Humoral immunodeficiencies are traditionally associated with prolonged and recurrent respiratory tract infections, including unusual pathogens. We describe a case of a 63-year-old man with a history of chronic obstructive pulmonary disease and recurrent pneumonias (including Pseudomonas) who presented with cough, dyspnea, and respiratory failure with computed tomography imaging showing bilateral consolidations and cavitary lesions. The bronchoalveolar lavage fungal culture grew Malbranchea species, whereas viral, bacterial, and mycobacterial cultures were negative. Because of multiple hospitalizations for pneumonia and the presence of this unusual pathogen, quantitative immunoglobulin levels were obtained, revealing an undetectable total immunoglobulin M (IgM) level (<5 mg/dL) with normal levels of IgG (1270 mg/dL) and IgA (108 mg/dL). Complete blood count with differential and lymphocyte subsets (ie, CD4, CD8) showed no deficiency in immune cell counts, and human immunodeficiency virus antibody/antigen testing was negative. The patient improved clinically after antifungal therapy with posaconazole, and he additionally received prophylactic inhaled tobramycin given his history of recurrent pulmonary infections and suspected selective IgM deficiency.
From the *Internal Medicine Residency, Scripps Mercy Hospital San Diego; and
†Department of Allergy and Immunology, Scripps Health, San Diego;
‡The Scripps Research Institute, La Jolla; and
§Department of Infectious Diseases, Scripps Mercy Hospital San Diego, San Diego, CA.
Correspondence to: Ronald F. Espinosa, DO, Internal Medicine Residency, Scripps Mercy Hospital San Diego, 4077 Fifth Ave MER35, San Diego CA 92103. E-mail: firstname.lastname@example.org.
No funding was received from National Institutes of Health; Wellcome Trust, Howard Hughes Medical Institute or others.
The authors have no funding or conflicts of interest to disclose.