In this individual patient, a number of factors associated with recurrent asthmatic exacerbation and sinusitis were considered. Coronal paranasal CT revealed normal anatomical structures. Quantitative sweat chloride test was 25 mmol/L (normal= <40 mmol/L), while serum immunoglobulin-A: 99 mg/dl (96-495), IgM: 92 mg/dL (70-322), IgG: 987 mg/dL (913-1884), IgE: 3.21 mg/dl and IgG subgroups were within normal range. Total serum IgG, A, and M levels were measured by nephelometry (BN ProSpec systems, Dade Behring Marburg GmbH, Marburg, Germany). Her lymphocyte subsets detected by flow-cytometry were within normal range for her age. Eventually thorax HRCT was taken, revealing an upper right lobe anterior segment minimal bronchiectatic pattern. PPD test was 5x5 mm.
* What can be the cause of bronchiectasis? *