The Effects of Pharmacological Urate-Lowering Therapy on Cardiovascular Disease in Older Adults with Gout.

Cardiovascular disease is an important cause of mortality in older patients. In addition to the traditional risk factors for cardiovascular disease, hyperuricemia has been increasingly associated with an elevated risk of cardiovascular disease. Uric acid itself has several unfavorable effects on the cardiovascular system, and hyperuricemia can lead to the development of gout. Gout is the most prevalent inflammatory rheumatic disease. Older patients with gout have an increased risk of cardiovascular morbidity and mortality due to an increased prevalence of traditional risk factors, as well as the inflammatory burden of gout activity. As the prevalence of traditional risk factors and the prevalence of both hyperuricemia and gout are increasing in older adults, cardiovascular risk management in these patients is very important. This risk management consists of, on the one hand, treatment of individual traditional risk factors and, on the other hand, of urate lowering, thereby decreasing inflammatory burden of gout. However, there is insufficient evidence to conclude that urate-lowering therapy reduces the risk of cardiovascular events. Moreover, from a cardiovascular point of view, there is no preference for one urate lowering drug over another in patients with gout, nor is there enough evidence to support a preference in patients with gout with increased cardiovascular risk. Personalized treatment in older patients with gout should be aimed at optimizing serum uric acid levels, as well as targeting traditional cardiovascular risk factors. Further prospective randomized trials are needed to support the hypothesis that urate lowering reduces cardiovascular risk in older patients with gout.

Methotrexate Polyglutamates Exposure - Response Modeling in a Large Cohort of Rheumatoid Arthritis Patients Starting Methotrexate.

Methotrexate polyglutamates (MTX-PG) concentrations in red blood cells (RBCs) have been suggested as a biomarker of response in patients with rheumatoid arthritis (RA) receiving low-dose MTX therapy. We investigated the association and interpatient variability between RBC-MTX-PG3-5 -exposure and response in patients with RA starting MTX. Data of three prospective cohorts were available. The relationship between exposure and Disease Activity Score in 28 joints (DAS28) was analyzed using a population pharmacokinetic-pharmacodynamic model. Relevant covariates were tested using full covariate modeling and backward elimination. From 395 patients, 3,401 MTX-PG concentrations and 1,337 DAS28 measurements were available between 0 and 300 days after MTX treatment onset. The developed model adequately described the time course of MTX-PG3-5 and DAS28. The median MTX-PG3-5 level at month 1 was 30.9 nmol/L (interquartile range (IQR): 23.6-43.7; n = 41) and at month 3: 69.3 nmol/L (IQR: 17.9-41.2; n = 351). Clearance of MTX-PG3-5 from RBCs was 28% lower (95% confidence interval (CI): 23.6-32.8%) in a woman and 10% lower (95% CI: 7.7-12.4%) in a 65-year-old compared with a 35-year-old patient. MTX-PG3-5 concentrations associated with DAS28: half-maximal effective concentration (EC50 ) was 9.14 nmol/L (95% CI: 4.2 nmol/L-14.1 nmol/L). EF at 80% (EC80 ) above 47 nmol/L was regarded as the optimal response. Independent of the MTX-PG 3-5 - response association, co-administration of disease-modifying antirheumatic drugs and corticosteroids improved response (additive effect on maximum effect (Emax )), whereas smoking, high body mass index and low albumin decreased Emax . In patients with RA starting MTX, RBC-MTX-PG3-5 was associated with clinical response. A dose increase is suggested when MTX-PG3-5 at month 1 is below 9.15 nmol/L, continued with the same dose when the concentration is above 47 nmol/L, and consider other treatment options above 78 nmol/L from 3 months onwards.

Gender-specific differences in patients with psoriatic arthritis receiving ustekinumab or tumour necrosis factor inhibitor: real-world data.

