F.P.J.G. Lafeber

Universitair Medisch Centrum Utrecht, Utrecht, Provincie Utrecht, Netherlands

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Publications (181)234.31 Total impact

  • Article: Skin pentosidine in very early hip/knee osteoarthritis (CHECK) is not a strong independent predictor of radiographic progression over 5 years follow-up.
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    ABSTRACT: OBJECTIVES: Age-related changes in articular cartilage are likely to play a role in the aetiology of osteoarthritis (OA). One of the major age-related changes in cartilage is the accumulation of advanced-glycation-endproducts (AGEs). The present study evaluates whether pentosidine can predict radiographic progression and/or burden over 5 years follow-up in a cohort of early knee and/or hip OA. DESIG: The 5 years follow-up data of 300 patients from CHECK were used. Radiographic progression and burden were assessed by X-rays of both knees and hips ( K&L and Altman scores). Baseline pentosidine levels (and urinary CTXII as a comparator) were measured by HPLC (and ELISA). Univariable and multivariable associations including baseline radiographic damage, age, gender, BMI and kidney function were performed. RESULTS: Both pentosidine and uCTXII correlated with radiographic progression and burden. In general pentosidine did not have an added predictive value to uCTXII for progression nor burden of the disease. The best prediction was obtained for burden of radiographic damage (R(2)=0.60-0.88), bus this was predominantly determined by baseline radiographic damage (without this parameter R(2)=0.07-0.17). Interestingly, pentosidine significantly added to prediction of osteophyte formation, whereas uCTXII significantly added to prediction of JSN in multivariable analysis. CONCLUSION: Pentosidine adds to prediction of radiographic progression and burden of osteophyte formation and uCTXII to radiographic progression and burden of JSN, but overall skin pentosidine did not perform better that uCTXII in predicting radiographic progression or burden. Burden of damage over 5 year is mainly determined by radiographic joint damage at baseline.
    Osteoarthritis and Cartilage 03/2013; · 3.90 Impact Factor
  • Article: Stimulation of naïve monocytes and PBMCs with coagulation proteases results in thrombin-mediated and PAR-1-dependent cytokine release and cell proliferation in PBMCs only.
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    ABSTRACT: RATIONALE: Protease-activated receptors (PARs) are stimulated by proteolytic cleavage of their extracellular domain.Coagulation proteases, such as FVIIa, the binary TF-FVIIa complex, free FXa, the ternary TF-FVIIa-FXa complex, and thrombin, are able to stimulate PARs. Whereas the role of PARs on platelets is well known, their function in naïve monocytes and peripheral blood mononuclear cells (PBMCs) is largely unknown. This is of interest because PAR-mediated interactions of coagulation proteases with monocytes and PBMCs in diseases with an increased activation of coagulation may promote inflammation. OBJECTIVES: To evaluate PAR-mediated inflammatory reactions in naïve monocytes and PBMCs stimulated with coagulation proteases. For this, PAR-expression at protein and RNA level on naïve monocytes and PBMCs was evaluated with flow cytometry and RT-PCR. In addition cytokine release (IL-1β, IL-6, IL-8, IL-10, TNF-α) in stimulated naïve and PBMC cell cultures was determined. FINDINGS: In this study it is demonstrated that naïve monocytes express all four PARs at the mRNA level, and PAR-1, -3, and -4 at the protein level. Stimulation of naïve monocytes with coagulation proteases did not result in alterations in PAR expression or in the induction of inflammation involved cytokines like interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8, interleukin-10, or tumor necrosis factor-α. In contrast, stimulation of PBMCs with coagulation proteases resulted in thrombin-mediated induction of IL-1β and IL-6 cytokine production and PBMC cell proliferation in a PAR-1-dependent manner. CONCLUSIONS: These data demonstrate that naïve monocytes are not triggered by coagulation proteases, whereas thrombin is able to elicit pro-inflammatory events in a PAR-1-dependent manner in PBMCs.
    Scandinavian Journal of Immunology 02/2013; · 2.23 Impact Factor
  • Article: Joint distraction: a treatment to consider for haemophilic arthropathy.
    Haemophilia 09/2012; · 2.60 Impact Factor
  • Article: Cross-sectional and predictive associations between plasma adipokines and radiographic signs of early-stage knee osteoarthritis: data from CHECK.
