ENT - September 2020 - 531

Sun et al
treatment outcomes. Considering the small sample size, it is
unreasonable to draw a conclusion, and further analysis based
on large sample size is needed. Interestingly, we found that the
change in prestin plasma concentration after treatment is indicative of treatment response. In the treatment responsive group,
6 of 10 patients' prestin levels decreased after treatment compared to those of after treatment, while in all the 4 patients with
no hearing recovery, prestin levels significantly increased. We
hypothesized that when the treatment is effective and pathogenic factors of OHC damage cease, prestin concentration is
expected to decrease, while as the treatment is ineffective and
pathogenic mechanisms persist, prestin concentration is
expected to increase. Similar phenomenon was observed in the
study of James Naples who suggested that prestin may serve as
a biomarker of cochlear injury that is sensitive to therapeutic
interventions in cisplatin ototoxicity.9 Therefore, we suggested
that changes in plasma prestin level may be a potential indicator of the prognosis of ISSHL.
There are some limitations in this study. First, the sample
size was small. Further studies are necessary to observe the
reference values in more control patients and changes in prestin
level in larger number of patients with ISSHL. Relationships
between prestin level and clinical variables of patients with
ISSHL also need to be investigated. Second, the plasma prestin
concentration and treatment results of patients with ISSHL
should be observed for a longer period of time, at least 4 weeks
after the end of treatment. Third, because of the different time
of treatment after onset, the time of prestin measurement in
patients with ISSHL is different. Finally, each sample was
measured only once, and few samples had concentrations
below the detection limit (7.8 pg/mL) specified in the manufacturer's instruction manual. Despite all these limitations, the
results of our study still indicate prestin may be a potential
biomarker for the diagnosis and treatment of ISSHL.
Authors' Note
Changling Sun and Xiaolin Xuan contributed equally to this study.

531
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to
the research, authorship, and/or publication of this article.

Funding
The author(s) disclosed receipt of the following financial support for
the research, authorship, and/or publication of this article: This study
was funded by the Natural Science Foundation of Jiangsu Province
[BK20160195]; Wuxi Young Medical Talents [QNRC054].

References
1. Yotsukura S, Mamitsuka H. Evaluation of serum-based cancer
biomarkers: a brief review from a clinical and computational viewpoint. Crit Rev Oncol Hematol. 2015;93(2):103-115.
2. Parham K. Prestin as a biochemical marker for early detection of
acquired sensorineural hearing loss. Med Hypotheses. 2015;85(2):
130-133.
3. Parham K, Dyhrfjeld-Johnsen J. Outer hair cell molecular protein,
prestin, as a serum biomarker for hearing loss: proof of concept.
Otol Neurotol. 2016;37(9):1217-1222.
4. Naples J, Cox R, Bonaiuto G, Parham K. Prestin as an otologic
biomarker of cisplatin ototoxicity in a guinea pig model. Otolaryngol Head Neck Surg. 2018;158(3):541-546.
5. Siegel LG. The treatment of idiopathic sudden sensorineural hearing loss. Otolaryngol Clin North Am. 1975;8(2):467-473.
6. Parham K, Sacks D, Bixby C, Fall P. Inner ear protein as a biomarker in circulation? Otolaryngol Head Neck Surg. 2014;151(6):
1038-1040.
7. Michel O, Deutsche Gesellschaft fu¨r Hals-Nasen-Ohren-Heilkunde,
Kopf- und Hals-Chirurgie. The revised version of the german
guidelines ''sudden idiopathic sensorineural hearing loss''.
Laryngorhinootologie. 2011;90(5):290-293.
8. Liba B, Naples J, Bezyk E, Campbell C, Mei M, Parham K.
Changes in serum prestin concentration after exposure to cisplatin.
Otol Neurotol. 2017;38(10):e501-e505.
9. Naples JG, Parham K. Cisplatin-induced ototoxicity and the effects
of intratympanic diltiazem in a mouse model. Otolaryngol Head
Neck Surg. 2016;154(1):144-149.

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