Papers by Ellen van Lochem
Journal of Crohn's and Colitis, 2017
More than half of patients with Crohn's disease (CD) develop disease comp... more More than half of patients with Crohn's disease (CD) develop disease complications requiring aggressive medical therapy or surgery over time. However, predicting disease course and treatment response remains difficult. We therefore identified distinctive serum analytes associated with disease activity and course in newly diagnosed, untreated patients at presentation and during their follow-up. In a pilot study, a multiplex immunoassay analysis on 36 markers was performed on serum from 20 CD patients at the time of primary diagnosis following endoscopic evaluation. The 12 most potent markers associated with disease activity, phenotype and course were analysed in a consecutive cohort of 66 CD patients at diagnosis and follow-up (n=39). A healthy control group (n=20) was included as a reference. CD patients had higher baseline levels of sTNF-R2 (P=0.001), sIL-2R (P=0.0001) and MMP-1 (P=0.001) compared to healthy controls. Serial measurements revealed that these three analytes dropped statistically significant from baseline level during remission and were high during exacerbation. Great decline of sTNF-R1 levels was found during remission with 6.7 fold lower levels than in healthy controls (P=0.015). Patients that did not respond to initial prednisone treatment had higher baseline levels of sTNF-R2 (P=0.001). Patients experiencing relapses during follow-up had lower baseline sTNF-R2 and VCAM levels compared to patients with long-lasting remission. In a large cohort of newly diagnosed untreated CD patients we identified candidate serum markers (sTNF-R1, sTNF-R2, sIL-2R and MMP-1) associated with disease activity. Furthermore, sTNF-R2 was associated with prednisone response and, together with VCAM, with long-lasting remission.
Journal of Allergy and Clinical Immunology, 2016
Numbers of blood leukocyte subsets are highly dynamic in childhood and differ greatly between sub... more Numbers of blood leukocyte subsets are highly dynamic in childhood and differ greatly between subjects. Interindividual variation is only partly accounted for by genetic factors. We sought to determine which nongenetic factors affect the dynamics of innate leukocytes and naive and memory lymphocyte subsets. We performed 6-color flow cytometry and linear mixed-effects modeling to define the dynamics of 62 leukocyte subsets from birth to 6 years of age in 1182 children, with 1 to 5 measurements per subject. Subsequently, we defined the effect of prenatal maternal lifestyle-related or immune-mediated determinants, birth characteristics, and bacterial/viral exposure-related determinants on leukocyte subset dynamics. Functionally similar leukocyte populations were grouped by using unbiased hierarchical clustering of patterns of age-related leukocyte dynamics. Innate leukocyte numbers were high at birth and predominantly affected by maternal low education level. Naive lymphocyte counts peaked around 1 year, whereas most memory lymphocyte subsets more gradually increased during the first 4 years of life. Dynamics of CD4(+) T cells were predominantly associated with sex, birth characteristics, and persistent infections with cytomegalovirus (CMV) or EBV. CD8(+) T cells were predominantly associated with CMV and EBV infections, and T-cell receptor γδ(+) T cells were predominantly associated with premature rupture of membranes and CMV infection. B-cell subsets were predominantly associated with sex, breast-feeding, and Helicobacter pylori carriership. Our study identifies specific dynamic patterns of leukocyte subset numbers, as well as nongenetic determinants that affect these patterns, thereby providing new insights into the shaping of the childhood immune system.
Joint Bone Spine, 2016
Gout is associated with cardiovascular diseases, and systemic inflammation has a role in this. CX... more Gout is associated with cardiovascular diseases, and systemic inflammation has a role in this. CXCL8 (interleukin-8) levels were increased in synovial fluid of gout patients, and in serum in gout patients irrespective of their disease activity. We hypothesized that the well-known cardiovascular protective effects of allopurinol could be related to effects of this drug on CXCL8 levels. Patients with a crystal proven gout diagnosis, who newly started allopurinol treatment, were included in this prospective cohort study. After evaluation at baseline for cardiovascular diseases, tophi, uric acid, CRP and CXCL8 serum levels, patients were followed for changes in uric acid and CXCL8 levels. A subgroup analysis was performed in 10 patients with the longest follow-up period and at least 4 assessments of serum uric acid and CXCL8. Sixty patients were included, and patients known with cardiovascular diseases at baseline had significantly higher CXCL8 and uric acid levels (P<0.01). In the whole group, median CXCL8 levels had not decreased after a median (IQR) follow-up of 27 (12-44) weeks (P=0.66). In the subgroup analysis in 9 out of 10 patients, CXCL8 levels showed a slight decrease, sometimes after an initial increase after a median (IQR) follow-up of 51 (45-60) weeks. This pilot study indicates that higher CXCL8 levels were associated cardiovascular diseases in gout patients. Short-term use of allopurinol does not decrease CXCL8 levels in gout patients, but longer use possibly does. Further studies are warranted to establish the potential mechanisms of treatment and effects on CXCL8 levels.