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    ABSTRACT: To investigate cross-sectional and predictive associations of plasma adipokines with biochemical markers of systemic joint metabolism and radiographic signs of early-stage knee osteoarthritis (OA). The adipokines pLeptin, pAdiponectin, and pResistin, the cartilage markers C-terminal telopeptide of type II collagen (uCTX-II), N-terminal propeptide of type IIA procollagen (sPIIANP), chondroitin sulfate 846 (sCS846), and cartilage oligomeric matrix protein (sCOMP), and the synovial markers hyaluronic acid (sHA) and N-terminal propeptide of type III procollagen (sPIIINP) were assessed by enzyme-linked immunosorbent assay or radioactive immunoassay in baseline samples of Cohort Hip and Cohort Knee (CHECK), a cohort of 1002 subjects with early-stage symptomatic knee and/or hip OA. Knee radiographs were obtained at baseline and after 2 and 5 years and scored according to Kellgren & Lawrence. pLeptin showed positive associations with uCTX-II, sCOMP, sPIIANP, sHA, and sPIIINP, and with presence and progression of radiographic knee OA. Associations expectedly disappeared after adjustment for body mass index. pResistin showed positive associations with sPIIINP and present and incident radiographic knee OA that were largely independent of BMI. pAdiponectin showed positive associations with uCTX-II and sCOMP. Furthermore, pAdiponectin did not show associations with radiographic knee OA on itself, but associations of pResistin with present radiographic knee OA were stronger in higher pAdiponectin tertiles (P = 0.024 for interaction between pAdiponectin and pResistin). Although statistically significant, all associations were weak. Adipokines may have aggravating, although may be minor, structural effects in early-stage knee OA.
    Osteoarthritis and Cartilage 08/2012; 20(11):1278-85. · 3.90 Impact Factor
  • Article: Serum adipokines in osteoarthritis; comparison with controls and relationship with local parameters of synovial inflammation and cartilage damage.
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    ABSTRACT: Adipose tissue is an endocrine tissue releasing adipokines suggested to be involved in the pathogenesis of osteoarthritis (OA). Nevertheless, their relative contribution and exact mechanisms are still ambiguous. The aim of this study is to compare serum adipokine levels between end-stage knee OA patients and controls and to relate these serum levels to local parameters of cartilage damage and synovial inflammation. Serum was collected from 172 severe knee OA patients, shortly before total knee replacement (TKR) surgery and from 132 controls without radiographic knee OA [Kellgren & Lawrence (K&L) = 0]. Serum adiponectin, leptin, and resistin levels were measured by enzyme-linked immunosorbent assay (ELISA). Cartilage and synovial tissue were collected at TKR surgery and assessed for cartilage degeneration and synovial inflammation by histochemistry and biochemical analyses. The adipokine levels were all distinctly higher in OA patients as compared to controls. Especially adiponectin and leptin were associated with female gender (stand beta = 0.239 and 0.467, respectively, P < 0.001) and body mass index (BMI) (stand beta = -0.189 and 0.396, respectively, P < 0.001). No associations between serum levels of adipokines and cartilage damage (histochemistry, proteoglycan content) were found whereas weak but positive associations with synovial inflammation were found [adiponectin and interleukin-1β (IL-1β), stand beta = 0.172, P = 0.02; resistin and histology, stand beta = 0.183, P = 0.034, adjusted for demographics]. This study suggests an important involvement of adipokines in OA patients considering their high serum levels compared to controls. Associations of systemic adipokines with local synovial tissue inflammation were found, although not represented by similar relations with cartilage damage, suggesting that adipokines are of relevance in the inflammatory component of OA.
    Osteoarthritis and Cartilage 05/2012; 20(8):846-53. · 3.90 Impact Factor
  • Article: Influence of variation in semiflexed knee positioning during image acquisition on separate quantitative radiographic parameters of osteoarthritis, measured by Knee Images Digital Analysis.
