Multidrug Resistance Protein1(MRP1) And Its Association With Refractory Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic systemic autoimmune inflammatory disease. It is characterized by inflammation and destruction of the joints and the tissues surrounding the joints, leading to impairment, deformity and dysfunction and consequent reduction in the quality of life of RA patients. RA affects around0.3-1%of the world population. With more research and understanding of the disease, better treatment options have been devised, namely disease modifying anti-rheumatic drugs (DMARDs), corticosteroids, and biologics.However, some patients do not respond to these drugs, or have an initial response and then gradually its efficacy diminishes. For them it is difficult to control disease activity and progressive joint damage and dysfunction. The patients who have received formal and full course of treatment (such as combination therapy of two or more DMARDs or DMARDs and biologic agents) while the condition has still not improved or is recurrent, or progressive joint destruction appears, are referred to as RRA (refractory rheumatoid arthritis). A major cause of RRA is multi-drug resistance (MDR). MDR has been extensively studied in the field of oncology, however research is lacking in the field of rheumatology. Causes of MDR are:diminished drug delivery, impaired drug uptake, energy dependent cellular drug extrusion via MDR transporters, decreased drug activation, drug sequestration or enhanced drug detoxification, alterations in the target of the drug and down-regulation of apoptosis. Drug efflux has been identified as one of the main reasons for development of MDR. Of great significance among the MDR transporters is multi-drug resistance protein1(MRP1). MRP1has been extensively studied in the field of oncology, however research in the field of rheumatology is lacking. In this review, we have tried to explore the relation between MRP1and RRA.