Mycophenolate mofetil hampers antibody responses to a broad range of vaccinations in kidney transplant recipients: Results from a randomized controlled study

OBJECTIVES

To study the effect of mycophenolate mofetil (MMF) on various vaccination responses in kidney transplant recipients.

METHODS

In a randomized controlled trial (EudraCT nr.: 2014-001372-66), low immunologically risk kidney transplant recipients were randomized to TAC/MMF or TAC-monotherapy (TACmono), six months post-transplantation. One year after transplantation, in a pre-specified sub-study, recipients were vaccinated against pneumococcus, tetanus and influenza. Blood was sampled before and 21 days after vaccination. Adequate vaccination responses were defined by international criteria. A post-hoc analysis was conducted on SARS-CoV-2 vaccination responses within the same cohort.

RESULTS

Seventy-one recipients received pneumococcal and tetanus vaccines (TAC/MMF: n = 37, TACmono: n = 34), with 29 also vaccinated against influenza. When vaccinated, recipients were 60 (54-66) years old, with median eGFR of 54 (44-67) ml/min, tacrolimus trough levels 6.1 (5.4-7.0) ug/L in both groups and TAC/MMF daily MMF dose of 1000 (500-2000) mg. Adequate vaccination responses were: pneumococcal (TAC/MMF 43%, TACmono 74%, p = 0.016), tetanus (TAC/MMF 35%, TACmono 82%, p < 0.0001) and influenza (TAC/MMF 20%, TACmono 71%, p = 0.0092). Only 7% of TAC/MMF responded adequately to all three compared to 36% of TACmono (p = 0.080). Additionally, 40% of TAC/MMF responded inadequately to all three, whereas all TACmono patients responded adequately to at least one vaccination (p = 0.041). Lower SARS-CoV-2 vaccination antibody responses correlated with lower pneumococcal antibody vaccination responses (correlation coefficient: 0.41, p = 0.040).

CONCLUSIONS

MMF on top of tacrolimus severely hampers antibody responses to a broad range of vaccinations.

Baseline TGF-β correlates with protection after immunization with Plasmodium falciparum sporozoites in the Controlled Human Malaria Infection model

BACKGROUND

Here we assessed a possible relationship between baseline TGF-β concentrations and acquisition of sterile immunity after Plasmodium falciparum sporozoite immunization.

METHODS

TGF-β concentrations were determined in samples of 65 malaria-naive volunteers in 4 studies either prior to and after challenge infection, or prior to and after first immunizing infection under chemoprophylaxis with P. falciparum sporozoites.

RESULTS

High baseline TGF-β concentrations were associated with rapid acquisition of sterile protection (p=0.028).

CONCLUSION

Baseline TGF-β concentrations predict the efficiency of acquisition of sterile immunity following sporozoite immunisation and may represent a steady-state regulatory mechanism to keep in check immune systems with a low threshold for activation.

Altered leukocyte subsets and immune proteome indicate pro-inflammatory mechanisms in mastocytosis

BACKGROUND

Indolent systemic mastocytosis (ISM) is characterized by pathological accumulation of mast cells. The mechanism behind its phenotypic heterogeneity is not well understood. Interaction of mast cells with other immune cells might cause systemic inflammation and thereby associated symptoms.

OBJECTIVE

To investigate peripheral leukocyte compartments and serum immune proteome in ISM.

METHODS

Peripheral blood leukocyte phenotyping using flowcytometry in a cohort of 18 adults with ISM and 12 healthy controls. Targeted proteomics was performed to measure 169 proteins associated with inflammation on serum of another 20 ISM patients and 20 healthy controls.

RESULTS

Proportions of plasmacytoid dendritic cells (pDC) and monocytes were significantly decreased while T-helper 2 cells were increased in peripheral blood of ISM patients. Furthermore, a shift from naïve to memory T-cells was observed. Hierarchical clustering of the serum proteome revealed two distinct subgroups within ISM patients. In subgroup A (n=8), 62 proteins were significantly overexpressed, whereas subgroup B (n=12) was comparable to healthy controls. Patients in subgroup A displayed upregulated signaling pathways downstream of Toll-like receptor 4, TNF-α and interferon-γFatigue was more often present in subgroup A compared to B (75% vs. 33% respectively, p 0.06).

CONCLUSIONS

Altered distribution of leukocyte subsets and a pro-inflammatory proteome were observed in subsequent two cohorts of ISM patients. We hypothesize that neoplastic mast cells recruit and activate pDC, monocytes and T-cells leading to a vicious cycle of inflammation.

CLINICAL IMPLICATION

Characterization of inflammatory mechanisms in ISM might uncover additional targets for treatment, in particular for constitutional symptoms such as fatigue.

POS0189 SERUM IFNα CONCENTRATIONS MEASURED WITH SINGLE-MOLECULE ARRAY TECHNOLOGY IN SJÖGREN’S SYNDROME REFLECT BLOOD INTERFERON-STIMULATED GENE EXPRESSION

Background:

Type I interferon (IFN-I) activation is a prominent feature of several Rheumatic and Musculoskeletal Diseases (RMDs) including primary Sjögren’s syndrome (pSS), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). Ultrasensitive single-molecule array (SiMoA) technology has facilitated the measurement of subfemtomolar concentrations of IFNs [1-3].

Objectives:

Here, we tested the performance of a commercially available SiMoA kit for detection of IFNα in serum from pSS, SLE, and SSc and correlated serum IFNα to whole blood IFN-stimulated gene (ISG) expression.