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    ABSTRACT: The clinical application of quantitative measurement of separate radiographic parameters of knee osteoarthritis (OA) might be hampered by a lack of reproducible semiflexed joint positioning during acquisition of radiographs. The influence of systematic variations in knee positioning on measurement of separate quantitative radiographic parameters was studied. Five components of knee position during radiographic acquisition (beam height, lower and upper leg extension, internal rotation, and lateral shift) were systematically varied within a clinically relevant range, using three cadaver legs. The influence of these variations on the measurement of the separate quantitative radiographic parameters by Knee Images Digital Analysis (KIDA) was evaluated. Significant changes were validated in vivo. Changes were compared with differences during 2-year follow-up in a radiographic progression cohort of early OA. Systematic variation in upper and lower leg extension induced changes in the measurement of joint space width (JSW). Lower leg extension also influenced osteophyte area and eminence height measurement. Also bone density measurement was influenced by variation in all five position components. Variations were of clinical relevance compared with 2-year differences in knees with radiographic progression, and were confirmed in vivo. Variations in semiflexed knee positioning, which are considered to occur easily during image acquisition in trials and clinical practice despite standardization, are of significant influence on the quantitative measurement of most separate radiographic parameters of OA using KIDA. The additional value of quantitative measurement might improve significantly by better standardization during radiographic acquisition; with radiography still being the gold standard for structure-modification in OA.
    Osteoarthritis and Cartilage 04/2012; 20(9):997-1003. · 3.90 Impact Factor
  • Article: Joint distraction results in clinical and structural improvement of haemophilic ankle arthropathy: a series of three cases.
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    ABSTRACT: The incidence of haemophilic arthropathy in multiple joints decreased due to treatment with clotting factor. Nowadays patients are enabled to live a rather normal life, resulting in more (sports) trauma-induced arthropathy in isolated joints like the ankle. As surgical treatment options, fusion of the tibiotalar joint and total ankle replacement are available. Both standard treatments have complications and therefore an alternative treatment is desired. In this study, treatment of haemophilic ankle arthropathy with joint distraction was explored. Three patients with haemophilic ankle arthropathy were treated with joint distraction using an Ilizarov external fixator. Clinical outcomes like function, participation and pain were evaluated in retrospect with three different questionnaires: haemophilia activities list, impact on participation and autonomy and the Van Valburg questionnaire. Structural changes were assessed blinded on X-ray by the Pettersson score and ankle images digital analysis (AIDA) and by an MRI score. All three patients were very satisfied with the clinical outcome of the procedure. They reported a clear improvement for self-perceived functional health, participation in society and autonomy and pain. Partial ankle joint mobility was preserved in the three patients. The Pettersson score remained the same in one patient and slightly improved in the two other patients, while joint space width measured by AIDA and the MRI score demonstrated improvement for all three patients after ankle distraction. This study suggests that joint distraction is a promising treatment for individual cases of haemophilic ankle arthropathy, without additional risk of bleedings during treatment.
    Haemophilia 04/2012; 18(5):810-7. · 2.60 Impact Factor
  • Article: Clusters within a wide spectrum of biochemical markers for osteoarthritis: data from CHECK, a large cohort of individuals with very early symptomatic osteoarthritis.
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    ABSTRACT: To assess a wide spectrum of biochemical markers (biomarkers) in a large cohort of individuals with (very) early symptomatic knee and/or hip osteoarthritis (OA). Secondly, to investigate associations between biomarkers and between biomarkers and demographics to demonstrate validity of the obtained dataset and further investigate the involvement and/or role of these biomarkers in OA. Fourteen biomarkers (uCTX-II, uCTX-I, uNTX-I, sCOMP, sPIIANP, sCS846, sC1,2C, sOC, sPINP, sHA, sPIIINP, pLeptin, pAdiponectin, pResistin) were assessed by ELISA or RIA in CHECK (Cohort Hip and Cohort Knee), a 10-year prospective cohort of 1,002 individuals with early symptomatic knee and/or hip OA. Quality controls revealed that gathered data were technically reliable. The majority of biomarkers showed relevant associations with demographic variables, which were expectedly different between genders and/or menopausal status for some. Principal component analysis enabled identification of five clusters, consecutively designated as 'bone-CTX-II', 'inflammation', 'synovium', 'C1,2C-adipokines', and 'cartilage synthesis' cluster. Notably, uCTX-II clustered with biomarkers of bone metabolism, while sCOMP clustered with biomarkers of synovial activity. The identified clusters extended knowledge on individual biomarkers from mostly smaller studies as did the observed associations between biomarker levels and demographics, from which validity of our data was deduced. uCTX-II may not only reflect articular cartilage but also bone metabolism and sCOMP may reflect synovial rather than cartilage metabolism. Major involvement of adipokines in joint metabolism was not identified.
