Impact of Vancomycin trough levels monitoring on uncomplicated methilcillin-resistant Staphylococcus aureus bacteremia in chronic kidney disease on hemodialysis, retrospective cohort.

BACKGROUND: CKD patients on hemodialysis (HD) with Staphylococcus aureus (SA) bacteremia present high morbidity, mortality and increased risk of MRSA. Vancomycin is the antibiotic of choice in these cases, it has a narrow therapeutic margin and inadequate dosage generates a risk of toxicity, therefore, the recommendation is to dosage it through serum levels. METHODS: This is a retrospective cohort study in 3 hospitals of third level of complexity in the city of Medellin in which there were differences in the measurement and implementation of vancomycin25 dosage based on trough levels (VL) in patients with chronic kidney disease on hemodialysis (CKD- HD) with uncomplicated bacteremia based infection by methilcillin-resistant Staphyloccocus aureus (MRSA). The primary outcome was the composite of hospital mortality, clinical response (fever, hemodynamic instability and altered consciousness), complications associated with bacteremia, or bacteriological response failure (positive cultures at first week follow-up) at 7 days. The composite variables were analyzed individually as secondary outcomes. RESULTS: The main unadjusted outcome (OR 1.3, CI 0.6 - 2.7) and adjusted for age, Charlson index, loading dose, initial dose, dosing frequency and MIC to vancomycin (OR 1.2, CI 0.5 - 2.7). Regarding adjusted secondary outcomes: clinical response (OR 1.4 CI 0.3 - 5.8), death (OR 1.3 CI 0.3 - 4.6) and complications (OR 0.9, CI 0.37 - 2.2). CONCLUSIONS: We conclude that the measurement of trough levels in patients with HD-CKD does not modify the composite outcome. The main limitation is the sample size and type of study, randomized control trials may be required to confirm the results presented.

Effect of low vs. high vancomycin trough level on the clinical outcomes of adult patients with sepsis or gram-positive bacterial infections: a systematic review and meta-analysis.

BACKGROUND & OBJECTIVE: The Infectious Disease Society of America guidelines recommend vancomycin trough levels of 15-20 mg/L for severe methicillin-resistant Staphylococcus aureus. However, recent consensus guidelines of four infectious disease organizations no longer recommend vancomycin dosing using minimum serum trough concentrations. Therefore, this study aimed to evaluate the impact of low (< 15 mg/L) vs. high (≥ 15 mg/L) vancomycin trough levels on clinical outcomes in adult patients with sepsis or gram-positive bacterial infections. METHOD: A systematic literature review from inception to December 2022 was conducted using four online databases, followed by a meta-analysis. The outcomes of interest included clinical response/efficacy, microbial clearance, length of ICU stay, treatment failure, nephrotoxicity, and mortality. RESULTS: Fourteen cohort studies met the inclusion criteria from which vancomycin trough concentration data were available for 5,228 participants. Our analysis found no association between vancomycin trough levels and clinical response [OR = 1.06 (95%CI 0.41-2.72], p = 0.91], microbial clearance [OR = 0.47 (95% CI 0.23-0.96), p = 0.04], ICU length of stay [MD=-1.01 (95%CI -5.73-3.71), p = 0.68], or nephrotoxicity [OR = 0.57 (95% CI 0.31-1.06), p = 0.07]. However, low trough levels were associated with a non-significant trend towards a lower risk of treatment failure [OR = 0.89 (95% CI 0.73-1.10), p = 0.28] and were significantly associated with reduced risk of all-cause mortality [OR = 0.74 (95% CI 0.62-0.90), p = 0.002]. CONCLUSION: Except for a lower risk of treatment failure and all-cause mortality at low vancomycin trough levels, this meta-analysis found no significant association between vancomycin trough levels and clinical outcomes in adult patients with sepsis or gram-positive bacterial infections.

IDEAL study: A real-world assessment of pattern of use and clinical outcomes with recombinant coagulation factor IX albumin fusion protein (rIX-FP) in patients with haemophilia B in Italy.