Methods:

Serum IFNα2 was measured in healthy controls (HC; n=68) and patients with pSS (n=85, n=110), SLE (n=24) and SSc (n=23) using a ready-to-use IFNα SiMoA kit on a HD-X Analyzer. IFN-I activation was additionally determined from paired samples of whole blood IFN-stimulated gene (ISG) expression of IFI44, IFI44L, IFIT1, IFIT3, and MxA by RT-PCR or MxA-ELISA.

Results:

Serum IFNα2 levels were elevated in pSS (median = 61.3 fg/mL) compared to HC (median < 5fg/mL) and SSc (median = 11.6 fg/mL), lower compared to SLE (median = 313.5 fg/mL), and positively correlated to whole blood ISG expression (rs=0.71-0.76, p<0.001). Comparable to MxA-ELISA (AUC=0.93), IFNα2 SiMoA identified pSS with high ISG expression (AUC=0.90) with 80-93% specificity and 71-84% sensitivity. Blinded validation in an independent pSS cohort yielded a comparable accuracy of 89%. Multiple linear regression indicated independent associations of autoantibodies, IgG, and use of hydroxychloroquine with serum IFNα2 concentrations in pSS. Confirming the literature [4], serum IFNα2 levels were lower in SLE patients in remission (DORIS classification) compared to patients not in remission.

Conclusion:

Thus, SiMoA serum IFNα2 reflects blood ISG expression in pSS, SLE and SSc. In light of IFN-targeting treatments, SiMoA could potentially be applied for patient stratification or high-throughput retrospective analysis of stored clinical trial material.

References:

[1]Rissin, D.M.; Kan, C.W.; Campbell, T.G.; Howes, S.C.; Fournier, D.R.; Song, L.; Piech, T.; Patel, P.P.; Chang, L.; Rivnak, A.J., et al. Single-molecule enzyme-linked immunosorbent assay detects serum proteins at subfemtomolar concentrations. Nat. Biotechnol. 2010, 28, 595-599.

[2]Wilson, D.H.; Rissin, D.M.; Kan, C.W.; Fournier, D.R.; Piech, T.; Campbell, T.G.; Meyer, R.E.; Fishburn, M.W.; Cabrera, C.; Patel, P.P., et al. The Simoa HD-1 Analyzer: A Novel Fully Automated Digital Immunoassay Analyzer with Single-Molecule Sensitivity and Multiplexing. Journal of Laboratory Automation 2015, 21, 533-547. DOI: 10.1177/2211068215589580.

[3]Rodero, M.P.; Decalf, J.; Bondet, V.; Hunt, D.; Rice, G.I.; Werneke, S.; McGlasson, S.L.; Alyanakian, M.A.; Bader-Meunier, B.; Barnerias, C., et al. Detection of interferon alpha protein reveals differential levels and cellular sources in disease. J. Exp. Med. 2017, 214, 1547-1555. DOI: 10.1084/jem.20161451.

[4]Mathian, A.; Mouries-Martin, S.; Dorgham, K.; Devilliers, H.; Yssel, H.; Garrido Castillo, L.; Cohen-Aubart, F.; Haroche, J.; Hie, M.; Pineton de Chambrun, M., et al. Ultrasensitive serum interferon-alpha quantification during SLE remission identifies patients at risk for relapse. Ann. Rheum. Dis. 2019, 78, 1669-1676. DOI: 10.1136/annrheumdis-2019-215571.

Disclosure of Interests:

None declared

POS0370 TYPE I INTERFERON PATHWAY ASSAYS IN PATIENTS WITH RHEUMATIC AND MUSCULOSKELETAL DISEASES - SYSTEMATIC LITERATURE REVIEW (SLR) AND DEVELOPMENT OF CONSENSUS TERMINOLOGY FROM A EULAR TASKFORCE

Background:

The interferon (IFN) pathway is a complex system with multiple proteins and diverse downstream effects on gene and protein expression. IFNs have been implicated in multiple RMDs. Despite significant potential, IFN assays have not progressed into clinical practice.

Objectives:

To perform a SLR on IFN assays in RMDs and propose a consensus terminology.

Methods:

OvidMedline, Embase and Web of Science were searched for reports of IFN and RMDs up to October 2019. Information about the properties of assays measuring type I IFN and measures of truth were extracted and summarised. Terminology was agreed through an interactive consensus process with reference to the existing evidence.

Results:

10037 abstracts were identified. 275 fulfilled eligibility criteria, and were used for data extraction. Some used more than one technique to measure IFN-I pathway activation. Hence, 275 papers generated data on 393 methods. There was great heterogeneity in the methods used and presentation of results. IFN-I pathway activation was measured using: qPCR (n=121), immunoassays (n=101), microarray (n=69), reporter cell assay (n=38), DNA methylation (n=14), flow cytometry (n=14), cytopathic effect assay (n=11), RNA sequencing (n=9), Plaque reduction assay (n=8), Nanostring (n=5), bisulphite sequencing (n=3). All papers fulfilled Face Validity. Due to lack of gold standard for IFN-I pathway activation, evidence of criterion validity was variable. Concurrent validity was presented for n=150 assays. The terminology used to describe aspects of type I IFN pathway activation was not consistent, so a consensus terminology for IFN research (Table 1) was proposed by the taskforce.

Table 1.

