epitope spreading. Rather, it localized to extrafollicular splenic bridging channels early in the response. Autoantibody produced by the initiating clone was not sufficient to drive the autoreactive response. Subsequent epitope spreading depended on antigen presentation and was compartmentalized by major histocompatibility complex (MHC). B cells carrying two MHC haplotypes could bridge the MHC barrier between B cells that did not share MHC. Thus, B cells directly relay autoreactivity between two separate compartments of MHC-restricted T cells, leading to inclusion of distinct B cell populations in germinal centers. Our findings demonstrate that B cells initiate and propagate the autoimmune response.

Increased maternofoetal transfer of antibodies in a murine model of systemic lupus erythematosus, but no immune activation and neuroimmune sequelae in offspring.

Maternally transferred autoantibodies can negatively impact the development and health of offspring, increasing the risk of neurodevelopmental disorders. We used embryo transfers to examine maternofoetal immune imprinting in the autoimmune BXSB/MpJ mouse model. Anti-double-stranded DNA antibodies and total immunoglobulins were measured, using allotypes of the IgG subclass to distinguish maternally transferred antibodies from those produced endogenously. Frequencies of germinal center and plasma cells were analysed by flow cytometry. Microglial morphology in offspring CNS was assessed using immunohistochemistry. In contrast to prior findings, our results indicate that BXSB/MpJ mothers display a mild autoimmune phenotype, which does not significantly impact the offspring.

Low levels of the innate immune system proteins MASP-2 and MAp44 in patients with common variable immunodeficiency.

Patients with common variable immunodeficiency (CVID) display low antibody levels and associated symptoms, including an increased risk of infections. The causes of CVID are uncertain and likely heterogeneous. The complement system protects against pathogens and plays essential roles in homeostasis and development. The influence of the complement system in CVID is not established. We investigated CVID patients and healthy individuals for plasma levels of the complement proteins: MASP-1, MASP-2, MASP-3, MAp19 and MAp44. We also tested other patients with symptoms similar to the CVID patients. CVID patients had lower average MASP-2 and MAp44 levels than healthy individuals (P < 0.01); the MASP-2 level was 0.73-fold lower, and the MAp44 level was 0.87-fold lower. This was not observed in the other patient cohorts studied. Our findings in this exploratory study provide new insights into CVID and introduce a complement perspective for future investigations into the underlying mechanisms of the disease.

The extrafollicular response is sufficient to drive initiation of autoimmunity and early disease hallmarks of lupus.

Introduction: Many autoimmune diseases are characterized by germinal center (GC)-derived, affinity-matured, class-switched autoantibodies, and strategies to block GC formation and progression are currently being explored clinically. However, extrafollicular responses can also play a role. The aim of this study was to investigate the contribution of the extrafollicular pathway to autoimmune disease development. Methods: We blocked the GC pathway by knocking out the transcription factor Bcl-6 in GC B cells, leaving the extrafollicular pathway intact. We tested the impact of this intervention in two murine models of systemic lupus erythematosus (SLE): a pharmacological model based on chronic epicutaneous application of the Toll-like receptor (TLR)-7 agonist Resiquimod (R848), and 564Igi autoreactive B cell receptor knock-in mice. The B cell intrinsic effects were further investigated in vitro and in autoreactive mixed bone marrow chimeras. Results: GC block failed to curb autoimmune progression in the R848 model based on anti-dsDNA and plasma cell output, superoligomeric DNA complexes, and immune complex deposition in glomeruli. The 564Igi model confirmed this based on anti-dsDNA and plasma cell output. In vitro, loss of Bcl-6 prevented GC B cell expansion and accelerated plasma cell differentiation. In a competitive scenario in vivo, B cells harboring the genetic GC block contributed disproportionately to the plasma cell output. Discussion: We identified the extrafollicular pathway as a key contributor to autoimmune progression. We propose that therapeutic targeting of low quality and poorly controlled extrafollicular responses could be a desirable strategy to curb autoreactivity, as it would leave intact the more stringently controlled and high-quality GC responses providing durable protection against infection.

