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Featured researches published by Johan Schiettecatte.


Thyroid | 2002

Thyroid dysfunction and autoimmunity in infertile women

Kris Poppe; Daniel Glinoer; André Van Steirteghem; Herman Tournaye; Paul Devroey; Johan Schiettecatte; Brigitte Velkeniers

A prospective study was undertaken in 438 women (ages, 32 +/- 5 years) with various causes of infertility, and in 100 age-matched (33 +/- 5 years) healthy parous controls with the aim of assessing the prevalence of autoimmune thyroid disease (AITD) and hitherto undisclosed alterations of thyroid function. Female origin of the infertility was diagnosed in 45% of the couples, with specific causes including endometriosis (11%), tubal disease (30%), and ovarian dysfunction (59%). Male infertility represented 38% and idiopathic infertility 17% of the couples. Overall, median thyrotropin (TSH) was significantly higher in patients with infertility compared to controls: 1.3 (0.9) versus 1.1 (0.8) mIU/L. Serum TSH above normal (>4.2 mIU/L) or suppressed TSH (<0.27 mIU/L) levels were not more prevalent in the infertile women than in controls. The prevalence of positive thyroid peroxidase antibody (TPO-Ab) was higher in all investigated women of infertile couples, compared to controls (14% vs. 8%), but the difference was not significant. However, in infertility of female origin, a significant higher prevalence of positive TPO-Ab was present, compared to controls: 18% versus 8%. Furthermore, among the female causes, the highest prevalence of positive antibodies was observed in women with endometriosis (29%). When thyroid antibodies were positive, both hypothyroidism and hyperthyroidism were more frequent in all women of infertile couples and in the women with a female infertility cause, compared to women in the same groups but without positive TPO-Ab. The present study shows that in infertile women, thyroid autoimmunity features are significantly more frequent than in healthy fertile controls and this was especially the case for the endometriosis subgroup.


Critical Care Medicine | 2006

Elevated serum levels of S-100β protein and neuron-specific enolase are associated with brain injury in patients with severe sepsis and septic shock

Duc Nam Nguyen; Herbert D. Spapen; Fuhong Su; Johan Schiettecatte; Lin Shi; Said Hachimi-Idrissi; Luc Huyghens

Objective:We investigated whether serum levels of neuron-specific enolase (NSE) and S-100&bgr; protein could be used to evaluate cerebral injury and to predict outcome in severe sepsis and severe septic shock. Design:Prospective study. Setting:University hospital. Patients and Measurements:In 170 consecutively enrolled patients with severe sepsis and septic shock, serum S-100&bgr; and NSE were measured daily during four consecutive days after intensive care unit admission. Admission Glasgow Coma Scale before sedation and daily Sequential Organ Failure Assessment scores were recorded in all patients. Acute encephalopathy was defined as either a state of agitation, confusion, irritability, and convulsions (type A) or characterized by somnolence, stupor, and coma (type B) and persistently observed during 72 hrs after withdrawing sedation. When clinically indicated, contrast computed tomography or magnetic resonance imaging were performed to evaluate brain injury. Main Results:S-100&bgr; and NSE increased in, respectively, 72 (42%) and 90 (53%) patients. High biomarker levels were associated with the maximum Sequential Organ Failure Assessment scores (p = .001), and the highest values were found in patients who died early, within 4 days of inclusion (p = .005). Low consciousness encephalopathy type B was more frequently observed in patients with elevated S-100&bgr; (p = .004). S-100&bgr; levels of ≥4 &mgr;g/L were associated with severe brain ischemia or hemorrhage, and values of <2 &mgr;g/L were found in patients with diffuse cerebral embolic infarction lesions. High S-100&bgr; levels were associated with higher intensive care unit mortality (p = .04) and represented the strongest independent predictor of intensive care unit survival, whereas NSE and the Glasgow Coma Scale failed to predict fatal outcome. Conclusions:S-100&bgr; and NSE are frequently increased and associated with brain injury in patients with severe sepsis and septic shock. S-100&bgr; levels more closely reflected severe encephalopathy and type of brain lesions than NSE and the Glasgow Coma Scale.


Clinical Biochemistry | 2010

Multicenter evaluation of the first automated Elecsys sFlt-1 and PlGF assays in normal pregnancies and preeclampsia.