INTRODUCTION: Factor IX replacement therapy is used for treatment and prophylaxis of bleeding in haemophilia B. rIX-FP is an extended half-life albumin-fusion protein, which, in clinical studies, has demonstrated prolonged dosing intervals up to 21 days for routine prophylaxis, providing therapeutic benefit. AIMS: To describe dosing frequency and consumption (primary endpoint), efficacy and safety of rIX-FP treatment during routine clinical practice in Italy. METHODS: Patients with moderate/severe haemophilia B on prophylaxis with rIX-FP for ≥6 months, were enrolled in this observational study from October 2017 to February 2019 and followed-up for 2 years. Descriptive analysis included prospective and retrospective data (12 months prior to switching to rIX-FP). RESULTS: Data were collected from 59 male patients (median age 30.1 years) enrolled by 23 Italian centres. Of them, 50 were on prophylaxis during the entire observation period and completed the study. The infusion frequency changed from 2-3 times/week in 86.0% of patients with previous treatment, to less than once a week in 84.0% of patients treated with rIX-FP at the 2nd-year follow-up. The annual number of infusions decreased by about 70%, whereas the mean FIX activity trough level increased from 3.8% to 14.4% (mean > 10% in all the infusion regimens). Median Annualised Bleeding Rate of .0 was achieved across all prophylaxis regimens. Subjects with zero bleedings increased from 66.0% to 78.0% with rIX-FP. CONCLUSION: Treatment with rIX-FP reduced infusion frequency, while providing higher FIX trough levels with substantial benefit in terms of annualised bleeding rate and a good safety profile.

Predictive value of infliximab trough levels in maintenance therapy for 5-year sustained clinical remission in patients with inflammatory bowel disease.

BACKGROUND: Despite long-term use of infliximab (IFX) in IBD treatment, its optimized use is unclear due to its complicated pharmacokinetics/dynamics. Hence, the predictive value of IFX trough levels (TL) is important in treatment management. METHODS: We performed a prospective, cross-sectional, observational study with 74 IBD patients treated with IFX (mean 9.1 years, SD ± 3). TL was measured during maintenance therapy, in which maintenance of remission was followed for 5 years. RESULTS:  TL > 3 µg/ml during maintenance therapy was a significant predictor of clinical remission in 5 years in UC patients (82 % vs 62 %, p 3 µg/ml during maintenance therapy in a cohort of IBD patients (p = 0.05). Deviations in percentage of remission and fraction of relapses in TL categories were insignificant in a cohort of CD patients (85 % vs 74 %, p > 0.05). CONCLUSIONS:  TL > 3 µg/ml during maintenance therapy is a strong predictor of sustained clinical remission for 5 years in UC patients. The use of combination therapy with AZA, due to its significant association with high TL, may have a practical benefit in achieving better clinical outcomes in UC patients (Tab. 2, Fig. 10, Ref. 20).

A Novel Class of On-Treatment Cancer Immunotherapy Biomarker: Trough Levels of Antibody Therapeutics in Peripheral Blood.

While immune checkpoint blockade has revolutionized cancer treatment, unfortunately most patients do not benefit from this treatment. Many pharmacodynamic (PD) studies have revealed essential requirements for successful cancer immunotherapy that may provide insight into how we can improve these agents. Despite enormous efforts focused on interrogating the immune system using different biospecimens (e.g. blood, primary tumor, metastatic tumor, microbiome samples), a variety of technologies (e.g. flow cytometry, bulk and single-cell RNA-sequencing, immunohistochemistry), and wide-ranging disciplines (e.g. pathology, genomics, bioinformatics, immunology, cancer biology, metabolomics, bacteriology), discovery of consistent biomarkers of response have remained elusive. Pharmacokinetics (PK) studies, however, not only provide critical information regarding safe dosing but may also reveal useful biomarkers. For example, recent studies found that trough levels of therapeutic monoclonal antibodies (mAbs) or clearance (CL) of them were associated with clinical outcome, which suggests that trough levels of mAbs may represent a new class of on-treatment cancer immunotherapy biomarker. In this review, we summarize the potential utility of trough levels of mAbs, the mechanism of varying PK, consideration for therapeutic drug monitoring, and assay attributes that will facilitate wider utilization of PK information in conjunction with PD assessments.