Long-Term Effects of a Web-Based Low-FODMAP Diet Versus Probiotic Treatment for Irritable Bowel Syndrome, Including Shotgun Analyses of Microbiota: Randomized, Double-Crossover Clinical Trial.

BACKGROUND: The long-term management of irritable bowel syndrome (IBS) poses many challenges. In short-term studies, eHealth interventions have been demonstrated to be safe and practical for at-home monitoring of the effects of probiotic treatments and a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs). IBS has been linked to alterations in the microbiota. OBJECTIVE: The aim of this study was to determine whether a web-based low-FODMAP diet (LFD) intervention and probiotic treatment were equally good at reducing IBS symptoms, and whether the response to treatments could be explained by patients' microbiota. METHODS: Adult IBS patients were enrolled in an open-label, randomized crossover trial (for nonresponders) with 1 year of follow-up using the web application IBS Constant Care (IBS CC). Patients were recruited from the outpatient clinic at the Department of Gastroenterology, North Zealand University Hospital, Denmark. Patients received either VSL#3 for 4 weeks (2 × 450 billion colony-forming units per day) or were placed on an LFD for 4 weeks. Patients responding to the LFD were reintroduced to foods high in FODMAPs, and probiotic responders received treatments whenever they experienced a flare-up of symptoms. Treatment response and symptom flare-ups were defined as a reduction or increase, respectively, of at least 50 points on the IBS Severity Scoring System (IBS-SSS). Web-based ward rounds were performed daily by the study investigator. Fecal microbiota were analyzed by shotgun metagenomic sequencing (at least 10 million 2 × 100 bp paired-end sequencing reads per sample). RESULTS: A total of 34 IBS patients without comorbidities and 6 healthy controls were enrolled in the study. Taken from participating subjects, 180 fecal samples were analyzed for their microbiota composition. Out of 21 IBS patients, 12 (57%) responded to the LFD and 8 (38%) completed the reintroduction of FODMAPs. Out of 21 patients, 13 (62%) responded to their first treatment of VSL#3 and 7 (33%) responded to multiple VSL#3 treatments. A median of 3 (IQR 2.25-3.75) probiotic treatments were needed for sustained symptom control. LFD responders were reintroduced to a median of 14.50 (IQR 7.25-21.75) high-FODMAP items. No significant difference in the median reduction of IBS-SSS for LFD versus probiotic responders was observed, where for LFD it was -126.50 (IQR -196.75 to -76.75) and for VSL#3 it was -130.00 (IQR -211.00 to -70.50; P>.99). Responses to either of the two treatments were not able to be predicted using patients' microbiota. CONCLUSIONS: The web-based LFD intervention and probiotic treatment were equally efficacious in managing IBS symptoms. The response to treatments could not be explained by the composition of the microbiota. The IBS CC web application was shown to be practical, safe, and useful for clinical decision making in the long-term management of IBS. Although this study was underpowered, findings from this study warrant further research in a larger sample of patients with IBS to confirm these long-term outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT03586622; https://clinicaltrials.gov/ct2/show/NCT03586622.

B Cell Intrinsic STING Signaling Is Not Required for Autoreactive Germinal Center Participation.

