Jacob Sont

Dr. Jacob Sont

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Research Focus & Metrics

Academic Career Length

35Years (1992-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 June 2014 in JAMA
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JLJacob M. van Laar
Jacob M. van Laar
DFDominique Farge
Dominique Farge
JSJacob Sont
Jacob Sont
KNKamran Naraghi
Kamran Naraghi
ZMZora Marjanovic
Zora Marjanovic
ATAlan Tyndall
Alan Tyndall
Quiz Ref ID Systemic sclerosis is a heterogeneous autoimmune connective tissue disease characterized by vasculopathy, autoantibody formation, low-grade inflammation, and fibrosis in skin and internal organs, with varying geographical prevalence (50-300 per million persons per year) and incidence (2.3-22.8 per million persons per year).1,2 Previous studies have shown that systemic sclerosis is amenable to treatment with autologous hematopoietic stem cell transplantation (HSCT).3-9 Improvement of skin involvement and functional ability was consistently observed, although some studies showed that HSCT can also ameliorate vasculopathy, improve skin and lung involvement, and correct immune abnormalities.10-13 The benefits of HSCT must be weighed against the risk of serious toxicities due to organ involvement in systemic sclerosis.14 It is still unclear whether HSCT prolongs survival in systemic sclerosis. We therefore conducted a randomized clinical trial called ASTIS (Autologous Stem Cell Transplantation International Scleroderma) to compare safety and efficacy of HSCT vs 12 successive monthly intravenous pulses of cyclophosphamide.

1 April 1999 in American Journal of Respiratory and Critical Care Medicine
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Journal Article
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JSJacob Sont
Jacob Sont
LWLuuk N. A. Willems
Luuk N. A. Willems
EBElisabeth H. Bel
Elisabeth H. Bel
JKJ.Han J. M. van Krieken
J.Han J. M. van Krieken
JVJan P. Vandenbroucke
Jan P. Vandenbroucke
TGthe AMPUL Study Group
the AMPUL Study Group
According to international guidelines, the level and adjustment of antiinflammatory treatment for asthma are based solely on symptoms and lung function. We investigated whether a treatment strategy aimed at reducing airway hyperresponsiveness (AHR strategy) in addition to the recommendations in the existing guidelines (reference strategy) led to: (1) more effective control of asthma; and (2) greater improvement of chronic airways inflammation. To accomplish this, we conducted a randomized, prospective, parallel trial involving 75 adults with mild to moderate asthma who visited a clinic every 3 mo for 2 yr. At each visit, FEV1 and AHR to methacholine were assessed, and subjects kept diaries of symptoms, β2-agonist use, and peak expiratory flow (PEF). Medication with corticosteroids (four levels) was adjusted according to a stepwise approach (reference strategy), to which four severity classes of AHR were added (AHR strategy). At entry and after 2 yr, bronchial biopsies were obtained by fiberoptic bronchoscopy. Patients treated according to the AHR strategy had a 1.8-fold lower rate of mild exacerbations than did patients in the reference strategy group (0.23 and 0.43 exacerbation/yr/patient, respectively). FEV1 also improved to a significantly greater extent in the AHR strategy group (p ⩽ 0.05). In bronchial biopsies this was accompanied by a greater reduction in thickness of the subepithelial reticular layer in the AHR strategy group than in the reference strategy group (mean difference [95% confidence interval (CI): 1.7 μ m (0.2 to 3.1) μ m]). The changes in AHR in both strategy groups were correlated with eosinophil counts in the biopsies (r = − 0.48, p = 0.003). We conclude that reducing AHR in conjunction with optimizing symptoms and lung function leads to more effective control of asthma while alleviating chronic airways inflammation. This implies a role for the monitoring of AHR or other surrogate markers of inflammation in the long-term management of asthma.

22 March 2000 in The Journal of Pathology
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WBWillem I. de Boer
Willem I. de Boer
JSJacob Sont
Jacob Sont
ASAnnemarie van Schadewijk
Annemarie van Schadewijk
JSJan Stolk
Jan Stolk
JKJ. Han van Krieken
J. Han van Krieken
PHPieter S. Hiemstra
Pieter S. Hiemstra

