Abstract
Background: An association between IL-6 levels and cytokine storm syndrome in COVID-19 patients has been suggested. Cases with higher IL-6 levels have more rapid progression and a higher complication rate. On the other hand, COVID-19 cases with anosmia have a milder course of the disease.
Objective: We aimed to investigate whether there is a relationship between serum IL-6 levels and presence of anosmia in COVID-19 patients.
Methods: Patients with a confirmed diagnosis of COVID-19 based on laboratory (PCR) were stratified into two groups based on presence of olfactory dysfunction (OD). In all cases with and without anosmia; psychophysical test (Sniffin’ Sticks test) and a survey on olfactory symptoms were obtained. Threshold (t) – discrimination (d) – identification (i), and total (TDI) scores reflecting olfactory function were calculated. Clinical symptoms, serum IL-6 levels, other laboratory parameters, and chest computed tomography (CT) findings were recorded.
Results: A total of 59 patients were included, comprising 23 patients with anosmia and 36 patients without OD based on TDI scores. Patients with anosmia (41.39 ± 15.04) were significantly younger compared to cases without anosmia (52.19 ± 18.50). There was no significant difference between the groups in terms of comorbidities, smoking history, and symptoms including nasal congestion and rhinorrhea. Although serum IL-6 levels of all patients were above normal values (7 pg/mL), patients with anosmia had significantly lower serum IL-6 levels (16.72 ± 14.28 pg/mL) compared to patients without OD (60.95 ± 89.33 pg/mL) (p = 0.026).
Conclusion: Patients with COVID-19 related anosmia tend to have significantly lower serum levels of IL-6 compared to patients without OD, and the lower IL-6 levels is related to milder course of the disease. With the effect of low cytokine storm and IL-6 level, it may be said that anosmic cases have a milder disease in COVID-19.
Keywords: Anosmia; COVID-19; Computed tomography; Cytokine storm; IL-6; Mild disease; Olfactory dysfunction; Prognosis; Sniffin’ Sticks test; Threshold discrimination identification.
【저자키워드】 COVID-19, Cytokine storm, Prognosis, IL-6, olfactory dysfunction, Anosmia, Computed tomography, Mild disease, Sniffin' Sticks test, Threshold discrimination identification., 【초록키워드】 Cytokine storm, Clinical symptoms, Prognosis, IL-6, Comorbidities, cytokine, Symptom, Cytokine storm syndrome, progression, smoking, olfactory dysfunction, nasal congestion, Symptoms, Anosmia, Laboratory, Computed tomography, Chest computed tomography, serum, PCR, clinical, Patient, Laboratory parameters, group, threshold, disease, COVID-19 patients, Mild disease, association, COVID-19 cases, COVID-19 patient, olfactory, IL-6 levels, normal values, olfactory function, Serum IL-6, two groups, no significant difference, Serum level, COVID-19 case, rhinorrhea, significantly lower, Course, significantly, the disease, calculated, suggested, two group, stratified, were recorded, diagnosis of COVID-19, IL-6 level, with COVID-19, 【제목키워드】 disease severity, Anosmia, serum, relationship, IL-6 level,