Germinal centers (GCs) are induced microanatomical structures wherein B cells undergo affinity maturation to improve the quality of the antibody response. Although GCs are crucial to appropriate humoral responses to infectious challenges and vaccines, many questions remain about the molecular signals driving B cell participation in GC responses. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway is an important mediator of type I interferon and proinflammatory cytokine responses during infection and cellular stress. Recent studies have reported important roles for STING in B cell responses, including an impact on GC B cells and downstream antibody responses, which could have great consequences for vaccine design and understanding STING-associated interferonopathies. GCs are also involved in untoward reactions to autoantigens in a plethora of autoimmune disorders, and it is generally thought that these responses coopt the mechanisms used in foreign antigen-directed GCs. Here, we set out to investigate the importance of the cGAS-STING pathway in autoreactive B cell responses. In a direct competition scenario in a murine mixed bone marrow chimera model of autoreactive GCs, we find that B cell intrinsic deficiency of cGAS, STING, or the type I interferon receptor IFNAR, does not impair GC participation, whereas Toll-like receptor (TLR)-7 deficiency mediates a near-complete block. Our findings suggest that physiological B cell responses are strictly sustained by signals linked to BCR-mediated endocytosis. This wiring of B cell signals may enable appropriate antibody responses, while at the same time restricting aberrant antibody responses during infections and in autoimmune or autoinflammatory settings.

Comparison of gamma and x-ray irradiation for myeloablation and establishment of normal and autoimmune syngeneic bone marrow chimeras.

Murine bone marrow (BM) chimeras are a versatile and valuable research tool in stem cell and immunology research. Engraftment of donor BM requires myeloablative conditioning of recipients. The most common method used for mice is ionizing radiation, and Cesium-137 gamma irradiators have been preferred. However, radioactive sources are being out-phased worldwide due to safety concerns, and are most commonly replaced by X-ray sources, creating a need to compare these sources regarding efficiency and potential side effects. Prior research has proven both methods capable of efficiently ablating BM cells and splenocytes in mice, but with moderate differences in resultant donor chimerism across tissues. Here, we compared Cesium-137 to 350 keV X-ray irradiation with respect to immune reconstitution, assaying complete, syngeneic BM chimeras and a mixed chimera model of autoimmune disease. Based on dose titration, we find that both gamma and X-ray irradiation can facilitate a near-complete donor chimerism. Mice subjected to 13 Gy Cesium-137 irradiation and reconstituted with syngeneic donor marrow were viable and displayed high donor chimerism, whereas X-ray irradiated mice all succumbed at 13 Gy. However, a similar degree of chimerism as that obtained following 13 Gy gamma irradiation could be achieved by 11 Gy X-ray irradiation, about 85% relative to the gamma dose. In the mixed chimera model of autoimmune disease, we found that a similar autoimmune phenotype could be achieved irrespective of irradiation source used. It is thus possible to compare data generated, regardless of the irradiation source, but every setup and application likely needs individual optimization.

ITIH4 acts as a protease inhibitor by a novel inhibitory mechanism.

Inter-α-inhibitor heavy chain 4 (ITIH4) is a poorly characterized plasma protein that is proteolytically processed in multiple pathological conditions. However, no biological function of ITIH4 has been identified. Here, we show that ITIH4 is cleaved by several human proteases within a protease-susceptible region, enabling ITIH4 to function as a protease inhibitor. This is exemplified by its inhibition of mannan-binding lectin-associated serine protease-1 (MASP-1), MASP-2, and plasma kallikrein, which are key proteases for intravascular host defense. Mechanistically, ITIH4 acts as bait that, upon cleavage, forms a noncovalent, inhibitory complex with the executing protease that depends on the ITIH4 von Willebrand factor A domain. ITIH4 inhibits the MASPs by sterically preventing larger protein substrates from accessing their active sites, which remain accessible and fully functional toward small substrates. Thus, we demonstrate that ITIH4 functions as a protease inhibitor by a previously undescribed inhibitory mechanism.

Effect of dipeptidyl peptidase-4 inhibitors on complement activation.