Consensus terminology

TermAbbreviationDefinitionInterferonIFNProteins with anti-viral activity; IFNs are mediators of an anti-viral response. They belong to the Type I, Type II and Type III IFN families.Type I interferonIFN-IThe IFNs alpha, beta, omega, kappa, epsilon, secreted by any nucleated cell, and binding to the IFNAR, which is expressed on any nucleated cell.Type II interferonIFN-IIIFN gamma, mostly secreted by T cells, binding to the IFNGR, which is expressed on most leucocytes.Type III interferonIFN-IIIIFN lambda, which are structurally more similar to IL-10 but share downstream signalling and gene expression with IFN-I.Interferon-stimulated genesISGsGenes whose expression is known to be upregulated by any kind of IFN. Individual ISGs may not exclusively represent Type I IFN pathway activation.Type I Interferon pathway activationAny evidence for function of the components of the Type I IFN pathway. This includes: secretion of a Type I IFN protein, binding to the IFNAR, initiation of JAK/STAT signalling pathways, expression of IFN-stimulated genes, expression of IFN-stimulated proteins.Type I interferon pathway assayAn assay measuring one or more components of the Type I IFN pathway at a molecular or functional level.Interferon stimulated gene expression signatureA qualitative description of coordinated expression of a set of ISGs that is indicative of Type I IFN pathway activation.Interferon stimulated gene expression scoreA quantitative variable derived from expression of a defined set of ISGs that is indicative of Type I IFN pathway activation.Interferon stimulated protein scoreA variable derived from expression of a defined set of soluble biomarkers known to be upregulated by IFN, although not specific for Type I IFN.InterferonopathyMonogenic diseases in which there is constitutive Type I IFN pathway activation with a causal role in pathology. The clinical picture may resemble rheumatic musculoskeletal diseases. However, most diseases with IFN pathway activation are not Interferonopathies.

Conclusion:

Diverse methods have been reported as IFN assays and these differ in what elements of type IFN-I pathway activation they measure. The taskforce consensus terminology on type I IFN reporting should be considered for research and clinical applications.

Disclosure of Interests:

Agata Burska: None declared, Javier Rodriguez Carrio: None declared, Philip G Conaghan: None declared, Willem A Dik: None declared, Robert Biesen: None declared, Maija-leena Eloranta: None declared, Giulio Cavalli: None declared, Marianne Visser: None declared, Dimitrios Boumpas: None declared, George Bertsias: None declared, Marie Wahren-Herlenius: None declared, Jan Rehwinkel: None declared, Marie-Louise Frémond: None declared, Mary K. Crow Consultant of: AstraZeneca, Bristol Meyers Squibb, Lilly, Shannon Pharmaceuticals, Grant/research support from: Gilead, Lars Ronnblom Consultant of: AstraZeneca, Edward Vital Speakers bureau: GSK, Consultant of: AURINIA, SANDOZ, GSK, AstraZeneca, Roche, Modus, Grant/research support from: AstraZeneca, Marjan Versnel: None declared

Clinical significance of soluble interleukin-2 receptor measurement in immune-mediated diseases

A soluble form of the interleukin-2 receptor (sIL-2R) is secreted upon T-cell activation. Increased blood levels of sIL-2R occur in a variety of immunological diseases. Although the biological function of sIL-2R is incompletely understood, both in health and disease, sIL-2R serum measurements are commonly conducted in clinical practice as it may help to facilitate diagnosis of specific immune-mediated diseases, such as haemophagocytic lymphohistiocytosis and sarcoidosis. In these, and in other immune-diseases, sIL-2R levels may be used as a biomarker to monitor/predict disease activity and treatment response. In this review, we will give a brief overview of the biology of the IL-2/IL-2R system and will subsequently discuss the clinical utility of sIL-2R measurement, especially in the context of haemophagocytic lymphohistiocytosis, sarcoidosis, rheumatoid arthritis, systemic lupus erythematosus, juvenile idiopathic arthritis, adult-onset Still's disease, ANCA-associated vasculitis, and IgG4-related disease.

Are Patients at Risk for Recurrent Disease Activity After Switching From Remicade® to Remsima®? An Observational Study

Background: Since the late ‘90s, infliximab (Remicade^®) is being used successfully to treat patients with several non-infectious immune mediated inflammatory diseases (IMIDs). In recent years, infliximab biosimilars, including Remsima^® were introduced in clinical practice.

Aim: To investigate the interchangeability of Remicade^® (originator infliximab) and its biosimilar Remsima^® in patients with rare immune-mediated inflammatory diseases (IMIDs).

Methods: This two-phased prospective open label observational study was designed to monitor the transition from Remicade^® to Remsima^® in patients with rare IMIDs. All included patients were followed during the first 2 years. The primary endpoint was the demonstration of non-difference in quality of life and therapeutic efficacy, as measured by parameters including a safety monitoring program, physicians perception of disease activity (PPDA) and patient self-reported outcomes (PSROs). Secondary outcomes included routine blood analysis, pre-infusion serum drug concentration values and anti-drug antibody formation.

Results: Forty eight patients treated with Remicade^® were switched to Remsima^® in June-July 2016 and subsequently monitored during the first 2 years. The group consisted of patients with sarcoidosis (n = 17), Behçet's disease (n = 12), non-infectious uveitis (n = 11), and other diagnoses (n = 8). There were no significant differences in PPDA, PSROs, clinical and laboratory assessments and pre-infusion serum drug concentrations between the groups. De novo anti-drug antibodies were observed in two patients. Seven patients with sarcoidosis and five with another diagnosis developed a significant disease relapse (n = 7) or adverse events (n = 5) within 2 years; 10 of these patients discontinued Remsima^® treatment, one withdrew from the study and one received additional corticosteroid therapy.