Redefining prophylaxis in the modern era.

Prophylaxis is the globally accepted standard of care for persons with haemophilia and presents many advantages over episodic treatment. The prophylaxis benefits include bleed reduction, reduction in musculoskeletal complications and improvement in the quality of life. The currently evolving novel therapies for the management of haemophilia has ushered a new era characterized by improved prophylaxis targets and outcomes. These redefined targets and outcomes have necessitated the need to also redefine prophylaxis. In this state-of-the-art review, we redefine prophylaxis in the modern era by revisiting its definition, presenting data to support higher trough levels to achieve with prophylaxis and introducing steady-state haemostasis as a possible new target for prophylaxis.

Outcomes of a pharmacist-driven vancomycin monitoring initiative in a community hospital.

WHAT IS KNOWN AND OBJECTIVE: Vancomycin, an antibiotic commonly used to treat MRSA infections, can be nephrotoxic. Administering vancomycin requires close monitoring of serum vancomycin levels and appropriate dosing based on patients' renal function, underlying infection type and serum concentration levels. This article discusses the results and implications of a pharmacist-driven vancomycin monitoring initiative, which was implemented at Mercy Catholic Medical Center's Philadelphia Campus (MPC) in July 2016. METHODS: MPC pharmacists were trained on how to give appropriate vancomycin dosing recommendations based on patients' vancomycin trough levels, renal function and underlying infection. This retrospective observational study consisted of patients who presented to MPC and were administered vancomycin over a 3-month period in 2015 for pre-implementation cohort and over a 3-month period in 2018 for post-implementation cohort. Patients with age ≥18 and receiving vancomycin for a minimum of 48 hours were included, whereas ESRD patients were excluded. Primary goal evaluated whether the incidence of AKI decreased with the pharmacist-driven initiative. Secondary goal assessed whether vancomycin level monitoring and achievement of goal serum levels improved with the initiative. RESULTS AND DISCUSSION: A total of 214 patients were included in the final data analysis, with 110 patients in the pre-implementation cohort and 104 patients in the post-implementation cohort. Although not statistically significant, a higher incidence of AKI was observed in the post-implementation cohort. However, compared to pre-implementation cohort, post-implementation group had higher percentage of patients with underlying comorbidities (such as CKD), higher number of cases of severe sepsis and septic shock, and greater number of patients with concomitant exposure to CT contrast and piperacillin-tazobactam-all of which were confounding factors that likely increased the AKI incidence in post-implementation cohort. With the initiative, there was a significant increase in the number of patients with appropriate vancomycin trough level monitoring (27.3% vs 55.8%, p value < 0.001) in the post-implementation cohort and a decrease in the number of patients with no trough level monitoring (30% vs. 7.6%, p value < 0.001). WHAT IS NEW AND CONCLUSION: Pharmacist-driven vancomycin monitoring significantly improved the monitoring compliance of vancomycin trough levels. In patients who developed AKI during their hospital course, pharmacist interventions improved the total percentage of patients attaining desired trough goals and helped reduce further renal insult from supratherapeutic vancomycin level. Incorporation of AUC-guided dosing and monitoring has the potential to further optimize vancomycin efficacy and safety.

Monitoring of infliximab trough levels and anti-infliximab antibodies in inflammatory bowel diseases: A comparison of three commercially available ELISA kits.