BACKGROUND: Adverse activation of the complement cascade in the innate immune system appears to be involved in development of vascular complications in diabetes. Dipeptidyl peptidase-4 (DPP-4) is a cell surface serine protease expressed in a variety of tissues. DPP-4 inhibitors are widely used in treatment of type 2 diabetes and appear to yield beneficial pleiotropic effects beyond their glucose-lowering action, for example, renoprotective and anti-inflammatory properties, but the exact mechanisms remain unknown. We hypothesised that DPP-4 inhibitors block adverse complement activation by inhibiting complement-activating serine proteases. MATERIALS AND METHODS: We analysed the effects of 7 different DPP-4 inhibitors on the lectin and classical pathway of the complement system in vitro by quantifying complement factor C4b deposition onto mannan or IgG coated surfaces, respectively. Furthermore, plasma concentrations of mannan-binding lectin (MBL), soluble membrane attack complex (sMAC), and C4b deposition were quantified in 71 patients with a recent acute coronary syndrome and glucose disturbances, randomly assigned to sitagliptin 100 mg (n = 34) or placebo (n = 37) for 12 weeks. RESULTS: All the 7 DPP-4 inhibitors tested in the study directly inhibited functional activity of the lectin pathway in a dose-dependent manner with varying potency in vitro. In vivo, MBL, sMAC, and C4b declined significantly during follow-up in both groups without significant effect of sitagliptin. CONCLUSIONS: We demonstrated an inhibitory effect of DPP-4 inhibitors on the lectin pathway in vitro. The clinical relevance of this effect of DPP-4 inhibitors remains to be fully elucidated.

Complement Receptor 2 Based Immunoassay Measuring Activation of the Complement System at C3-Level in Plasma Samples From Mice and Humans.

We aimed at establishing a sensitive and robust assay for estimation of systemic complement activation at complement component C3 level in mouse and human plasma samples. In order to capture the activation products iC3b and C3dg in a specific and physiological relevant manner we utilized a construct consisting of the iC3b/C3dg-binding site of human complement receptor 2 (CR2) attached to an Fc-part of mouse IgG. This construct binds C3dg and iC3b from both mice and humans. We purified the CR2-IgG construct from mouse B myeloma cell line supernatants, J558L-CR2-IgG, by protein G affinity chromatography. The CR2-IgG construct was used for capturing C3 fragments in microtiter wells and an anti-mouse or an anti-human-C3 antibody was used for detection of bound C3 fragments. Initially we tested the specificity of the assays with the use of purified C3 fragments. Further, with the use of the CR2-based assay, we measured an up to three-fold higher signal in activated mouse serum as compared to non-activated mouse serum, whereas activated serum from a C3 knock-out mouse gave no signal. We tested in vivo generated samples from a mouse experiment; complement activation was induced by injecting cobra venom factor or heat aggregated IgG into C57bl6 mice, followed by withdrawal of EDTA blood samples at different time points and measurement of iC3b/C3dg. We observed a clear time-dependent distinction in signals between samples with expected high and low complement activation. Furthermore, with the use of the assay for human C3 fragments, we observed that patients with systemic lupus erythematosus (SLE) (n = 144) had significantly higher iC3b/C3dg levels as compared to healthy individuals (n = 144) (p < 0.0001). We present two functional immunoassays, that are able to measure systemic levels of the C3-activation products iC3b and C3dg in mice and humans. To our knowledge, these are the first assays for complement activation that use a physiological relevant capture construct such as CR2. These assays will be a relevant tool when investigating mouse models and human diseases involving the complement system.

Pattern Recognition Molecules of the Lectin Pathway-Screening of Patients with Suspected Immunodeficiency.

