Idiopathic inflammatory-demyelinating disorders of the central nervous system. MS typifies this spectrum of disorders. This has been a major interest area for Dr. Kantarci's clinical practice and research. Together with Aksel Siva, M.D., FEAN, Istanbul University Cerrahpasa School of Medicine, Dr. Kantarci has established the largest multicenter database for MS in Turkey. Drs. Kantarci and Siva have conducted the first internationally recognized natural history study of MS in Turkey using this database. Under the guidance of Brian G. Weinshenker, M.D., an emeritus Mayo Clinic neurologist, Dr. Kantarci has made multiple contributions to the understanding of genetic aspects of MS during his time at Mayo Clinic.
Dr. Kantarci is actively involved as a principal investigator on several projects on genetics and natural history of MS. Recently, Dr. Kantarci and his research team furthered the understanding of clinical progression in MS with a series of publications. The research team definitively defined that the progressive phase of MS depends on age and is not related to previous relapsing disease duration. They have shown that ongoing relapses after progressive MS onset continue to contribute to additional disability. They also have shown that recovery from the earliest relapses impacts when and how fast a person will enter the progressive phase of MS later in the course of the disease.
In partnership with Biogen, Dr. Kantarci and his research team have proved that recovery from relapses is a phenomenon that depends on age. In a clinical trial setting, the research team also has shown that a poor recovery from the first presenting relapse, coupled with a delayed treatment initiation of only two years, leads to irreversible disability accumulation that culminates in nonbenign MS.
With the completion of these studies, Dr. Kantarci and his research team argue that the impacting onset of progressive MS should be thought of at the beginning of MS by intervening and recovering from relapses fully. Also, further relapses should be avoided early on when the disease is most active.
Dr. Kantarci has helped define radiologically isolated syndrome (RIS). He is a founder of the international RIS consortium (RISC). RISC has published the large natural history of this cohort, showing the conversion rate of RIS to MS. Together with the team in RISC, Dr. Kantarci also has identified the prognostic factors that determine 2-, 5- and 10-year outcomes in this earliest presymptomatic presentation of MS.
Under Dr. Kantarci's leadership, RISC also has shown that RIS can directly evolve into primary progressive MS (PPMS). This was the first time the pre-progression phase of PPMS was studied prospectively and shown not to differ from that of the pre-progression phase of secondary progressive MS (SPMS). This finding paved the way to accept that treatment in the RIS phase may be the only way to avoid developing the devastating disease course of PPMS. This work formed the basis of two multicenter trials where RISC, including Dr. Kantarci, confirmed that beginning treatment at this stage can delay and potentially prevent the clinical onset of MS.
Dr. Kantarci, with colleagues in RISC, recently validated and expanded the diagnostic criteria of RIS to be more inclusive of the earliest presentations. This extensive effort by Dr. Kantarci and his colleagues in RISC led to the 2024 update of international diagnostic criteria of MS recognizing presymptomatic and asymptomatic forms of the disease.