Conclusions: We observed no significant differences in PSROs, PPDA and laboratory parameters after treatment was switched from Remicade^® to Remsima^®. However, disease relapse or serious events were observed in 12 out of 48 patients when treatment was switched from Remicade^® to Remsima^®. The choice to switch anti-TNF alpha biologics in patients with rare IMIDs, particularly in sarcoidosis, requires well-considered decision-making and accurate monitoring due to a possibly higher incidence of disease worsening.

A multicentre cohort study of serum and peritoneal biomarkers to predict anastomotic leakage after rectal cancer resection

AIM

Anastomotic leakage (AL) is one of the most feared complications after rectal resection. This study aimed to assess a combination of biomarkers for early detection of AL after rectal cancer resection.

METHOD

This study was an international multicentre prospective cohort study. All patients received a pelvic drain after rectal cancer resection. On the first three postoperative days drain fluid was collected daily and C-reactive protein (CRP) was measured. Matrix metalloproteinase-2 (MMP2), MMP9, glucose, lactate, interleukin 1-beta (IL1β), IL6, IL10, tumour necrosis factor alpha (TNFα), Escherichia coli, Enterococcus faecalis, lipopolysaccharide-binding protein and amylase were measured in the drain fluid. Prediction models for AL were built for each postoperative day using multivariate penalized logistic regression. Model performance was estimated by the c-index for discrimination. The model with the best performance was visualized with a nomogram and calibration was plotted.

RESULTS

A total of 292 patients were analysed; 38 (13.0%) patients suffered from AL, with a median interval to diagnosis of 6.0 (interquartile ratio 4.0-14.8) days. AL occurred less often after partial than after total mesorectal excision (4.9% vs 15.2%, P = 0.035). Of all patients with AL, 26 (68.4%) required reoperation. AL was more often treated by reoperation in patients without a diverting ileostomy (18/20 vs 8/18, P = 0.03). The prediction model for postoperative day 1 included MMP9, TNFα, diverting ileostomy and surgical technique (c-index = 0.71). The prediction model for postoperative day 2 only included CRP (c-index = 0.69). The prediction model for postoperative day 3 included CRP and MMP9 and obtained the best model performance (c-index = 0.78).

CONCLUSION

The combination of serum CRP and peritoneal MMP9 may be useful for earlier prediction of AL after rectal cancer resection. In clinical practice, this combination of biomarkers should be interpreted in the clinical context as with any other diagnostic tool.

Soluble Interleukin-2 Receptor: A Potential Marker for Monitoring Disease Activity in IgG4-Related Disease

BACKGROUND

IgG4-related disease (IgG4-RD) is a fibroinflammatory condition. T-cells play a crucial role in the pathogenesis, and therefore, serum soluble interleukin-2 receptor (sIL-2R) may be a potential biomarker.

METHOD

We studied the levels of sIL-2R in 26 histologically proven IgG4-RD patients with available serum sIL-2R and compared them to those in newly diagnosed and untreated sarcoidosis patients (n = 78) and controls (n = 101) and the serum sIL-2R levels in patients after treatment of IgG4-RD (n = 15). The disease activity was measured using the IgG4-Related Disease Responder Index (IgG4-RD RI).

RESULTS

Median serum sIL-2R in IgG4-RD patients was 4667 pg/ml compared to 1515 pg/ml in controls (P < 0.001) and 6050 pg/ml in sarcoidosis patients (P = 0.004 compared to IgG4-RD). All IgG4-RD patients had elevated serum sIL-2R levels compared to the reference value of <2500 pg/ml in controls and 85% elevated serum IgG4; however, these did not correlate with each other. Both serum sIL-2R and IgG4 levels declined significantly after treatment (P = 0.001 and P = 0.01, resp.). Before treatment, serum sIL-2R level and IgG4-RD RI did not correlate with each other. However, the decrease in serum sIL-2R upon treatment did correlate significantly (P = 0.04) with the decrease in disease activity assessed by IgG-RD RI.

CONCLUSION

Serum sIL-2R is elevated in IgG4-RD reflecting the inflammatory process with enhanced T-cell activation. Furthermore, serum sIL-2R might serve as a potential marker of response to treatment in IgG4-RD.

The peripheral blood compartment in patients with Graves' disease: activated T lymphocytes and increased transitional and pre-naive mature B lymphocytes

Graves' disease (GD) is an autoimmune disease that involves aberrant B and T lymphocyte responses. Detailed knowledge about lymphocyte subpopulation composition will therefore enhance our understanding of the pathogenesis of GD and might support the development of new immunomodulatory treatment approaches. The aim of this study was to gain detailed insight into the composition of the peripheral blood lymphocyte compartment in GD before and during anti-thyroid drug therapy. Major B and T lymphocyte subpopulations were investigated by flow cytometry in peripheral blood from newly diagnosed GD patients (n = 5), GD patients treated with anti-thyroid drugs (n = 4), patients with recurrent GD (n = 7) and healthy controls (HC; n = 10). In GD patients, numbers of activated T lymphocytes [human leucocyte antigen D-related (HLA-DR)⁺ and CD25⁺] were increased. The B lymphocyte compartment in GD was characterized by significantly higher numbers of transitional (CD38(high) CD27⁻, P < 0.03) and pre-naive mature (CD38(low) CD27⁻ IgD⁺ CD5⁺, P < 0.04) B lymphocytes, while memory populations were slightly decreased. The increased numbers of CD5⁺, transitional and pre-naive mature B lymphocytes correlated positively with fT4 plasma levels. GD is associated with increased numbers of activated T lymphocytes and transitional and pre-naive mature CD5⁺ B lymphocytes within the peripheral blood. The increase in CD5⁺ B lymphocytes was due mainly to an increase in transitional and pre-naive mature B lymphocytes. Increased fT4 plasma levels might be associated with this increase in transitional and pre-naive mature CD5⁺ B lymphocytes.