PURPOSE: To compare plasma concentrations of all lectin pathway (LP) pattern recognition molecules (PRMs) in patients referred for laboratory evaluation due to recurrent infections with healthy individuals. METHODS: Patients were divided into categories according to referral: recurrent airway infections (RAI), recurrent abscesses, common variable immunodeficiency (CVID), lung transplantation candidates (LTX), and 'other causes'. LP PRMs (mannose-binding lectin (MBL), collectin liver 1 (CL-L1), H-ficolin, L-ficolin, M-ficolin) and C-reactive protein (CRP) were determined in 332 patients and 150 healthy blood donors using time-resolved immunofluorometric assays. RESULTS: None of the LP PRMs was found in lower concentration in the patient categories; however, several PRMs were detected in higher concentrations. M-ficolin was found in higher concentrations in all patient categories. Patients suffering from RAI had higher concentrations of CL-L1 and H-ficolin. Patients suffering from abscesses exhibited higher concentrations of MBL and CL-L1, whereas LTX had higher concentrations of MBL. Patients with other causes of referral had higher concentrations of MBL and CL-L1. Prevalence of combined deficiencies of PRMs in patient categories and controls did not differ. CRP was used as a marker of ongoing inflammation and was significantly higher among all patient categories. Furthermore, CRP was found to correlate with both M-ficolin and L-ficolin. CONCLUSION: The results suggest that neither single nor combined deficiencies of LP PRMs are more frequent among patients referred for an immunological evaluation than in healthy individuals. Future studies are needed and should focus on deficiencies of LP PRMs combined with deficiencies in other parts of the immune system.

The C3dg Fragment of Complement Is Superior to Conventional C3 as a Diagnostic Biomarker in Systemic Lupus Erythematosus.

Introduction/objectives: In 2012, hypocomplementemia was included in the classification criteria of systemic lupus erythematosus (SLE). The suggested measurement of C3 or C4 often reflect disease activity poorly. Our objective was to establish an assay measuring C3dg, which is generated following complement activation, and to evaluate the assay in a cross-sectional SLE cohort. Method: We included SLE patients (n = 169) and controls (n = 170) and developed a modified C3dg assay where C3dg fragments were separated from the large plasma proteins by polyethylene glycol (PEG), and the supernatant containing the C3dg fragment was used for analysis in an antibody-based sandwich-type assay. Gel permeation chromatography and western blotting were used to establish the optimal conditions for PEG precipitation. Results: 16% PEG was optimal for separating C3dg from C3 and the larger protein fragments. The assay showed a high degree of stability when using EDTA plasma, and measurements correlated well with commercially available complement activation assays. SLE patients had higher concentrations in plasma of C3dg than controls (p < 0.05). ROC analysis showed that the C3dg activation fragment of C3 with an AUC of 0.96 (CI 0.94-0.98) was superior to C3 (AUC 0.52) in differentiating between patients and controls. Conclusion: Our results present a modified assay for the measurement of C3dg. We demonstrate that C3dg was superior to conventional C3 measurements in discriminating SLE patients from controls. We suggest that C3dg should be considered as a complement activation measurement in the SLE classification criteria.

Analysis of Factor D Isoforms in Malpuech-Michels-Mingarelli-Carnevale Patients Highlights the Role of MASP-3 as a Maturase in the Alternative Pathway of Complement.

Factor D (FD), which is also known as adipsin, is regarded as the first-acting protease of the alternative pathway (AP) of complement. It has been suggested that FD is secreted as a mature enzyme that does not require subsequent activation. This view was challenged when it was shown that mice lacking mannose-binding lectin (MBL)-associated serine protease-1 (MASP-1) and MASP-3 contain zymogenic FD (pro-FD), and it is becoming evident that MASP-3 is implicated in pro-FD maturation. However, the necessity of MASP-3 for pro-FD cleavage has been questioned, because AP activity is still observed in sera from MASP-1/3-deficient Malpuech-Michels-Mingarelli-Carnevale (3MC) patients. The identification of a novel 3MC patient carrying a previously unidentified MASP-3 G665S mutation prompted us to develop an analytical isoelectric focusing technique that resolves endogenous FD variants in complex samples. This enabled us to show that although 3MC patients predominantly contain pro-FD, they also contain detectable levels of mature FD. Moreover, using isoelectric focusing analysis, we show that both pro-FD and FD are present in the circulation of healthy donors. We characterized the naturally occurring 3MC-associated MASP-3 mutants and found that they all yielded enzymatically inactive proteins. Using MASP-3-depleted human serum, serum from 3MC patients, and Masp1/3-/- mice, we found that lack of enzymatically active MASP-3, or complete MASP-3 deficiency, compromises the conversion of pro-FD to FD. In summary, our observations emphasize that MASP-3 acts as an important maturase in the AP of complement, while also highlighting that there exists MASP-3-independent pro-FD maturation in 3MC patients.