BACKGROUND: There are many studies presenting data of biologics and several ELISA kits commercially available for monitoring infliximab serum trough levels (s-IFXt) and anti-drug antibodies (ADAb). We propose to compare technical characteristics and results of three different assays on a cohort of 35 patients under infliximab (IFX) and suffering from inflammatory bowel disease (IBD). PATIENTS AND METHODS: s-IFXt and ADAb were systematically measured with three ELISA kits: Lisa-Tracker® Duo infliximab (Theradiag®), Ridascreen® IFX Monitoring (R-Biopharm AG®) and Promonitor® IFX (Progenika Biopharma SA®). RESULTS: The main technical features that differed between kits for measuring s-IFXt were: (i) TNF coating, (ii) immune complexes revelation strategy and/or (iii) interference with other anti-TNFα agents. For kits measuring ADAb, they were revelation steps and unit of results. There was an excellent mathematical correlation of s-IFXt between assays however Bland-Altman analysis denoted (i) s-IFXt were on average 48 to 69% higher in Ridascreen® than in the other two assays, and (ii) elevated s-IFXt were higher with Promonitor® compared to Lisa-Tracker®. As a consequence, there were some substantial discrepancies between assays for classification of s-IFXt into concentration ranges. Despite unstandardized units, pairwise qualitative comparison showed a perfect agreement between the three pairs of ADAb assays. CONCLUSION: Our data show that the evaluated assays are not quantitatively interchangeable due to substantial variations in some results that could lead, for some patients, to divergent therapeutic decisions. We remind to be cautious when comparing study results issued from different kits and recommend using the same assay for the longitudinal follow-up of IBD patients.

Higher vedolizumab serum levels do not increase the risk of adverse events in patients with inflammatory bowel disease.

Background: Although its mechanism of action may confer a safety benefit, vedolizumab has still been associated with adverse events (AE). We investigated whether inflammatory bowel disease (IBD) patients with higher trough vedolizumab serum levels experienced an increased risk of AEs.Methods: This was a retrospective study of 76 IBD patients with at least one measurement of serum vedolizumab available. Vedolizumab levels ranged from <3.5 mcg/mL to 87.2 mcg/mL (median = 15.8 mcg/mL). The primary outcome was the rate of overall AEs. Secondary outcomes included the rates of infections, dermatologic reactions, infusion reactions, and other AEs. Multivariate logistic regression analysis was performed to evaluate the relationship between serum vedolizumab levels and AEs.Results: 19 patients out of 76 reported AEs. In patients with higher vedolizumab levels, there were 10 AEs reported out of 38 patients, which was not significantly different from the 9 AEs reported in 38 patients with lower vedolizumab levels (26.3% vs. 23.7%, p = .79). After adjustment for potential covariates, IBD patients with higher vedolizumab levels did not have higher odds of an AE than patients with lower levels (OR 0.92, 95% CI 0.30-2.81). Longer duration of therapy had higher odds of AEs, (OR of 1.04 at 95% CI 1.00-1.09, p = .0494 per additional month). None of the other variables were associated with a greater risk of AEs.Conclusions: There does not appear to be an increased risk of adverse events in IBD patients with higher vedolizumab levels, but duration of therapy may increase the risk of AEs.

Flucloxacillin decreases tacrolimus blood trough levels: a single-center retrospective cohort study.

PURPOSE: Tacrolimus and everolimus are widely used to prevent allograft rejection. Both are metabolized by the hepatic cytochrome P450 (CYP) enzyme CYP3A4 and are substrate for P-glycoprotein (P-gp). Drugs influencing the activity or expression of CYP enzymes and P-gp can cause clinically relevant changes in the metabolism of immunosuppressants. Several case reports have reported that flucloxacillin appeared to decrease levels of drugs metabolized by CYP3A4 and P-gp. The magnitude of this decrease has not been reported yet. METHODS: In this single-center retrospective cohort study, we compared the tacrolimus and everolimus blood trough levels (corrected for the dose) before, during, and after flucloxacillin treatment in eleven transplant patients (tacrolimus n = 11 patients, everolimus n = 1 patient, flucloxacillin n = 11 patients). RESULTS: The median tacrolimus blood trough level decreased by 37.5% (interquartile range, IQR 26.4-49.7%) during flucloxacillin treatment. After discontinuation of flucloxacillin, the tacrolimus blood trough levels increased by a median of 33.7% (IQR 22.5-51.4%). A Wilcoxon signed-rank test showed statistically significantly lower tacrolimus trough levels during treatment with flucloxacillin compared with before (p = 0.009) and after flucloxacillin treatment (p = 0.010). In the only available case with concomitant everolimus and flucloxacillin treatment, the same pattern was observed. CONCLUSIONS: Flucloxacillin decreases tacrolimus trough levels, possibly through a CYP3A4 and/or P-gp-inducing effect. It is strongly recommended to closely monitor tacrolimus and everolimus trough levels during flucloxacillin treatment and up to 2 weeks after discontinuation of flucloxacillin.

