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Introduction: Placental vascular disease, characterized by Maternal Vascular Malperfusion (MVM) lesions, is considered to be the underlying cause of pregnancy complications. Aim is to evaluate the relationship between the cumulative number of MVM lesion types, and adverse pregnancy- and neonatal outcomes.Methods: This retrospective cohort study included 272 women with singleton gestations who gave birth at a Dutch tertiary hospital between 2017 and 2018 with available placental histopathology reports. Analyzed according to the Amsterdam Placental Workshop Group Consensus Statement, placentas were divided into groups based on the cumulative number of MVM lesions: no lesions (n = 124), 1-2 types (n = 124) and 3-5 types of lesions (n = 24).Results: The proportion of placenta syndrome (PS) was highest (95.8%) in the 3-5 MVM lesions group (p < 0.001). The presence of MVM lesions was highly associated with PS during pregnancy (aOR 6.81, 95% CI 3.76-12.33). Furthermore, every additional type of MVM lesion corresponded with a threefold increased odds for the occurrence of PS (aOR 3.00, 95% CI 2.10-4.29). The group with 3-5 types of MVM lesions showed the highest incidence of adverse neonatal outcomes, lower mean birth weight, prolonged hospitalization, NICU admissions and neonatal deaths (aOR 6.47, 95% CI 0.33-127.68), corresponding with a fourfold increased odds for the occurrence of neonatal death for every additional MVM lesion (aOR 4.19, 95% CI 1.39-12.68).Discussion: A higher number of MVM lesion types is strongly associated with an increased incidence of adverse pregnancy- and neonatal outcomes, indicating that guidelines should focus also on the amount of MVM lesion types for the monitoring/management of subsequent pregnancies. [ABSTRACT FROM AUTHOR]

Context: No consensus exists about the optimal duration of the low-iodine diet (LID) in the preparation of 131I therapy in differentiated thyroid cancer (DTC) patients. Objective: This work aimed to investigate if a LID of 4 days is enough to achieve adequate iodine depletion in preparation for 131I therapy. In addition, the nutritional status of the LID was evaluated. Methods: In this prospective study, 65 DTC patients treated at 2 university medical centers were included between 2018 and 2021. The patients collected 24-hour urine on days 4 and 7 of the LID and kept a food diary before and during the LID. The primary outcome was the difference between the 24-hour urinary iodine excretion (UIE) on both days. Results: The median 24-hour UIE on days 4 and 7 of the LID were not significantly different (36.1 mcg [interquartile range, 25.4-51.2 mcg] and 36.5 mcg [interquartile range, 23.9-47.7 mcg], respectively, P = .43). On day 4 of the LID, 72.1% of the DTC patients were adequately prepared (24-hour UIE < 50 mcg), and 82.0% of the DTC patients on day 7 (P = .18). Compared to the self-reported regular diet, DTC patients showed a significantly (P < .01) lower percentage of nutrient intake (calories, protein, calcium, iodine, and water) during the LID. Conclusion: The 24-hour UIE on day 4 of the LID did not differ from day 7, and therefore shortening the LID from 7 to 4 days seems justified to prepare DTC patients for 131I therapy in areas with sufficient iodine intake and may be beneficial to maintain a sufficient nutritional intake during DTC treatment. [ABSTRACT FROM AUTHOR]

Vitamin D is an important factor in bone metabolism. Animal studies have shown a positive effect of vitamin D3 supplementation on fracture healing, but evidence from clinical trials is inconclusive. A randomized controlled trial was performed to assess the effects of vitamin D3 supplementation on fracture healing using HR‐pQCT–based outcome parameters. Thirty‐two postmenopausal women with a conservatively treated distal radius fracture were included within 2 weeks postfracture and randomized to a low‐dose (N = 10) and a high‐dose (N = 11) vitamin D intervention group receiving a 6‐week bolus dose, equivalent to 700 and 1800 IU vitamin D3 supplementation per day, respectively, in addition to a control group (N = 11) receiving no supplementation. After the baseline visit 1–2 weeks postfracture, follow‐up visits were scheduled at 3–4, 6–8, and 12 weeks postfracture. At each visit, HR‐pQCT scans of the fractured radius were performed. Cortical and trabecular bone density and microarchitectural parameters and microfinite element analysis–derived torsion, compression, and bending stiffness were assessed. Additionally, serum markers of bone resorption (CTX) and bone formation (PINP) were measured. Baseline serum levels of 25OHD3 were <50 nmol/L in 33% of all participants and <75 nmol/L in 70%. Compared with the control group, high‐dose vitamin D3 supplementation resulted in a decreased trabecular number (regression coefficient β: −0.22; p < 0.01) and lower compression stiffness (B: −3.63; p < 0.05, together with an increase in the bone resorption marker CTX (B: 0.062; p < 0.05). No statistically significant differences were observed between the control and low‐dose intervention group. In conclusion, the bolus equivalent of 700 U/day vitamin D3 supplementation in a Western postmenopausal population does not improve distal radius fracture healing and an equivalent dose of 1800 IU/day may be detrimental in restoring bone stiffness during the first 12 weeks of fracture healing. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). [ABSTRACT FROM AUTHOR]