OBJECTIVE: Investigate effects of gender on disease characteristics and treatment impact in patients with PsA. METHODS: PsABio is a non-interventional European study in patients with PsA starting a biological DMARD [bDMARD; ustekinumab or TNF inhibitor (TNFi)]. This post-hoc analysis compared persistence, disease activity, patient-reported outcomes and safety between male and female patients at baseline and 6 and 12 months of treatment. RESULTS: At baseline, disease duration was 6.7 and 6.9 years for 512 females and 417 males respectively. Mean (95% CI) scores for females vs males were: clinical Disease Activity Index for Psoriatic Arthritis (cDAPSA), 32.3 (30.3, 34.2) vs 26.8 (24.8, 28.9); HAQ-Disability Index (HAQ-DI), 1.3 (1.2, 1.4) vs 0.93 (0.86, 0.99); total PsA Impact of Disease-12 (PsAID-12) score, 6.0 (5.8, 6.2) vs 5.1 (4.9, 5.3), respectively. Improvements in scores were smaller in female than male patients. At 12 months, 175/303 (57.8%) female and 212/264 (80.3%) male patients achieved cDAPSA low disease activity, 96/285 (33.7%) and 137/247 (55.5%), achieved minimal disease activity (MDA), respectively. HAQ-DI scores were 0.85 (0.77, 0.92) vs 0.50 (0.43, 0.56), PsAID-12 scores 3.5 (3.3, 3.8) vs 2.4 (2.2, 2.6), respectively. Treatment persistence was lower in females than males (P ≤ 0.001). Lack of effectiveness was the predominant reason to stop, irrespective of gender and bDMARD. CONCLUSIONS: Before starting bDMARDs, females had more severe disease than males and a lower percentage reached favourable disease states, with lower persistence of treatment after 12 months. A better understanding of the mechanisms underlying these differences may improve therapeutic management in females with PsA. TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT02627768.

Genome-wide Association Study of Methotrexate-Induced Liver Injury in Rheumatoid Arthritis Patients.

Hepatotoxicity is a serious adverse drug reaction related to methotrexate (MTX). However, the cause of drug-induced liver injury (DILI) is still unclear and unpredictable. Genetic risk factors may predispose for MTX-DILI. Therefore, we conducted a nested case-control genome-wide association study to explore genetic risk factors associated with MTX-DILI. Seven international groups contributed blood samples and data of patients with rheumatoid arthritis who used MTX. MTX-DILI was defined as an alanine aminotransferase (ALT) level of at least three times the upper limit of normal (ULN), to increase contrast controls ALT levels did not raise above two times the ULN. Per study site, control subjects and patients with MTX-DILI (ratio 3:1) were matched for age, gender, and duration of MTX use. Patients were genotyped using Illumina GSA MD-24v1-0 and data were imputed using the 1000 Genomes reference panel. Single-nucleotide polymorphisms (SNPs) were analyzed using an additive genetic model, corrected for sex, country, and age. A P-value of ≤ 5 × 10-8 was considered significant, whereas a  P-value of ≤ 5 × 10-6 was considered suggestive. A total of 108 MTX-DILI cases and 311 controls were included for association analysis. None of the SNPs were significantly associated with MTX-DILI. However, we found seven suggestive genetic variants associated with MTX-DILI (P-values 7.43 × 10-8 to 4.86 × 10-6 ). Of those, five SNPs were in the intronic protein-coding regions of FTCDNL1, BCOR, FGF14, RBMS3, and PFDN4/DOK5. Investigation of candidates SPATA9 (rs72783407), PLCG2 (rs60427389), RAVER2 (rs72675408), JAK1 (rs72675451), PTPN2 (rs2476601), MTHFR C677T (rs1801133), and into the HLA region did not show significant findings. No genetic variants associated with MTX-DILI were found, whereas suggestive SNPs need further investigation.

Patients' and health-care professionals' perspectives on adverse drug reaction burden attributed to the use of biological DMARDs: a qualitative study.

