David Drobne

Early Trough Levels and Antibodies Predict Safety and Success of Restarting Infliximab After Long Drug Holiday

BACKGROUND: Measurement of antibodies to infliximab (ATI) and the correlation observed between serum drug concentration and disease status have provided both insight into infliximab (IFX) immunogenicity and clinical utility to these markers for managing IBD patients on IFX. For adalimumab, such data are not readily available nor is clinical utility known. The prevalence of antibodies to adalimumab (ATA) in IBD patients is sparsely reported outside of one company sponsored clinical trial (2.6%). Correlation between ATA/ drug concentration and objective markers of inflammation (CRP) as well as clinical symptoms is poorly described. METHODS: An independent investigator-initiated cross-sectional study prospectively recruited 54 IBD patients on ADA (2 with ulcerative colitis) from a tertiary center to determine 1) prevalence of detectable ATA and drug concentration; 2) correlation between ATA /drug concentration and an objective measure of inflammation, C-reactive protein (CRP); and 3) whether stratified category of ATA/ drug concentration correlated with patients self-described symptoms (remission, response, active flare). Patients were approached based on use of ADA for Crohns or ulcerative colitis and not clinical status (remission, response, active). Questionnaire of symptoms, IBD history, ADA dosing, weight and CRP measurement were conducted within two weeks of ATA/drug concentration measurement. ATA/drug concentration blood draw was performed at trough, just prior to next ADA dose, and processed by Prometheus Laboratories. Detectable ATA was defined as .= 1U/ml and detectable drug as .=1 mcg/ml. RESULTS: The prevalence of detectable ATA was 22.2% (n=12/54) and detectable ADA concentration was 90.7% (n=49/54). Serum concentration of ,5 mcg/ml of ADA was associated with an elevated CRP (p=0.001). Detectable ATA was positively associated with an elevated CRP, and notably this correlation was independent of drug concentration (p=0.002) (Figure). Stratification of patients based on ATA/drug concentration demonstrated more active disease in patients with low drug concentration (,5 mcg/ml) and/or detectable ATA (p=0.01). CONCLUSION: Antibodies to adalimumab in ADA-treated IBD patients are more prevalent than reported in clinical trials and almost all patients on ADA have a detectable drug concentration. Both detectable ATA and ADA drug concentration ,5 mcg/ml have an important association with increased inflammation. The observation that detectable ATA correlates with elevated CRP independent of drug concentration is a novel finding and suggests preventing ATA may be the more critical of the two variables to address for maximizing clinical efficacy. That detectable ATA/ low drug concentration correlates with active disease suggests there may be clinical utility in obtaining these measurements, however longer-term data are needed.

Impact of Infliximab and Cyclosporine on the Risk of Colectomy in Hospitalized Patients with Ulcerative Colitis Complicated by Cytomegalovirus-A Multicenter Retrospective Study.

Background: Cytomegalovirus (CMV) is frequently detected in patients with ulcerative colitis (UC). The impact of CMV infection on the outcome of UC exacerbation remains unclear. The benefit of combining antiviral with anti-inflammatory treatment has not been evaluated yet. The aim of this study was to compare the outcome of CMV-positive hospitalized patients with UC treated with antiviral therapy either alone or combined with salvage anti-inflammatory therapy (infliximab [IFX] or cyclosporine A [CsA]). Methods: This was a multicenter retrospective study of hospitalized CMV-positive patients with UC. The patients were classified into 2 groups: antiviral—if treated with antivirals alone; combined—if treated with both antiviral and anti-inflammatory therapy. The outcomes included the rate of colectomy in both arms during the course of hospitalization and after 3/12 months. Results: A total of 110 patients were included; 47 (42.7%) patients did not receive IFX nor CsA; 36 (32.7%) received IFX during hospitalization or within 1 month before hospitalization; 20 (18.1%) patients received CsA during hospitalization; 7 (6.4%) were exposed to both IFX and CsA. The rate of colectomy was 14.5% at 30 days, 20.0% at 3 months, and 34.8% at 12 months. Colectomy rates were similar across treatment groups. No clinical and demographic variables were independently associated with the risk of colectomy. Conclusions: IFX or cyclosporine therapy is not associated with additional risk for colectomy over antiviral therapy alone in hospitalized CMV-positive patients with UC.

Clinically important neutralizing anti-drug antibodies detected with an in-house competitive ELISA

Therapeutic drug monitoring of TNF-alpha inhibitors is crucial for evaluating patients with inflammatory diseases on a personalized level. It has been clinically observed that many patients receiving TNF-alpha inhibitors, with negative drug and anti-drug antibody results from bridging ELISA (bELISA), lose their drug response over time, despite dose optimization. Our aims were to develop innovative in-house competitive ELISAs (cELISAs) for the detection of neutralizing antibodies against infliximab and adalimumab and compare their results to reporter gene assay (RGA) and in-house bELISA. Furthermore, we aimed to evaluate patient anti-drug antibody results in regard to their clinical records and potential benefits of therapeutic drug monitoring with the novel cELISAs. Sera of patients treated with infliximab (n = 46) or adalimumab (n = 31), having undetectable drug levels, were tested with our in-house cELISA. Briefly, samples were incubated with a fixed amount of drug and the neutralizing capacity of the samples was determined. The cELISA results were compared to RGA and bELISA results using Spearman’s correlation coefficient. Additionally, patient clinical data were evaluated in line with the results of cELISA, bELISA, and RGA using the Kaplan-Meier analysis and the Log Rank test. Both anti-infliximab and anti-adalimumab cELISAs showed very good correlation to RGA (r = 0.932, p < 0.0001 and r = 0.947, p < 0.0001, respectively). Furthermore, a positive result in anti-infliximab cELISA can predict treatment failure in 100% of patients with negative bELISA, while a positive result in anti-adalimumab cELISA can predict treatment failure in 80% of patients with negative bELISA. Taken together, we developed innovative cELISAs enabling quantification of functional and neutralizing anti-drug antibodies, comparable to RGA. The association between cELISA results and loss of drug response in patients identified clinically important anti-drug antibodies, as measured by cELISA.

Sarcoidosis and Collagenous Colitisâ Important Clinical Association orCoincidence?

We present a case of a 57-year-old woman with two rare concomitant diseases; sarcoidosis and collagenous colitis. Patient was admitted to our hospital with the symptoms of watery diarrhea that intermittently lasted for years because of delayed diagnosis. Despite increasing awareness of microscopic colitis, the delayed diagnosis remains an important problem. Diagnosis was quickly confirmed with flexible proctosigmoidoscopy. Rectal biopsies were sufficient for diagnosis. Symptoms improved dramatically the second day of the induction therapy with budesonide. Causal relationship between sarcoidosis and microscopic colitis is not yet confirmed, and to our knowledge, this is the first such case report.