Background and Objectives: The aim of this study was to evaluate the value of adding fetal growth velocity and first trimester maternal biomarkers to baseline screening, for the prediction of small-for-gestational age (SGA) and adverse neonatal outcomes.Method: A retrospective cohort study was conducted of singleton pregnancies in the Maastricht University Medical Centre between 2012 and 2016. The biomarkers PAPP-A, β-hCG, PlGF, and sFlt-1 were measured at 11-13 weeks of gestational age (GA) and two fetal growth scans were performed (18-22 and 30-34 weeks of GA). Differences in biomarkers and growth velocities were compared between appropriate-for-gestational age (AGA; birth weight percentile 10-90) and SGA (birth weight percentile <10). Combinations of the biomarkers and fetal growth velocity were added to baseline screening for the prediction of SGA and adverse neonatal outcome.Results: We included 296 singleton pregnancies. Compared to AGA (n = 251), SGA neonates (n = 45) had significantly lower growth velocities in the abdominal circumference (mm/week): 10.1 ± 0.98 versus 10.8 ± 0.98, p = 0.001. Compared with AGA, the SGA neonates had higher sFlt-1 multiples of the median (MoM): 0.89 (0.55) versus 0.76 (0.44), p = 0.023, and a higher sFlt-1/PlGF MoM ratio: 1.09 (1.03) versus 0.90 (0.64), p = 0.027. For a 15% false-positive rate, the prediction of SGA neonates increased from 44.8% for the baseline screening model to 56.5% after the addition of fetal growth velocities, and to 73.9% after the further addition of maternal biomarkers (PPV 9.6%, NPV 82.4%). The corresponding AUC for the three models were 0.722, 0.804, and 0.839, respectively. In addition, AGA neonates with reduced fetal growth velocity had more adverse neonatal outcomes compared to the AGA reference group (12.4 vs. 3.9%, p = 0.013).Conclusions: Combining fetal growth velocity with first trimester biomarkers resulted in a better prediction of SGA compared to baseline screening parameters alone. This approach could possibly result in reduced adverse neonatal outcomes in neonates, who are at a potential risk due to late mild placental dysfunction. [ABSTRACT FROM AUTHOR]

Summary: Background: Sarcoidosis is a multi-systemic inflammatory disorder, which affects the lungs in 90% of the cases. The main pathologic feature is chronic inflammation resulting in non-caseating granuloma formation. Until now there is no satisfying biomarker for diagnosis or prognosis of sarcoidosis. This study is focused on the detection of potential biomarkers in serum for the diagnosis of sarcoidosis using surface-enhanced laser desorption ionization-time of flight-mass spectrometry (SELDI-TOF-MS). Methods: For detection of potential biomarkers, protein profiles of anion exchange fractionated serum of 35 sarcoidosis patients and 35 healthy controls were compared using SELDI-TOF-MS. Sensitivities and specificities of the potential biomarkers obtained with SELDI-TOF-MS, generated with decision tree algorithm, were compared to the conventional markers angiotensin converting enzyme (ACE) and soluble interleukin-2 receptor (sIL-2R). Results: Optimal classification was achieved with metal affinity binding arrays. A single marker with a mass-to-charge (m/z) value of 11,955 resulted in a sensitivity and specificity of 86% and 63%, respectively. A multimarker approach of two peaks, m/z values of 11,734 and 17,377, resulted in a sensitivity and specificity of 74% and 71%, respectively. These sensitivities and specificities were higher compared to measurements of ACE and sIL-2R. Identification of the peak at m/z 17,377 resulted in the α-2chain of haptoglobin. Conclusions: This study acts as a proof-of-principle for the use of SELDI-TOF-MS in the detection of new biomarkers for sarcoidosis. The peak of the multimarker at m/z 17,377 was identified as the α-2chain of haptoglobin. [Copyright &y& Elsevier]

