Myung Hyun Sohn

Airway hyperresponsiveness to mannitol and methacholine and exhaled nitric oxide in children with asthma

ABSTRACT Objective: Asthma is characterized by airway hyperresponsiveness (AHR), inflammation, and obstruction. AHR to stimuli that indirectly cause bronchial smooth muscle (BSM) contractions via release of endogenous mediators is thought to better reflect airway inflammation than AHR to stimuli that act directly on BSM. Fractional exhaled nitric oxide (FeNO) is a useful parameter for noninvasive clinical airway inflammation assessments. Accordingly, this study aimed to examine the relationships of mannitol and methacholine challenge test outcomes with FeNO and the influence of inhaled corticosteroid treatment in children with asthma. Methods: One hundred thirty-four asthmatic children (89 males; ages: 5–17 years, median: 9 years) underwent spirometry, FeNO measurement, serum total/specific IgE testing, and blood eosinophil count. All subjects were challenged with mannitol dry powder (MDP; AridolH, Pharmaxis, Australia) and methacholine at 7-day intervals. Data of steroid-treated and steroid-naïve children were compared. Results: Positive responses to MDP and methacholine challenge tests were observed in 74.6% and 67.2% of total subject group, respectively, and 72 children had positive response to both challenge tests. The median FeNO level, response-dose ratio (RDR) of PC20 methacholine, and RDR of PD15 MDP were significantly higher in the steroid-treated group than in the steroid-naïve group (p < 0.001, 0.226, and 0.004, respectively). FeNO levels associated significantly with PD15 MDP and RDR PD15 MDP in total subject populations (p = 0.016 and 0.003, respectively); however, a significant correlation between FeNO and RDR PD15 MDP was observed only in the steroid-naïve group. Conclusions: Compared with AHR to methacholine, AHR to MDP more closely reflected the level of FeNO in steroid-naïve asthmatic children.

Fatal pulmonary renal syndrome and treatment in adults with Schönlein–Henoch purpura: Comment

Dear Editor, We read with interest the article “Diffuse pulmonary hemorrhage as a fatal complication of Schönlein– Henoch purpura” by Usui et al. They reported a 69-year-old man with Schönlein–Henoch purpura (SHP) who developed diffuse pulmonary hemorrhage, leading to death despite methylprednisolone pulse therapy (MPT). Pulmonary hemorrhage of SHP is extremely rare, but if it occurs, it can lead to hypoxemia and death in elderly patients. This might be due to severe damage of the alveolocapillary membrane (capillaritis) by immunoglobulin (Ig)A-mediated immune deposits. MPT or immunosuppressive drugs have been shown to be effective in patients with SHP and pulmonary hemorrhage, but this patient did not respond to MPT. In contrast, plasmapheresis has been effectively used as a first-line therapy or rescue therapy for various vasculitides by removing circulating immune complex. Although plasmapheresis has not been used in pulmonary hemorrhage associated with SHP, Afessa et al. reported a 66-year-old man with diffuse alveolar hemorrhage and rapidly progressive glomerulonephritis associated with IgA nephropathy, who was successfully treated by plasmapheresis. Furthermore, Medcalf et al. suggested that immunosuppression conferred no benefit in elderly patients with pulmonary hemorrhage associated with IgA nephropathy. Plasmapheresis may also be one of the useful therapeutic methods in elderly patients with SHP and IgA-mediated immune alveolar hemorrhage because SHP: (i) has a common pathogenesis with IgA nephropathy; (ii) is associated with a significantly higher incidence of systemic symptoms than IgA nephropathy; and (iii) has a more severe clinical course in adults than in children. Therefore, early plasmapheresis in addition to MPT should be considered in SHP patients with massive pulmonary hemorrhage, because immune complexmediated pulmonary injury could lead to a fatal outcome within a relatively short time.