Infliximab and its biosimilar produced similar first-year therapy outcomes in patients with inflammatory bowel disease.

AIM: Tumour necrosis factor α inhibitors (anti-TNFα) are the main therapy for moderate to severe inflammatory bowel disease (IBD) in children. Biosimilars to the original drug infliximab are now available, but there are few reports on their real-life use. We compared the outcomes of patients treated with infliximab and its biosimilar, CT-P13. METHODS: We collected outcome data on anti-TNFα-naive patients who started infliximab in the Children's Hospital, University of Helsinki, Finland, in 2015-2016. We studied 51 paediatric patients with IBD at a median age of 12 (range 4-16): 65% had Crohn disease, 23 received the original infliximab drug and 28 received the biosimilar. During 2015, infliximab was introduced to all treatment-naïve patients, and during 2016, all treatment-naïve patients received the biosimilar. RESULTS: We found no statistically significant differences between the two drug products related to the outcome of the therapy during the first year. There were no significant differences in the trough levels between the treatment groups. Likewise, the proportion of patients with therapy enhancement was comparable between the two treatment groups. CONCLUSION: The first-year therapy outcomes of infliximab and its biosimilar were comparable. There were no alarming signs of differences in safety.

Changes in the commercial brand of tacrolimus lead to subtherapeutic trough levels and acute rejection in renal transplant recipients.

BACKGROUND: The vigilance of tacrolimus (TAC) trough levels is an essential part of renal transplant follow up. Reduced TAC trough levels and high variability are related to adverse outcomes. The aim of this study was to evaluate the impact of brand changes on tacrolimus (TAC) subtherapeutic (SubT) trough levels, acute rejection (AR), and kidney function. METHODS: This is a prospective, observational cohort study of renal transplant recipients, between January 2016 and October 2018. Tacrolimus trough levels and brand used by the patient were both registered at every consult. Tacrolimus values ≤3.5 ng/mL were considered SubT. RESULTS: 445 patients were included. The median number of TAC brand changes was 2 (IQR, 1-4). Patients were grouped according to the number of brand changes: Group 1 = 0 (n = 107), Group 2 = 1-4 (n = 236), and Group 3 = ≥5 (n = 102). Patients with the greatest number of brand changes had a greater proportion and number of SubT TAC trough levels (Group 1 = 36.4%, average 0.53; Group 2 = 39.8%, average 0.65, Group 3 = 59.8%, average 1.17, P < .001) and AR (Group 1 = 0.9%, Group 2 = 11%, Group 3 = 14.7%, P < .001). On multivariate analysis, SubT levels and the number of brand changes were related to AR. CONCLUSIONS: In Mexico, changes in TAC brand are associated with an elevated frequency of SubT levels. Brand changes and SubT levels are independently associated with acute rejection. The supply policies on TAC brands in Mexico require revision to avoid changing brands as much as possible.

Fecal Calprotectin Pretreatment and Induction Infliximab Levels for Prediction of Primary Nonresponse to Infliximab Therapy in Crohn's Disease.