PDGF enhances orbital fibroblast responses to TSHR stimulating autoantibodies in Graves' ophthalmopathy patients

PURPOSE

Thyroid-stimulating hormone receptor (TSHR) stimulating autoantibodies are associated with Graves' ophthalmopathy (GO), the orbital manifestation of Graves' disease (GD). TSHR autoantibody levels and orbital TSHR expression levels correlate positively with GO disease activity. Platelet-derived growth factors (PDGF) are increased in GO and potently activate orbital fibroblast effector functions. We investigated the possible relationship between PDGF and TSHR expression on orbital fibroblasts and how that influences the immunopathological effects of TSHR autoantibodies on orbital fibroblast activity.

METHODS

Orbital fibroblasts were stimulated with PDGF-AA, PDGF-AB, and PDGF-BB, and TSHR expression was determined by flow cytometry. Stimulatory effects of bovine TSH and GD immunoglobulins on orbital fibroblasts (with or without PDGF-BB preincubation) were determined by IL-6, IL-8, chemokine (C-C motif) ligand (CCL)-2, CCL5, CCL7, and hyaluronan ELISA. The TSHR blocking antibody K1-70 and the cAMP inhibitor H89 were used to determine involvement of TSHR signaling.

RESULTS

PDGF-AB and PDGF-BB stimulation increased TSHR expression on orbital fibroblasts, whereas PDGF-AA did not. Furthermore, stimulation with bovine TSH and immunoglobulins from GD patients induced IL-6, IL-8, CCL2, and hyaluronan production by orbital fibroblasts, and PDGF-BB preincubation enhanced this response of orbital fibroblasts. Blocking studies with a TSHR blocking antibody and a cAMP inhibitor inhibited these effects, indicating the involvement of TSHR signaling and thus of TSHR stimulating autoantibodies herein.

CONCLUSIONS

These findings indicate that PDGF-B containing PDGF isoforms amplify the immunopathological effects of TSHR-stimulating autoantibodies in GO patients by stimulating TSHR expression on orbital fibroblasts.

Adalimumab (antitumour necrosis factor-α) treatment of hidradenitis suppurativa ameliorates skin inflammation: an in situ and ex vivo study

BACKGROUND

Hidradenitis suppurativa (HS) is a difficult-to-manage disease. Randomized controlled trials with antitumour necrosis factor (TNF)-α biologics have been conducted and in most studies disease activity was reduced. However, the mechanism of action in HS skin is so far unknown.

OBJECTIVES

To assess whether anti-TNF-α treatment affects in situ cytokine production and frequency of inflammatory cell populations in HS lesional skin.

METHODS

Nine patients with HS, participating in a larger placebo-controlled, double-blind phase IIb clinical trial on the efficacy and safety of adalimumab in patients with moderate to severe HS (M10-467), were randomized and treated for 16weeks. In a mechanism-of-action substudy, biopsies were obtained at fixed time points pre- and post-treatment. One part of the biopsy was cultured for 24h for cytokine release in the culture medium, while another part was used for in situ analysis.

RESULTS

Secretion of cytokines, including interleukin (IL)-1β, CXCL9 [monokine induced by interferon-γ (MIG)], IL-10, IL-11, B-lymphocyte chemoattractant (BLC) and IL-17A, was significantly elevated in HS. Adalimumab treatment was associated with decreased production of cytokines in HS skin, especially IL-1β, CXCL9 (MIG) and BLC. Treatment significantly reduced the number of CD11c+,CD14+ and CD68+ cells in HS lesional skin. The numbers of CD3+ and CD4+ T cells, and CD20+ and CD138+ B cells were also reduced by adalimumab treatment.

CONCLUSIONS

Adalimumab treatment inhibits important cytokines and inflammatory cell numbers in lesional HS skin, especially levels of IL-1β and numbers of inflammatory CD11c+ dendritic cells.

Orbit-infiltrating mast cells, monocytes, and macrophages produce PDGF isoforms that orchestrate orbital fibroblast activation in Graves' ophthalmopathy

PURPOSE

Platelet-derived growth factors (PDGF) are regulators of fibroblast activity that may be involved in the pathophysiology of Graves' ophthalmopathy (GO). We unraveled the expression and origin of PDGF family members in GO orbital tissue and investigated the effect of PDGF isoforms on IL-6 and hyaluronan production and proliferation by orbital fibroblasts.

METHODS

PDGF-A, PDGF-B, PDGF-C, PDGF-D, PDGF-Rα, and PDGF-Rβ expression was determined by real-time quantitative PCR and PDGF-A and PDGF-B protein expression was determined by Western blot in orbital tissues. Orbital tissues were immunohistochemically stained for PDGF-A and PDGF-B expression, together with stainings for T cells, monocytes, B cells, macrophages, and mast cells. Effects of PDGF-AA, PDGF-AB, and PDGF-BB on orbital fibroblast proliferation and IL-6 and hyaluronan production were examined. Finally, effects of PDGF-BB- and PDGF-AA-neutralizing antibodies on IL-6 and hyaluronan production in GO whole orbital tissue cultures were tested.

RESULTS

GO orbital tissue showed increased PDGF-A and PDGF-B mRNA and protein levels. Increased numbers of PDGF-A- and PDGF-B-positive monocytes, macrophages, and mast cells were present in GO orbital tissue. PDGF-BB stimulated proliferation and hyaluronan and IL-6 production by orbital fibroblasts the most, followed by PDGF-AB and PDGF-AA. Finally, in particular imatinib mesylate and PDGF-BB-neutralizing antibodies reduced IL-6 and hyaluronan production by whole orbital tissue cultures from GO patients.

