Investigation of disease severity predictors in patents with croup

Introduction and Objective:The aim of this study is investigating role of cytokines (TNF, IL-6, IL-10, PAF), cortisol, and IgE in croup pathogenesis and factors that determine clinical severity of the croup disease. Materials and Methods: Patients diagnosed with croup at Pediatric Emergency Clinic between October 2013-October 2014 were included in the study. Also 30 healthy children were included as a control group. Patients demographic characteristics, presenting symptoms, clinical findings, recurrent croup history, and patients and families atopy history were recorded. All patients were grouped according to the Westley croup scoring system as a mild and moderate/severe group. Blood samples were taken for complete blood count and cytokine levels from control group and the patients before the treatment. Respiratory pathogens were studied with PCR from nasopharyngeal swabs Results: A total of 69 croup patients were admitted to the study; 34 (49%) patients were were classified as mild, 31 (45%) were moderate and 4 (6%) were severe croup. From 52 croup patients (75.4%) were boys and the median age was 32.0 (IQR: 16.5 to 52.0) months, in the control group 17 (56.7%) were male and the median age was 27.5 (IQR: 15.5 to 72.0) months (p = 0.064; p = 0.486). There wasn't any significant difference between mild and moderate/severe group in terms of age (p = 0.107). In mild group 18 (52.9%) of patients and in the moderate/severe group 15 (42.8%) of patients, totally 33 (47.8%) patients was diagnosed with recurrent croup (p = 0.405). Totally 32% of patients was admitted in the clinic between 12:00 am 06:00 pm. Viral agents were isolated in 45 of patients (%65.2). Rhinovirus PCR tests were positive in 22 of patients. When the patients and control groups compared, there was no statistically significant difference between levels of TNF-alpha, IL-6, IL-10, PAF and IgE. However, mean white blood cell count and plasma cortisol levels of all croup patients were found higher than the control group (p = 0.005; p = <0.01). There was no significant difference between the mild and moderate / severe group in terms of TNF-alpha, IL-6, PAF, IgE levels and the white blood cell count. In the moderate / severe group IL-10 and cortisol levels were higher than mild group (p=0.044, p=0.012). Cortisol levels between 12:00 am and 06:00 pm (p <0.05) were found significantly higher in moderate/severe group. PAF and TNF alpha levels were detected significantly higher in patients with a history of atopy (p = 0.032, p = 0.035). Conclusions: In this study, rhinovirus was the most common etiology for croup. Increased levels of IL-10 and cortisol (antiinflammatory cytokine / hormone) were found in the moderate / severe group. There was no significant increase in systemic inflammatory cytokine levels. In addition, high levels of PAF and TNF-alpha was found in patients with history of atopy. These findings showed that the local and systemic inflammatory response could play a role in the pathogenesis of croup. There is need for further studies on this subject.