INTRODUCTION: The association between infliximab (IFX) and fecal calprotectin (FC) levels on one hand, and the clinical and endoscopic response of patients with inflammatory bowel disease on the other, is well established. OBJECTIVE AND METHODS: To investigate the association between inflammatory biochemical parameters and serum concentrations of IFX during induction treatment with a primary nonresponse in a prospective cohort of Crohn's disease (CD) patients. RESULTS: Of the 35 patients included, 8 (22.8%) had primary nonresponse at the end of induction. Induction IFX levels were lower among primary nonresponders at weeks 6 and 14 (week 6: median IFX level 7.3 vs. 11.2 µg/mL, respectively, p = 0.090; week 14: median IFX level 1.5 vs. 4.7 µg/mL, respectively, p = 0.020). FC levels were higher in patients with primary nonresponse versus primary response at weeks 0, 6, and 14 (week 0: median FC level 1,830 vs. 410 µg/g, -respectively, p = 0.030; week 6: median FC level 1,150 vs. 230 µg/g, respectively, p = 0.074; week 14: median FC level 1,210 vs. 208 µg/g, respectively, p = 0.060). For the multivariate analysis, the median IFX level at week 14 and median FC level at week 0 were independently associated with primary nonresponse. A significant inverse correlation was determined between FC level at week 0 and IFX level at week 14 (Spearman's rho correlation, 0.440; p < 0.05). CONCLUSIONS: IFX levels (at week 14) and baseline FC levels could predict primary nonresponse after induction IFX therapy in patients with CD. A high baseline inflammatory load might modify the pharmacokinetic processes of anti-tumor necrosis factor drugs. Drug level monitoring and measurement of baseline inflammatory parameters could improve the efficacy of IFX in the induction therapy of patients with active CD.

Reduction of exposure to tacrolimus trough level variability is associated with better graft survival after kidney transplantation.

PURPOSE: High tacrolimus trough drug level variability was found to be associated with reduced graft survival. The primary goal of this study was to find whether reduction of exposure to high tacrolimus trough level variability in patients in which previously had high variability was associated with better graft survival. METHODS: All tacrolimus drug level values in patients that underwent kidney transplantation at our center between 2006 and 2015 were collected. Exposure to variability was calculated using a time-weighted coefficient of variability (TWCV). Time-dependent univariate and multivariate Cox proportional hazard models were used to analyze the primary outcome of graft survival and to determine a cutoff value for TWCV as a predictor of this outcome. RESULTS: A total of 878 patients were included in the study with a median follow-up of 1263 days. TWCV above 25% was significantly associated with reduced graft survival (HR3.66, 95% CI 2.3-5.8, p < 0.001). Of the 480 patients (54.7%) who had a cumulative TWCV of > 25% at a certain time during the follow-up, 110 (22.9%) later returned to a cumulative TWCV of less than 25%. Reduction of TWCV to values below 25% was associated with a hazard of graft loss that was not different from patients who had cumulative TWCV of less than 25% during the entire follow-up period (HR 1.81, 95% CI 0.71-4.62, p = 0.218 and HR 1.08, 95% CI 0.39-2.99, p = 0.780) in univariate and multivariate analyses, respectively. CONCLUSIONS: Monitoring TWCV can help detect the high-risk patients. Interventions intended to reduce variability on long-term graft survival may have a positive effect on graft survival.

Attention to age: similar dosing regimens lead to different vancomycin levels among older and younger patients.

BACKGROUND: little is known on the clinical implications of vancomycin trough levels among older patients. OBJECTIVE: to evaluate the association between vancomycin levels and outcomes among older versus younger patients. DESIGN: retrospective study. SUBJECTS: patients aged 18-64 and ≥65 years treated with vancomycin for documented methicillin resistant Staphylococcus aureus (MRSA) infections. METHODS: we compared the effectiveness and toxicity of vancomycin according to trough levels in older versus younger patients. Subgroup analysis of patients with glomerular filtration rate (GFR) > 60 ml/min/1.73 m2 was performed. RESULTS: we included 181 patients aged ≥65 years and 104 younger patients. Mean age in the older group was 76.9 ± 8 years versus 50.9 ± 12.4 in the younger group. Vancomycin trough levels and 24-hours area under the curve to minimal inhibitory concentrations (AUC/MIC) were significantly higher in older patients who were also significantly more likely to achieve trough levels of ≥15 mg/l within 4 days, (98/181 (54.1%) vs. 38/104 (36.5%) in younger patients, P = 0.004). Results were similar among patients with GFR > 60. Thirty-day mortality was significantly higher in older (74/181, 40.9% vs. 13/104, 12.5%, respectively, P < 0.001). There was no association between vancomycin trough levels and mortality among older patients. No significant differences were demonstrated in clinical or microbiological success or nephrotoxicity. CONCLUSIONS: applying uniform dosing recommendations across age groups among adults with MRSA infections results in higher vancomycin levels and AUC/MIC in older versus younger patients. Yet, mortality rates remain higher among older adults. Prospective studies are needed to define the optimal approach for using this drug in older patients.