BACKGROUND: Previous studies showed a discrepancy between health-care professionals' (HCPs') and patients' perspective on adverse drug reaction (ADR) burden. However, it is unclear which factors make an ADR burdensome. We aimed to give insight into why ADRs are perceived as burdensome by inflammatory rheumatic disease (IRD) patients, and whether this differs from the HCPs' perspective. RESEARCH DESIGN AND METHODS: A qualitative study was conducted using Dutch Biologic Monitor data. Participants received bimonthly questionnaires on experienced ADRs attributed to biological DMARDs and were asked to elaborate on ADR burden using a Likert-type scale and an open-ended question for clarification. Data of 440 IRD patients were analyzed following thematic analysis. A similar analysis was done with semi-structured interviews with 13 HCPs. RESULTS: We identified seven themes associated with ADR burden: 'effect on medication prescription,' 'impact on appearance,' 'impact on autonomy,' 'impact on daily life,' 'psychological consequences,' 'distressing aspects of ADR,' and 'physical consequences.' Identical themes were identified by HCPs, although they identified most subthemes in 'psychological consequences,' and less subthemes in 'impact on daily life' and 'impact on autonomy.' CONCLUSION: Patients describe perceived ADR burden in both physical and psychological themes. The HCPs' perspective is comparable, but mostly focuses on psychological impact.

The Prevalence of Cardiac Diseases in a Contemporary Large Cohort of Dutch Elderly Ankylosing Spondylitis Patients-The CARDAS Study.

OBJECTIVES: The aim of the present study was to determine the prevalence of specific cardiac manifestations, i.e., conduction disorders, valvular disease and diastolic left ventricular (LV) dysfunction, in a large cross-sectional controlled cohort of elderly ankylosing spondylitis (AS) patients. METHODS: This cross-sectional study assessed the prevalence of valvular disease, conduction disorders and LV dysfunction in 193 randomly selected AS patients compared with 74 osteoarthritis (OA) controls aged 50-75 years. Patients underwent conventional and tissue Doppler echocardiography in combination with clinical and laboratory assessments. Multivariate regression analyses were performed to compare the odds of mitral valve regurgitation (MVR) and aortic valve regurgitation (AVR) between AS patients and OA controls. RESULTS: The prevalence of diastolic dysfunction was trivial and comparable in AS patients compared to controls (respectively, 4% and 3%) and had no further clinical relevance. In addition, the prevalence of conduction disturbances was similar in both groups, with little clinical relevance, respectively 23% vs. 24%. The prevalence of AVR was significantly higher in AS patients compared to the controls, respectively 23% (9% trace, 12% mild, 1% moderate, 1% severe, 1% prosthesis) vs. 11%, p = 0.04. After correcting for age, sex and CV risk factors, AS patients had an odds ratio of 4.5 (95% CI 1.1-13.6) for AVR compared to the controls. In contrast, the prevalence values of MVR were similar and mostly not clinically relevant in AS patients and controls, respectively 36% and 32% and p = 0.46. CONCLUSION: The prevalence of diastolic LV dysfunction and conduction disorders was mostly not clinically relevant, and similar in AS patients and controls. However, AS patients had an up to five times increased odds to develop AVR compared to controls. Therefore, echocardiographic screening of elderly (50-75 years) AS patients should be considered.

[Increased cardiovascular risk due to glucocorticoids: how strong is the evidence?] / Verhoogd cardiovasculair risico door glucocorticoïden.

Glucocorticoids are important for treatment of (auto-)immune diseases. Prolonged use of high dose glucocorticoids increases the cardiovascular disease risk. Underlying mechanisms have not been fully elucidated but increased incidence of traditional cardiovascular risk factors and enhanced (V)LDL-cholesterol synthesis are important contributors. If and to what extent this also holds for low-dose corticosteroids (< 7.5mg prednisolone/day) is still unknown. The current evidence is based on observational studies which are often dominated by 'confounding by indication', as disease activity itself is an independent cardiovascular risk factor, and particularly patients with active disease are more likely to receive higher doses of glucocorticoids. Future studies (preferably RCT's) with disease activity data and medication use are required to solve this issue. Obviously, we must always remain critical regarding the use of glucocorticoids and aim for the lowest possible adequate dose and shortest treatment duration.

Are Health Care Professionals' Implicit and Explicit Attitudes Toward Conventional Disease-Modifying Antirheumatic Drugs Associated With Those of Their Patients?

