Cerebral amyloid angiopathy related vasculitis: successful treatment with azathioprine

Spontaneous ARIA-like Events in Cerebral Amyloid Angiopathy-Related Inflammation: A Multicenter Prospective Longitudinal Cohort Study

BACKGROUND AND OBJECTIVES

The goal of this work was to investigate the natural history and outcomes after treatment for spontaneous amyloid-related imaging abnormalities (ARIA)-like in cerebral amyloid angiopathy-related inflammation (CAA-ri).

METHODS

This was a multicenter, hospital-based, longitudinal, prospective observational study of inpatients meeting CAA-ri diagnostic criteria recruited through the Inflammatory Cerebral Amyloid Angiopathy and Alzheimer's Disease βiomarkers International Network from January 2013 to March 2017. A protocol for systematic data collection at first-ever presentation and at subsequent in-person visits, including T1-weighted, gradient recalled echo-T2*, fluid-suppressed T2-weighted (fluid-attenuated inversion recovery), and T1 postgadolinium contrast-enhanced images acquired on 1.5T MRI, was used at the 3-, 6-, 12-, and 24-month follow-up. Centralized reads of MRIs were performed by investigators blinded to clinical, therapeutic, and time-point information. Main outcomes were survival, clinical and radiologic 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). Their mean age was 72.9 years; 43.4% were female; 37.1% were APOEε4 carriers; 36.3% had a history of Alzheimer disease; and 33.6% had a history of ICH. A history of ICH and the occurrence of new ICH at follow-up were 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% confidence interval [CI] 61.6%-78.5%) and 84.1% (95% CI 76.2%-90.6%) clinically recovered within 3 and 12 months, followed by radiologic recovery in 45.1% (95% CI 36.4%-54.8%) and 77.4% (95% CI 67.7%-85.9%), respectively. After clinicoradiologic resolution of the first-ever episode, 38.3% (95% CI 22.9%-59.2%) had at least 1 recurrence within the following 24 months. Recurrence was more likely if IV 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-radiologic acute manifestations of the disease and the effectiveness of slow oral tapering off after IV corticosteroid pulse therapy in preventing recurrences. Our results highlight the importance of differential diagnosis for spontaneous ARIA-like events in β-amyloid-driven diseases, including treatment-related ARIA in patients with Alzheimer disease exposed to immunotherapy drugs.

Cerebral amyloid angiopathy and related inflammatory disorders

Inflammatory cerebral amyloid angiopathy is a largely reversible inflammatory vasculopathy that develops in an acute or subacute fashion in reaction to amyloid protein deposition in the central nervous system blood vessels. There are two recognized pathologically characterized variants: cerebral amyloid angiopathy-related inflammation (CAAri) and A beta-related angiitis (ABRA). Both variants produce a clinical picture that resembles primary angiitis of the CNS but is distinguished by a characteristic radiologic appearance. Although originally defined as a clinicopathologic diagnosis, it can now often be diagnosed based on clinicoradiologic criteria, though confirmation with brain and meningeal biopsy is still required in some cases. This disorder typically responds to steroids but addition of other immune suppressants may be needed in some cases to control the disease.

[Cerebral amyloid angiopathy associated with inflammation]

Cerebral amyloid angiopathy (CAA) associated with inflammation is a rare form of a potentially reversible encephalopathy in a subgroup of patients with CAA. The cerebral amyloid deposition can in isolated cases induce an inflammation predominantly of the cerebral blood vessels and a multifocal edema of the cerebral white matter. The courses can occur as monophasic, relapsing remitting and primarily progressive forms. We present seven cases with different courses of the disease and give an overview of the pathophysiology, clinical aspects and treatment of the disease with reference to the current literature. The cases presented show a very different and often difficult differential diagnostic clinical picture and all showed a significant improvement under steroid medication without signs of recurrence of the disease during the course. The recognition and early consistent treatment of inflammatory forms of CAA with and without direct inflammatory involvement of vessels can be decisive for successful treatment.

Cerebral amyloid angiopathy associated with inflammation: A systematic review of clinical and imaging features and outcome

Background

Cerebral amyloid angiopathy associated with inflammation is an increasingly recognized condition, characterized by an inflammatory response to the vascular deposits of β-amyloid within the brain that are the hallmark of cerebral amyloid angiopathy. Two main patterns of this inflammatory response have been identified to date: one involving a perivascular inflammatory cell infiltrate (cerebral amyloid angiopathy-related inflammation); the other a transmural vasculitic process (A-beta related angiitis). Unlike cerebral amyloid angiopathy itself, which predisposes to intracerebral hemorrhage and has no known treatment, cerebral amyloid angiopathy associated with inflammation typically presents in diverse ways and diagnosis may be challenging and delayed.