1 May 1996 in Thorax
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Journal Article
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JSJacob Sont
Jacob Sont
JHJ. Han
J. Han
JKJ. M. van Krieken
J. M. van Krieken
CEC. E. Evertse
C. E. Evertse
RHR. Hooijer
R. Hooijer
PSP. J. Sterk
P. J. Sterk
BACKGROUND: Current guidelines on the management of asthma advocate the use of anti-inflammatory treatment in all but mild disease. They define disease control in terms of clinical criteria such as lung function and symptoms. However, the relationship between the clinical control of the disease and inflammation of the airways is not clear. A cross sectional study was therefore undertaken to investigate the relationship between airways inflammation and measures of clinical control and bronchial hyperresponsiveness in asthmatic patients treated with inhaled steroids. METHODS: Twenty six atopic adults (19-45 years) with mild to moderate asthma (baseline forced expiratory volume in one second (FEV1) > or = 50% predicted, concentration of histamine causing a 20% fall in FEV1 (PC20) 0.02-7.6 mg/ml) on regular treatment with inhaled steroids entered the study. Diary card recordings during the two weeks before a methacholine challenge test and bronchoscopic examination were used to determine peak flow variability, symptom scores, and use of beta 2 agonists. Biopsy specimens were taken by fibreoptic bronchoscopy from the carina of the right lower and middle lobes, and from the main carina. Immunohistochemical staining was performed on cryostat sections with monoclonal antibodies against: eosinophil cationic protein (EG1, EG2), mast cell tryptase (AA1), CD45, CD22, CD3, CD4, CD8, CD25, and CD45RO. The number of positively stained cells in the lamina propria was counted twice by using an interactive display system. RESULTS: There were no differences in cell numbers between the three sites from which biopsy specimens were taken. The PC20 for methacholine was inversely related to the average number of total leucocytes, EG1+, and EG2+ cells, mast cells, CD8+, and CD45RO+ cells in the lamina propria. These relationships were similar for each of the biopsy sites. Symptom scores, beta 2 agonist usage, FEV1, and peak flow variability were not related to any of the cell counts. CONCLUSIONS: Infiltration of inflammatory cells in the lamina propria of the airways seems to persist in asthmatic outpatients despite regular treatment with inhaled steroids. The number of infiltrating leucocytes such as mast cells, (activated) eosinophils, CD8+, and CD45RO+ cells in bronchial biopsy specimens from these patients appears to be reflected by airway hyperresponsiveness to methacholine, but not by symptoms or lung function. These findings may have implications for the adjustment of anti-inflammatory treatment of patients with asthma.

9 September 2011 in Brain
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FCFieke M. Cox
Fieke M. Cox
MTMaarten J. Titulaer
Maarten J. Titulaer
JSJacob Sont
Jacob Sont
AWAxel R. Wintzen
Axel R. Wintzen
JVJan J. G. M. Verschuuren
Jan J. G. M. Verschuuren
UBUmesh A. Badrising
Umesh A. Badrising
Sporadic inclusion body myositis is considered to be a slowly progressive myopathy. Long-term follow-up data are, however, not yet available. Follow-up data are important with a view to informing patients about their prognosis and selecting appropriate outcome measures for clinical trials. We performed a follow-up study of 64 patients with sporadic inclusion body myositis who participated in a national epidemiological study in the Netherlands. Case histories were recorded, and manual and quantitative muscle tests as well as laboratory tests were performed at baseline and 12 years (median) after the first out-patient visit. Date and cause of death were recorded for all deceased patients. Forty-six patients died during the follow-up period, two patients chose not to participate and one patient was lost to follow-up. The remaining 15 surviving patients had a mean disease duration of 20 years and were clinically evaluated at the second time point. The mean decline in strength was 3.5 and 5.4% per year according to the manual muscle testing and quantitative muscle testing, respectively. This decline was most pronounced in the lower legs, which were also the weakest extremities. Life expectancy was normal at 81 years, but activities of daily life were clearly restricted. At follow-up, all patients were found to be using a wheelchair, seven of them (47%) being completely wheelchair-bound. Disorders of the respiratory system were the most common cause of death. In three patients, euthanasia was requested and in another three, continuous deep sedation was applied. The fact that end-of-life care interventions were used in six patients (13%) reflects the severe disability and loss of quality of life at the end stage of this disease. Sporadic inclusion body myositis is a chronic progressive disorder, leading to major disabilities at the end stage of the disease due to extensive muscle weakness.

1 March 2011 in Journal of Clinical Oncology
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MTMaarten J. Titulaer
Maarten J. Titulaer
PMPaul Maddison
Paul Maddison
JSJacob Sont
Jacob Sont
PWPaul W. Wirtz
Paul W. Wirtz
DHDavid Hilton-Jones
David Hilton-Jones
JVJan J.G.M. Verschuuren
Jan J.G.M. Verschuuren
Purpose: Approximately one half of patients with Lambert-Eaton myasthenic syndrome (LEMS) have small-cell lung carcinomas (SCLC), aggressive tumors with poor prognosis. In view of its profound impact on therapy and survival, we developed and validated a score to identify the presence of SCLC early in the course of LEMS. Patients and Methods: We derived a prediction score for SCLC in LEMS in a nationwide cohort of 107 Dutch patients, and validated it in a similar cohort of 112 British patients. A Dutch-English LEMS Tumor Association Prediction (DELTA-P) score was developed based on multivariate logistic regression. Results: Age at onset, smoking behavior, weight loss, Karnofsky performance status, bulbar involvement, male sexual impotence, and the presence of Sry-like high-mobility group box protein 1 serum antibodies were independent predictors for SCLC in LEMS. A DELTA-P score was derived allocating 1 point for the presence of each of the following items at or within 3 months from onset: age at onset ≥ 50 years, smoking at diagnosis, weight loss ≥ 5%, bulbar involvement, erectile dysfunction, and Karnofsky performance status lower than 70. The area under the curve of the receiver operating curve was 94.4% in the derivation cohort and 94.6% in the validation set. A DELTA-P score of 0 or 1 corresponded to a 0% to 2.6% chance of SCLC, whereas scores of 4, 5, and 6 corresponded to chances of SCLC of 93.5%, 96.6%, and 100%, respectively. Conclusion: The simple clinical DELTA-P score discriminated patients with LEMS with and without SCLC with high accuracy early in the course of LEMS.