Glial Fibrillary Acidic Protein Autoimmunity: A French Cohort Study

Objectives:To report the clinical, biological, imaging features, and the clinical course of a French cohort of patients with glial fibrillar acidic protein (GFAP) autoantibodies.Methods:We retrospectively included all patients tested positive for GFAP antibodies in the cerebrospinal fluid, by immunohistochemistry and confirmed by cell-based assay using cells expressing human GFAPα, since 2017, from two French referral centers.Results:We identified 46 patients with GFAP antibodies. Median age at onset was 43 years, and 65% were men. Infectious prodromal symptoms were found in 82%. Other auto-immune diseases were found in 22% of patients, and coexisting neural autoantibodies in 11%. Tumors were present in 24%, and T cell dysfunction in 23%. The most frequent presentation was subacute meningoencephalitis (85%) with cerebellar dysfunction in 57% of cases. Other clinical presentation included myelitis (30%), visual (35%) and peripheral nervous system involvement (24%). MRI showed perivascular radial enhancement in 32%, periventricular T2 hyperintensity in 41%, brainstem involvement in 31%, leptomeningeal enhancement in 26%, and reversible splenial lesions in 4 cases. 33/40 patients had a monophasic course, associated to a good outcome at last follow-up (Rankin Score≤2: 89%), despite a severe clinical presentation. Adult and pediatric features are similar. Thirty-two patients were treated with immunotherapy. 11/22 patients showed negative conversion of GFAP antibodies.Interpretation:GFAP auto-immunity is mainly associated with acute/subacute meningoencephalomyelitis with prodromal symptoms, for which tumors and T cell dysfunction are frequent triggers. The majority of patients followed a monophasic course with a good outcome.

Le suivi multidisciplinaire de patients adultes atteints de dystrophie myotonique de type 1 dans le Sud Aquitain

DM1 is characterized by a multisystemic involvement. Our objective was to determine the proportion of adequate follow-up for each affected organ in DM1 patients based on the recently published American and Spanish recommendations. To this end, we conducted a descriptive cross-sectional survey by phone in adult, genetically proven DM1 patients followed in the two French neuromuscular centers of Bayonne and Hendaye located in South Aquitaine, France. The questionnaire selected the most stringent criteria of the two international recommendations for each item of follow-up. Seventy-three patients were included, 55% of which were women (mean age of 48 years) with an average number of 467 CTG repeats. The proportion of patients receiving clinical follow-up in accordance with the recommendations was 90% in cardiology, 60% in neurology, 68% in ophthalmology, 53% in physiotherapy, 23% in pneumology, and 12% in rehabilitation. The high rate of neurological, cardiological, and ophthalmological monitoring might be explained by a locally dense medical demography whereas low rate of respiratory follow up and rehabilitation may reflect an incomplete knowledge of both the disease and the questionnaire. These results should be carefully interpretated as cognitive status may influence such a declarative study. Our study nevertheless disclosed important disparities according to the recommended multidisciplinary follow-up criteria in this French cohort of adult DM1 patients. These results highlight the major role of a multidisciplinary care and monitoring in DM1.

Predictive usefulness of RT-PCR testing in different patterns of Covid-19 symptomatology: analysis of a French cohort of 12,810 outpatients

Reverse transcriptase polymerase chain reaction (RT-PCR) is a key tool to diagnose Covid-19. Yet it may not be the most efficient test in all patients. In this paper, we develop a clinical strategy for prescribing RT-PCR to patients based on data from COVIDOM, a French cohort of 54,000 patients with clinically suspected Covid-19, including 12,810 patients tested by RT-PCR. We use a machine-learning algorithm (decision tree) in order to predict RT-PCR results based on the clinical presentation. We show that symptoms alone are sufficient to predict RT-PCR outcome with a mean average precision of 86%. We identify combinations of symptoms that are predictive of RT-PCR positivity (90% for anosmia/ageusia) or negativity (only 30% of RT-PCR+ for a subgroup with cardiopulmonary symptoms): in both cases, RT-PCR provides little added diagnostic value. We propose a prescribing strategy based on clinical presentation that can improve the global efficiency of RT-PCR testing.