Aims

We sought to summarize the clinical features, imaging appearances and available data on outcome and treatment responses, using information derived from a systematic review of pathologically proven cases of cerebral amyloid angiopathy associated with inflammation.

Summary of review

We identified 213 distinct pathologically proven cases of cerebral amyloid angiopathy-related inflammation/A-beta related angiitis, from 104 publications. The clinical presentation, imaging features, pathology, treatment, and outcomes of cerebral amyloid angiopathy associated with inflammation are described.

Conclusions

Cerebral amyloid angiopathy associated with inflammation is an important and increasingly recognized clinical condition, which affects the older patient population and presents most commonly with cognitive decline, seizures, and headaches. Future research is required to develop and validate diagnostic criteria and determine optimum treatment strategies.

Cerebral Amyloid Angiopathy Associated with Inflammation: Report of 3 Cases and Systematic Review

INTRODUCTION

Cerebral amyloid angiopathy associated with inflammatory process (CAA-I) is a rare potentially treatable encephalopathy, characterized by an inflammatory response to vascular deposits of β-amyloid. We aimed to describe 3 clinical cases and perform a systematic review of all neuropathologically proved CAA-I case reports to describe its clinical and pathologic features and outcome under different treatments.

METHODS

We searched PubMed and Cochrane Library and screened references of included studies and review articles for additional citations. Outcome was classified at the last available follow-up by the modified Rankin Scale (mRS).

RESULTS

A total of 67 publications, reporting on 155 patients, were included. Mean age was 66.9 years, and 53.5% were men. The most common clinical presentation was cognitive dysfunction (48.0%) followed by headaches (38.7%), seizures (36.7%), and pyramidal signs (20.0%). Perivascular and vasculitic inflammation with granuloma was the most common pathologic pattern (27.5%). Eighty-six percent were treated with corticosteroids and 33.9% with cyclophosphamide. Forty-two percent regained independence (mRS score 0-2), whereas 20.5% were left with a severe handicap (mRS score 3-5) and 37.5% died. There were no statistically significant differences in outcome between patients treated with therapy with corticosteroids alone comparing with those treated with combination corticosteroids with cytostatic agents.

CONCLUSIONS

The most common clinical manifestation of CAA-I was cognitive dysfunction. The functional outcome was unfavorable in the majority of the patients, with death or severe disability in almost two third of the cases, despite treatment. No differences in outcome could be detected between patients treated with corticosteroids versus patients treated with cytostatics, combined with corticosteroids.

Advances in our Understanding of the Pathophysiology, Detection and Management of Cerebral Amyloid Angiopathy

Cerebral amyloid angiopathy (CAA) is pathologically defined as the deposition of amyloid protein, most commonly the amyloid β peptide (Aβ), primarily within the media and adventitia of small and medium-sized arteries of the leptomeninges, cerebral and cerebellar cortex. This deposition likely reflects an imbalance between Aβ production and clearance within the brain and leads to weakening of the overall structure of brain small vessels, predisposing patients tolobar intracerebral haemorrhage (ICH), brain ischaemia and cognitive decline. CAA is associated with markers of small vessel disease, like lobar microbleeds and white matter hyperintensities on magnetic resonance imaging. Therefore, it can be now be diagnosed during life with reasonable accuracy by clinical and neuroimaging criteria. Despite the lack of a specific treatment for this condition, the detection of CAA may help in the management of patients, regarding the prevention of major haemorrhagic complications and genetic counselling. This review discusses recent advances in our understanding of the pathophysiology, detection and management of CAA.

Cerebral amyloid angiopathy: a systematic review

Cerebral amyloid angiopathy (CAA) is a disorder characterized by amyloid deposition in the walls of leptomeningeal and cortical arteries, arterioles, and less often capillaries and veins of the central nervous system. CAA occurs mostly as a sporadic condition in the elderly, its incidence associating with advancing age. All sporadic CAA cases are due to deposition of amyloid-β, originating from proteolytic cleavage of the Amyloid Precursor Protein. Hereditary forms of CAA are generally familial (and therefore rare in the general population), more severe and earlier in onset. CAA-related lobar intracerebral hemorrhage is the most well-studied clinical condition associated with brain amyloid deposition. Despite ever increasing understanding of CAA pathogenesis and availability of reliable clinical and diagnostic tools, preventive and therapeutic options remain very limited. Further research efforts are required in order to identify biological targets for novel CAA treatment strategies. We present a systematic review of existing evidence regarding the epidemiology, genetics, pathogenesis, diagnosis and clinical management of CAA.