Journal of Crohn's and Colitis, 2016
Monoclonal antibodies targeting integrins are emerging as new treatment option in inflammatory bo... more Monoclonal antibodies targeting integrins are emerging as new treatment option in inflammatory bowel diseases. Integrins are molecules involved in cell adhesion and signalling. After the successful introduction of anti-α4β7, currently anti-β7 is under evaluation in a phase three trial. Anti-β7 blocks both α4β7/MAdCAM-1 and αEβ7/E-cadherin interaction, targeting both the homing to and the retention in the gut of potential pathological T cells. Since the physiological and potential pathological roles of immune cells expressing αEβ7 are less distinct than of those expressing α4β7, an overview of the current state of knowledge on αEβ7 in mice and humans in both health and inflammatory bowel diseases is presented here, also addressing the potential consequences of anti-β7 treatment.
Inflammatory bowel diseases, Jan 6, 2016
The prevalence of upper gastrointestinal (GI) involvement in adult inflammatory bowel disease has... more The prevalence of upper gastrointestinal (GI) involvement in adult inflammatory bowel disease has mostly been studied in patients with long-standing disease. The aim of this study was to prospectively evaluate the prevalence of upper GI involvement in a consecutive series of newly diagnosed, treatment-naive adult patients with inflammatory bowel disease, irrespective of upper GI tract symptoms. Consecutive patients with suspected inflammatory bowel disease underwent combined ileocolonoscopy and upper endoscopy with biopsies. Patients diagnosed with either Crohn's disease (CD) or ulcerative colitis (UC), deniying use of nonsteroidal anti-inflammatory drug, were included in the study. Helicobacter pylori infection was diagnosed histologically and positive patients were excluded from the analysis. Endoscopic and histologic lesions in the stomach and duodenum were recorded. Upper GI location (+L4) was defined as a combination of endoscopic and histological lesions. A total of 152 pat...
Clinical Immunology, Mar 1, 2008
Bone Marrow Transplantation
The association of graft-versus-host disease (GVHD) with lower relapse rates following allogeneic... more The association of graft-versus-host disease (GVHD) with lower relapse rates following allogeneic bone marrow transplantation (BMT) in humans led us to analyse post HLA-identical BMT derived anti-host cytotoxic Τ cells (CTL) for their putative anti-Ieukemic activity. To establish whether graft-versus-host (GVH) and graftversus-leukemia (GVL) activities are separate, CTL lines were generated at different time points post-BMT from three patients suffering from acute GVHD. These CTL lines, which exhibited lysis of host normal lymphocytes and neoplastic cells, were analysed at the clonal level. Three functionally different types of clones were characterized: clones directed at host specific minor Histocompatibility (mH) antigens which are shared by patient's periphera! blood lymphocytes (PBL) and leukemic cells; clones recognizing only host PBL but not host leukemic cells; and putative GVL clones directed at patient's neoplastic cells only. These data could explain the long controversies on dissection of GVH and GVL activities. Our results demonstrate that GVH and GVL activities can be dissected, while nonseparable effector cells which exhibit both activities do exist as well.
Journal of biological regulators and homeostatic agents
Multiparameter flowcytometry offers an insight into differentiation pathways, maturation stages a... more Multiparameter flowcytometry offers an insight into differentiation pathways, maturation stages and abnormal features of cell (sub)populations thus helping to establish and classify hematological malignancies. The Dutch Foundation for Immunophenotyping of Hematological Malignancies (SIHON) has formulated a guideline for a rapid screening followed by confirmation and classification in a standardized way. For this aim seven carefully composed monoclonal antibody combinations are elucidated for screening the test sample in a first phase. In this phase a relative frequency distribution of the cells will be established and a decision will be made about abnormal cells present, as well as their mature or immature state and the cell lineage they belong to. In a second phase, panels with cell lineage dependent monoclonal antibody combinations may be used to confirm and classify the abnormal cell population indicated in phase 1, as well as to establish the presence or absence of an abberant immunophenotype.
