IMPORTANCE Cerebral amyloid angiopathy-related inflammation (CAA-ri) is an important diagnosis to reach in clinical practice because many patients with the disease respond to immunosuppressive therapy. Reliable noninvasive diagnostic criteria for CAA-ri would allow some patients to avoid the risk of brain biopsy. OBJECTIVE To test the sensitivity and specificity of clinical and neuroimaging-based criteria for CAA-ri. DESIGN, SETTING, AND PARTICIPANTS We modified the previously proposed clinicoradiological criteria and retrospectively analyzed clinical medical records and magnetic resonance imaging fluid-attenuated inversion recovery and gradient-echo scans obtained from individuals with CAA-ri and noninflammatory CAA.

Our data support the hypothesis that the pathogenesis of CAA-ri may be mediated by a selective autoimmune reaction against cerebrovascular Aβ, directly related to autoantibody concentration and soluble Aβ. The CSF dosage of anti-Aβ autoantibodies with the technique here described can thus be proposed as a valid alternative tool for the diagnosis of CAA-ri. Moreover, given the similarities between ARIA developing spontaneously and those observed during immunization trials, anti-Aβ autoantibodies can be considered as novel potential biomarkers in future amyloid-modifying therapies for the treatment of AD and CAA.

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BACE1 (␤-site amyloid precursor protein-cleaving enzyme 1) is a membrane-tethered member of the aspartyl proteases, essential for the production of ␤-amyloid, a toxic peptide that accumulates in the brain of subjects affected by Alzheimer disease. The BACE1 C-terminal fragment contains a DXXLL motif that has been shown to bind the VHS (VPS27, Hrs, and STAM) domain of GGA1-3 (Golgi-localized ␥-ear-containing ARFbinding proteins). GGAs are trafficking molecules involved in the transport of proteins containing the DXXLL signal from the Golgi complex to endosomes. Moreover, GGAs bind ubiquitin and traffic synthetic and endosomal ubiquitinated cargoes to lysosomes. We have previously shown that depletion of GGA3 results in increased BACE1 levels and activity because of impaired lysosomal degradation. Here, we report that the accumulation of BACE1 is rescued by the ectopic expression of GGA3 in H4 neuroglioma cells depleted of GGA3. Accordingly, the overexpression of GGA3 reduces the levels of BACE1 and ␤-amyloid. We then established that mutations in the GGA3 VPS27, Hrs, and STAM domain (N91A) or in BACE1 di-leucine motif (L499A/L500A), able to abrogate their binding, did not affect the ability of ectopically expressed GGA3 to rescue BACE1 accumulation in cells depleted of GGA3. Instead, we found that BACE1 is ubiquitinated at lysine 501 and is mainly monoubiquitinated and Lys-63-linked polyubiquitinated. Finally, a GGA3 mutant with reduced ability to bind ubiquitin (GGA3L276A) was unable to regulate BACE1 levels both in rescue and overexpression experiments. These findings indicate that levels of GGA3 tightly and inversely regulate BACE1 levels via interaction with ubiquitin sorting machinery.Alzheimer disease (AD) 3 is a devastating neurodegenerative disorder that results in loss of memory and cognitive function, eventually leading to dementia. A key neuropathological event in AD is the cerebral accumulation of an ϳ4-kDa peptide termed A␤, the principal component of senile plaques. Amyloid plaques are formed by aggregates of amyloid-␤-peptides, 37-43-amino acid fragments (predominantly A␤ 40 and A␤ 42 ) derived by serial proteolysis of the amyloid precursor protein (APP) by ␤-and ␥-secretase (1).The ␤-site APP-cleaving enzyme (BACE1) is a membranetethered member of the aspartyl proteases that has been identified as ␤-secretase (2-4). APP proteolysis by ␤-secretase results in the production of secreted ␤-APP polypeptide (␤APPs) along with a membrane-associated APP C-terminal fragment of 99 amino acids, which then serves as substrate for ␥-secretase resulting in the production of A␤.

