Ciliary ultrastructural abnormalities in Mycoplasma pneumoniae pneumonia in 22 pediatric patients.

Mycoplasma pneumoniae pneumonia (MPP) is characterized by ciliary ultrastructural abnormalities that cause abnormal mucociliary function leading to refractory or persistent pneumonia. Herein, we analyzed ciliary ultrastructural defects in 22 children with MPP and determined the association of these defects with prognosis. Ciliary ultrastructural abnormalities occurred in all patients. Ciliated cells with loss of cilia occurred in 15. Cytoplasmic blebbing occurred in eight. Ambiguity of the "9 + 2" microtubule array occurred in six. Transposition or disarray of the peripheral microtubules occurred in five. Compound cilia occurred in three. Central complex defects occurred in three. Squamous metaplasia occurred in two. Compound cilia with multiple axonemes within a single outer sheath occurred in one. Multiple abnormalities occurred in 14. The recovery time in patients with multiple abnormalities was longer than that in patients with single abnormality. Patients with central complex defects required more than 1 month to recover. In conclusion, ciliated cells with loss of cilia, cytoplasmic blebbing, and ambiguity of the "9 + 2" microtubule array were the most commonly encountered abnormal findings in MPP. Multiple abnormalities, especially those associated with central complex defects, may indicate an unfavorable prognosis.