Mechanically ventilated children with 2009 pandemic influenza A/H1N1: results from the National Pediatric Intensive Care Registry in Japan.

OBJECTIVE: To outline the characteristics, clinical course, and outcome of pediatric patients requiring mechanical ventilation with influenza A/H1N1 infection in Japan. DESIGN: Prospective case registry analysis. SETTING: Eleven pediatric or general intensive care units in Japan. PATIENTS: Consecutive patients infected with A/H1N1, aged from 1 month to 16 yrs old admitted to the intensive care unit for mechanical ventilation between July 2009 and March 2010. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Eighty-one children, aged 6.3 [0.8-13.6] (median [interquartile range]) years, were enrolled. Seventy-four (91%) had mechanical ventilation with tracheal intubation. Median duration of mechanical ventilation was 4 days (range 0.04-87) and 18 patients (23%) required mechanical ventilation >7 days. Two patients (2%) required extracorporeal membrane oxygenation. The in-hospital mortality was 1%. Forty-one patients (50%) had at least one underlying chronic condition, including 31 with asthma. Associated clinical symptoms and diagnosis were as follows: acute respiratory distress syndrome (9%), asthma or bronchitis (37%), pneumonia (68%) with 8 (14%) having bacterial pneumonia, neurological symptoms (32%), myocarditis (2%), and rhabdomyolysis (1%). Therapeutic interventions include inotropic support (21%), methylprednisolone therapy (33%), and antimicrobial therapy (88%). Multivariate analysis revealed that inotropic support was the only statistically significant factor associated with mechanical ventilation for more than a week (odds ratio 5.5, 95% confidence interval 1.5-20.5, p = .005). CONCLUSIONS: The clinical presentations of pediatric patients requiring mechanical ventilation for A/H1N1 in Japan were diverse. In-hospital mortality of this population was remarkably low. Rapid access to medical facilities in combination with early administration of antiviral agents may have contributed to the low mortality in this population.

Basophil activation marker CD203c is useful in the diagnosis of hen's egg and cow's milk allergies in children.

BACKGROUND: The diagnosis of food allergy (FA) is usually based on oral food challenge tests (OFC). However, OFCs occasionally induce severe adverse reactions. CD203c expression on basophils is emerging as a potential diagnostic index. We evaluated whether CD203c expression on basophils would be a useful marker of OFC-associated symptoms in hen's egg and cow's milk allergies in children. METHODS: Seventy-one patients who had been diagnosed with FA based on OFCs or a convincing history of FA symptoms in the Department of Pediatrics, Sagamihara National Hospital, were recruited. CD203c expression was assessed after stimulation with antigens (egg white, ovomucoid, milk or casein) using allergenicity kits. The CD203c stimulation index (SI = the allergen-induced CD203c expression level divided by the baseline expression level) and the threshold of CD203c expression (the minimum concentration of antigen to induce CD203c SI >or=2) were analyzed in association with tolerance acquisition. RESULTS: For the CD203c SI, the areas under the receiver-operating characteristic curve were 0.72 for egg white, 0.82 for ovomucoid, 0.84 for milk and 0.67 for casein. The positive predictive value for the threshold of CD203c expression was 94.7% for egg white, 100% for ovomucoid, 85.7% for milk and 75.0% for casein. CONCLUSIONS: Assessment of food antigen-induced CD203c expression on basophils is useful to determine if children will outgrow FA as well as in decision making regarding whether or not to perform OFCs.