Pegvaliase-induced immediate hypersensitivity reaction after the discontinuation of antihistamine therapy in a patient with phenylketonuria - Case report.

Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine (Phe) metabolism, resulting from the deficient activity of phenylalanine hydroxylase that converts Phe to tyrosine in the liver, leading to elevated levels of Phe. Pegvaliase is an innovative and effective enzyme replacement therapy for reducing Phe concentration, but it has been associated with severe drug-induced hypersensitivity adverse events (HAEs). Limited data is available on the management of these HAEs, thus, we aimed to present a case report of a successful management strategy. The patient was a 28-year-old Caucasian male with classical PKU, who was otherwise healthy. Due to poor metabolic control, the pegvaliase treatment was initiated. The titration phase was uneventful, with transient and mild side effects, localized to the injection site. After the patient was on a maintenance dose of pegvaliase and had no reactions to the drug, we discontinued the H1-antihistamine. In the following days, within minutes after receiving the pegvaliase injection, an acute hypersensitivity reaction occurred that required emergency treatment. H1-antihistamine treatment was reintroduced. Four days after the incident he received pegvaliase under medical supervision and did not experience any symptoms. In conclusion, cautious reintroduction of pegvaliase in a hospital setting can be safely performed after HAE due to the discontinuation of H1-antihistamines. HAEs could be successfully mitigated by scheduling daily antihistamines administration closer to the pegvaliase injection. This approach can enable PKU patients to maintain their access to an effective and quality-of-life-improving therapy.

Neuroimaging Modalities Used for Ischemic Stroke Diagnosis and Monitoring.

Strokes are one of the global leading causes of physical or mental impairment and fatality, classified into hemorrhagic and ischemic strokes. Ischemic strokes happen when a thrombus blocks or plugs an artery and interrupts or reduces blood supply to the brain tissue. Deciding on the imaging modality which will be used for stroke detection depends on the expertise and availability of staff and the infrastructure of hospitals. Magnetic resonance imaging provides valuable information, and its sensitivity for smaller infarcts is greater, while computed tomography is more extensively used, since it can promptly exclude acute cerebral hemorrhages and is more favorable speed-wise. The aim of this article was to give information about the neuroimaging modalities used for the diagnosis and monitoring of ischemic strokes. We reviewed the available literature and presented the use of computed tomography, CT angiography, CT perfusion, magnetic resonance imaging, MR angiography and MR perfusion for the detection of ischemic strokes and their monitoring in different phases of stroke development.