Staphylococcus infection-associated glomerulonephritis

Staphylococcus infection-associated glomerulonephritis (SAGN) is a well-recognized disease entity, and over the last decade has been seen with increasing frequency in western countries. The associated Staphylococcal infections tend to be quite aggressive and invasive and the affected population is primarily elderly patients with one or more preexisting comorbidities, which can make this a difficult disease to treat. Furthermore, the diagnosis can be challenging due to subtle clinical presentation of the underlying infection, varied histopathological features, and occasional positive ANCA serology. Importantly, the glomerulonephritis either coincides with the onset of infection or occurs during the course of the infection, which is in contrast to post-streptococcal glomerulonephritis which typically occurs after a distinct latent period following complete resolution of the infection. This chapter succinctly describes the wide spectrum of histologic features, immunofluorescence staining patterns and ultrastructural features in SAGN along with diagnostic pitfalls. The last section gives a brief overview of the microbiologic and immunologic aspects of Staphylococcus.