OBJECTIVE: It is generally unknown how the attitudes and beliefs of health care professionals (HCPs) might affect the attitudes, beliefs, and medication-taking behavior of patients with rheumatoid arthritis (RA). This study aims 1) to examine the attitudes, health-related associations (both implicit and explicit), and beliefs of HCPs about conventional disease-modifying antirheumatic drugs, and 2) to assess whether these attitudes, health-related associations, and beliefs of HCPs are associated with those of their patients, with their patients' medication-taking behavior, and disease activity. METHODS: HCPs were recruited from 2 centers that specialized in rheumatology across The Netherlands, and patient recruitment followed. In this observational study, implicit outcomes were measured with single-category implicit association tests, whereas explicit outcomes were measured with a bipolar evaluative adjective scale and the Beliefs About Medicines Questionnaire-Specific. Spearman's rank correlations were used to describe correlations between implicit and explicit measures of the attitudes of HCPs. Multilevel, mixed-effects linear models were used to examine the association of HCP-related characteristics, including the implicit and explicit outcomes of HCPs, with those of their patients, their medication-taking behaviors, and disease activity. RESULTS: Of the 1,659 initially invited patients, 254 patients with RA (mean age 62.8 years, mean disease duration 11.8 years, and 68.1% of the patients were female) who were treated by 26 different HCPs agreed to participate in this study. The characteristics, attitudes, health-related associations, and beliefs about medicines of HCPs were not significantly associated with those of their patients, nor with their medication-taking behaviors or disease activity scores. CONCLUSION: This study demonstrated that the attitudes, health-related associations (as measured both implicitly and explicitly), and beliefs of HCPs were not significantly associated with the attitudes, beliefs, medication-taking behavior, and disease activity of patients with RA.

Efficacy and safety of subcutaneous infliximab versus adalimumab, etanercept and intravenous infliximab in patients with rheumatoid arthritis: a systematic literature review and meta-analysis.

OBJECTIVES: There are few comparative data for tumor necrosis factor inhibitors in patients with rheumatoid arthritis (RA). METHODS: Historical data for reference product/biosimilar intravenous infliximab, or adalimumab and etanercept, were pooled and compared with phase 3 study results for a subcutaneous (SC) formulation of the infliximab biosimilar CT-P13, in a systematic review and meta-analysis (PROSPERO: CRD42019149621). RESULTS: The authors identified 13 eligible controlled trials that randomized over 5400 participants to prespecified treatments of interest. Comparison with pooled historical data suggested a numerical advantage for CT-P13 SC over intravenous infliximab for almost every prespecified efficacy outcome evaluated, including Disease Activity Score in 28 joints (C-reactive protein/erythrocyte sedimentation rate), Clinical/Simplified Disease Activity Index scores, American College of Rheumatology responses, and multiple measures of disease remission and low disease activity; for the majority of outcomes, there was no overlap in 95% confidence intervals between groups. A numerical advantage for CT-P13 SC was also observed for safety outcomes (adverse events, infections, and discontinuations). Similar, but less marked, trends were observed for comparison with historical efficacy and safety data for adalimumab/etanercept. CONCLUSION: CT-P13 SC offers an improved or similar benefit-to-harm ratio compared with infliximab (intravenous) and adalimumab/etanercept, for the treatment of moderate-to-severe RA.

The Effect of Anti-TNF Therapy on Cardiac Function in Rheumatoid Arthritis: An Observational Study.

Congestive heart failure (CHF) is the second most prevalent cause of death in rheumatoid arthritis (RA). The systemic inflammatory state in RA patients is deemed responsible for this finding. Anti-inflammatory treatment with anti-tumor necrosis factor (anti-TNF) therapy decreases CV risk and subsequently might improve the cardiac function by lowering the overall inflammatory state. This study investigated the effect of anti-TNF on the cardiac function in RA patients. Fifty one RA patients were included, of which thirty three completed follow-up. Included patients were >18 years, had moderate-high disease activity and no history of cardiac disease. Patients were assessed at baseline and after six months of anti-TNF treatment. Patients underwent conventional Speckle tracking and tissue Doppler echocardiography in combination with clinical and laboratory assessments at baseline and follow-up. The left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) showed no changes during follow-up, LVEF 63% (±9) to 62% (±8) p = 0.097 and GLS -20 (±4) to -20 (±3) p = 0.79, respectively. Furthermore, E/e' nor E/A changed significantly between baseline and follow-up, respectively 8 (7-9) and 8 (7-9) p = 0.17 and 1.1 (±0.4) and 1.1 (±0.4) p = 0.94. Follow-up NT-proBNP decreased with 23%, from 89 ng/L (47-142) to 69 ng/L (42-155), p = 0.10. Regression analysis revealed no association between change in inflammatory variables and cardiac function. Echocardiography showed no effect of anti-TNF treatment on the cardiac function in RA patients with low prevalence of cardiac dysfunction. Moreover, NT-proBNP decreased, possibly indicating (subtle) improvement of the cardiac function.

