Efficacy of tacrolimus as long-term immunotherapy for neuronal surface antibody-mediated autoimmune encephalitis

Aims: We aimed to verify the efficacy and safety of tacrolimus as long-term immunotherapy for the treatment of neuronal surface antibody-mediated autoimmune encephalitis (AE) during the first attack. Methods: In this retrospective observational cohort study, patients with neuronal surface antibody-mediated AE who experienced the first attack were enrolled. We compared the outcomes of 17 patients who received tacrolimus with those of 47 patients treated without tacrolimus. Patients were assessed at onset and 3, 6, and 12 months, as well as at the last follow-up, by using the modified Rankin scale (mRS) and the Clinical Assessment Scale in Autoimmune Encephalitis (CASE). The efficacy of tacrolimus was also compared in a subgroup of patients with anti-NMDA receptor encephalitis. Results: Among all patients with neuronal surface antibody-mediated AE, those receiving tacrolimus had lower median mRS scores [1 (IQR = 0–1) versus 2 (IQR = 1–3) in controls, p = 0.001)], CASE scores [2 (IQR = 1–3) versus 3 (IQR = 2–7), p = 0.006], and more favorable mRS scores (94.1% versus 68.1%, p = 0.03) at the 3-month follow-up. No difference was found at the last follow-up. There was no significant difference in the occurrence of relapse and adverse events between the two groups (11.8% versus 14.9%, p = 0.75). In the subgroup of patients with anti-NMDA receptor encephalitis, patients treated with tacrolimus had a lower median mRS score at the 3-month follow-up [1 (IQR = 0–2) versus 2 (IQR = 1–3), p = 0.03]; however, no difference in the outcome was detected at the last follow-up. Conclusion: Tacrolimus can be used as long-term immunotherapy in patients with neuronal surface antibody-mediated AE during the first attack. Treatment with tacrolimus appears to accelerate the clinical improvement of neuronal surface antibody-mediated AE.

Rate of Anti-NMDA Receptor Encephalitis in Ovarian Teratomas

Background The rate of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) in ovarian teratomas is unknown. We aim to identify the prevalence of NMDARE as well as volumetric and histopathologic characteristics of ovarian teratomas in patients with versus without. Methods We performed a retrospective cohort study to identify patients with confirmed ovarian teratomas and the characteristics of teratomas in NMDARE compared with non-NMDARE patients. Patients aged between 0 and 21 years with confirmed histopathological diagnosis of ovarian teratoma after resection were included. The rate of NMDARE in ovarian teratomas was identified. Moreover, volumes of ovarian teratomas and the frequency of neuronal glial elements on histopathology in NMDARE versus non-NMDARE patients were assessed. Results Five out of one-hundred-and-sixty-three (3.07%) patients with histopathology confirmed ovarian teratomas were diagnosed with NMDARE. Age was not different between the NMDARE (mean: 13.8 years, standard deviation: 3.9) and non-NMDARE groups (median: 14, interquartile range [IQR]: 5). Teratoma volumes from NMDARE patients were smaller than those of non-NMDARE patients (median 28.3 cm3 with IQR of 431.2 and median 182.8 with IQR of 635.0, respectively). Both age and NMDARE diagnosis were statistically significant variables in the analysis of variance on a multiple linear regression model. Age (p = 0.013) had a positive correlation with teratoma size, whereas presence of NMDARE had a negative correlation (p = 0.008). Conclusion The rate of NMDARE in ovarian teratomas is low and NMDARE patients have smaller teratomas than non-NMDARE. Further studies are needed to understand the timing of anti-NMDA receptor antibodies in teratomas and the development of NMDARE.