Histoplasmosis. Association with circulating immune complexes, eosinophilia, and mesangiopathic glomerulonephritis

A patient with disseminated histoplasmosis, eosinophilia, and transient mesangiopathic glomerulonephritis stimulated a search for the presence of circulating immune complexes. Serum samples obtained on the fifth and 11th hospital days were strongly positive for ciculating immune complexes by both the Raji cell radioassay and the C1q solid phase assay. During the course of complete clinical recovery without therapy, both assays were weakly positive for circulating immune complexes on day 33. On day 56 they were negative. Using this case as a prototype, possible mechanisms for the renal immunopathology and the eosinophilic response are discussed with reference to the immunological perturbations thay may be observed in systemic mycotic infection.