Plasma-Free Amino Acid Profiling of Nasal Polyposis Patients
Authors: Celik Mustafa , Şen Alper , Koyuncu İsmail , Gönel Ataman 
Published: September 2019

Aim and Objective::
To determine the mechanisms present in the etiopathogenesis of nasal
polyposis. It is not clear whether amino acids contribute in a causal way to the development of the
disease. Therefore, the aim of this study was to determine the plasma-free amino acid profile in
patients with nasal polyposis and to compare the results with a healthy control group.

Materials and Methods::
This was a prospective controlled study that took place in the Otolaryngology
Department at the Harran University Faculty of Medicine between April 2017 and April 2018. Plasmafree
amino acid profile levels were studied in serum samples taken from a patient group and a healthy
control group. Patients who were diagnosed with bilateral diffuse nasal polyposis and were scheduled
for surgical interventions were included in this study. Individuals whose age, gender, and body mass
index values were compatible with that of the patient group and who did not have any health problems
were included in the control group. All the participants whose levels of plasma-free amino acid were
thought to be affected by one or more of the following factors were excluded from the study: smoking
and alcohol use, allergic rhinitis presence, the presence of acute or chronic sinusitis, a history of
endoscopic sinus surgery, unilateral nasal masses, a history of chronic drug use, systemic or topical
steroid use in the last three months for any reason, and liver, kidney, hematological, cardiovascular,
metabolic, neurological, or psychiatric disorders or malignancies.

Results:
In patients with nasal polyposis, 3-methyl histidine (3-MHIS: nasal polyposis group (ng) = 3.22
(1.92 – 6.07); control group (cg) = 1.21 (0.77 – 1.68); p = 0.001); arginine (arg: ng = 98.95 (70.81 –
117.75); cg = 75.10 (54.49 – 79.88); p = 0.005); asparagine (asn: ng = 79.84 (57.50 – 101.44); cg = 60.66
(46.39 – 74.62); p = 0.021); citrulline (cit: ng = 51.83 (43.81 – 59.78); cg = 38.33 (27.81 – 53.73); p =
0.038); cystine (cys: ng = 4.29 (2.43 – 6.66); cg = 2.41 (1.51 – 4.16); p = 0.019); glutamic acid (glu: ng =
234.86 (128.75 – 286.66); cg = 152.37 (122.51 – 188.34); p = 0.045); histidine (his: ng = 94.19 (79.34 –
113.99); cg = 74.80 (62.76 – 98.91); p = 0.018); lysine (lys: ng = 297.22 (206.55 – 371.25); cg = 179.50
(151.58 – 238.02); p = 0.001); ornithine (ng = 160.62 (128.36 – 189.32); cg = 115.91 (97.03 – 159.91); p
= 0.019); serine (ser: ng = 195.15 (151.58 – 253.07); cg = 83.07 (67.44 – 92.44); p = 0.001); taurine (tau:
ng = 74.69 (47.00 – 112.13); cg = 53.14 (33.57 – 67.31); p = 0.006); tryptophan (trp: ng = 52.31 (33.81 –
80.11); cg = 34.44 (25.94 – 43.07); p = 0.005), homocitrulline (ng = 1.75 (1.27 – 2.59); cg = 0.00 (0.00 –
0.53); p = 0.001); norvaline (ng = 6.90 (5.61 – 9.18); cg = 4.93 (3.74 – 7.13); p = 0.021); argininosuccinic
acid (ng = 14.33 (10.06 – 25.65); cg = 12.22 (5.77 – 16.87) p = 0.046); and plasma concentrations were
significantly higher than in the healthy control group (p <0.05). However, the gamma-aminobutyric acid
(gaba: ng = 0.16 (0.10 – 0.24); cg = 0.21 (0.19 – 0.29); p = 0.010) plasma concentration was significantly
lower in the nasal polyposis group than in the healthy control group.

Conclusion:
In this study, plasma levels of 15 free amino acids were significantly higher in the nasal
polyposis group than in the healthy control group. A plasma level of 1 free amino acid was found to be
significantly lower in the nasal polyposis group compared to the healthy control group. Therefore, it is
important to determine the possibility of using the information obtained to prevent the recurrence of
the condition and to develop effective treatment strategies. This study may be a milestone for studies of
this subject. However, this study needs to be confirmed by further studies conducted in a larger series.