The Role of Complement, Immunoglobulin and Bacterial Antigen in Coagulase-negative Staphylococcal Shunt Nephritis

We describe three patients with arrested hydrocephalus in whom glomerulonephritis developed secondary to Staphylococcus epidermidis bacteremia from an infected ventriculoatrial shunt. Investigation of the immune-mediated renal disease associated with this chronic infection showed that (1) complement depletion during the acute phase of bacteremia and nephritis was predominantly via the classic pathway; (2) rheumatoid factor was associated with bacteremia, fever, proteinuria and low complement levels; (3) early complement components (C1q, C4, C3), immunoglobulin (predominantly immunoglobulin M [IgM], Staph. epidermidis antigen(s) and electron denxe subendothelial deposits were localized within the renal glomerulus; (4) C1q, and IgM derived from patient serums, were the most prominent in vitro immunoreactants to Staph. epidermidis cell walls; and (5) the causative organisms, Staph. epidermidis, shared common antigens with Staph. aureus, and antibody from patient serums cross reacted with extracts from both of these organisms.