Stakeholders' perspectives on a patient-reported outcome measure-based drug safety monitoring system for immune-mediated inflammatory diseases.

BACKGROUND: Biologics are used as effective therapeutics to treat a variety of diseases. Even though biologics are widely used, knowledge on the post-marketing experience of patients is limited. Therefore, a framework was established for a patient-reported outcome measure (PROM)-based drug safety monitoring system for ADRs attributed to biologics, known as the 'Dutch Biologic Monitor'. OBJECTIVE: Generation of a multi-stakeholder perspective on the preferred setup, potential and added value of a PROM-based national drug safety monitoring system. METHODS: Nineteen stakeholders were interviewed following a structured interview guide. Transcribed data were coded and analyzed to count frequencies and to generate recurring themes. RESULTS: Stakeholders (84.2%) support the establishment of a national drug safety monitoring system, but the feasibility depends on the implementation process. The need for integration and assessment of PROMs on ADRs in clinical practice and the preference to monitor small molecules and new drugs were emphasized. Preferably, all pharmacological options per indication should be monitored. CONCLUSIONS: Stakeholders recommend to establish a PROM-based national drug safety monitoring system focused on ADRs attributed to biologics, small molecules, and new drugs. Moreover, PROMs on ADRs ideally need to become integrated in clinical practice to provide health-care providers more insight in patients' perspectives.

Immune-mediated inflammatory disease patients' preferences in adverse drug reaction information regarding biologics.

OBJECTIVES: Patient-reported outcomes (PROs) are increasingly used in studies and medical practice to obtain information on patients' perspectives toward their treatment or disease. However, most study outcomes are primarily directed at healthcare professionals. It was aimed to obtain insight in which type of information immune-mediated inflammatory disease (IMID) patients prefer to receive after participating in the Dutch Biologic Monitor (DBM), a PRO-based prospective cohort event monitoring system focused on adverse drug reactions (ADRs). METHODS: A survey was conducted among DBM participants that wanted information about the results. Patients' preferences were identified using twelve statements and rated with five-point Likert-type scales. Subgroup analyses and differences between statements were performed using Mann-Whitney U Tests. RESULTS: The survey was completed by 591 patients (response rate 67.6%). Most respondents had inflammatory rheumatic diseases (76.8%) and used adalimumab (37.2%) or etanercept (33.2%). Respondents preferred results per IMID over aggregated results (p = <0.001). Information on whether patients with similar IMIDs experience ADRs (average 4.5), which biologics are most likely to cause ADRs (4.4) and whether ADRs disappear (4.4) were most interesting. CONCLUSION: DBM participants prefer to receive disease-specific information on ADRs that is tailored to their own biologic and IMID, including the outcome of ADRs.

Presence of active MRI lesions in patients suspected of non-radiographic axial spondyloarthritis with high disease activity and chance at conversion after a 6-month follow-up period.

OBJECTIVES: The primary aim is to evaluate signs of inflammation on MRI of sacroiliac joints (SIJ)/spine in inflammatory back pain (IBP) patients suspected of nr-axSpA with high disease activity. Secondary aims are to describe the onset of new inflammatory lesions at MRI after 6 months and to evaluate gender differences in the presence of inflammation. METHOD: Consecutively, patients with IBP with at least two spondyloarthritis features, high disease activity (BASDAI ≥ 4), and who were TNFi naïve, had a MRI of SIJ and spine. In the absence of active lesions, MRI was repeated after 6 months. MRI images were scored according to the Spondyloarthritis Research Consortium of Canada method. RESULTS: Sixty-nine patients were included (53% female), of whom 39% showed signs of inflammation at the first MRI: 30.9% of the SIJ, 19.1% of the spine and 2.4% at both sites, irrespective of the CRP levels. Males more often showed inflammatory signs at the MRI of the SIJ and spine compared with females (45.5% vs. 33.3%). Consistently, the median SPARCC score was higher in males: for SIJ 14.0 (IQR 2.3-25.0) and for spine 11.5 (IQR 8.5-25.6). Only one patient (4.7%) without baseline inflammatory signs showed active lesions of SIJ after 6 months. CONCLUSIONS: Almost 40% of the IBP patients suspected of nr-axSpA, with high disease activity, showed inflammatory lesions on MRI of SIJ and/or spine, which occurred more often in males compared with females. In the majority (95.3%), an MRI without inflammatory lesions remained negative after 6 months despite high disease activity.Key Points• Forty percent of inflammatory back pain patients with high disease activity showed inflammatory signs on MRI of the SIJ and/or spine.• Only 4% of baseline MRIs without inflammatory signs at baseline conversed to an MRI with inflammatory signs after 6 months.• Male inflammatory back pain patients with high disease activity showed more often inflammatory signs on MRI compared with females.

