Description of clinical and genetic features of 122 patients included in the Spanish Pompe registry.

Pompe disease is a rare genetic disorder with an estimated prevalence of 1:60.000. The two main phenotypes are Infantile Onset Pompe Disease (IOPD) and Late Onset Pompe Disease (LOPD). There is no published data from Spain regarding the existing number of cases, regional distribution, clinical features or, access and response to the treatment. We created a registry to collect all these data from patients with Pompe in Spain. Here, we report the data of the 122 patients registered including nine IOPD and 113 LOPD patients. There was a high variability in how the diagnosis was obtained and how the follow-up was performed among different centres. Seven IOPD patients were still alive being all treated with enzymatic replacement therapy (ERT) at last visit. Ninety four of the 113 LOPD patients had muscle weakness of which 81 were receiving ERT. We observed a progressive decline in the results of muscle function tests during follow-up. Overall, the Spanish Pompe Registry is a valuable resource for understanding the demographics, patient's journey and clinical characteristics of patients in Spain. Our data supports the development of agreed guidelines to ensure that the care provided to the patients is standardized across the country.

The impact of rituximab infusion protocol on the long-term outcome in anti-MuSK myasthenia gravis.

Objective: To evaluate whether the clinical benefit and relapse rates in anti-muscle-specific kinase (MuSK) myasthenia gravis (MG) differ depending on the protocol of rituximab followed. Methods: This retrospective multicentre study in patients with MuSK MG compared three rituximab protocols in terms of clinical status, relapse, changes in treatment, and adverse side effects. The primary effectiveness endpoint was clinical relapse requiring a further infusion of rituximab. Survival curves were estimated using Kaplan-Meier methods and survival analyses were undertaken using Cox proportional-hazards models. Results: Twenty-five patients were included: 11 treated with protocol 4 + 2 (375 mg/m2/4 weeks, then monthly for 2 months), five treated with protocol 1 + 1 (two 1 g doses 2 weeks apart), and nine treated with protocol 4 (375 mg/m2/4 weeks). Mean follow-up was 5.0 years (SD 3.3). Relapse occurred in 18.2%, 80%, and 33.3%, and mean time to relapse was 3.5 (SD 1.5), 1.1 (SD 0.4), and 2.5 (SD 1.4) years, respectively. Based on Kaplan-Meier estimates, patients treated with protocol 4 + 2 had fewer and later relapses than patients treated with the other two protocols (log-rank test P = 0.0001). Patients treated with protocol 1 + 1 had a higher risk of relapse than patients treated with protocol 4 + 2 (HR 112.8, 95% CI, 5.7-2250.4, P = 0.002). Patients treated with protocol 4 showed a trend to a higher risk of relapse than those treated with protocol 4 + 2 (HR 9.2, 95% CI 0.9-91.8, P = 0.059). Interpretation: This study provides class IV evidence that the 4 + 2 rituximab protocol has a lower clinical relapse rate and produces a more durable response than the 1 + 1 and 4 protocols in patients with MuSK MG.