Peripheral Lymphocyte Multidrug Resistance Activity as a Predictive Tool of Biological Therapeutic Response in Rheumatoid Arthritis

Abstract

Objective.Multidrug resistance (MDR) transporters may be used as biomarkers to monitor disease progression in RA and as a predictive tool to establish responsiveness to biological therapy. In this multicenter clinical trial, we aimed to assess the predictive value of activity measurement of transporters MDR1, MD resistance protein (MRP)1, and breast cancer resistance protein (BCRP) for biological therapeutic response in RA before the initiation of biological therapy as well as 4 to 6 and 12 weeks after.Methods.Peripheral blood samples were collected from 27 responders and 12 nonresponders to biological disease-modifying antirheumatic drugs (bDMARD) at the indicated timepoints as well as from 35 healthy controls. MDR activity factor (MAF) of MDR1, MRP1, and BCRP was measured in CD3+ and CD19+ cells using the Solvo MDQ Kit and cell surface staining by flow cytometry following peripheral blood mononuclear cells isolation.Results.At the start of therapy, MAFC (composite MAF of MRP1 and MDR1) and MAFMDR values, and at 4 to 6 weeks of treatment, MAFC, MAFMRP, and MAFMDR values of CD3 cells were higher in nonresponders compared to responders. Receiver-operation characteristic curve analysis revealed that RA patients with MAFC values above 21.3 in CD3 cells at the start of bDMARD therapy are likely to be nonresponders. At 4 to 6 weeks of treatment, these also predict unfavorable response: MAFC values above 20.3, MAFMRP values above 6.0, and MAFMDR values above 13.9 in CD3 cells.Conclusion.Our results indicate that the determination of MAFC values in CD3 cells of patients with RA may be of predictive value prior to the initiation of biological therapy, to establish whether the patient will demonstrate sufficient therapeutic response.

Guidelines for the use of flow cytometry and cell sorting in immunological studies (second edition)

“…Performing real‐time transporter activity measurements using fluorescent reporter substrates is highly beneficial in the clinical setting for personalized therapy and monitoring in certain hematologic malignancies and in autoimmune diseases, since the activities of MDR1, MRP1, and BCRP serve as biomarkers to predict the patient's response to small molecule therapy in treatment naïve conditions and during small molecule drug treatment . Furthermore, the determination of transporter activity is also relevant in cell lines in pharmaceutical research.…”

Expression profiling of ABC transporters in peripheral blood lymphocytes and monocyte-derived macrophages of rheumatoid arthritis patients

“…Although the current treatment of RA with DMARDs has proven its effectiveness, patients are still confronted either with inherent or acquired resistance phenomena to DMARD therapy [14,15,16,19,20,23,24,48,71] for which the underlying molecular mechanisms remain still unclear. It has been recognized that enhanced cellular drug extrusion, facilitated by MDR efflux pumps of the ABC superfamily, could contribute to an attenuated response/resistance to DMARDs [23,24,26,27,52,55]. Moreover, there is cumulative evidence that beyond a pharmacological function of ABC transporters, some of them may also elicit a physiological function by mediating the efflux of proinflammatory factors, thereby promoting (anti) inflammatory responses [23,25,53,72,73,74,75,76,77,78].…”

“…Taken together, there is consensus that ABC transporters could play a role in DMARD resistance. Since thus far most studies on this topic either focussed on one specific ABC transporters or specific cell types, there is a need to extend these studies to multiple MDR/ABC transporters on immune cells derived from RA patients in relation to clinical status of DMARD (non) responsiveness [55]. For this purpose, we herein determined the expression levels of key ABC transporters (ABCB1, ABCC1-6, ABCC10-12 and ABCG2) on peripheral blood lymphocytes (PBLs) and monocyte-derived macrophages (Mφ) from HC and RA patients and assessed whether or not these parameters correlated with the clinical response to DMARDs.…”