Johan Schiettecatte; Henk Russcher; E. Anckaert; M. Mees; B. Leeser; A.S. Tirelli; G.M. Fiedler; Hilmar Luthe; B. Denk; Johan Smitz

OBJECTIVES Performance evaluation of Elecsys sFlt-1 and PlGF assays. DESIGN AND METHODS Within-, between-run, total imprecision, functional sensitivity, inter-laboratory comparison, method comparison and lot-to-lot reproducibility were evaluated. RESULTS Within- and between-run CVs were below 4% for sFlt-1 >60 and PlGF > 20 pg/mL. Total imprecision CVs were below 4.3%. Functional sensitivity was < 5 pg/mL. Inter-laboratory CVs were <5%. Elecsys correlated well with Quantikine VEGF-R1 (r=0.960) and PlGF (r=0.968). Lot-to-lot comparisons yielded highly correlated results (r>0.999). In healthy pregnancies, the median levels of sFlt-1 remained constant in first (1107 pg/mL) and second trimesters (1437 pg/mL) but increased in the third trimester (2395 pg/mL), while median PlGF levels increased in the first (30 pg/mL) and second trimesters (279 pg/mL) and peaked at 29 to 32 weeks (626 pg/mL) and decreased thereafter (340 pg/mL). The sFlt-1/PlGF ratio is highest in the first trimester (median: 28) but remained constant in the second (median: 4.7) and third trimesters (median: 5.1). In PE/HELPP samples matched for gestational age the sFlt-1 levels were significantly higher (6894-34,624 pg/mL), whereas PlGF levels were lower (9.2-80 pg/mL) and the median sFlt-1/PlGF ratio is much higher (461; range: 121-2614) than in apparently healthy pregnancies (3.6; range: 0.3-105). CONCLUSION The new Roche Elecsys sFlt-1 and PlGF immunoassay showed excellent precision and reliability. There was a clear difference in the Elecsys sFlt-1/PlGF ratio between samples obtained from women with apparently normal pregnancy at the time of blood collection and those diagnosed with PE/HELLP at the same age of gestation.


Resuscitation | 2002

S-100 protein as early predictor of regaining consciousness after out of hospital cardiac arrest.

Said Hachimi-Idrissi; Marcel Van der Auwera; Johan Schiettecatte; G. Ebinger; Yvette Michotte; Luc Huyghens

BACKGROUND AND PURPOSE Patients resuscitated from cardiac arrest (CA) have a high mortality rate. Prognostic evaluation based on clinical observations is uncertain and would benefit from the use of biochemical markers of hypoxic brain damage. The purpose of the study was to validate the use of the serum astroglial protein S-100 levels at admission with regard to regaining consciousness after out of hospital CA. METHODS Fifty-eight patients resuscitated from out-of-hospital CA were followed up until they regained consciousness or until their death or permanent vegetative state occurred. Serum samples for measurement of S-100, using an immunoradiometric assay, were obtained at admission. RESULTS At admission, the mean value+/-standard error of the mean of serum S-100 protein was significantly higher in patients who did not regain consciousness compared with patients who regained consciousness, respectively 4.66+/-0.61 microg/l and 0.84+/-0.21 microg/l. A serum S-100 value of >0.7 microg/l at admission was found to be a predictor that consciousness would not be regained, with a specificity of 85%, a sensitivity of 66.6%, a positive predictive value of 84%, a negative predictive value of 78% and an accuracy of 77.6%. CONCLUSIONS Serum S-100 protein at admission gives reliable and independent information concerning the short term neurological outcome after resuscitation; and could be a good marker of brain cell damage.


Clinica Chimica Acta | 2010

FT4 immunoassays may display a pattern during pregnancy similar to the equilibrium dialysis ID–LC/tandem MS candidate reference measurement procedure in spite of susceptibility towards binding protein alterations

Ellen Anckaert; Kris Poppe; Kathleen Van Uytfanghe; Johan Schiettecatte; Walter Foulon; Linda M. Thienpont

