The Impact of Autoantibody Profiles on Treatment Response in Idiopathic Inflammatory Myopathies

To evaluate how myositis-specific and -associated autoantibody profiles inform prognosis and guide therapeutic decision-making in idiopathic inflammatory myopathies (IIMs). By synthesizing recent cohort studies, meta-analyses, and clinical trials, this review aims to establish a practical, serology-driven framework for individualizing treatment—ranging from corticosteroids and conventional immunosuppressants to targeted biologics, intravenous immunoglobulin, and emerging modalities such as JAK inhibitors and CAR-T cell therapy.

Distinct autoantibody endotypes exhibit predictable organ involvement, malignancy risk, and treatment responsiveness. Anti-Mi-2 dermatomyositis demonstrates robust steroid sensitivity and low incidence of cancer, whereas anti-TIF1-γ and anti-NXP2 require intensive oncologic surveillance due to a heightened risk of neoplasia. Anti-MDA5 positivity presents with rapidly progressive interstitial lung disease best managed with upfront combination immunosuppression and JAK inhibitors. Immune-mediated necrotizing myopathies (anti-SRP, anti-HMGCR) benefit from IVIG and or early B-cell depletion, and anti-synthetase syndrome responses are enhanced by rituximab in refractory interstitial lung disease. Preliminary data support the use of interferon pathway blockade in cutaneous dermatomyositis and CAR-T therapy for refractory necrotizing myopathy.

Incorporating autoantibody profiling into routine evaluation enables targeted surveillance and timely escalation to biologics or novel therapies, reducing morbidity and mortality. A serology-guided algorithm optimizes immunosuppressive regimens, cancer screening, and supportive measures, thereby advancing precision medicine in IIM management.