Plasma p-tau217 in Alzheimer's disease: Lumipulse and ALZpath SIMOA head-to-head comparison.

Background: Plasma phosphorylated-tau217 (p-tau217) has been shown to be one of the most accurate diagnostic markers for Alzheimer's disease (AD). No studies have compared the clinical performance of p-tau217 as assessed by the fully automated Lumipulse and SIMOA ALZpath p-tau217. Aim: To evaluate the diagnostic accuracy of Lumipulse and SIMOA plasma p-tau217 assays for AD. Methods: The study included 392 participants, 162 with AD, 70 with other neurodegenerative diseases (NDD) with CSF biomarkers and 160 healthy controls. Plasma p-tau217 levels were measured using the Lumipulse and ALZpath SIMOA assays. The ability of p-tau217 assessed by both techniques to discriminate AD from NDD and controls was investigated using ROC analyses. Results: Both techniques showed high internal consistency of p-tau217 with similar correlation with CSF p-tau181 levels. In head-to-head comparison, Lumipulse and SIMOA showed similar diagnostic accuracy for differentiating AD from NDD (area under the curve [AUC] 0.952, 95%CI 0.927-0.978 vs 0.955, 95%CI 0.928-0.982, respectively) and HC (AUC 0.938, 95%CI 0.910-0.966 and 0.937, 95% CI0.907-0.967 for both assays). Conclusions: This study demonstrated the high precision and diagnostic accuracy of p-tau217 for the clinical diagnosis of Alzheimer's disease using either fully automated or semi-automated techniques.

Clinical and pathological findings of a fatal systemic capillary leak syndrome (Clarkson disease): a case report.

Systemic capillary leak syndrome (SCLS) is a rare disorder with episodes of hypotension, hypoalbuminemia, and hemoconcentration. During attacks endothelial hyperpermeability results in leakage of plasma proteins into the interstitial space. Attacks vary in severity and may be lethal.A 49-year-old previously healthy man was admitted to hospital for hypovolemic shock, anasarca with pleuropericardial effusion, muscle fatigue, and oliguria occurring after a flu-like syndrome. Laboratory data showed an increase in hematocrit (65%), leucocytes (24.590 µ/L), creatinine (2.5 mg/dL), creatine phosphokinase (10.000 U/L), and a decrease in serum albumin (17 g/L) without proteinuria. Immunoglobulins of class G/λ monoclonal gammopathy were detected (1.3 g/L). The initial suspicions addressed to a protein-loosing syndrome or to an effort-related rhabdomyolysis. Initial therapy was based on steroids, albumin, and high molecular weight plasma expanders (hydroxyethyl starch). Because of high hematocrit, phlebotomy was also performed. The patient had complete clinical remission and a diagnosis of SCLS was finally made. He received prophylactic therapy with verapamil and theophylline that was self-stopped for intolerance (hypotension and tachycardia). He had a new crisis 2 days after a physical effort, and was admitted in intensive care unit. The patient died for severe hypovolemic shock with multiorgan failure and sudden cardiac arrest 15 hours after hospital admission. Postmortem investigation revealed massive interstitial edema of main organs with myocardial hyperacute ischemia.Studies on SCLS are limited for the rarity of the disease and its unpredictable course. Both prophylactic and acute crisis treatments are empirical and optimal management of severe attacks is still lacking.

Myasthenia Gravis following Low-Osmolality Iodinated Contrast Media.

We describe the case of 79-year-old man admitted to our general hospital for a 6-week history of progressive dysphagia to solids and liquids associated with weight loss. To reach a diagnosis a total body CT scan with low-osmolality iodinate contrast agent was performed. Two hours later the patient developed an acute respiratory failure requiring orotracheal intubation and mechanical ventilation. The laboratory and neurological tests allow formulating the diagnosis of myasthenia gravis. In literature, other three case reports have associated myasthenic crisis with exposure to low-osmolality contrast media. This suggests being careful in administering low-osmolality contrast media in myasthenic patients.