Introduction
Coronavirus disease (COVID-19) first emerged in Wuhan, China, in
December 2019, and it was found to be caused by severe acute respiratory
syndrome coronavirus-2 (SARS-CoV-2), a novel coronavirus. Genetic
sequencing of the virus has shown that it is a betacoronavirus that is
closely linked to the severe acute respiratory syndrome (SARS) virus
(1). Coronaviruses are among the main pathogens that primarily target
the human respiratory system. SARS-CoV and Middle East respiratory
syndrome coronavirus (MERS-CoV) causes fatal infections. As a novel
betacoronavirus, SARS-CoV-2 is more contagious. Although it has a lower
mortality rate than SARS-CoV and MERS-CoV do, the severity of disease is
more variable with SARS-CoV-2 (2).
Severe disease characterized by interstitial pneumonia develops in
10%–20% of patients (especially in elderly individuals and those with
underlying comorbidities). Particularly, macrophage activation syndrome
characterized by hyperferritinemia, hepatic dysfunction, and diffuse
intravascular coagulation and rapidly developing acute respiratory
distress syndrome (ARDS) characterized by high levels of acute phase
reactants or septic shock may occur (3,4).
Periostin has been associated with many respiratory disorders. It has
been recently shown to be an indicator of disease progression in
idiopathic pulmonary fibrosis (5-7) and asthma (8). It is a
matricellular protein. Matricellular proteins are nonstructural,
extracellular matrix (ECM) proteins that are highly expressed at sites
of injury or inflammation. They interact with other ECM proteins to
mediate tissue remodeling, and they bind to growth factors and cytokines
to modulate their activities (9). Expression of POSTN , the gene
encoding human periostin, can be induced by the cytokines transforming
growth factor beta (TGF-β), interleukin (IL)-4, and IL-13 (10,11).
Periostin interacts with multiple molecules involved in signal cascades
to modulate the expression of various genes such as those encoding
collagen, chemokines, and TGF-β (12,13).
In this study, we aimed to investigate whether periostin could be a
useful new biomarker in the follow-up and severity assessment of the
disease in patients with COVID-19 pneumonia. In addition, this is the
first study on periostin levels in patients with COVID-19.