CONCLUSIONS

In GO, mast cells, monocytes, and macrophages may activate orbital fibroblasts via secretion of especially PDGF-AB and PDGF-BB. Preclinical studies with whole orbital tissue cultures show that blocking PDGF-B chain containing isoforms can be a promising treatment for GO.

Elevated levels of tumour necrosis factor (TNF)-α, interleukin (IL)-1β and IL-10 in hidradenitis suppurativa skin: a rationale for targeting TNF-α and IL-1β

BACKGROUND

The pathogenesis of hidradenitis suppurativa (HS) is largely unknown and the disease is difficult to treat. Patients are in high need of an effective treatment. Although it is not known whether the levels of tumour necrosis factor (TNF)-α are aberrant in HS skin, anti-TNF-α biologics are used, with variable clinical efficacy.

OBJECTIVES

To determine the cytokine profile in lesional and perilesional HS skin.

METHODS

We cultured 20 lesional and 10 normal-appearing perilesional HS skin samples, seven psoriasis and six healthy control skin samples in a transwell culture system. Two distinct cytokine bead arrays were used to measure the spectrum of inflammatory cytokines in the culture supernatant. Results from HS skin samples were compared with those of healthy and psoriasis skin.

RESULTS

The proinflammatory cytokines interleukin (IL)-1β and TNF-α as well as the anti-inflammatory cytokine IL-10 were significantly elevated in HS skin. Elevated levels of these cytokines were also found in perilesional HS skin. Fold increases relative to control skin of IL-1β, TNF-α and IL-10 in HS were 31, 5 and 34, compared with psoriasis: 4, 1 and 2, respectively. Levels of all three cytokines showed a trend towards a positive correlation with disease severity. IL-2, IL-4, IL-5 and interferon-γ were hardly detectable in HS or healthy control skin.

CONCLUSIONS

This study shows for the first time that IL-1β, TNF-α and IL-10 levels are elevated in HS skin. These data provide a rationale for therapies with biologics targeting cytokines such as TNF-α and IL-1.

Mitigation of septic shock in mice and rhesus monkeys by human chorionic gonadotrophin-related oligopeptides

The marked improvement of several immune-mediated inflammatory diseases during pregnancy has drawn attention to pregnancy hormones as potential therapeutics for such disorders. Low molecular weight fractions derived from the pregnancy hormone human chorionic gonadotrophin (hCG) have remarkable potent immunosuppressive effects in mouse models of diabetes and septic shock. Based on these data we have designed a set of oligopeptides related to the primary structure of hCG and tested these in models of septic shock in mice and rhesus monkeys. We demonstrate that mice exposed to lipopolysaccharide (LPS) and treated subsequently with selected tri-, tetra-, penta- and hepta-meric oligopeptides (i.e. MTR, VVC, MTRV, LQGV, AQGV, VLPALP, VLPALPQ) are protected against fatal LPS-induced septic shock. Moreover, administration of a cocktail of three selected oligopeptides (LQGV, AQGV and VLPALP) improved the pathological features markedly and nearly improved haemodynamic parameters associated with intravenous Escherichia coli-induced septic shock in rhesus monkeys. These data indicate that the designed hCG-related oligopeptides may present a potential treatment for the initial hyperdynamic phase of septic shock in humans.

Granulocytosis and thrombocytosis in renal cell carcinoma: a pro-inflammatory cytokine response originating in the tumour

BACKGROUND

In up to 20% of patients with renal cell cancer (RCC) an inflammatory response consisting of low-grade fever, weight loss and an elevated ESR and CRP may occur with modest granulocytosis and thrombocytosis. Clinical and experimental data suggest a pathogenic role for tumour-derived cytokine production, especially interleukin-6.

CASE REPORT

A 79-year-old female with RCC presented with low-grade fever, weight loss and overt granulocytosis and thrombocytosis. Radiological examination revealed a right-sided renal tumour. During nephrectomy a gradient between the IL-6 levels in the renal artery and vein was demonstrated, providing direct evidence for in vivo production of IL-6 by the tumour affected kidney, which was confirmed by the demonstration of IL -6 in the tumour cells by immunohistochemical staining and in the supernatant of the homogenised tumour. Cytogenetic examination revealed complex abnormalities including a gain of chromosome 7. In addition we demonstrated production of IL-1alpha, IL-1beta, IL-8 and ICAM-1 in the tumour with systemic elevated levels of IL-6 and IL-8 with secondary increased serum G-CSF and TPO levels.

CONCLUSION

We have provided direct evidence for the production of pro-inflammatory cytokines by renal cancer cells in a patient with RCC and a profound inflammatory response, with a central role of IL-6, probably due to a gain of chromosome 7. The extreme granulocytosis and thrombocytosis may have resulted from the secondary systemic production of G-CSF and TPO.

Human T-cell lines with well-defined T-cell receptor gene rearrangements as controls for the BIOMED-2 multiplex polymerase chain reaction tubes

The BIOMED-2 multiplex polymerase chain reaction (PCR) tubes for analysis of immunoglobulin and T-cell receptor (TCR) gene rearrangements have recently been introduced as a reliable and easy tool for clonality diagnostics in suspected lymphoproliferations. Quality and performance assessment of PCR-based clonality diagnostics is generally performed using human leukemia/lymphoma cell lines as controls. We evaluated the utility of 30 well-defined human T-cell lines for quality performance testing of the BIOMED-2 PCR primers and protocols. The PCR analyses of the TCR loci were backed up by Southern blot analysis. The clonal TCRB, TCRG and TCRD gene rearrangements were analyzed for gene segment usage and for the size and composition of their junctional regions. In 29 out of 30 cell lines, unique clonal TCR gene rearrangements could be easily detected. Besides their usefulness in molecular clonality diagnostics, these cell lines can now be authenticated based on their TCR gene rearrangement profile. This enables their correct use in molecular clonality diagnostics and in other cancer research studies.

