The glucocorticoid dexamethasone alleviates allergic inflammation through a mitogen-activated protein kinase phosphatase-1-dependent mechanism in mice

Glucocorticoids are widely used in the treatment of allergic and inflammatory diseases. Glucocorticoids have a widespread action on gene expression resulting in their pharmacological actions and also an array of adverse effects which limit their clinical use. It remains, however, to be studied which target gene effects are essential for the anti-allergic activity of glucocorticoids. Mitogen-activated protein kinase phosphatase-1 (MKP-1) inhibits proinflammatory signalling by suppressing the activity of mitogen activated protein kinase (MAP kinase) pathways. MKP-1 is one of the anti-inflammatory genes whose expression is enhanced by glucocorticoids. In the present study, we aimed to investigate the role of MKP-1 in the therapeutic effects of the glucocorticoid dexamethasone in acute allergic reaction. The effects of dexamethasone were studied in wild-type and MKP-1 deficient mice. The mice were first sensitized to ovalbumin, and the allergic reaction was then induced by a subcutaneous ovalbumin injection in the hind paw. Inflammatory edema was quantified with plethysmometer and expression of inflammatory factors was measured by quantitative reverse transcription polymerase chain reaction (RT-PCR). Dexamethasone reduced the ovalbumin-induced paw edema at 1.5, 3 and 6 h time points in wild-type mice by 70%, 95% and 89%, respectively. The effect was largely abolished in MKP-1 deficient mice. Furthermore, dexamethasone significantly attenuated the expression of ovalbumin-induced inflammatory factors cyclooxygenase-2 (COX-2); inducible nitric oxide synthase (iNOS); interleukins (IL) 1β, 6 and 13; C-C motif chemokine 11 (CCL-11); tumour necrosis factor (TNF) and thymic stromal lymphopoietin (TSLP) in wild-type mice by more than 40%. In contrast, in MKP-1 deficient mice dexamethasone had no effect or even enhanced the expression of these inflammatory factors. The results suggest that dexamethasone alleviates allergic inflammation through an MKP-1-dependent mechanism. The results also demonstrate MKP-1 as an important conveyor of the favourable glucocorticoid effects in ovalbumin-induced type I allergic reaction. Together with previous findings, the present study supports the concept of MKP-1 enhancing compounds as potential novel anti-inflammatory and anti-allergic drugs.

Comorbidities of chronic rhinosinusitis in children and adults

BACKGROUND

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease of the nose and paranasal sinuses lasting ≥12 weeks. CRS may exist with (CRSwNP) or without (CRSsNP) nasal polyps. The aim was to evaluate conditions associated with CRS in a randomized hospital cohort. We hypothesized that comorbidities and surgical procedures differ between pediatric and adult patients.

METHODS

This study consisted of hospital registry data of a random sample of rhinosinusitis patients (age range 0-89 years) with the diagnosis of J32 or J33, correspondingly, registered during outpatient visits from 2005 to 2019 (n = 1461). The covariates of interest were collected from electronic health records based on ICD-10 codes and keyword searches.

RESULTS

Among pediatric patients (n = 104), the relative proportions of CRSsNP and CRSwNP were 86% and 14% respectively. The relative proportions of adult patients (n = 1357) with CRSsNP and CRSwNP were 60% and 40%, respectively. The following comorbidities significantly differed (p < 0.05) between pediatric and adult populations: allergy, chronic otitis media, and tonsillar diseases. In total, 41 % of the children and 46% of the adults underwent baseline endoscopic sinus surgery (ESS). Additional surgeries of the ear, nose and pharynx were significantly more common among children compared with adults. Risk of revision after baseline ESS was associated (p < 0.05) with allergy, asthma, eosinophilia, CRSwNP, immunodeficiency or its suspicion, non-steroidal anti-inflammatory drug exacerbated respiratory disease, and number of any diseases ≥2.

CONCLUSIONS

Our study showed that comorbidities differ between pediatric and adult rhinosinusitis patients, as allergy, asthma and allergy, chronic otitis media, mental health disorders, and tonsils disease were significantly more prevalent among pediatric patients. Children and adults were equally treated with ESS. Notably, children underwent additional surgery on adenoids and tonsils more frequently. The effectiveness of ESS in multimorbid adults should be assessed at an individual level.