Correlation Between Anti-TNF Serum Levels and Endoscopic Inflammation in Inflammatory Bowel Disease Patients.

OBJECTIVES: (a) To evaluate the diagnostic accuracy of anti-TNF trough levels to predict mucosal healing in inflammatory bowel disease (IBD); (b) to determine the best cut-off point to predict mucosal healing in IBD patients treated with anti-TNF. METHODS: This is a multicenter, prospective study. IBD patients under anti-TNF treatment for at least 6 months that had to undergo an endoscopy were included. Mucosal healing was defined as: Simple endoscopic score for Crohn's Disease < 3 for Crohn's disease (CD), Rutgeerts score < i2 for CD in postoperative setting, or Mayo endoscopic score ≤ 1 for ulcerative colitis (UC). Anti-TNF concentrations were measured using SMART ELISAs at trough. RESULTS: A total of 182 patients were included. Anti-TNF trough levels were significantly higher among patients that had mucosal healing than among those who did not. The area under the curve of infliximab for mucosal healing was 0.63 (best cutoff value 3.4 µg/mL), and for adalimumab 0.60 (best cutoff value 7.2 µg/mL). In the multivariate analysis, having anti-TNF drug levels above the cutoff values [odds ratio (OR) 3.1]) and having UC instead of CD (OR 4) were associated with a higher probability of having mucosal healing. Additionally, the need for an escalated dosage (OR 0.2) and current smoking habit (OR 0.2) were also associated with a lower probability of mucosal healing. CONCLUSIONS: There was an association between anti-TNF trough levels and mucosal healing in IBD patients; however, the accuracy of the determination of infliximab and adalimumab concentrations able to predict mucosal healing was suboptimal.

Reprint of "Anti-therapeutic antibodies and their clinical impact in patients treated with the TNF antagonist adalimumab".

Patients treated with the TNF antagonist adalimumab develop anti-therapeutic antibodies (ATA), the prevalence of which varies depending on the assay used. Most assays are compromised due to the presence of adalimumab in the clinical samples. Our objective was to develop an antibody assay, applicable for clinical testing, which overcomes the limitation of therapeutic interference and to further determine the relationship between ATA development, adalimumab levels and disease activity in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) or ankylosing spondylitis (AS). Use of an electrochemiluminescence platform permitted development of fit-for-purpose immunoassays. Serum samples from patients, taken prior to and at 12 and 24 weeks of treatment, were retrospectively analysed for levels of adalimumab and ATA. Overall, the antibody prevalence was 43.6% at 12 weeks and 41% at 24 weeks of treatment. Disruption of immune complexes by acid dissociation, a strategy often adopted for this purpose, only marginally increased the antibody prevalence to 48.7% and 46% at 12 and 24 weeks respectively. We found that antibody formation was associated with decreasing levels of circulating adalimumab, but no direct effect on disease activity was evident as assessed using DAS28 for RA patients and BASDAI for PsA and AS patients. However, a negative correlation of free adalimumab trough levels with disease activity scores was observed. Data showed that adalimumab levels can serve as an indicator of ATA development which can then be confirmed by ATA testing. Monitoring of both therapeutic and antibodies should be considered during adalimumab therapy to allow clinicians to personalise treatments for maximal therapeutic outcomes.

Anti-therapeutic antibodies and their clinical impact in patients treated with the TNF antagonist adalimumab.