Serum protein profiling by Surface-Enhanced Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (SELDI-TOF-MS) appears to be an important diagnostic tool for a whole range of diseases. Sensitivities and specificities obtained with this new technology often seem superior to those obtained with current biomarkers. However, reproducibility and standardization are still problematic. The present review explains the SELDI-TOF-MS technique and discusses some important aspects for proteomics studies, like pre- and post-analytical aspects and quality control procedures. Own data about biomarker discovery for the diagnosis of sarcoidosis are also presented in this review. [ABSTRACT FROM AUTHOR]

Introduction Small-for-gestational age (SGA) neonates are a major cause of perinatal morbidity. The detection of SGA needs to be improved. Objective/hypothesis To evaluate the value of adding fetal growth velocity parameters to maternal biochemical biomarkers for the detection of SGA neonates. Methods A retrospective cohort study of 1094 singleton pregnancies (SGA and AGA), in the Maastricht University Medical Centre (MUMC) between 2011 and 2016. All women had ultrasound data of fetal growth from two periodes: 18–22 and 30–34 weeks. In a subgroup the PAPP-A, β-hCG, PlGF and sFlt-1 at 11–13 weeks were measured. Differences in maternal biochemical biomarkers and fetal growth velocities (mm/week) of the abdominal circumference (AC), biparietal diameter (BPD), head circumference (HC) and femur length (FL) were compared between the AGA (birth weight percentiles 10–90)), and SGA (birth weight percentiles <10), using one-way ANOVA and post hoc. Results Compared to AGA (n = 1049) as reference group, SGA (n = 45) had significant lower growth velocities ACv (10.08 ± 0.98 vs. 11.26 ± 1.00, p < 0.0001) BPDv (2.78 ± 0.29 vs.3.08 ± 0.27, p < 0.0001), HCv (9.98 ± 0.83 vs 10.67 ± 0.82, p < 0.0001) and FLv (2.34 ± 0.252 vs. 2.52 ± 0.20, p < 0.0001). SGA compared with optimal AGA had lower PAPP-a MoM (0.87 ± 0.48 vs 1.13 ± 0.70, p = 0.015), higher Sflt-1 (1283.96 ± 699.36 vs. 1088.21 ± 480.80, p = 0.048), and a higher PlGF/ sFlt-1 ratio (50.16 ± 41.56 vs. 35.67 ± 19.68, 0.002). Combining all maternal biomarkers resulted in an AUC of 0.762 (0.655–0.869) for prediction of SGA. The combination of growth velocities resulted in an AUC of 0.729 (0.631–0.828). However, the addition of fetal growth velocities to the maternal biomarkers, improves the prediction of SGA with an AUC of 0.823(0.741–0.906) sensitivity 92.3% (95%CI 79.4–97.7%); specificity 50.0% (95%CI 43.7–56.3%); and NPV 97.3% (95%CI 92.3–99.2%). Discussion Detection of small-for-gestational neonates can be improved using the combination of fetal growth velocity parameters and maternal biochemical markers. A larger prospective study including serial maternal biochemical markers is needed. [ABSTRACT FROM AUTHOR]

Introduction Preeclampsia and related complication known as placental syndrome (PS), are most likely caused by abnormal placentation. Longitudinal measurements of these markers are suggested to be better predictors of PS than measurements at a single time. Objective To investigate thepredictive value of longitudinal sFlt-1, PlGF and sFlt-1/PlGF ratio measurements in predicting PS. Methods This was a retrospective longitudinal cohort study in women with singleton pregnancies, identified as high risk patients between January 2015 and December 2017. All patients had serial measurements of PLGF and sFlt-1 at different intervals (12, 16, 20 and 30 weeks). We evaluated the absolute and relative differences(delta) in serum concentrations. The AUC of ROC curve analysis were compared to assess the performance in the prediction of PS. Results A total of 556 samples were analyzed in 139 patients of which 26 developed PS (18.7%). Women who developed PS had a lower increase in PlGF in the 12–30 interval: absolute difference: 258.5(±211.7) versus 364.4(±215.0), (p = 0.025) and relative 9.4(±7.3) versus 13.6(±7.1), (p = 0.007), respectively. Similar differences were found in the delta PLGF in the 16–30 weeks interval: absolute 211.3(±192.7) versus 319.2(±203.0), (p = 0.015) and relative: 3.5(±1.7) versus 5.4(±2.9) (p = 0.001). Patients who developed PS had a higher absolute sFlt-1 in the 16–30 weeks interval: 610.8(±849.2) versus 299.8(±672.4), (p = 0.045). There were no significant differences found in absolute or relative sFlt-1 or in absolute or relative sFlt-1/PLGF ratio between women who developed PS versus those who did not at other time intervals. The AUC of PLGF at the 4 different intervals combined was: 0.75 (CI95%:0.65–0.86, p = 0.00) the AUC of delta PlGF between 12 and 30 weeks was 0.67 (CI95%:0.54–0.80, p = 0.01), for the prediction of PS. Conclusion In our population, longitudinal measurements could play a role in better prediction of PS than measurements at a single time point during pregnancy. [ABSTRACT FROM AUTHOR]