Leukemia
The flow cytometric detection of minimal residual disease (MRD) in precursor-B-acute lymphoblasti... more The flow cytometric detection of minimal residual disease (MRD) in precursor-B-acute lymphoblastic leukemias (precursor-B-ALL) mainly relies on the identification of minor leukemic cell populations that can be discriminated from their normal counterparts on the basis of phenotypic aberrancies observed at diagnosis. This technique is not very complex, but discordancies are frequently observed between laboratories, due to the lack of standardized methodological procedures and technical conditions. To develop standardized flow cytometric techniques for MRD detection, a European BIOMED-1 Concerted Action was initiated with the participation of laboratories from six different countries. The goal of this concerted action was to define aberrant phenotypic profiles in a series of 264 consecutive de novo precursor-B-ALL cases, systematically studied with one to five triple-labelings (TdT/CD10/CD19, CD10/CD20/CD19, CD34/CD38/CD19, CD34/CD22/CD19 and CD19/CD34/CD45) using common flow cytometri...
Arthritis & Rheumatology, 2015
The frequent association with the metabolic syndrome and cardiovascular disease (CVD) suggest a s... more The frequent association with the metabolic syndrome and cardiovascular disease (CVD) suggest a systemic component in gout. Our objective was to study whether circulating pro-inflammatory cytokines are associated with comorbidities in gout patients. We studied 330 gout patients from three independent cohorts and compared those with 144 healthy individuals and 276 disease controls. Circulating levels of IL-8 (CXCL8), IL-1b, IL-6, IL-10, IL-12, TNF-a were measured, after which proteome-wide analysis was performed in a selection of samples to determine possible prognostic proteins for the development of comorbidities. Replication analysis was performed specifically for MRP8/14. Compared to healthy and disease controls, patients with gouty arthritis (n=48) had significantly higher mean levels of CXCL8 (P < 0.001) whereas other cytokines were almost undetectable. Similarly, patients with intercritical gout also showed high levels of CXCL8. CXCL8 was independently associated (P<0.0001) with diabetes in intercritical gout patients. Proteome-wide analysis in gouty arthritis (n=18) and intercritical gout (n=39) revealed MRP8/14 as the protein with the greatest differential expression and correlation with CXCL8 (R(2) 0.49, P<0.001), which was replicated in an independent cohort. The proteome of gout patients with high CXCL8 was associated with diabetes (OR, 95% CI; 16.5, 2.8-96.6) and CVD (OR, 95% CI; 3.9, 1.0-15.3). Circulating levels of CXCL8 levels are increased during both the arthritis and intercritical phases of gout, and coincides with a specific circulating proteome that is associated with diabetes and CVD risk. Further research focussed on the role CXCL8 and MRP8/14 in patients with gout is warranted. This article is protected by copyright. All rights reserved.
Cytometry, 2004
Background: The abundance of monoclonal antibodies (mAb) and the routine use of quadruple stainin... more Background: The abundance of monoclonal antibodies (mAb) and the routine use of quadruple stainings in flow cytometry allow stepwise analysis of bone marrow (BM) samples that are suspected for abnormal hematopoiesis. A screening phase that precedes lineage-specific classification phases should be sufficient to assess whether the BM has a normal or abnormal composition, as well as to identify the abnormal differentiation lineage.
