Heat shock protein 70 and anti-heat shock protein 70 antibodies in nasal secretions of patients with chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a complex inflammatory disease, with a prevalence of‘∼10.9% in Europe, which consists of several phenotypic variants with different underlying pathophysiologic mechanisms.1 CRS with nasal polyps (CRSwNP) represents the clinical phenotype in up to 4% of the population and CRS without nasal polyps (CRSsNP) is another clinical phenotype in up to 7% of the population.1 CRS is characterized by chronic inflammation in an environment colonized by bacteria and fungi with or without biofilms, with an increase in the numbers of cells of the adaptive immune response.2,3 Recent studies demonstrated that apoptotic and necrotic cells release damage-associated molecular pattern molecules, such as heat shock proteins (HSP), which promote early innate and adaptive immune responses through their interaction with pattern recognition receptors.4 HSPs are a family of highly conserved proteins found in cells of all organisms, from bacteria to mammals; of all HSPs, the HSP70 family constitutes the most conserved and best-studied damage-associated molecular patterns. When HSP70 is released into the extracellular compartment, it delivers a maturation signal to dendritic cells and activates the nuclear factor (NF) κB pathway, which modulates production of several cytokines.5,6 Several studies have indicated an important role of damage-associated molecular patterns in the pathogenesis of allergic diseases.7 The sputum and plasma concentrations of HSP70 are increased in asthma and are related to disease severity.8 Some HSPs serve a role of self-antigens, which results in the production of autoantibodies, which are involved in the pathogenesis and/or prognosis of numerous diseases.9,10 Previously, autoantibodies against HSP70 were found to be associated with the severity of asthma and correlated with higher levels of total immunoglobulin E (IgE) and interleukin (IL) 4.11 CRS is characterized by increases in local production of several immunoglobulin isotypes, especially IgA and IgE.12 The locally produced immunoglobulins from nasal polyp tissues of patients with CRSwNP include self-antigens, which indicate autoimmunity in its pathogenesis.13 However, to our knowledge, the concentrations of HSP70 and anti-HSP70 antibodies in nasal secretions (NS) have not been evaluated in patients with CRS. In the present study, we determined the NS levels of HSP70 and anti-HSP70 antibodies in subjects with CRS and in healthy controls, evaluated their associations with CRS clinical severity, and their correlation with NS IL-4, IL-5, and interferon (IFN) λ.