Platelet glycoproteins and fibrinogen in recovery from idiopathic sudden hearing loss.
BACKGROUND
The pathomechanism and location of idiopathic sudden sensorineural hearing loss (ISSHL) is unclear. In a previous case-control study, we found elevated fibrinogen concentrations and a higher prevalence of T allele carriers of the glycoprotein (Gp) Ia C807T polymorphism in ISSHL patients.


METHODS
127 patients with ISSHL (mean age 53.3 years, 48.8% females), who underwent a standard therapy with high dose steroids, pentoxifyllin and sterofundine over 8 days were included. We examined the influence of GpIa genotype and fibrinogen (BclI-, A312-, HaeIII-) genotype and fibrinogen plasma levels on hearing recovery after 8 weeks (change from baseline: 0 dB  =  no recovery, >0 to 10 dB = moderate recovery, >10 dB = good recovery). In a subsample of 59 patients with ISSHL, we further studied the association of platelet glycoprotein GpIa, Ib and IIIa densities on hearing recovery as well as the possible effect-modification of platelet glycoproteins on hearing recovery by plasma fibrinogen.


RESULTS
In univariate analysis, neither the GpIa genotype nor fibrinogen genotype (all p>0.1) but lower fibrinogen levels (p = 0.029), less vertigo (p = 0.002) and lower GpIIIa receptor density (p = 0.037, n = 59) were associated with hearing recovery. In multivariate analysis, fibrinogen significantly modified the effect of GPIa receptor density on good hearing recovery (effect-modification on multiplicative scale OR = 0.45 (95% confidence interval (0.21-0.94)), p = 0.03). GPIb receptor density below the mean was associated with a 2-fold increase in good hearing recovery both in patients with fibrinogen levels above (p = 0.04) as well as in patients with fibrinogen levels below the mean (p = 0.06). There was no indication for an effect-modification (p = 0.97).


CONCLUSIONS
The findings suggest a vascular/rheological origin of ISSHL with unique features of thrombosis in the inner ear artery that may include complex interrelationships among platelet glycoproteins and plasma fibrinogen.
Department of Otorhinolaryngology, Head and Neck Surgery, University of Münster, Münster, Germany.
Daniel
D
Weiss
Department of Anaesthesiology and Intensive Care Medicine, Campus Virchow-Klinikum and Campus Charité-Mitte, Charité - University Medicine, Berlin, Germany.
Bruno
B
Neuner
Institute of Laboratory Medicine, Unfallkrankenhaus Berlin, Berlin, Germany.
Kerstin
K
Gorzelniak
Department of Otorhinolaryngology, Head and Neck Surgery, University of Münster, Münster, Germany.
Alexis
A
Bremer
Department of Otorhinolaryngology, Head and Neck Surgery, University of Münster, Münster, Germany.
Claudia
C
Rudack
Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Campus Virchow-Klinikum, Charité - University Medicine & Labor Berlin - Charité Vivantes Services GmbH, Berlin, Germany.
Michael
M
Walter
D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood*; D016022:Case-Control Studies; D005260:Female; D005340:Fibrinogen / Q000235:genetics / Q000378:metabolism*; D005434:Flow Cytometry; D005838:Genotype; D003639:Hearing Loss, Sudden / Q000097:blood / Q000188:drug therapy* / Q000235:genetics*; D006801:Humans; D039421:Integrin alpha2 / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*
D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D039421:Integrin alpha2; D005340:Fibrinogen