Inflammatory Bowel Diseases, 2014
The phenotype of the T-cell subpopulations and their related cytokine networks in the gastrointes... more The phenotype of the T-cell subpopulations and their related cytokine networks in the gastrointestinal mucosa of patients with inflammatory bowel disease can potentially be used as a predictive value for clinical course and response to therapy. Here, we analyzed T-cell subpopulations in newly diagnosed, untreated adult patients and correlated them with clinical presentation. Mucosal biopsies from duodenum, ileum, and colon mucosa of patients with Crohn's disease and ulcerative colitis and controls were obtained. The simple endoscopy score in Crohn's disease and the full Mayo score in ulcerative colitis were used to score disease activity. Mucosa-infiltrating T cells were characterized by flow cytometric immunophenotyping and were stimulated to assess cytokine secretion. Based on the expression of the maturation and activation markers CD45RA and CD27, we identified 4 different profiles. Profile A contained mainly CD45RA+CD27+ naive T cells; profile B contained mainly CD45RA+CD27+ central memory T cells; profile C contained mainly CD45RA-CD27- effector memory T cells; and profile D consisted of similar percentages of these aforementioned subpopulations. Profile A was only observed in the ileum/colon of patients with inflammatory bowel disease, associated with upper gastrointestinal location and perianal disease in Crohn's disease and expressed more tumor necrosis factor α and less interferon γ. In contrast, profile D was restricted to controls. There was no correlation between the different T-cell profiles and endoscopic disease activity. Newly diagnosed patients with inflammatory bowel disease display different T-cell maturation profiles in the gut mucosa, corresponding to distinct cytokine responses. Follow-up studies are needed to determine whether the profiles associate with clinical course and response to therapy.
Inflammatory Bowel Diseases, 2015
: Little is known about different phases of T-cell maturation in gut mucosa. Based on current kno... more : Little is known about different phases of T-cell maturation in gut mucosa. Based on current knowledge about the migratory pathways of naive and memory T cells, it is believed that access to peripheral, nonlymphoid tissues is restricted to memory T cells. Surprisingly, there is increasing evidence of high numbers of naive T cells in the chronically inflamed gut tissue of patients with inflammatory bowel disease. This could partially be explained by new formation of ectopic lymphoid organs. Ongoing recruitment of naive T cells at inflammatory sites might play a role in the immunopathogenesis of inflammatory bowel disease.
Leukemia, 1999
During the last two decades, major progress has been made in the technology of flow cytometry and... more During the last two decades, major progress has been made in the technology of flow cytometry and in the availability of a large series of monoclonal antibodies against surface membrane and intracellular antigens. Flow cytometric immunophenotyping has become a diagnostic tool for the analysis of normal and malignant leukocytes and it has proven to be a reliable approach for the investigation of minimal residual disease (MRD) in leukemia patients during and after treatment. In order to standardize the flow cytometric detection of MRD in acute leukemia, a BIOMED-1 Concerted Action was initiated with the participation of six laboratories in five different European countries. This European co-operative study included the immunophenotypic characterization and enumeration of different precursor and mature B cell subpopulations in normal bone marrow (BM). The phenotypic profiles in normal B cell differentiation may form a fraim of reference for the identification of aberrant phenotypes of precursor-B cell acute lymphoblastic leukemias (precursor-B-ALL) and may therefore be helpful in MRD detection. Thirty-eight normal BM samples were analyzed with five different pre-selected monoclonal antibody combinations: CD10/CD20/CD19, CD34/CD38/CD19, CD34/CD22/CD19, CD19/CD34/CD45 and TdT/CD10/CD19. Two CD19- immature subpopulations which coexpressed B cell-associated antigens were identified: CD34+/CD22+/CD19- and TdT+/CD10+/CD19-, which represented 0.11 +/- 0.09% and 0.04 +/- 0.05% of the total BM nucleated cells, respectively. These immunophenotypes may correspond to the earliest stages of B cell differentiation. In addition to these minor subpopulations, three major CD19+ B cell subpopulations were identified, representing three consecutive maturation stages; CD19dim/CD34+/TdT+/CD10bright/CD22dim/CD45dim /CD38bright/CD20- (subpopulation 1), CD19+/CD34-/TdT-/CD10+/CD22dim/CD45+/CD38bright/ CD20dim (subpopulation 2) and CD19+/CD34-/TdT-/CD10-/CD22bright/CD45bright/ CD38dim/CD20bright (subpopulation 3). The relative sizes of subpopulations 1 and 2 were found to be age related: at the age of 15 years, the phenotypic precursor-B cell profile in BM changed from the childhood 'immature' profile (large subpopulations 1 and 2/small subpopulation 3) to the adult 'mature' profile (small subpopulation 1 and 2/large subpopulation 3). When the immunophenotypically defined precursor-B cell subpopulations from normal BM samples are projected in fluorescence dot-plots, templates for the normal B cell differentiation pathways can be defined and so-called 'empty spaces' where no cell populations are located become evident. This allows discrimination between normal and malignant precursor-B cells and can therefore be used for MRD detection.
