Palhete-Ferreira, LígiaLeal, B.Santos, C.Franco, S.Parreira, S.Peralta, A. R.Moniz, I.Gaibino, N.Teixeira, A.Mateus, C.Santos, R.Bentes, C.2026-04-202026-04-202025-09Palhete-Ferreira L, Leal B, Santos C, Franco S, Parreira S, Peralta AR, et al. Circulating miR-146ª and mir-134 as potential therapeutic biomarkers in refractory status epilepticus: an exploratory study. In: 36th International Epilepsy Congress, Lisbon (Portugal), August 30 – September 3, 2025. Epilepsia. 2025;66 Suppl 4:S492-3. poster 1262.http://hdl.handle.net/10400.21/22815H&TRC authors gratefully acknowledge the FCT/MCTES national support through the UIDB/05608/2020 and UIDP/05608/2020; IDI&CA-2022 (IPL/2022/PRSE1_ESTeSL), LPCE-2023 Scientific Grant.Purpose: Refractory Status Epilepticus (RSE) is defined by persisting electroclinical/electrographic seizures despite intravenous therapy with two anti-seizure medication (ASM), including a benzodiazepine. The therapeutic approach includes underlying cause treatment, other ASMs and intravenous anesthetic therapy (IVAT). In clinical practice, biomarkers for RSE treatment are needed, aiming for its effective reversal and diligent IVAT reduction. MicroRNAs (miR) have been identified in epileptogenesis, including refractory epilepsies, with promising roles as diagnostic, prognostic and therapeutic response biomarkers. Previous studies, animal model of RSE and SE patients, reported miR upregulation. However, serum miR in RSE clinical model have not been studied. We aim to evaluate circulating levels of miR-146a and mir-134 in patients under IVAT for RSE treatment. Method: MiR-146a and miR-134 were quantified by real-time PCR in serum of adult patients with optimized IVAT for RSE treatment (EEG validated) and healthy individuals. Anoxic etiology was excluded. Relative expression values were calculated using 2-ΔΔCT method and compared with controls (Mann-Whitney and T-Student, p<0.05). Results: MiR circulating levels were quantified in 19 patients (8.53±15.70 years), 84,21% with electroclinical status epilepticus and 15,79% with electrographic status epilepticus, and 10 healthy individuals (27.60±12.00 years). RSE patients with optimized IVAT dose presented downregulated serum levels of miR-146a (20-fold lower (p<0,001) and miR-134 (3-fold lower,p<0,001). Conclusion: In this work, a significant downregulation in serum levels of miR-146a and miR-134 was demonstrated in optimized IVAT for RSE treatment, contradicting miR upregulation stated in SE, both in animal and human models. We postulate that our results are due to the therapy established for RSE, reflecting the importance of intervention models in mechanisms of neuroinflammation, neuronal excitability and dendritic spine morphology. Future work should analyze the role of miRs as RSE therapeutical response biomarkers.engEpilepsiaTherapeutic biomarkerRefractory status epilepticusmiR-146amir-134FCT_UIDB/05608/2020FCT_UIDP/05608/2020IPL/2022/PRSE1_ESTeSLconference poster