Amplified prevalence and incidence of cardiovascular disease in patients with inflammatory arthritis and coexistent autoimmune disorders.

OBJECTIVE: This study aims to assess the prevalence proportion and incidence rate of cardiovascular morbidity in patients with inflammatory arthritis compared with that in controls, and to determine whether the co-existence of multiple autoimmune disorders is associated with an amplified risk of cardiovascular disease. METHODS: Data from the Nivel Primary Care Database were used to assess prevalence proportion and incidence rate of cardiovascular disease in patients with inflammatory arthritis only, patients with inflammatory arthritis coexistent with another autoimmune disorder, and controls. Hazard ratios were calculated using Cox regression models. RESULTS: The prevalence proportions in inflammatory arthritis patients were increased for type 1 diabetes [odds ratio (OR) 1.80, 95% CI: 1.27, 2.55], hypothyroidism (OR 1.49, 95% CI: 1.37, 1.61), psoriasis (OR 2.72, 95% CI: 2.49, 2.97) and IBD (OR 2.64, 95% CI: 2.28, 3.07) compared with that in controls. Cardiovascular disease prevalence (OR 1.34, 95% CI: 1.28, 1.41) and incidence rates (incidence rate ratio 1.3, 95% CI: 1.23, 1.41) were higher in inflammatory arthritis patients compared with that in controls, and were further increased in the presence of a second autoimmune disorder. The hazard ratio for cardiovascular disease was 1.32 (95% CI: 1.23, 1.41) for patients with inflammatory arthritis only, and 1.49 (95% CI: 1.31, 1.68) for patients with inflammatory arthritis co-existent with another autoimmune disorder. CONCLUSION: The amplification of cardiovascular disease risk in inflammatory arthritis patients with multiple autoimmune disorders warrants greater awareness, and since autoimmune disorders often co-exist, the need for cardiovascular risk management in these patients is once again emphasized.

Patients with inflammatory rheumatic diseases: quality of self-reported medical information in a prospective cohort event monitoring system.

OBJECTIVES: Assessment of the quality of patient-reported medical information in the Dutch Biologic Monitor and evaluation of the representativeness of the sampled participants. METHODS: Consecutive adult patients using a biologic DMARD (bDMARD) for an immune-mediated inflammatory disease were included in eight Dutch centres. For this substudy, data of 550 patients with inflammatory rheumatic diseases were used. Patient-reported bDMARD prescription, indication and combination therapy were verified for patients that permitted access to their electronic health record using percentage agreement and/or Cohen's kappa (n = 483). Conservative post hoc sensitivity analysis was performed to account for missing data. Population representativeness was tested for the entire substudy population by comparing age, gender and prescribed bDMARD to the centres' reference populations using Mann-Whitney U-test, χ2 goodness-of-fit or Fisher's exact test with Monte Carlo simulation (n = 550). RESULTS: The correct bDMARD was reported by 95.8% of the participants. Agreement between patients and electronic health record was almost perfect for indications (κ = 0.832) and substantial for combination therapies (κ = 0.725). Agreement on combination therapies remained substantial after post hoc sensitivity analysis (κ = 0.640). Gender distribution (P > 0.05) and bDMARD use (P > 0.05) were similar to the reference populations. Median age was different (58.0 vs 56.0 years, P = 0.04), but considered clinically irrelevant. CONCLUSION: The Dutch Biologic Monitor seems to be a valid tool to obtain patient-reported medical information. Reported medical information generally corresponded to the electronic health records and the participants represented their reference populations regarding age, gender and prescribed bDMARD.

