A 65-year-old male with Grade 1, Stage IV follicular lymphoma (FL) and
chronic asymptomatic mild to moderate eosinophilic leukocytosis was
admitted with dyspnea, hypoxia, and hemoptysis. After diagnosis with FL
in 2005 and again upon relapse in 2010, he was treated with rituximab based
chemoimmunotherapy. Rituximab maintenance therapy was
administered after relapse. His absolute eosinophil count (AEC) ranged
from 900 to 2,300/μL from 2007 until admission, at which time it increased
to 6,174/μL despite a two-week prednisone taper. Stool studies and ELISA
for strongyloides antibodies were negative on two occasions, including
admission. A CT chest showed patchy ground glass opacities in the
bilateral upper lobes. Sputum microscopy showed Strongyloides
stercoralis (Image A and B). Rituximab, a monoclonal antibody targeting
CD20, likely exacerbated a Strongyloides hyperinfection and masked
ELISA-based diagnosis due to suppression of Strongyloides antibody
production. Despite treatment with ivermectin and empiric antibiotics,
patient unfortunately died due to acute respiratory failure.