BACKGROUND Serum free thyroxine (FT4) testing in pregnancy is known to be challenging for immunoassays (IAs). We verified the reliability of FT4 results by 3 commercial IAs throughout pregnancy, by comparison of the pattern to that obtained with an equilibrium dialysis isotope dilution-mass spectrometry (ED ID-MS) candidate reference measurement procedure. METHODS Pregnant females (107) and age-matched non-pregnant controls (26) were enrolled. The IAs tested were those performed on the Cobas 6000 (Roche Diagnostics), ARCHITECT i2000SR (Abbott Diagnostics) and Immulite 2000 (Siemens Healthcare) platforms. RESULTS Compared to the controls (mean FT4: 18.2pmol/L), ED ID-MS gave in the late first trimester pregnancy an 8.8% lower (p<0.05) mean; in the second trimester it was 29.1% lower (p<0.001), to stabilize in the third trimester (p=0.99). Similar observations were made for the Cobas and Immulite IAs. The ARCHITECT IA showed no significant decrease in the late first trimester (mean 13.5pmol/L versus 13.6pmol/L in controls), but a significant, less pronounced, decrease in the second and third trimesters (15% and 14.4%, respectively). All IAs were susceptible towards alterations in T4 binding proteins during pregnancy. CONCLUSION We proved that IAs may give a FT4 pattern during pregnancy similar to that obtained by ED ID-MS.


Human Reproduction | 2012

The value of anti-Müllerian hormone measurement in the long GnRH agonist protocol: association with ovarian response and gonadotrophin-dose adjustments

Ellen Anckaert; Johan Smitz; Johan Schiettecatte; Bjarke Mirner Klein; Joan-Carles Arce

BACKGROUND This study evaluated the predictive value of serum and follicular fluid (FF) concentrations of anti-Müllerian hormone (AMH) with respect to treatment outcome variables in an IVF cycle. METHODS A retrospective analysis was performed with data from 731 normogonadotrophic women undergoing controlled ovarian stimulation after stimulation with highly purified menotrophin (HP-hMG) or rFSH following a long GnRH agonist protocol. RESULTS In both treatment groups, the serum AMH concentration at the start of the stimulation was significantly (P < 0.001) positively correlated with the serum levels of estradiol (HP-hMG: r = 0.45; rFSH: r = 0.55), androstenedione (HP-hMG: r = 0.50; rFSH: 0.49) and total testosterone (HP-hMG: r = 0.40; rFSH: r = 0.36) at the end of the stimulation as well as the number of oocytes retrieved (HP-hMG: r = 0.48; rFSH: r = 0.62), the AMH concentration in FF (HP-hMG: r = 0.55; rFSH: 0.61) and the serum progesterone concentration (HP-hMG: r = 0.39; rFSH: r = 0.50) at oocyte retrieval. For both treatments, serum AMH at the start of the stimulation was a good predictor of the need to increase or decrease the gonadotrophin dose on stimulation day 6 and of ovarian response below (<7 oocytes) or above (>15 oocytes) the target. No significant relationships were observed between serum AMH and embryo quality or ongoing pregnancy. CONCLUSION The serum AMH concentration at the start of the stimulation in IVF patients down-regulated with GnRH agonist in the long protocol revealed a positive relationship with ovarian response to gonadotrophins in terms of oocytes retrieved and accompanying endocrine response. AMH is a good predictor of the need for gonadotrophin-dose adjustment on stimulation day 6 for patients with a fixed starting dose, but a poor predictor of embryo quality and pregnancy chances in individual patients.


Human Reproduction | 2014

Vitamin D deficiency and pregnancy rates in women undergoing single embryo, blastocyst stage, transfer (SET) for IVF/ICSI

Nikolaos P. Polyzos; Ellen Anckaert; L. Guzman; Johan Schiettecatte; Lisbet Van Landuyt; Michel Camus; Johan Smitz; Herman Tournaye