    Osteoarthritis and Cartilage 04/2012; 20(7):745-54. · 3.90 Impact Factor
  • Article: In end stage osteoarthritis, cartilage tissue pentosidine levels are inversely related to parameters of cartilage damage.
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    ABSTRACT: Age is the most prominent predisposition for development of osteoarthritis (OA). Age-related changes of articular cartilage are likely to play a role. Advanced glycation endproducts (AGEs) accumulate in cartilage matrix with increasing age and adversely affect the biomechanical properties of the cartilage matrix and influence chondrocyte activity. In clinical studies AGEing of cartilage and its relation to actual cartilage damage can only be measured by surrogate markers (e.g., serum, skin or urine AGE levels and imaging or biochemical markers of cartilage damage). In this study actual cartilage AGE levels were directly related to actual cartilage damage by use of cartilage obtained at joint replacement surgery. Cartilage and urine samples were obtained from 69 patients undergoing total knee replacement. Samples were analyzed for pentosidine as marker of AGE. Cartilage damage was evaluated macroscopically, histologically, and biochemically. Cartilage and urine pentosidine both increased with increasing age. The higher the macroscopic, histological, and biochemical cartilage damage the lower the cartilage pentosidine levels were. In multiple regression analysis age is not found to be a confounder. There is an inverse relation between cartilage AGEs and actual cartilage damage in end-stage OA. This is likely due to ongoing (ineffective) increased turnover of cartilage matrix proteins even in end stage disease.
    Osteoarthritis and Cartilage 03/2012; 20(3):233-40. · 3.90 Impact Factor
  • Article: Evaluation of separate quantitative radiographic features adds to the prediction of incident radiographic osteoarthritis in individuals with recent onset of knee pain: 5-year follow-up in the CHECK cohort.
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    ABSTRACT: Detailed radiographic evaluation might enable the identification of osteoarthritis (OA) earlier in the disease. This study evaluated whether and which separate quantitative features on knee radiographs of individuals with recent onset knee pain are associated with incidence of radiographic OA and persistence and/or progression of clinical OA during 5-year follow-up. From the Cohort Hip & Cohort Knee study participants with knee pain at baseline were evaluated. Radiographic OA development was defined as Kellgren & Lawrence (K&L) grade ≥ II at 5-year follow-up. Clinical OA was defined as persistent knee pain and as progression of Westen Ontario & McMaster Universities Osteoarthritis index (WOMAC) pain and function score during follow-up. At baseline radiographic damage was determined by quantitative measurement of separate features using Knee Images Digital Analysis, and by K&L-grading. Measuring osteophyte area [odds ratio (OR) =7.0] and minimum joint space width (OR=0.7), in addition to demographic and clinical characteristics, improved the prediction of radiographic OA 5 years later [area under curve receiver operating characteristic=0.74 vs 0.64 without radiographic features]. When the predictive score (based on multivariate regression coefficients) was larger than the cut-off for optimal specificity, the chance of incident radiographic OA was 54% instead of the prior probability of 19%. Evaluating separate quantitative features performed slightly better than K&L-grading (AUC=0.70). Radiographic characteristics hardly added to prediction of clinical OA. In individuals with onset knee pain, radiographic characteristics added to the prediction of radiographic OA development 5 years later. Quantitative radiographic evaluation in individuals with suspected OA is worthwhile when determining treatment strategies and designing clinical trials.
    Osteoarthritis and Cartilage 02/2012; 20(6):548-56. · 3.90 Impact Factor
  • Article: Increased interleukin (IL)-7Rα expression in salivary glands of patients with primary Sjogren's syndrome is restricted to T cells and correlates with IL-7 expression, lymphocyte numbers and activity.
