a significant trendp < 0.001
With regards to age, there was a significant trend of higher total IgG levels in older children within the patient cohort (median of 4.90 g/L for 0–3-year-olds vs 7.15 g/L for 4–10-year-olds, p < 0.001 and vs 7.90 g/L for 11–18-year-olds, p < 0.0001, Figure 2A ).