Two cases of primary ciliary dyskinesia with different responses to macrolide treatment.

We herein report two cases of primary ciliary dyskinesia (PCD) with different responses to macrolides. Case 1: a 17-year-old Japanese man with Pseudomonas aeruginosa infection and combined defect of both inner and outer dynein arms in the cilia was unsuccessfully treated with long-term macrolides (clarithromycin, erythromycin, and azithromycin). Case 2: a 70-year-old Japanese man with deficiency of only the inner dynein arm was successfully treated with clarithromycin. Though the reasons for the different responses to macrolides are unclear, differences of ultrastructural abnormalities of the cilia might be one of the predictive factors in PCD just as in Pseudomonas aeruginosa infection.