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    ABSTRACT: To identify interleukin (IL)-7Rα expression in the labial salivary gland (LSG) of patients with primary Sjögren's syndrome (pSS) and non-Sjögren's syndrome sicca (nSS-sicca) and to study its correlation with glandular inflammation and IL-7 expression. The presence of infiltrating immune cells and IL-7Rα cells in inflamed LSG of patients with pSS (n=12) and nSS-sicca controls (n=7) was studied by immunohistochemistry and fluorescence activated cell sorting analysis upon tissue digestion (n=15 and n=13, respectively). Additionally, the correlations of IL-7Rα cells with hallmark disease parameters of pSS, major infiltrating inflammatory cells and IL-7 were assessed. In the LSG of patients with pSS increased numbers of IL-7Rα cells were found as compared with nSS-sicca patients. IL7Rα cells strongly correlated with the lymphocytic focus score, IL-7 expression, the decrease in percentage of IgA plasma cells and numbers of CD3 T cells, CD20 B cells, and CD1a and CD208 myeloid dendritic cells. Analysis of isolated cells from the LSG demonstrated strongly increased percentages of IL-7Rα CD3 T cells in pSS as compared with nSS, showing abundant IL-7Rα expression on both CD4 and CD8 T cells. Other CD45 leucocytes and CD45- tissue cells scarcely expressed IL-7Rα. Percentages of IL-7Rα T cells also significantly correlated with glandular inflammation. This study shows the presence of increased IL-7Rα T cells in the LSG of patients with pSS and their association with the severity of sialadenitis, disease parameters and IL-7 expression. Considering the immunostimulatory ability of IL-7Rα T cells and IL-7, this suggests that IL-7(R)-dependent T cell-driven immune activation plays an important role in inflammation in pSS.
    Annals of the rheumatic diseases 02/2012; 71(6):1027-33. · 8.11 Impact Factor
  • Article: Feasibility of bone density evaluation using plain digital radiography.
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    ABSTRACT: For the radiographic evaluation of subchondral bone changes (sclerosis) in osteoarthritis (OA), bone density (BD) is commonly subjectively assessed. BD evaluation using plain digital radiography might be influenced by acquisition and post-processing (PP) settings. Objective of this study was to evaluate the effects of these settings on the measurement of BD using digital radiographs. A bone density standard (BDS) of hydroxyapatite (HA) mimicked a BD range of 1.0-5.75 g/cm(2). Digital radiographs were acquired with variation in acquisition settings, and with clinical and minimal PP. An aluminum step wedge served as an internal reference to express the gray values of the BDS in mm aluminum equivalents (mmAl). The relation (R(2)) between actual BD and BD normalized to the reference wedge was evaluated with linear regression analyses for radiographs with variations in PP and acquisition settings. Precision of BD measurement of the BDS was evaluated for application in clinical practice. The correlation between actual BD and BD normalized to the reference was improved by changing PP from clinical (R(2)=0.96) to minimal (R(2)=0.98). Higher tube voltage [kilovolt (kV)] improved the correlation further. Even for clinical PP, average standard deviation (SD) was 0.97 mmAl, much smaller than the change of 2.51 mmAl clinically observed in early OA, which implies the feasibility of BD measurements on digital radiographs. Changing PP and acquisition settings in clinical practice can have profound effect on outcome. If done with care, accurate BD measurement is feasible using plain digital radiography.
    Osteoarthritis and Cartilage 08/2011; 19(11):1343-8. · 3.90 Impact Factor
  • Article: Early clinical response to treatment predicts 5-year outcome in RA patients: follow-up results from the CAMERA study.
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    ABSTRACT: To investigate the long-term effects of the tight control (TC) and conventional (CT) methotrexate-based strategies of the Computer Assisted Management in Early Rheumatoid Arthritis trial in early rheumatoid arthritis and evaluate the predictive value of an early response to treatment. Clinical and radiographic 5-year outcome was compared between initial strategies. Patients were classified according to the EULAR response criteria. The prognostic value of early response to treatment in addition to established predictors was analysed by multiple linear regression analyses. 5 years of data were available for 205 of 299 patients, with no indication for selective drop-out. At 5 years there was no longer any significant difference for clinical and radiographic outcomes between treatment strategies applied during the first 2 years. Good-responders had a mean disease activity score of 2.39 (1.2) and median yearly radiographic progression rate of 0.6 (0.0 to 2.2) at 5 years; significantly lower (both p<0.02) when compared to moderate- and non-responders. Multiple regression analysis showed that early response to treatment is an independent predictor of 5-year outcome, irrespective of treatment strategy. The difference in disease activity between treatment strategies disappeared over the years. Good-response to treatment independently predicts significantly better 5-year clinical and radiographic outcome. The TC principle probably should be continued in the long-term.
