IgG, IgA, and C3 deposition has been demonstrated along the alveolar basement membrane of infected guinea pigs in a similar pattern to that seen in Goodpasture's syndrome.[16] In view of presence of antibodies and complement and the paucity of spirochetes in lung tissue, authors have postulated that the infection might have precipitated an immune process that led to pulmonary hemorrhage through damage to the alveolar septa. This evidence concerns the gene C3 and infection.