Development of Insulin Detemir/Insulin Aspart Cross-Reacting Antibodies Following Treatment with Insulin Detemir: 104-week Study in Children and Adolescents with Type 1 Diabetes Aged 2-16 Years.

BACKGROUND: To study the long-term development (104 weeks) of insulin antibodies during treatment with insulin detemir (IDet) and insulin aspart (IAsp) in children with type 1 diabetes aged 2-16 years. METHODS: A 52-week, two-arm, randomized trial comparing IDet and neutral protamine Hagedorn insulin, both in combination with IAsp, was followed by a one-arm, 52-week extension trial of the IDet + IAsp arm. The present analysis was conducted in children who completed the randomized trial and entered into the extension trial. RESULTS: Of the 177 children randomized to IDet treatment, 146 entered the extension trial. IDet-IAsp cross-reacting antibodies peaked within the first 39 weeks of treatment before gradually declining. A similar pattern was seen for IDet-specific and IAsp-specific antibodies. At end of trial (EOT), no correlation was observed between the level of IDet-specific or IAsp-specific antibodies or IDet-IAsp cross-reacting antibodies and either glycated hemoglobin (HbA1c) or basal insulin dose. Mean HbA1c was stable during the treatment period, with a slight increase over time from 8.41% (68.4 mmol/mol) at baseline to 8.74% (72 mmol/mol) at EOT. Mean IDet dose increased from 0.43 U/kg at baseline to 0.66 U/kg at EOT. Mean IAsp dose increased from 0.46 U/kg to 0.51 U/kg at EOT. CONCLUSION: Although treatment with IDet and IAsp is associated with development of specific and cross-reacting antibodies, no correlation between insulin antibodies and basal insulin dose or HbA1c was found. FUNDING: Novo Nordisk A/S. ClinicalTrials.gov identifiers: NCT00435019 and NCT00623194.

Non-targeted screening for contaminants in paper and board food-contact materials using effect-directed analysis and accurate mass spectrometry.

Due to large knowledge gaps in chemical composition and toxicological data for substances involved, paper and board food-contact materials (P&B FCM) have been emerging as a FCM type of particular concern for consumer safety. This study describes the development of a step-by-step strategy, including extraction, high-performance liquid chromatography (HPLC) fractionation, tentative identification of relevant substances and in vitro testing of selected tentatively identified substances. As a case study, we used two fractions from a recycled pizza box sample which exhibited aryl hydrocarbon receptor (AhR) activity. These fractions were analysed by gas chromatography (GC) and ultra-HPLC (UHPLC) coupled to quadrupole time-of-flight mass spectrometers (QTOF MS) in order tentatively to identify substances. The elemental composition was determined for peaks above a threshold, and compared with entries in a commercial mass spectral library for GC-MS (GC-EI-QTOF MS) analysis and an in-house built library of accurate masses for substances known to be used in P&B packaging for UHPLC-QTOF analysis. Of 75 tentatively identified substances, 15 were initially selected for further testing in vitro; however, only seven were commercially available and subsequently tested in vitro and quantified. Of these seven, the identities of three pigments found in printing inks were confirmed by UHPLC tandem mass spectrometry (QqQ MS/MS). Two pigments had entries in the database, meaning that a material relevant accurate mass database can provide a fast tentative identification. Pure standards of the seven tentatively identified substances were tested in vitro but could not explain a significant proportion of the AhR-response in the extract. Targeted analyses of dioxins and PCBs, both well-known AhR agonists, was performed. However, the dioxins could explain approximately 3% of the activity observed in the pizza box extract indicating that some very AhR active substance(s) still remain to be identified in recycled low quality P&B.

