The roles of thrombophilia and cardiovascular risk factors in sudden sensorineural hearing loss (SSNHL) remain controversial. Cochlear micro-thrombosis has been hypothesized as a possible pathogenic mechanism of SSNHL. The objective was thus to measure the levels of markers of macrovascular thrombosis and microvascular risk factors
To recruit adult consecutive outpatients referred for SSNHL to the otolaryngologist clinic of our university hospital starting June 2016 and prospectively until december 31th 2018. Plasma sampling and biomarkers quantification : After a 48-hours diet excluding serotonin- and tryptophan-rich food, fasting blood samples were collected into vacuum tubes containing 109 mM sodium citrate (Becton-Dickinson, Le Pont de Claix, France) with a 9:1 blood-to-anticoagulant ratio. After removing 0.5 mL of whole blood for serotonin measurements, the remainder was centrifuged at 1,000 x g for 10 minutes, and the supernatant was then centrifuged at 3,000 x g for 15 minutes to isolate platelets and obtain platelet-poor plasma. Importantly, the time between blood sampling and platelet/plasma isolation was less than one hour. Aliquots of whole blood, platelets, and plasma were kept frozen (-20°C) until serotonin and homocysteine measurements performed within one week after congelation. Whole blood, platelet and plasma 5-HT as well as plasma homocysteine (Hcy) levels were measured by high pressure liquid chromatography coupled to fluorimetric detections . Thrombophilia screening included measurements of antithrombin , protein C, protein S, factor V Leiden, prothrombin G20210A, methylene tetrahydrofolate reductase (MTHFR) C677T, antiphospholipid antibodies anticardiolipin IgG and IgM and anti-beta2 glycoprotein 1 IgG), dilute Russell viper venom time , Rosner index, factor VIII, von Willebrand factor (vWF) activity and antigen. Tests were performed on citrated plasma, serum or DNA as appropriate and as previously described
Study Type
OBSERVATIONAL
Enrollment
394
follow up of microvascular biomarkers during patient follow up
HLariboisier otholaryngology clinic
Paris, France
change from Baseline of plasma serotonin at three months
plasma serotonin level (HPLC, frequent value \<15nM)
Time frame: at three months and then once a year up to five years
change from Baseline of plasma homocystein at three months
plasma homocystein (HPLC, fequent value \<15 µM)
Time frame: at three months and then once a year up to five years
change from Baseline serum of anticardiolipine antibody at three months
serum anticardiolipin antiboy (ELISA, frequent value \<10units)
Time frame: at three months and then once a year up to five years
change from Baseline of hearing characteristics at three months
audiogram
Time frame: at three months and then once a year up to five years
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