The role of toll-like receptor (TLR)-2 and TLR-4 in pediatric patients with pneumonia (preprint)

Background: Since rapid and accurate diagnosis of pneumonia and the determination of its severity are challenging, especially in childhood, we aimed to evaluate the role of toll-like receptors (TLRs) in pneumonia, the investigation of which has been limited in animal and adult studies. Methods: : TLR-2, TLR-4, interleukin (IL)-1β, IL-4, IL-6, IL-10, interferon (IFN)-α, and tumor necrosis factor (TNF)-α levels were evaluated in the serum samples of 67 pediatric patients with community-acquired pneumonia (CAP) (43 inpatients and 24 outpatients) and 22 healthy pediatric controls. Saliva samples from 30 pediatric patients with CAP (19 inpatients and 11 outpatients) and 20 healthy pediatric controls were also investigated. Results: : In saliva samples obtained at the time of diagnosis, the threshold levels were 1.16 2 for TLR-2 and 1.28 2 for TLR-4 to differentiate patients with and without pneumonia, respectively. The sensitivity of salivary TLR-2 and TLR-4 assessment was 0.80 and 0.86, respectively. In the serum samples, TLR-2, TLR-4, IL-1β, IL-4, IL-6, IL-10, IFN-α, and TNF-α levels were significantly decreased in patients with novel coronavirus disease 2019 (COVID-19) compared with other viruses (p<0.05 for all). In the serum samples of patients with pneumonia due to COVID-19, IL-6 and IFN-α levels were significantly lower than in the control group (p<0.05 for all). Conclusion: Salivary analysis of TLR-2 and TLR-4 is beneficial in the diagnosis of severe pneumonia, especially in childhood.

Methylprednisolone use in children with severe pneumonia caused by SARS-CoV-2 (preprint)

Objective: This study aimed to evaluate the effectiveness and optimal use of corticosteroids in children with severe coronavirus disease 2019 (COVID-19) pneumonia. Methods: We conducted a retrospective study and included patients (aged<18 years) with severe COVID-19 pneumonia and/or acute respiratory distress syndrome (ARDS) who received standard doses (2–4 mg/kg/day) and high doses (>250 mg/day) of methylprednisolone (MPZ). We adjusted for patients on steroid treatments with a propensity score and patient survival. Results: Fifty-nine patients were included: 61% were male, the median age was 8 (interquartile range [IQR], 2–15) years. The overall survival was 84.4% in patients treated with standard-dose MPZ (n = 45, 76.3%) and 92.2% in patients treated with high-dose MPZ (n = 14, 23.7%; p = 0.67). The demographic, clinical, and laboratory data didn’t differ significantly after propensity score matching, apart from bradycardia, which was a prominent feature of the high-dose group. The clinical and radiological response rates on Day 7 were higher and the need for invasive mechanical ventilation (IMV) was lower in the high-dose group. Conclusion: Pulse MPZ treatment seems to result in better clinical and radiological responses, with less need for IMV, although the mortality rate doesn’t differ between standard and high-dose regimens of MPZ.

Oxidant and Antioxidant Balance in Patients with COVID-19 (preprint)

Background: A crucial balance exists between oxidant and antioxidant mechanisms in the functional immune system. We aimed to evaluate the contributions of balance between these systems to coronavirus disease 2019 (COVID-19), a devastating pandemic caused by viral infection. Method: We analyzed serum oxidant and antioxidant stress parameters according to the clinical and demographic characteristics of children and adults with COVID-19 and compared them against the values of healthy controls. Serum native thiol (NT), total thiol (TT), disulfide, total antioxidant status, total oxidant status, and ischemia-modified albumin levels were evaluated and compared between groups. Results: A total of 79 children and 74 adults were evaluated in the present study, including 46 children and 40 adults with COVID-19, 33 healthy children, and 34 healthy adults. TT, NT, and disulfide levels were significantly lower in the adult COVID-19 group than in all other groups (p = 0.001, p = 0.001, and p = 0.005, respectively). Additionally, TT and NT levels were significantly lower in both pediatric and adult COVID-19 cases with severe disease course than mild/moderate course. TT and NT levels were identified as predictors for the diagnosis of the adult COVID-19 cases and as independent predictors for disease severity in both children and adults with COVID-19. Conclusion: Parameters that reveal the oxidant and antioxidant capacity, including TT and NT, appear to be good candidates for the accurate prediction of the clinical course among patients with COVID-19.