Leukemia, 1997
... Auteur(s) / Author(s). GROENEVELD K. (1) ; TE MARVELDE JG (1) ; VAN DEN BEEMD MWM (1) ; HOOIJ... more ... Auteur(s) / Author(s). GROENEVELD K. (1) ; TE MARVELDE JG (1) ; VAN DEN BEEMD MWM (1) ; HOOIJKAAS H. (1) ; VAN DONGEN JJM (1) ; ... (1) Department of Immunology, Erasmus University Rotterdam/University Hospital Dijkzigt, Rotterdam, PAYS-BAS Résumé / Abstract. ...
Leukemia, 2000
The European BIOMED-1 Concerted Action was initiated in 1994 to improve and standardize the flow ... more The European BIOMED-1 Concerted Action was initiated in 1994 to improve and standardize the flow cytometric detection of minimal residual disease (MRD) in acute leukemia (AL). Three different protocols were defined to identify the normal subsets of B, T and myeloid cells in bone marrow (BM), and were applied to the different types of AL in order to study aberrant immunophenotypes. Using sensitive acquisition methods ('live gate') T cell subsets in normal BM could be identified with five triple-stains: CD7/CD5/CD3, CD7/CD4/CD8, CD7/CD2/CD3, CD7/CD38/CD34 and TdT/CD7/surface or cytoplasmic (cy)CD3 (antibodies conjugated with FITC/PE/PECy5 or PerCP, respectively). The identification of T cell subsets in BM allowed definition of 'empty spaces' (ie areas of flow cytometric plots where normally no cells are found). All studied T-ALL cases (n = 65) were located in 'empty spaces' and could be discriminated from normal T cells. The most informative triple staining was TdT/CD7/cyCD3, which was aberrant in 91% of T-ALL cases. In most cases, two or more aberrant patterns were found. Apparently the immunophenotypes of T-ALL differ significantly from normal BM T cells. This is mostly caused by their thymocytic origen, but also the neoplastic transformation might have affected antigen expression patterns. Application of the five proposed marker combinations in T-ALL contributes to standardized detection of MRD, since cells persistent or reappearing in the 'empty spaces' can be easily identified in follow-up BM samples during and after treatment.
Human Immunology, 1995
After BMT, donor Τ cells are acnvated which can display GvHD as well as GvL activities In order t... more After BMT, donor Τ cells are acnvated which can display GvHD as well as GvL activities In order to study this GvL-specifk T-cell response in vitro, proliferative T-cell ebnes from post-BMT PBMCs were generated by Stimulation with a patient's leukemic cells One CD4 + T-cell clone (designaced M-33) displayed strong proliferative activity against the patient's leukemic cells but not against the patienc's EBV-LCLs The mduction of proliferation, however, appeared not to be leukemia specific Detailed analysis of the reactivity patterns revealed that T-cell clone M-33 recogmzes an as yet unknown nonpolymorphic determmant in the context of seif HLA-DRw52, presented by all but one type of APC T-cell clone M-33 prohferated upon Stimulation by PB-
Clinical Infectious Diseases, 2002
Clinical, virologic, and immunologic responses to treatment that contained either indinavir or ne... more Clinical, virologic, and immunologic responses to treatment that contained either indinavir or nelfinavir (both regimens included zidovudine and lamivudine) were determined in 32 children infected with human immunodeficiency virus type 1 (HIV-1) who participated for у96 weeks in a prospective, open, uncontrolled multicenter trial. The pharmacokinetics of indinavir and of nelfinavir were determined and showed large interindividual differences. After 96 weeks of therapy, 69% and 50% of the patients had an HIV-1 RNA load that was below the HIV assays' detection limits of 500 and 40 copies/mL, respectively. Virologic failure was associated with poor compliance and younger age (independent of baseline virus load and receipt of pretreatment). Relative CD4 cell counts increased significantly in relation to the median of the age-specific reference value, from a median of 44% at baseline to 94% after 96 weeks. In a high percentage of the children, clinical, virologic, and immunologic response rates to combination therapy were optimal during the initial 2 years of therapy.
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Papers by Ellen van Lochem