Patients treated with the TNF antagonist adalimumab develop anti-therapeutic antibodies (ATA), the prevalence of which varies depending on the assay used. Most assays are compromised due to the presence of adalimumab in the clinical samples. Our objective was to develop an antibody assay, applicable for clinical testing, which overcomes the limitation of therapeutic interference and to further determine the relationship between ATA development, adalimumab levels and disease activity in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) or ankylosing spondylitis (AS). Use of an electrochemiluminescence platform permitted development of fit-for-purpose immunoassays. Serum samples from patients, taken prior to and at 12 and 24weeks of treatment, were retrospectively analysed for levels of adalimumab and ATA. Overall, the antibody prevalence was 43.6% at 12weeks and 41% at 24weeks of treatment. Disruption of immune complexes by acid dissociation, a strategy often adopted for this purpose, only marginally increased the antibody prevalence to 48.7% and 46% at 12 and 24weeks respectively. We found that antibody formation was associated with decreasing levels of circulating adalimumab, but no direct effect on disease activity was evident as assessed using DAS28 for RA patients and BASDAI for PsA and AS patients. However, a negative correlation of free adalimumab trough levels with disease activity scores was observed. Data showed that adalimumab levels can serve as an indicator of ATA development which can then be confirmed by ATA testing. Monitoring of both therapeutic and antibodies should be considered during adalimumab therapy to allow clinicians to personalise treatments for maximal therapeutic outcomes.

Switching maintenance infliximab therapy to biosimilar infliximab in inflammatory bowel disease patients.

BACKGROUND: Clinical use of biosimilar infliximab (CT-P13) in inflammatory bowel diseases (IBDs) is based on extrapolation of indication from clinical studies performed in rheumatological diseases. Only few data exist of behaviour of infliximab trough levels (TLs) and anti-drug antibodies (ADAs) during switching. AIM: The objective of this study was to evaluate changes in TLs, ADA formation and disease activity after switching from originator infliximab to biosimilar one. METHODS: All our IBD patients receiving maintenance infliximab therapy were switched to biosimilar infliximab. TLs and ADAs were measured before the last originator infusion and before the third biosimilar infusion. Laboratory values, disease activity indices (partial Mayo score and Harvey-Bradshaw index) and demographic data were collected from patient records. RESULTS: A total of 62 patients were included in the final analysis (32 Crohn's disease, 30 ulcerative colitis (UC) or IBD-unclassified). No significant changes in median TLs before (5.5 mg/l) and after switching (5.5 mg/l, p = .05) occurred in the entire study group or in the Crohn's disease (CD) subgroup (5.75 and 6.5 mg/l, p = .68). However, in the subgroup of ulcerative colitis, the change in median TL was significantly different (from 5.2 to 4.25 mg/l, p = .019). Two patients developed ADAs after switching. No changes in disease activity were detected during switching and no safety concerns occurred. CONCLUSIONS: Switching from originator to biosimilar infliximab resulted in statistically significant differences in infliximab TLs in patients with UC but not in patients with Crohn's disease. The clinical significance for this difference is doubtful and in neither group changes in disease activity occurred.

Patient-reported non-adherence and immunosuppressant trough levels are associated with rejection after renal transplantation.

BACKGROUND: Different measures of non-adherence to immunosuppressant (IS) medication have been found to be associated with rejection episodes after successful transplantation. The aim of the current study was to investigate whether graft rejection after renal transplantation is associated with patient-reported IS medication non-adherence and IS trough level variables (IS trough level variability and percentage of sub-therapeutic IS trough levels). METHODS: Patient-reported non-adherence, IS trough level variability, percentage of sub-therapeutic IS trough levels, and acute biopsy-proven late allograft rejections were assessed in 267 adult renal transplant recipients who were ≥12 months post-transplantation. RESULTS: The rate of rejection was 13.5%. IS trough level variability, percentage of sub-therapeutic IS trough levels as well as patient-reported non-adherence were all significantly and positively associated with rejection, but not with each other. Logistic regression analyses revealed that only the percentage of sub-therapeutic IS trough levels and age at transplantation remained significantly associated with rejection. CONCLUSIONS: Particularly, the percentage of sub-therapeutic IS trough levels is associated with acute rejections after kidney transplantation whereas IS trough level variability and patient-reported non-adherence seem to be of subordinate importance. Patient-reported non-adherence and IS trough level variables were not correlated; thus, non-adherence should always be measured in a multi-methodological approach. Further research concerning the best combination of non-adherence measures is needed.