CD8+ T-cell predominance in autoimmune glial fibrillary acidic protein astrocytopathy.

BACKGROUND AND OBJECTIVE: We aimed to report the pathological features of T lymphocytes in autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy (GFAP-A). METHODS: A retrospective pathological analysis of patients with GFAP-A was performed. RESULTS: Eight patients with GFAP-immunoglobulin G (IgG) and pathological data were included. Their biopsy findings were similar, and all showed marked lymphocytic infiltration in the white matter, with perivascular predominance. The lymphocytic infiltration was predominantly composed of CD8+ T lymphocytes rather than CD4+ T lymphocytes, except in one patient who had overlapping positive myelin oligodendrocyte glycoprotein-IgG. Unlike CD4+ T cells, CD8+ T cells were frequently observed adjacent to dystrophic neurons and astrocytes. There was also diffuse infiltration by CD68+ and CD163+ macrophages. CD8+ astrocytes were identified in two samples, but no CD4+ astrocytes were observed. CONCLUSIONS: A predominance of CD8+ T cells may be an important pathological and diagnostic feature in GFAP-A.

Different Phenotypes at Onset in Neuromyelitis Optica Spectrum Disorder Patients with Aquaporin-4 Autoimmunity.

BACKGROUND: Although rare, brain abnormalities without optic neuritis (ON) or transverse myelitis (TM) diagnosed with neuromyelitis optica spectrum disorder (NMOSD) have been reported in patients positive for the aquaporin-4 (AQP4) antibody. OBJECTIVE: To analyze demographic and clinical differences among NMOSD patients without ON or TM, those with either ON or TM, and patients with simultaneous ON and TM at disease onset. METHODS: In this retrospective study, patients who were positive for the AQP4 antibody, as detected using a cell-based assay, at the Second Affiliated Hospital of Guangzhou Medical University in China were recruited. Demographic and clinical data were obtained from each patient's medical record. RESULTS: A total of 292 patients were included in this study and were divided into four subgroups based on their initial manifestations: (i) NMOSD without ON or TM (NMOSD-ON-TM-, n = 70); (ii) NMOSD with ON (NMOSD-ON+, n = 95); (iii) NMOSD with TM (NMOSD-TM+, n = 116); and (iv) simultaneous ON and TM [neuromyelitis optica (NMO), n = 11]. We found that age at onset was lower in the NMOSD-ON-TM- group than that in the other groups. The interval from the first episode to relapse was shorter in the NMOSD-ON-TM- group than that in NMOSD-TM+ group. Cerebral spinal fluid white cell counts and protein levels were significantly higher in the NMOSD-ON-TM- group than those in the other groups. Lower Expanded Disability Status Scale scores were observed in the NMOSD-ON-TM- group. Brain abnormalities, including in area postrema and hemisphere lesions, were more frequent in the NMOSD-ON-TM- group. Kaplan-Meier analysis showed that patients in the NMOSD-ON-TM- group experienced earlier relapse than those in other groups. Conversion to NMO in the NMOSD-ON+ group was greater than that in the other groups. Only 14 patients (4.8%, 14/292) had pure brain abnormalities, of which 12 had disease duration of several more years and 8 (57.1%) experienced relapses. CONCLUSION: NMOSD patients with different initial manifestations present with significant differences in clinical features during follow-up. Patients with long-term AQP4 autoimmunity in the brain in the absence of ON or TM are not common.

Hypothalamic abnormality in patients with inflammatory demyelinating disorders.

BACKGROUND: Hypothalamic lesions in neuromyelitis optica (NMO) patients might be more specific for NMO than multiple sclerosis (MS). However, this is controversial. OBJECTIVE: To characterize clinical features of patients with inflammatory demyelinating disorders (IDDs) with visible hypothalamic lesions using magnetic resonance imaging (MRI). METHODS: Patients with IDDs (n = 429) were recruited retrospectively. RESULTS: Of 52 patients with hypothalamic images enrolled, 42 were positive for aquaporin-4 (AQP4) antibodies, including 28 patients with NMO, 6 with recurrent transverse myelitis, 3 with recurrent optic neuritis, and 5 with brainstem and brain syndrome. The remaining 10 patients were anti-AQP4-negative, including 3 with MS, 3 with acute disseminated encephalomyelitis, and 4 with other disorders. In the AQP4-positive group, manifestations, including ataxia, intractable hiccup and nausea, syndrome of inappropriate antidiuretic hormone secretion and encephalopathy were more frequent in those with hypothalamic lesions than those without. Cell counts of cerebrospinal fluid in patients with hypothalamic lesions differed from patients without lesions. Brain MRI abnormalities were more frequent in brainstem and hemisphere of the hypothalamic lesion group. CONCLUSIONS: Hypothalamic lesions were observed frequently in patients with AQP4 antibodies. Clinical manifestations and paraclinical features in AQP4-positive patients with hypothalamic lesions differed from those without lesions.