    Annals of the rheumatic diseases 03/2011; 70(6):1099-103. · 8.11 Impact Factor
  • Article: Subchondral bone remodeling is related to clinical improvement after joint distraction in the treatment of ankle osteoarthritis.
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    ABSTRACT: OBJECTIVE: In osteoarthritis (OA), subchondral bone changes alter the joint's mechanical environment and potentially influence progression of cartilage degeneration. Joint distraction as a treatment for OA has been shown to provide pain relief and functional improvement through mechanisms that are not well understood. This study evaluated whether subchondral bone remodeling was associated with clinical improvement in OA patients treated with joint distraction. METHOD: Twenty-six patients with advanced post-traumatic ankle OA were treated with joint distraction for 3 months using an Ilizarov frame in a referral center. Primary outcome measure was bone density change analyzed on CT scans. Longitudinal, manually segmented CT datasets for a given patient were brought into a common spatial alignment. Changes in bone density (Hounsfield Units (HU), relative to baseline) were calculated at the weight-bearing region, extending subchondrally to a depth of 8mm. Clinical outcome was assessed using the ankle OA scale. RESULTS: Baseline scans demonstrated subchondral sclerosis with local cysts. At 1 and 2 years of follow-up, an overall decrease in bone density (-23% and -21%, respectively) was observed. Interestingly, density in originally low-density (cystic) areas increased. Joint distraction resulted in a decrease in pain (from 60 to 35, scale of 100) and functional deficit (from 67 to 36). Improvements in clinical outcomes were best correlated with disappearance of low-density (cystic) areas (r=0.69). CONCLUSIONS: Treatment of advanced post-traumatic ankle OA with 3 months of joint distraction resulted in bone density normalization that was associated with clinical improvement.
    Osteoarthritis and Cartilage 02/2011; 19(6):668-75. · 3.90 Impact Factor
  • Article: A systematic review of the association between radiographic and clinical osteoarthritis of hip and knee.
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    ABSTRACT: There is ongoing debate on whether an association between radiographic and clinical osteoarthritis (OA) exists. We hypothesized that the inconsistency in the detection of an association might be caused by different definitions of OA, by different radiographic protocols, and by scoring methods for radiographic damage and symptoms. The goal of this study was to evaluate which methodological criteria are important to detect an association between radiographic and clinical OA of hip and knee. A literature search was performed with the keywords 'OA', 'hip', 'knee', 'radiographic', and 'clinical' and results were screened for relevant studies. Quality criteria for study characteristics and methodology were developed. Studies were classified according to these criteria and the presence of an association between radiographic and clinical OA was scored. The importance of methodological quality and patient characteristics on the presence of an association was evaluated. The literature search resulted in 39 studies describing an association between radiographic and clinical OA. The frequency of an association between radiographic and clinical OA outcome measures diminished when less quality criteria were fulfilled. Specifically the criterion for standardized outcome measures appeared important in the detection of an association. The association was not influenced by patient characteristics. Only four studies were identified that fulfilled all quality criteria and in these studies an association was found for the knee joint and an inconsistent association was found for the hip joint. Methodological quality criteria are of importance to reveal an association between radiographic and clinical OA.
    Osteoarthritis and Cartilage 01/2011; 19(7):768-78. · 3.90 Impact Factor
  • Article: Decrease in immunoglobulin free light chains in patients with rheumatoid arthritis upon rituximab (anti-CD20) treatment correlates with decrease in disease activity.