STUDY QUESTION What is the influence of vitamin D deficiency on pregnancy rates among women undergoing IVF/ICSI and Day 5 (blastocyst stage) single embryo transfer (SET)? SUMMARY ANSWER Vitamin D deficiency results in significantly lower pregnancy rates in women undergoing single blastocyst transfer. WHAT IS KNOWN ALREADY Preliminary experiments have identified the presence of vitamin D receptors in the female reproductive system. However, results regarding the effect of vitamin D deficiency on clinical outcomes are conflicting. None of the previous studies adopted a SET strategy. STUDY DESIGN, SIZE, DURATION Serum vitamin D concentration was measured retrospectively in patients who underwent SET on Day 5. Overall 368 consecutive infertile women treated within a period of 15 months were included in the study. PARTICIPANTS/MATERIALS, SETTING, METHODS All patients underwent ovarian stimulation for IVF/ICSI and Day 5 SET. Serum samples were obtained 7 days prior to embryo transfer and stored frozen at -20°C. Samples were collectively analyzed for their 25-OH vitamin D content. Vitamin D deficiency was defined as serum 25-OH vitamin D levels <20 ng/ml in accordance with the Institute of Medicine and the Endocrine Society clinical practice guidelines. MAIN RESULTS AND THE ROLE OF CHANCE Clinical pregnancy rates were significantly lower in women with vitamin D deficiency compared with those with higher vitamin D values (41 versus 54%, P = 0.015).Logistic regression analysis was performed to identify whether vitamin D deficiency is independently associated with clinical pregnancy rates after controlling for 16 potential confounding factors. According to our results vitamin D deficiency was independently associated with lower clinical pregnancy rates, odds ratios [ORs (95% confidence interval (CI) 0.61 (0.39-0.95)] for vitamin D deficiency (deficient versus non-deficient women), P = 0.030. Finally, even when restricting our analysis to women undergoing elective SET (274 patients), vitamin D deficiency was again independently associated with pregnancy rates [OR (95% CI) 0.56 (0.33-0.93), P = 0.024]. LIMITATIONS, REASONS FOR CAUTION Our results refer only to patients undergoing Day 5 SET. Although vitamin D deficiency appears to compromise pregnancy rates in this population, no guidance can be provided regarding a potential relationship between vitamin D deficiency and ovarian reserve or response to ovarian stimulation. WIDER IMPLICATIONS OF THE FINDINGS Vitamin D deficiency impairs pregnancy rates in women undergoing single blastocyst transfer. Future prospective confirmatory studies are needed to validate our results and examine the exact underlying mechanism by which vitamin D levels may impair pregnancy rates in infertile women undergoing IVF/ICSI. STUDY FUNDING/COMPETING INTERESTS None declared.


Clinical Chemistry and Laboratory Medicine | 2001

Rapid detection of macroprolactin in the form of prolactin-immunoglobulin G complexes by immunoprecipitation with anti-human IgG-agarose.

Johan Schiettecatte; Jean De Schepper; Brigitte Velkeniers; Johan Smitz; André Van Steirteghem

Abstract Immunoprecipitation with anti-human immunoglobulin G-agarose was evaluated for the detection of prolactin-immunoglobulin G (PRL-IgG) complexes in macroprolactinemic samples from hyperprolactinemic patients (prolactin measured using the automated Elecsys PRL assay; Roche Diagnostics, Mannheim, Germany). Using the polyethylene glycol (PEG) precipitation test on serum samples with PRL above 1000 mIU/l, we detected macroprolactin in 38 out of 175 samples with a recovery below 50%. Gel filtration chromatography on a subset of hyperprolactinemic samples confirmed that macroprolactin was the predominant immunoreactive form of PRL in samples which showed a recovery ≤50%. In 37 out of 38 samples containing macroprolactin, immunoprecipitation with anti-human IgG (anti-hIgG)-agarose revealed a higher PRL-binding (19.1–91.3%) than in the sera containing monomeric PRL (<10%). In conclusion, we found that PEG precipitation detected macroprolactin in 21.7% of samples with elevated PRL levels as measured by the Elecsys PRL assay, and that in the vast majority of these samples the presence of PRL-IgG complexes could be demonstrated by immunoprecipitation with anti-hIgG-agarose. In view of the high prevalence of PRL-IgG complexes in hyperprolactinemic patients and the simplicity of the test, immunoprecipitation with anti-hIgG-agarose might play a role in the routine laboratory handling of hyperprolactinemic samples, especially with regards to PRL assays where PEG causes interference.