Background: Direct access of patients to their web-based patient portal, including laboratory test results, has become increasingly common. Numeric laboratory results can be challenging to interpret for patients, which may lead to anxiety, confusion, and unnecessary doctor consultations. Laboratory results can be presented in different formats, but there is limited evidence regarding how these presentation formats impact patients' processing of the information., Objective: This study aims to synthesize the evidence on effective formats for presenting numeric laboratory test results with a focus on outcomes related to patients' information processing, including affective perception, perceived magnitude, cognitive perception, perception of communication, decision, action, and memory., Methods: The search was conducted in 3 databases (PubMed, Web of Science, and Embase) from inception until May 31, 2023. We included quantitative, qualitative, and mixed methods articles describing or comparing formats for presenting diagnostic laboratory test results to patients. Two reviewers independently extracted and synthesized the characteristics of the articles and presentation formats used. The quality of the included articles was assessed by 2 independent reviewers using the Mixed Methods Appraisal Tool., Results: A total of 18 studies were included, which were heterogeneous in terms of study design and primary outcomes used. The quality of the articles ranged from poor to excellent. Most studies (n=16, 89%) used mock test results. The most frequently used presentation formats were numerical values with reference ranges (n=12), horizontal line bars with colored blocks (n=12), or a combination of horizontal line bars with numerical values (n=8). All studies examined perception as an outcome, while action and memory were studied in 1 and 3 articles, respectively. In general, participants' satisfaction and usability were the highest when test results were presented using horizontal line bars with colored blocks. Adding reference ranges or personalized information (eg, goal ranges) further increased participants' perception. Additionally, horizontal line bars significantly decreased participants' tendency to search for information or to contact their physician, compared with numerical values with reference ranges., Conclusions: In this review, we synthesized available evidence on effective presentation formats for laboratory test results. The use of horizontal line bars with reference ranges or personalized goal ranges increased participants' cognitive perception and perception of communication while decreasing participants' tendency to contact their physicians. Action and memory were less frequently studied, so no conclusion could be drawn about a single preferred format regarding these outcomes. Therefore, the use of horizontal line bars with reference ranges or personalized goal ranges is recommended to enhance patients' information processing of laboratory test results. Further research should focus on real-life settings and diverse presentation formats in combination with outcomes related to patients' information processing., (©Frederieke A M van der Mee, Fleur Schaper, Jesse Jansen, Judith A P Bons, Steven J R Meex, Jochen W L Cals. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 12.08.2024.)

Vitamin D is an important factor in bone metabolism. Animal studies have shown a positive effect of vitamin D 3 supplementation on fracture healing, but evidence from clinical trials is inconclusive. A randomized controlled trial was performed to assess the effects of vitamin D 3 supplementation on fracture healing using HR-pQCT-based outcome parameters. Thirty-two postmenopausal women with a conservatively treated distal radius fracture were included within 2 weeks postfracture and randomized to a low-dose (N = 10) and a high-dose (N = 11) vitamin D intervention group receiving a 6-week bolus dose, equivalent to 700 and 1800 IU vitamin D 3 supplementation per day, respectively, in addition to a control group (N = 11) receiving no supplementation. After the baseline visit 1-2 weeks postfracture, follow-up visits were scheduled at 3-4, 6-8, and 12 weeks postfracture. At each visit, HR-pQCT scans of the fractured radius were performed. Cortical and trabecular bone density and microarchitectural parameters and microfinite element analysis-derived torsion, compression, and bending stiffness were assessed. Additionally, serum markers of bone resorption (CTX) and bone formation (PINP) were measured. Baseline serum levels of 25OHD 3 were <50 nmol/L in 33% of all participants and <75 nmol/L in 70%. Compared with the control group, high-dose vitamin D 3 supplementation resulted in a decreased trabecular number (regression coefficient β: -0.22; p < 0.01) and lower compression stiffness (B: -3.63; p < 0.05, together with an increase in the bone resorption marker CTX (B: 0.062; p < 0.05). No statistically significant differences were observed between the control and low-dose intervention group. In conclusion, the bolus equivalent of 700 U/day vitamin D 3 supplementation in a Western postmenopausal population does not improve distal radius fracture healing and an equivalent dose of 1800 IU/day may be detrimental in restoring bone stiffness during the first 12 weeks of fracture healing. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR)., (© 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).)

