[Successful macrolide therapy for recurrent pneumococcal pneumonia in a man with X-linked agammaglobulinemia].

A 55-year-old man, who had not suffered from any severe or recurrent bacterial infections previously, visited our hospital because of symptoms of fever, cough, sputum, and otorrhea. Chest X-ray and computed tomography demonstrated infiltrates in the right middle lobe and lingula. Pneumococcal pneumonia and tympanitis were diagnosed based on the isolation of Streptococcus pneumoniae from sputum and otorrhea specimens. A peripheral blood analysis showed a remarkable reduction in serum IgG level and the flow cytometric analysis of his peripheral monocytes indicated a significant reduction in Bruton's tyrosine kinase expression. Thus, we diagnosed his illness as X-linked agammaglobulinemia (XLA). Although immunoglobulin replacement therapy was performed, he developed recurrent lower respiratory tract infections. Low-dose long-term erythromycin treatment resulted in decreased frequency of respiratory tract infections. These results suggest that erythromycin therapy may be useful for the control of lower respiratory tract infections in patients with XLA. Even in adults with recurrent bacterial respiratory tract infections, the presence of XLA as an underlying disease should be considered. The effect of macrolide therapy for chronic lower respiratory tract infection associated with humoral immunodeficiency has rarely been reported. This case study may provide valuable information about macrolide therapy for such an infection in patients with humoral immunodeficiency.