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    ABSTRACT: Immunoglobulin (Ig) free light chains (FLCs) are short-lived B cell products that contribute to inflammation in several experimental disease models. In this study, FLC concentrations in inflamed joints of patients with rheumatoid arthritis (RA) as compared to patients with osteoarthritis were investigated. In addition, the relationship of FLCs and disease activity upon B cell depletion (rituximab) in patients with RA was studied. Synovial fluid (SF) and tissue from patients with RA were analysed for local presence of FLCs using ELISA and immunohistochemistry. In addition, FLC concentrations were measured (at baseline, 3 and 6 months after treatment) in 50 patients with RA with active disease who were treated with rituximab. Changes in FLCs were correlated to changes in disease activity and compared to alterations in IgM, IgG, IgA, IgM-rheumatoid factor (RF) and IgG-anti-citrullinated protein antibody (ACPA) concentrations. FLCs were detected in synovial tissue from patients with RA, and high FLC concentrations were found in SF from inflamed joints, which positively correlate with serum FLC concentrations. Serum FLC concentrations significantly correlated with disease activity score using 28 joint counts, erythrocyte sedimentation rate (ESR) and C reactive protein, and changes in FLC correlated with clinical improvement after rituximab treatment. Moreover, effect of treatment on FLC concentrations discriminated clinical responders from non-responders, whereas IgM-RF and IgG-ACPA significantly decreased in both patient groups. FLCs are abundantly present in inflamed joints and FLC levels correlate with disease activity. The correlation of FLC concentrations and disease activity indicates that FLCs may be relevant biomarkers for treatment response to rituximab in patients with RA and suggests that targeting FLC may be of importance in the therapy of RA.
    Annals of the rheumatic diseases 12/2010; 69(12):2137-44. · 8.11 Impact Factor
  • Article: Are switches from oral to subcutaneous methotrexate or addition of ciclosporin to methotrexate useful steps in a tight control treatment strategy for rheumatoid arthritis? A post hoc analysis of the CAMERA study.
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    ABSTRACT: To investigate the effects of a switch from oral methotrexate (MTX) to subcutaneous MTX (scMTX) or adding ciclosporin to oral MTX with a simultaneous reduction of the MTX dose, in case of adverse events (AE) or insufficient effect (IE) in rheumatoid arthritis (RA). The tight control treatment arm of the Computer Assisted Management in Early RA (CAMERA) trial was evaluated. The change in 28-joint Disease Activity Score (DAS28) after taking scMTX (over 1 month) or adding ciclosporin (over 3 months) was compared to the average monthly change in the preceding 3 months. Analyses were performed separately for strategy steps because of AE or IE. Of 151 patients, 57 needed the scMTX strategy step (21 because of AE, 36 because of IE) and 40 the following ciclosporin strategy step (20 and 20, respectively). The decrease in DAS28 after taking the scMTX strategy step was 0.30 points (p<0.05); no significant change in DAS28 was seen after the ciclosporin strategy step. In both strategy steps for AE or IE, quite similar observations were made. Of the patients who took the scMTX strategy step, 63% showed improvement. scMTX seems a useful treatment step after oral MTX in a tight control strategy, whereas the ciclosporin step seems ineffective.
    Annals of the rheumatic diseases 10/2010; 69(10):1849-52. · 8.11 Impact Factor
  • Article: Skin and urine pentosidine weakly correlate with joint damage in a cohort of patients with early signs of osteoarthritis (CHECK).
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    ABSTRACT: Age-related changes in articular cartilage are likely to play a role in the aetiology of osteoarthritis (OA). One of the major age-related changes in cartilage is the accumulation of advanced-glycation-endproducts (AGEs). Since, cartilage tissue is not readily available from patients for studying AGE levels, alternative approaches such as analyzing skin and urine are needed to study the role of cartilage AGE levels in OA. Paired human skin and cartilage samples were obtained post mortem. Paired skin and urine samples were obtained from the CHECK cohort (early OA patients). Pentosidine levels were measured by high-performance liquid chromatography (HPLC). As marker of cumulative cartilage damage X-rays of both knees and hips were scored. Urinary CTXII (uCTXII) levels were measured, to assess current cartilage breakdown. Cartilage and skin pentosidine correlate well (R=0.473, P=0.05). Skin pentosidine was higher in mild (summed (Kellgren & Lawrence K&L) over four large joints ≥4) compared to no (summed K&L≤3) radiographic OA (P=0.007). Urinary pentosidine was not different between these two groups. Skin pentosidine levels were not related to cartilage breakdown (highest vs lowest tertile of uCTXII). Urinary pentosidine, however, was higher in the highest compared to the lowest uCTXII tertile (P=0.009). Multiple regression analysis showed age to be the only predictor of the summed K&L score and age, creatinine clearance and urinary pentosidine as predictors of uCTXII. The higher skin and urinary pentosidine levels in those with mild compared to no radiographic joint damage and low vs high cartilage breakdown respectively suggest that AGEs may contribute to disease susceptibility and/or progression. However, relations are weak and cannot be used as surrogate markers of severity of OA.
