Amyloid-related imaging abnormalities (ARIA) are abnormal differences seen in magnetic resonance imaging of the brain in patients with Alzheimers disease. ARIA is associated with amyloid-modifying therapies, particularly human monoclonal antibodies such as aducanumab. There are two types of ARIA: ARIA-E and ARIA-H. The phenomenon was first seen in trials of bapineuzumab. ARIA-E
ARIA-E refers to cerebral edema, involving the breakdown of the tight endothelial junctions of the blood-brain barrier and subsequent accumulation of fluid. In a double-blind trial of the humanised monoclonal antibody solanezumab (n = 2042), sixteen patients (11 taking the drug, 5 taking a placebo), or 0.78% developed ARIA-E. A further 7 patients developed ARIA-E during an open-label extension of the trial.The effect of ARIA-E depends on the severity and location of the edema. Symptoms may include headache, changes in mental state, confusion, vomiting, nausea, tremor and gait disturbances. ARIA-H
ARIA-H refers to cerebral microhaemorrhages (mH), small haemorrhages on the brain, often accompanied by hemosiderosis. mH are usually seen as small, round and low intensity lesions and are small haemosiderin deposits. Some studies define mH as being less than or equal to 10mm, while others define the cut-off as ≤ 5mm. The prevalence of mH in healthy elderly people is approximately 6%, but this value increases to between 50% and 80% in elderly people with cerebrovascular disease. ARIA MRI Classification Criteria
References


== External links ==
: 160  CD3 is one of the proteins that make up the TCR complex. : 166  The TCR transduces the signal for the T cell to proliferate and attack the antigen. : 160 Muromonab-CD3 is a murine (mouse) monoclonal IgG2a antibody which was created using hybridoma technology. It binds to the T cell receptor-CD3-complex (specifically the CD3 epsilon chain) on the surface of circulating T cells, initially leading to an activation, but subsequently inducing the clearance of TCR complex from cell surface and apoptosis of the T cells. This protects the transplant against the T cells. When administered for transplant induction, the drug is administered daily thereafter for up to 7 days.Newer monoclonal antibodies in development with the same mechanism of action include otelixizumab (also known as TRX4), teplizumab (also known as hOKT3γ1(Ala-Ala) ), and visilizumab (with a tentative trade name of Nuvion). They are being investigated for the treatment of other conditions like Crohns disease, ulcerative colitis, and type 1 diabetes. Further development of teplizumab is uncertain, due to one-year data from a recent Phase III trial being "disappointing". Adverse effects
Especially during the first infusion, the binding of muromonab-CD3 to CD3 can activate T cells to release cytokines like tumor necrosis factor and interferon gamma. This cytokine release syndrome, or CRS, includes side effects like skin reactions, fatigue, fever, chills, myalgia, headaches, nausea and diarrhea, and could lead to life-threatening conditions like apnoea, cardiac arrest, and flash pulmonary edema.