Objective : Previous studies have shown that patients with hereditary fructose intolerance (HFI) are characterized by a greater intrahepatic triglyceride content, despite a fructose-restricted diet. The present study aimed to examine the long-term consequences of HFI on other aldolase-B-expressing organs, i.e. the kidney and vascular endothelium. Methods : Fifteen adult HFI patients were compared to healthy control individuals matched for age, sex and body mass index. Aortic stiffness was assessed by carotid-femoral pulse wave velocity (cf-PWV) and endothelial function by peripheral arterial tonometry, skin laser doppler flowmetry and the endothelial function biomarkers soluble E -selectin [sE-selectin] and von Willebrand factor. Serum creatinine and cystatin C were measured to estimate the glomerular filtration rate (eGFR). Urinary glucose and amino acid excretion and the ratio of tubular maximum reabsorption of phosphate to GFR (TmP/GFR) were determined as measures of proximal tubular function. Results : Median systolic blood pressure was significantly higher in HFI patients (127 versus 122 mmHg, p  = .045). Pulse pressure and cf-PWV did not differ between the groups ( p  = .37 and p  = .49, respectively). Of all endothelial function markers, only sE-selectin was significantly higher in HFI patients ( p  = .004). eGFR was significantly higher in HFI patients than healthy controls (119 versus 104 ml/min/1.73m 2 , p  = .001, respectively). All measurements of proximal tubular function did not differ significantly between the groups. Conclusions : Adult HFI patients treated with a fructose-restricted diet are characterized by a higher sE-selectin level and slightly higher systolic blood pressure, which in time could contribute to a greater cardiovascular risk. The exact cause and, hence, clinical consequences of the higher eGFR in HFI patients, deserves further study., (© 2020 The Authors.)

Background: In the region Limburg (The Netherlands) almost all of the five participating laboratories use a different immunoassay platform to determine thyroid stimulating hormone (TSH) and free thryoxine (FT4). With the frequent transfer of patients within the region, harmonization of test result interpretation is necessary. In this study, we investigated dysthyroxinemia classification between participating laboratories and developed procedures for improvement., Methods: Two ring surveys with an interval of 2 years were performed. Four patient groups (n=100) with different dysthyroxinemia classification were based on biochemical results of the Autodelphia analyzer. Samples were tested in five participating laboratories. In each group the percentage of patients classified with dysthyroxinemia was calculated and differences were analyzed by the Fisher's exact test., Results: After the first survey, the percentage of patients with hyperthyroxinemia was more than 20% lower in three laboratories compared to the other two. Bhattacharya analysis revealed that the upper reference limit of FT4 was 20%-30% too high in two laboratories. Adjustments of reference ranges appeared to be effective in the second survey. The third laboratory reported significantly lower percentages of patients with hyperthyroxinemia in the second survey. New FT4 reference ranges were determined for this laboratory, resulting in adequate classification of hyperthyroxinemia., Conclusions: This study illustrates the potential of a multicenter evaluation of dysthyroxinemia in a biochemical-defined patient cohort. In particular, classification of hyperthyroxinemia differed between laboratories. Adjustments of reference ranges resulted in better agreement of dysthyroxinemia classification. Even using internal and external quality assurance programs, application of multicenter ring surveys is advised to prevent inadequate reference ranges.