Development and Validation of a Sensitive UHPLC-MS/MS-Based Method for the Analysis of Folylpolyglutamate Synthetase Enzymatic Activity in Peripheral Blood Mononuclear Cells: Application in Rheumatoid Arthritis and Leukemia Patients.

BACKGROUND: Folylpolyglutamate synthetase (FPGS) is a crucial enzyme in both cellular folate homeostasis and the intracellular retention of folate analogue drugs such as methotrexate (MTX), which is commonly used for the treatment of (pediatric) leukemia and the anchor drug in rheumatoid arthritis (RA) treatment. To date, assessment of FPGS catalytic activity relies on assays using radioactive substrates that are labor-intensive and require relatively large numbers of cells. Here, we describe a nonradioactive, ultra-high-performance liquid chromatography-tandem mass spectrometer (UHPLC-MS/MS)-based method allowing for sensitive and accurate measurements of FPGS activity in low cell numbers (ie, 1-2 × 10) of biological specimens, including leukemic blast cells of acute lymphoblastic leukemia patients and peripheral blood mononuclear cells of patients with RA. METHODS: The UHPLC-MS/MS assay was validated with 2 CCRF-CEM human leukemia cells, one proficient and one deficient in FPGS activity. Linearity of time and protein input were tested by measuring FPGS activity at 30-180 minutes of incubation time and 10-300 mcg protein extract. In addition, FPGS enzyme kinetic parameters were assessed. RESULTS: The FPGS enzymatic assay showed a linear relation between FPGS activity and protein input (R ≥ 0.989) as well as incubation time (R ≥ 0.996). Moreover, the UHPLC-MS/MS method also allowed for evaluation of FPGS enzyme kinetic parameters revealing Km values for the substrates MTX and L-glutamic acid of 64 µmol/L and 2.2 mmol/L, respectively. The mean FPGS activity of acute lymphoblastic leukemia blast cells (n = 4) was 3-fold higher than that of CCRF-CEM cells and 44-fold and 88-fold higher than that of peripheral blood mononuclear cells from MTX-naive (n = 9) and MTX-treated RA patients (n = 6), respectively. CONCLUSIONS: Collectively, given its sensitivity with low cell numbers and avoidance of radioactive substrates, UHPLC-MS/MS-based analysis of FPGS activity may be eligible for routine therapeutic drug monitoring of MTX in RA and leukemia for therapy (non)response evaluations.

Efficacious transition from reference infliximab to biosimilar infliximab in clinical practice.

OBJECTIVES: To evaluate the transition from reference infliximab Remicade to biosimilar Remsima in patients with rheumatoid arthritis (RA) or psoriatic arthritis (PsA). METHODS: Patients were informed through a letter about the transition to a biosimilar and were subsequently contacted for possible additional questions and whether they agreed upon the transition. Once agreed, Remsima was administered at the same dosage and interval as previous treatment with Remicade. Data on the transition were analyzed in January 2018. The primary outcome was the percentage of patients continuing treatment with Remsima and secondary outcome was the change in disease activity measured with the Disease Activity Score in 28 joints using erythrocyte sedimentation rate (DAS28-ESR). In addition, the reasons for discontinuation with infliximab or restarting Remicade were recorded. RESULTS: In total 47 patients were approached, 45 patients switched from Remicade to Remsima, two patients disagreed upon transition and continued Remicade. At the end of the follow-up period of 2 years, 39 patients (87%) continued with Remsima, three patients (7%) restarted Remicade due to inefficacy according to the patient (this was not objectified by the rheumatologist) 2 (4%) patients switched to another biological due to lack of effect and in one patient (2%) infliximab was stopped because of lung malignancy. Furthermore, the DAS28-ESR remained comparable before and after the switch, with a mean (SD) of 2.34 (±1.02) and 2.31 (±1.11) respectively. CONCLUSION: In our population, 87% of patients continued Remsima during the follow-up period of approximately 2 years. Three patients restarted Remicade, while retaining stable DAS28-ESR.