Clinical Chemistry and Laboratory Medicine | 2006

Rheumatoid factor interference in the determination of carbohydrate antigen 19-9 (CA 19-9)

Mario Berth; Eugene Bosmans; Jacques Everaert; Jan Dierick; Johan Schiettecatte; Ellen Anckaert; Joris R. Delanghe

Abstract Background: Investigation of a 61-year-old Caucasian male suffering from fatigue and weight loss led to the finding of a carbohydrate antigen 19-9 (CA 19-9) concentration of 80kU/L using an ADVIA Centaur analyser. Determination of CA 19-9 on Vidas, AxSYM and Architect i2000 systems gave normal results. His rheumatoid factor concentration was very high (900kIU/L) and assay interference was suspected. Methods: Besides using several laboratory procedures to show the cause of the interference, we tried to estimate the frequency of the suspected interference. Therefore, two studies were performed. The first was carried out in a multicentre setting using four different CA 19-9 methods on 51 randomly selected samples with high rheumatoid factor concentrations and ten samples containing no or very low rheumatoid factor. In the second study we used heterophilic blocking tubes for 68 routinely analysed samples with CA 19-9 concentrations ranging between 37 and 250kU/L using an ADVIA Centaur analyser. Results: In the multicentre study we found eight discrepant CA 19-9 results, but only one was clearly due to interference. We showed that the interference detected, just as in the index case, was caused by rheumatoid factor. The other discrepancies could not be explained, but are probably related to method-dependent differences. In the 68 routinely analysed samples, no interference could be shown using the heterophilic blocking tubes. Conclusions: Although interferences in the CA 19-9 assay are not frequent, the ADVIA Centaur system appears to be more sensitive to rheumatoid factor interference. The lack of standardisation remains an important issue for this assay. The determination of CA 19-9 during the follow-up of patients should be performed using a single method. If, however, there is any clinical doubt about a result, CA 19-9 should be determined using another method to exclude possible interferences. Clin Chem Lab Med 2006;44:1137–9.


Thyroid | 2013

Thyroglobulin autoantibodies: is there any added value in the detection of thyroid autoimmunity in women consulting for fertility treatment?

David Unuane; Brigitte Velkeniers; Ellen Anckaert; Johan Schiettecatte; Herman Tournaye; Patrick Haentjens; Kris Poppe

BACKGROUND Thyroid autoimmunity (TAI) is frequent in infertile women, but to what extent thyroglobulin autoantibodies (Tg-Abs) contribute to TAI is unclear in the literature. The aims of the present study were to determine the prevalence of TAI in women consulting for fertility problems and to investigate the impact of isolated Tg-Abs, isolated thyroid peroxidase autoantibodies (TPO-Abs), and the presence of both autoantibody types on thyroid function. Furthermore, thyroid function was compared between women with and without TAI and between infertile and fertile women. METHODS A cross-sectional data analysis nested within an ongoing prospective cohort study was performed in order to determine the prevalence of TAI in unselected women consulting our tertiary referral center for reproductive medicine (CRM). The women underwent a determination of serum thyrotropin (TSH), free thyroxine (FT4), TPO-Abs, and Tg-Abs. The cause of infertility, age, body-mass index (BMI), and smoking habits were recorded. RESULTS The prevalence of TAI was 16% (163/992). In 8% of cases, both types of autoantibodies were present, in 5% isolated positive Tg-Abs were found, and 4% had isolated positive TPO-Abs (p=0.025 and p=0.003 respectively). The prevalence of TAI was significantly higher in infertile women as compared to that in fertile controls (19% vs. 13%; p=0.047). The median serum TSH level was significantly higher in the women with TAI and with isolated positive Tg-Abs compared to that in women without TAI (1.83 [1.44] and 1.90 [0.85] vs. 1.47 [0.94] mIU/L; p<0.001 respectively). The median FT4, age, BMI, and smoking habits were comparable between the study groups. CONCLUSIONS The prevalence of TAI was higher in infertile women as compared to fertile women consulting our CRM. Five percent of the women had isolated positive Tg-Abs and a significantly higher serum TSH compared to that in women without TAI.

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Dive into the Johan Schiettecatte's collaboration.

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Johan Smitz

Vrije Universiteit Brussel

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Ellen Anckaert

Vrije Universiteit Brussel

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Herman Tournaye

Vrije Universiteit Brussel

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Luc Huyghens

Free University of Brussels

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Paul Devroey

Vrije Universiteit Brussel

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Kris Poppe

Vrije Universiteit Brussel

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Duc Nam Nguyen

Free University of Brussels

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Jean Louis Vincent

Université libre de Bruxelles

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F. Belva

Vrije Universiteit Brussel

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