    Osteoarthritis and Cartilage 10/2010; 18(10):1329-36. · 3.90 Impact Factor
  • Article: Increased expression of interleukin-7 in labial salivary glands of patients with primary Sjögren's syndrome correlates with increased inflammation.
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    ABSTRACT: To study the expression levels and immunostimulatory capacities of interleukin-7 (IL-7) in primary Sjögren's syndrome. Labial salivary gland (LSG) IL-7 expression was determined by immunohistochemistry, using a quantitative scoring system, in 30 patients with sicca syndrome: 15 patients with primary Sjögren's syndrome (SS) and 15 patients with non-SS sicca syndrome. The correlation of IL-7 expression in LSGs with parameters of local and peripheral disease was studied, and serum and salivary IL-7 levels were determined. Additionally, the effects of IL-7 on cytokine production by peripheral blood mononuclear cells (PBMCs) from patients with primary SS were determined in vitro by Luminex multicytokine assay and compared with the effects in control subjects. The expression of IL-7 in LSGs was higher in patients with primary SS compared with that in patients with non-SS sicca syndrome. IL-7 was observed primarily in the vicinity of lymphocytic infiltrates. Salivary IL-7 levels in patients with primary SS were higher than those in control subjects. In all 30 patients with sicca syndrome, IL-7 expression in LSGs correlated with parameters of both local and peripheral disease. Furthermore, IL-7 stimulated T cell-attracting and T cell-differentiating cytokines (monokine induced by interferon-gamma [IFNgamma], IFNgamma-inducible 10-kd protein, IL-12, and IL-15), as well as Th1 (IFNgamma), Th2 (IL-4), Th17 (IL-17A), proinflammatory (tumor necrosis factor alpha and IL-1alpha), and regulatory (IL-10 and IL-13) cytokine production by PBMCs. All of these cytokines were previously shown to be associated with primary SS. The IL-7-induced increase in IL-10 production in patients with primary SS was reduced compared with that in control subjects. The correlation between LSG IL-7 expression and (local) disease parameters in primary SS as well as the IL-7-mediated induction of inflammatory cytokines indicate that IL-7 might contribute to the immunopathology of primary SS.
    Arthritis & Rheumatism 04/2010; 62(4):969-77. · 7.87 Impact Factor
  • Article: Serum and urinary biochemical markers for knee and hip-osteoarthritis: a systematic review applying the consensus BIPED criteria.
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    ABSTRACT: Molecules that are released into biological fluids during matrix metabolism of articular cartilage, subchondral bone, and synovial tissue could serve as biochemical markers of the process of osteoarthritis (OA). Unfortunately, actual breakthroughs in the biochemical OA marker field are limited so far. By reviewing the status of commercially available biochemical OA markers according to the "Burden of disease, Investigative, Prognostic, Efficacy of intervention, and Diagnostic" ("BIPED") classification, future use of this "BIPED" classification is encouraged and more efficient biochemical OA marker research stimulated. Three electronic databases [PubMed, Scopus, EMBASE (1997-May 2009)] were searched for publications on blood and urinary biochemical markers in human primary knee and hip-OA. Stepwise selection of original English publications describing human studies on blood or urinary biochemical markers in primary knee or hip-OA was performed. Selected articles were fully read to determine whether biochemical markers were investigated on performance within any of the "BIPED" categories. Eighty-four relevant publications were identified. Data from relevant publications were tabulated according to the "BIPED" classification. Individual analyses within a publication were summarized in general "BIPED" scores. An uneven distribution of scores on biochemical marker performance and heterogeneity among the publications complicated direct comparison of individual biochemical markers. Comparison of categories of biochemical markers was therefore performed instead. In general, biochemical markers of cartilage degradation were investigated most extensively and performed well in comparison with other categories of biochemical markers. Biochemical markers of bone metabolism performed less adequately. Biochemical markers of synovial tissue metabolism were not investigated extensively, but performed quite well. Specific biochemical markers and categories of biochemical markers as well as their nature, origin and metabolism, need further investigation. International standardization of future investigations should be pursued to obtain more high-quality, homogenous data on the full spectrum of biochemical OA markers.
    Osteoarthritis and Cartilage 02/2010; 18(5):605-12. · 3.90 Impact Factor