Cellular immunophenotyping in multiple sclerosis: advances and clinical implications

PURPOSE OF REVIEW: Multiple sclerosis is a clinically heterogeneous disease that is driven by complex immune mechanisms. This review summarizes recent methodological advances in immunophenotyping and discusses clinical implications for diagnosis, prognosis, therapy selection, and monitoring. RECENT FINDINGS: Methodological advances like high-dimensional flow cytometry and single-cell technologies aim to define Multiple sclerosis immunological endophenotypes associated with different disease trajectories. Novel spectral flow and mass cytometry panels reveal distinct immune cell subsets. Myeloid cell populations have been identified in aggressive disease variants and tissue-resident T cells in cerebrospinal fluid. Clinically, baseline immune signatures aim to predict disease progression and treatment response. Patients with a highly inflammatory immune profile have been found to exhibit more rapid progression and to be prone to treatment failure. Immunophenotyping may therefore guide treatment, from identifying those at risk of Alemtuzumab-induced autoimmunity to monitoring B-cell repopulation for personalized dosing schedules. SUMMARY: Immunophenotyping enables increasingly precise characterization of Multiple sclerosis immuno-pathogenesis. While not yet routine, these tools show promise for improving differential diagnosis, individualizing therapy initiation and monitoring. Ongoing research and standardization are paving the way towards precision immunology-approaches in clinical practice.