Background and Objectives:To investigate the natural history and outcomes following treatment for spontaneous amyloid-related imaging abnormalities (ARIA)-like in cerebral amyloid angiopathy-related inflammation (CAA-ri).Methods:A multicenter, hospital-based, longitudinal, prospective observational study of inpatients meeting CAA-ri diagnostic criteria, recruited through the iCAβ International Network, in the period January 2013 - March 2017. A protocol for systematic data collection at first-ever presentation and at subsequent in-person visits, including T1-weighted, GRE-T2*, fluid-suppressed T2-weighted (FLAIR), and T1 post-gadolinium contrast-enhancement images aquired on 1.5T MRI, was employed at 3, 6, 12, 24-months follow-up. Centralized reads of MRI images were performed blinded to clinical, therapeutic, and time-points information. Main outcomes were survival, clinical and radiological recovery, intracerebral hemorrhage (ICH), and recurrence of CAA-ri.Results:The study enrolled 113 participants (10.6% definite, 71.7% probable, and 17.7% possible CAA-ri), mean age 72.9 years, 43.4% female, 37.1% APOEε4 carriers. 36.3% had a history of Alzheimer’s disease, 33.6% of ICH. A history of ICH, as well as the occurrence of new ICH at follow-up, was more common in patients with cortical superficial siderosis at baseline (52.6% vs 14.3%; p< 0.0001 and 19.3% vs 3.6%; p<0.009, respectively). After the first-ever presentation of CAA-ri, 70.3% (95% CI, 61.6-78.5) and 84.1% (95% CI, 76.2-90.6) clinically recovered within three and twelve months, followed by radiological recovery in 45.1% (95% CI, 36.4 - 54.8) and 77.4% (95% CI, 67.7 - 85.9), respectively. After clinicoradiological resolution of the first-ever episode, 38,3% (95% CI, 22.9 - 59.2) had at least one recurrence within the following 24 months. Recurrence was more likely if intravenous high dose corticosteroid pulse therapy was suddenly stopped compared to slow oral tapering-off (Hazard Ratio 4.68; 95% CI, 1.57-13.93; p=0.006).Discussion:These results from the largest longitudinal cohort registry of patients with CAA-ri support the transient and potentially relapsing inflammatory nature of the clinical-radiological acute manifestations of the disease and the effectiveness of slow oral tapering-off after intravenous corticosteroid pulse therapy in preventing recurrences. Our results highlight the importance of differential diagnosis for spontaneous ARIA-like events in Aβ-driven diseases, including treatment-related ARIA in Alzheimer’s disease patients exposed to immunotherapy drugs.

Introduction Observations performed in a subset of subjects treated with finasteride (an inhibitor of the enzyme 5α-reductase) for male pattern hair loss seem to indicate that sexual dysfunction as well as anxious/depressive symptomatology may occur at the end of the treatment and continue after discontinuation. Aim A possible hypothesis to explain depression symptoms after finasteride treatment might be impairment in the levels of neuroactive steroids. Therefore, neuroactive steroid levels were evaluated in paired plasma and cerebrospinal fluid samples obtained from male patients who received finasteride for the treatment of androgenic alopecia and who, after drug discontinuation, still show long-term sexual side effects as well as anxious/depressive symptomatology. Methods The levels of neuroactive steroids were evaluated by liquid chromatography–tandem mass spectrometry in three postfinasteride patients and compared to those of five healthy controls. Main Outcome Measures Neuroactive steroid levels in plasma and cerebrospinal fluid of postfinasteride patients and healthy controls. Results At the examination, the three postfinasteride patients reported muscular stiffness, cramps, tremors, and chronic fatigue in the absence of clinical evidence of any muscular disorder or strength reduction. Severity and frequency of the anxious/depressive symptoms were quite variable; overall, all the subjects had a fairly complex and constant neuropsychiatric pattern. Assessment of neuroactive steroid levels in patients showed some interindividual differences. However, the most important finding was the comparison of their neuroactive steroid levels with those of healthy controls. Indeed, decreased levels of tetrahydroprogesterone, isopregnanolone and dihydrotestosterone and increased levels of testosterone and 17β-estradiol were reported in cerebrospinal fluid of postfinasteride patients. Moreover, decreased levels of dihydroprogesterone and increased levels of 5α-androstane-3α,17β-diol and 17β-estradiol were observed in plasma. Conclusion The present observations confirm that an impairment of neuroactive steroid levels, associated with depression symptoms, is still present in androgenic alopecia patients treated with finasteride despite the discontinuation of the treatment.

Amyloid-related imaging abnormalities (ARIA) represent the major severe side effect of amyloid-beta (Aβ) immunotherapy for Alzheimer’s disease (AD). Early biomarkers of ARIA represent an important challenge to ensure safe and beneficial effects of immunotherapies, given that different promising clinical trials in prodromal and subjects at risk for AD are underway. The recent demonstration that cerebrospinal fluid (CSF) anti-Aβ autoantibodies play a key role in the development of the ARIA-like events characterizing cerebral amyloid angiopathy-related inflammation generated great interest in the field of immunotherapy. Herein, we critically review the growing body of evidence supporting the monitoring of CSF anti-Aβ autoantibody as a promising candidate biomarker for ARIA in clinical trials.

We report a biomarker and genetic evaluation of four patients with cerebral amyloid angiopathy-related inflammation (CAA-ri) treated with corticosteroids. Patients presented with focal symptomatology and cognitive impairment. MRI revealed cortical microbleeds and asymmetrical hyperintense white matter lesions (WML). Cerebrospinal fluid (CSF) biomarker analyses showed increased anti-Aβ autoantibodies, t-Tau, and p-Tau and decreased Aβ40 and Aβ42. After treatment, focal symptomatology disappeared, and WML and anti-Aβ autoantibodies decreased. The APOEɛ4 allele was overrepresented. Florbetapir-PET showed cortical deposition with lower retention in swollen areas. In the case of suspected CAA-ri, both CSF anti-Aβ autoantibodies levels and Florbetapir-PET could provide highly useful data to guide the correct diagnosis.