Aim: Ankylosing spondylitis (AS) is a chronic systemic inflammatory rheumatic disorder that primarily affects the axial skeleton. To date there is no satisfactory biomarker for diagnosis or prognosis of AS. This study is focused on detection of potential biomarkers for the diagnosis of AS using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) with the ultimate goal of developing a progression biomarker for AS., Materials & Methods: Protein profiles of sera of 38 AS patients and 38 healthy controls were obtained using ProteinChip arrays. Different arrays and conditions were compared with find out which condition resulted in the optimal discrimination of both groups., Results: Optimal discrimination was reached using weak cation exchange (CM10) and immobilized metal affinity capture coupled with copper (IMAC-Cu(2+)) arrays. Using a multimarker approach on protein profiles obtained with CM10 arrays resulted in a sensitivity of 66% and a specificity of 74%. Using a multimarker approach on protein profiles obtained with IMAC-Cu(2+) arrays resulted in a sensitivity and specificity of 70%., Conclusions: This is the first study that shows that protein profiling in serum using SELDI-TOF-MS can be used as a diagnostic tool for AS. The biomarkers will be validated to confirm if they can be used as progression biomarkers.

Background: This report describes an in-house developed immunoprecipitation method to isolate insulin-like growth factor binding protein-3 (IGFBP-3) and its isoforms from serum. The method was compared to other existing immunoprecipitation methods. The study of IGFBP-3 isoforms is relevant for further studies on congenital defects in glycosylation (CDG), galactosemia, and alcoholic liver cirrhosis., Methods: Monoclonal and/or polyclonal anti-human IGFBP-3 antibodies were covalently immobilised on protein-A Sepharose beads using dimethyl pimelimidate as cross-linker. By incubation with these immobilised antibodies, intact IGFBP-3 and fragments of IGFBP-3 were isolated from serum. Enzyme-linked immunosorbent assay (ELISA) and one-dimensional gel electrophoresis (1-DE) experiments were performed to define the optimal immunoprecipitation method. Isolated proteins were separated by 1-DE and two-dimensional gel electrophoresis (2-DE) and visualised by Western blotting., Results: ELISA and 1-DE results illustrated that an optimal isolation was performed using PBS for the incubation with serum. Laemmli sample buffer, containing 2-amino-2-(hydroxymethyl)-1,3-propanediol hydrochloride and sodium dodecyl sulfate, or urea/CHAPS was optimal for the elution. Clinical validation was performed using CDG-Ia serum samples. The 2-DE experiments showed characteristic isoform patterns for CDG-Ia., Conclusions: The optimized in-house developed immunoprecipitation method resulted in specific detection of IGFBP-3 isoforms and is suitable for further studies on glycosylation defects.

There is a need for better markers for the diagnosis and prognosis of chronic inflammatory diseases. Proteomic strategies can be helpful to detect new biomarkers. Proteomic analyses are performed to characterize the behaviour of the system rather than the behaviour of any single component. Since the genome has been unravelled, the proteome received more attention. Aim of this review was to focus on the use of different proteomics techniques to detect potential and/or common biomarkers in chronic inflammatory diseases. The identified and validated proteins detected in the different studies are compared and discussed to conclude if there are some common markers which can be used in the diagnosis and prognosis of the three chronic inflammatory diseases described in this study; multiple sclerosis, rheumatic diseases and lung inflammatory diseases. The heat shock protein family (hsp) was entitled as biomarkers with potential for further research in multiple sclerosis. Myeloid-related protein 8 (MRP-8) was found in three different rheumatoid arthritis (RA) studies with different sample materials and could be a potential marker for RA. α1-Antitrypsin was validated in two studies as a marker for sarcoidosis and α1-antitrypsin was also found to be a marker for cystic fibrosis (CF), together with myeloperoxidase and IgG., (Copyright © 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: Protein profiling by surface enhanced laser desorption ionization-time of flight-mass spectrometry (SELDI-TOF-MS) is gaining importance as a diagnostic tool for a whole range of diseases. This report describes a QC procedure, which acts prospectively by checking the calibration before starting profiling experiments., Methods: A well-defined protocol for calibration of the Protein Biosystem IIc instrument was established, using a commercial QC sample containing independent certified standards and by determination of acceptance criteria. Instrument calibration was performed externally every week with the standards provided by the manufacturer. QC was performed for the period of 5 months., Results: According to the acceptance criteria defined in this study, data points should be in the established range of the process mean+/-2 standard deviations for the mass-to-charge ratios (m/z values), peak intensities, signal-to-noise ratios (S/N), and peak resolutions for insulin and apomyoglobin in the QC sample. Moreover, it was demonstrated that the pipetting variability in the handling of the QC sample significantly contributed to systematic errors and that spotting of a larger volume of QC sample resulted in a better reproducibility., Conclusions: Stringent quality control of the calibration part of SELDI-TOF-MS experiments prevents unreliable data acquisition from the very start.