CALM-AF10+ T-ALL expression profiles are characterized by overexpression of HOXA and BMI1 oncogenes

The t(10;11)(p13;q14-21) is found in T-ALL and acute myeloid leukemia and fuses CALM (Clathrin-Assembly protein-like Lymphoid-Myeloid leukaemia gene) to AF10. In order to gain insight into the transcriptional consequences of this fusion, microarray-based comparison of CALM-AF10+ vs CALM-AF10- T-ALL was performed. This analysis showed upregulation of HOXA5, HOXA9, HOXA10 and BMI1 in the CALM-AF10+ cases. Microarray results were validated by quantitative RT-PCR on an independent group of T-ALL and compared to mixed lineage leukemia-translocated acute leukemias (MLL-t AL). The overexpression of HOXA genes was associated with overexpression of its cofactor MEIS1 in CALM-AF10+ T-ALL, reaching levels of expression similar to those observed in MLL-t AL. Consequently, CALM-AF10+ T-ALL and MLL-t AL share a specific HOXA overexpression, indicating they activate common oncogenic pathways. In addition, BMI1, located close to AF10 breakpoint, was overexpressed only in CALM-AF10+ T-ALL and not in MLL-t AL. BMI1 controls cellular proliferation through suppression of the tumor suppressors encoded by the CDKN2A locus. This locus, often deleted in T-ALL, was conserved in CALM-AF10+ T-ALL. This suggests that decreased CDKN2A activity, as a result of BMI1 overexpression, contributes to leukemogenesis in CALM-AF10+ T-ALL. We propose to define a HOXA+ leukemia group composed of at least MLL-t, CALM-AF10 and HOXA-t AL, which may benefit from adapted management.

Purity for clarity: the need for purification of tumor cells in DNA microarray studies

It is now well established that gene expression profiling using DNA microarrays can provide novel information about various types of hematological malignancies, which may lead to identification of novel diagnostic markers. However, to successfully use microarrays for this purpose, the quality and reproducibility of the procedure need to be guaranteed. The quality of microarray analyses may be severely reduced, if variable frequencies of nontarget cells are present in the starting material. To systematically investigate the influence of different types of impurity, we determined gene expression profiles of leukemic samples containing different percentages of nonleukemic leukocytes. Furthermore, we used computer simulations to study the effect of different kinds of impurity as an alternative to conducting hundreds of microarray experiments on samples with various levels of purity. As expected, the percentage of erroneously identified genes rose with the increase of contaminating nontarget cells in the samples. The simulations demonstrated that a tumor load of less than 75% can lead to up to 25% erroneously identified genes. A tumor load of at least 90% leads to identification of at most 5% false-positive genes. We therefore propose that in order to draw well-founded conclusions, the percentage of target cells in microarray experiment samples should be at least 90%.

Disruption of the BCL11B gene through inv(14)(q11.2q32.31) results in the expression of BCL11B-TRDC fusion transcripts and is associated with the absence of wild-type BCL11B transcripts in T-ALL

T-cell acute lymphoblastic leukemia (T-ALL) is associated with chromosomal aberrations characterized by juxtaposition of proto-oncogenes to T-cell receptor gene loci (TCR), resulting in the deregulated transcription of these proto-oncogenes. Here, we describe the molecular characterization of a novel chromosomal aberration, inv(14)(q11.2q32.31), in a T-ALL sample, involving the recently described BCL11B gene and the TCRD locus. The inversion joined the 5' part of BCL11B, including exons 1-3, to the TRDD3 gene segment of the TCRD locus, whereas the reciprocal breakpoint fused the TRDV1 gene segment to the fourth exon of BCL11B. The TRDV1-BCL11B joining region was 1344 bp long and contained fragments derived from 20q11.22, 3p21.33 and from 11p12, indicating the complex character of this aberration. A strong expression of in-frame transcripts with truncated BCL11B and TCRD constant region (TRDC) were observed, but in contrast to normal T cells and other T-ALL samples, no wild-type BCL11B transcripts were detected in the T-ALL sample. Screening of 37 other T-ALLs revealed one additional case with expression of the BCL11B-TRDC fusion transcript. As BCL11B appears to play a key role in T-cell differentiation, BCL11B disruption and disturbed expression may contribute to the development of T-cell malignancies in man.

Short course dexamethasone treatment following injury inhibits bleomycin induced fibrosis in rats

BACKGROUND

Corticosteroids are routinely used in patients with pulmonary fibrosis. The timing for initiation of treatment is likely to be crucial for corticosteroids to exert an antifibrotic effect. Experimental studies in animals have examined the effect of corticosteroid treatment starting before or at the time of lung injury. However, this is not representative of the human condition as treatment only begins after disease has been established. We examined the effect of a short course corticosteroid treatment starting 3 days after bleomycin induced lung injury on the development of pulmonary fibrosis.

METHODS

Bleomycin (1.5 mg/kg) was instilled intratracheally into rats to induce pulmonary fibrosis. The effect of a 3-day course of dexamethasone (0.5 mg/kg) initiated 3 days after bleomycin induced lung injury on cell proliferation and collagen deposition was examined by analysing bronchoalveolar lavage (BAL) fluid and lung tissue.

