Introduction: Rheumatoid arthritis (RA) improves during pregnancy and flares after delivery. It has been hypothesized that high levels of the complement factor mannose-binding lectin (MBL) are... Show moreIntroduction: Rheumatoid arthritis (RA) improves during pregnancy and flares after delivery. It has been hypothesized that high levels of the complement factor mannose-binding lectin (MBL) are associated with a favourable disease course of RA by facilitating the clearance of pathogenic immunoglobulin G (IgG) lacking galactose sugar moieties. During pregnancy, increased galactosylation of IgG and simultaneously increased MBL levels can be observed, with the latter being strictly related to maternal MBL genotypes. Therefore, increased MBL levels in concert with increased IgG galactosylation may be associated with pregnancy-induced improvement of RA. The objective of this study was to investigate whether MBL genotypes are associated with changes in RA disease activity and with changes in IgG galactosylation during pregnancy and in the postpartum period. We also studied the association between MBL genotypes and pregnancy outcomes in RA. Methods: Serum from 216 patients with RA and 31 healthy controls participating in the Pregnancy-induced Amelioration of Rheumatoid Arthritis (PARA) Study was collected before, during and after pregnancy. IgG galactosylation was determined by performing matrix-assisted laser desorption/ionization time of flight mass spectrometry. Disease activity was determined using the internationally recognized Disease Activity Score 28 (DAS28). MBL genotypes were determined. The pregnancy outcome measures studied were gestational age, birth weight, miscarriage and hypertensive disorders. Results: No association was found between the MBL genotype groups and changes in RA disease activity (P = 0.89) or changes in IgG galactosylation (patients, P = 0.75, and controls, P = 0.54) during pregnancy and in the postpartum period. Furthermore, MBL genotype groups were not related to the studied pregnancy outcome measures. Conclusions: This study does not provide evidence for a role for MBL in the improvement of RA during pregnancy or for a role for MBL in pregnancy outcome. Show less
Emonts, M.; Hazes, M.J.M.W.; Houwing-Duistermaat, J.J.; Gaast-de Jongh, C.E. van der; Vogel, L. de; Han, H.K.H.; ... ; Dolhain, R.J.E.M. 2011
Background: Various cytokines and inflammatory mediators are known to be involved in the pathogenesis of rheumatoid arthritis (RA). We hypothesized that polymorphisms in selected inflammatory... Show moreBackground: Various cytokines and inflammatory mediators are known to be involved in the pathogenesis of rheumatoid arthritis (RA). We hypothesized that polymorphisms in selected inflammatory response and tissue repair genes contribute to the susceptibility to and severity of RA. Methods: Polymorphisms in TNFA, IL1B, IL4, IL6, IL8, IL10, PAI1, NOS2a, C1INH, PARP, TLR2 and TLR4 were genotyped in 376 Caucasian RA patients and 463 healthy Caucasian controls using single base extension. Genotype distributions in patients were compared with those in controls. In addition, the association of polymorphisms with the need for anti-TNF-alpha treatment as a marker of RA severity was assessed. Results: The IL8 781 CC genotype was associated with early onset of disease. The TNFA -238 G/A polymorphism was differentially distributed between RA patients and controls, but only when not corrected for age and gender. None of the polymorphisms was associated with disease severity. Conclusions: We here report an association between IL8 781 C/T polymorphism and age of onset of RA. Our findings indicate that there might be a role for variations in genes involved in the immune response and in tissue repair in RA pathogenesis. Nevertheless, additional larger genomic and functional studies are required to further define their role in RA. Show less
Ruhaak, L.R.; Hennig, R.; Huhn, C.; Borowiak, M.; Dolhain, R.J.E.M.; Deelder, A.M.; ... ; Wuhrer, M. 2010
High throughput methods for oligosaccharide analysis are required when searching for glycan based biomarkers Next to mass spectrometry based methods which allow fast and reproducible analysis of... Show moreHigh throughput methods for oligosaccharide analysis are required when searching for glycan based biomarkers Next to mass spectrometry based methods which allow fast and reproducible analysis of such compounds further separation based techniques are needed which allow for quantitative analysis Here an optimized sample preparation method for N glycan profiling by multiplexed capillary gel electrophoresis with laser induced fluorescence detection (CGE LIF) was developed, enabling high throughput glycosylation analysis First, glycans are released enzymatically from denatured plasma glycoproteins Second, glycans are labeled with APTS using 2-picoline borane as a nontoxic and efficient reducing agent Reaction conditions are optimized for a high labeling efficiency short handling times and only limited loss of sialic acids Third samples are subjected to hydrophilic interaction chromatography (HILIC) purification at the 96 well plate format Subsequently, purified APTS labeled N glycans are analyzed by CGE LIF using a 48-capillary DNA sequencer The method was found to be robust and suitable for high-throughput glycan analysis Even though the method comprises two overnight incubations, 96 samples can be analyzed with an overall labor allocation time of 2 5 h The method was applied to serum samples from a pregnant woman, which were sampled during first second and third trimesters of pregnancy, as well as 6 weeks 3 months, and 6 months postpartum Alterations in the glycosylation patterns were observed with gestation and time after delivery Show less