The pattern recognition molecule collectin-L1 in critically ill children.

BACKGROUND: Critically ill children are prone to nosocomial infections, which may lead to adverse outcome. Low serum concentrations upon admission to the pediatric intensive care unit (PICU) of the mannan-binding lectin (MBL)-associated serine protease (MASP)-3 protein of the lectin pathway of complement activation have been associated with risk of infection and prolonged need for intensive care. We hypothesized that also a low upon-admission concentration of collectin-L1 (CL-L1), a novel member of this pathway, is independently associated with these adverse outcomes. METHODS: We quantified the serum concentrations of CL-L1 in 81 healthy children and in 700 critically ill children upon PICU admission. RESULTS: CL-L1 concentrations were significantly lower in the critically ill children as compared with the healthy children. However, corrected for baseline characteristics, risk factors and several lectin pathway proteins, a higher CL-L1 concentration upon PICU admission was independently associated with an increased risk of acquiring a new infection and with a prolonged time to PICU discharge. In contrast, a low MASP-3 concentration remained independently associated with these adverse outcomes. CONCLUSION: A high serum CL-L1 concentration in critically ill children upon PICU admission is associated with an increased risk of infection and prolonged need of intensive care, and counteracts the protective effect of having a high MASP-3 concentration.

Follow-up of patients with functional bowel symptoms treated with a low FODMAP diet.

AIM: To investigate patient-reported outcomes from, and adherence to, a low FODMAP diet among patients suffering from irritable bowel syndrome and inflammatory bowel disease. METHODS: Consecutive patients with irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD) and co-existing IBS fulfilling the ROME III criteria, who previously attended an outpatient clinic for low FODMAP diet (LFD) dietary management and assessment by a gastroenterologist, were invited to participate in a retrospective questionnaire analysis. The questionnaires were sent and returned by regular mail and gathered information on recall of dietary treatment, efficacy, symptoms, adherence, satisfaction, change in disease course and stool type, and quality of life. Before study enrolment all patients had to sign an informed written consent. RESULTS: One hundred and eighty patients were included, 131 (73%) IBS and 49 (27%) IBD patients. Median age was 43 years (range: 18-85) and 147 (82%) were females. Median follow-up time was 16 mo (range: 2-80). Eighty-six percent reported either partial (54%) or full (32%) efficacy with greatest improvement of bloating (82%) and abdominal pain (71%). The proportion of patients with full efficacy tended to be greater in the IBD group than in the IBS group (42% vs 29%, P = 0.08). There was a significant reduction in patients with a chronic continuous disease course in both the IBS group (25%, P < 0.001) and IBD group (23%, P = 0.002) along with a significant increase in patients with a mild indolent disease course of 37% (P < 0.001) and 23% (P = 0.002), respectively. The proportion of patients having normal stools increased with 41% in the IBS group (P < 0.001) and 66% in the IBD group (P < 0.001). One-third of patients adhered to the diet and high adherence was associated with longer duration of dietary course (P < 0.001). Satisfaction with dietary management was seen in 83 (70%) IBS patients and 24 (55%) IBD patients. Eighty-four percent of patients lived on a modified LFD, where some foods rich in FODMAPs were reintroduced, and 16% followed the LFD by the book without deviations. Wheat, dairy products, and onions were the foods most often not reintroduced by patients. CONCLUSION: These data suggest that a diet low in FODMAPs is an efficacious treatment solution in the management of functional bowel symptoms for IBS and IBD patients.

Breast carcinosarcoma: clinical and pathological features.

Carcinosarcoma of the breast is an extremely rare and highly aggressive breast tumor.It has two distinct malignant cell lines involving epithelial (carcinomatous) and mesenchymal (sarcomatous) components. The literature on the topic is sparse. We report a rare case of carcinosarcoma of the breast containing a small fraction of a pancytokeratin positive sarcomatous-appearing cell population i.e. a metaplastic cell population. The patient was treated with a multidisciplinary approach.