RESULTS

Treating bleomycin exposed animals after injury with dexamethasone for 3 days inhibited lung collagen deposition compared with animals exposed to bleomycin without dexamethasone treatment (15.2 (2.2) mg collagen/lung v 22.5 (2.1) mg/lung; p<0.05). Dexamethasone treatment reduced pulmonary parenchymal cell proliferation in bleomycin exposed rats but did not influence BAL fluid mitogenic activity for lung fibroblasts or alter the BAL fluid levels of the fibrogenic mediators transforming growth factor-beta(1), platelet derived growth factor-AB, and thrombin.

CONCLUSIONS

A 3 day course of dexamethasone treatment initiated 3 days after bleomycin induced lung injury reduces lung cell proliferation and collagen deposition by mechanisms other than through reduction of transforming growth factor-beta(1), platelet derived growth factor-AB, and thrombin levels in BAL fluid. We propose that an early short course treatment with dexamethasone may be useful in inhibiting pulmonary fibrosis.

Dexamethasone treatment does not inhibit fibroproliferation in chronic lung disease of prematurity

Pulmonary fibrosis results from excessive fibroblast proliferation and increased collagen deposition and occurs in chronic lung disease of prematurity (CLD). Platelet-derived growth factor (PDGF)-BB is mitogenic for fibroblasts and levels are increased in fibrotic lung disorders. Systemic dexamethasone (DEX) treatment improves pulmonary function and reduces inflammation in infants with or at risk of CLD. However, the effect of DEX treatment on fibroblast activity, PDGF-BB and collagen synthesis in the lungs of CLD patients is uncertain. Bronchoalveolar lavage (BAL) fluids, obtained from 15 infants at risk of CLD before and after DEX treatment, were analysed for fibroblast mitogenicity, PDGF-BB, N-terminal propeptide of collagen type III (PIIINP) and interleukin (IL)-1beta levels and inflammatory cell numbers. After DEX treatment, the mitogenic activity of BAL fluid for fibroblasts was not reduced but increased. The change in mitogenicity correlated with a change in BAL fluid PDGF-BB levels. Furthermore, BAL fluid-induced fibroblast proliferation was blocked using an inhibitor of the PDGF receptor. DEX treatment did not influence PIIINP levels, but reduced IL-1beta levels and inflammatory cell numbers in BAL fluid. This study suggests that dexamethasone treatment does not reduce fibroblast proliferation despite apparent downregulation of inflammation. The present findings do not support the use of dexamethasone for prevention of the fibrotic response in infants at risk of chronic lung disease of prematurity.

Localization and potential role of matrix metalloproteinase-1 and tissue inhibitors of metalloproteinase-1 and -2 in different phases of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) can evolve in prematurely born infants who require mechanical ventilation because of hyaline membrane disease (HMD). The development of BPD can be divided in an acute, a regenerative, a transitional, and a chronic phase. During these different phases, extensive remodeling of the lung parenchyma with re-epithelialization of the alveoli and formation of fibrosis occurs. Matrix metalloproteinase-1 (MMP-1) is an enzyme that is involved in re-epithelialization processes, and dysregulation of MMP-1 activity contributes to fibrosis. Localization of MMP-1 and its inhibitors, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2, were investigated in lung tissue obtained from infants who died during different phases of BPD development. In all studied cases (n = 50) type-II pneumocytes were found to be immunoreactive for MMP-1, TIMP-1, and TIMP-2. During the acute and regenerative phase of BPD, type-II pneumocytes re-epithelialize the injured alveoli. This may suggest that MMP-1 and its inhibitors, expressed by type-II pneumocytes, play a role in the re-epithelialization process after acute lung injury. Although MMP-1 staining intensity remained constant in type-II pneumocytes during BPD development, TIMP-1 increased during the chronic fibrotic phase. This relative elevation of TIMP-1 compared with MMP-1 is indicative for reduced collagenolytic activity by type-II pneumocytes in chronic BPD and may contribute to fibrosis. Fibrotic foci in chronic BPD contained fibroblasts immunoreactive for MMP-1 and TIMP-1 and -2. This may indicate that decreased collagen turnover by fibroblasts contributes to fibrosis in BPD development.

Factor Xa is a fibroblast mitogen via binding to effector-cell protease receptor-1 and autocrine release of PDGF

The coagulation cascade protease thrombin is a fibroblast mitogen, but the proliferative potential of other coagulation proteases is not known. In this study we show that factor Xa stimulated human fetal lung fibroblast DNA synthesis in a concentration-dependent manner from 1 nM onward with a fourfold increase at 200 nM. The mitogenic effect of factor Xa was confirmed using a colorimetric proliferation assay and direct cell counting. Factor Xa and thrombin had equivalent potencies, and their stimulatory effects followed a similar time course. Comparable results were also obtained with primary human adult fibroblasts derived from lung, kidney, heart, skin, and liver. Factor VIIa also stimulated fibroblast proliferation, but only at concentrations >10 nM, whereas factor IXa had no effect. To begin to address the mechanism by which factor Xa is acting, we show that human fibroblasts express effector-cell protease receptor-1 and that blocking antibodies to this receptor and the catalytic site of factor Xa inhibited its mitogenic effect. Furthermore, factor Xa upregulated platelet-derived growth factor-A (PDGF-A) mRNA expression, whereas PDGF-B could not be detected, and a blocking antibody to PDGF inhibited the mitogenic effect of factor Xa. We conclude that factor Xa acts as a fibroblast mitogen via binding to effector-cell protease receptor-1 and the autocrine release of PDGF.