A. Koyama et al., GLOMERULONEPHRITIS ASSOCIATED WITH MRSA INFECTION - A POSSIBLE ROLE OF BACTERIAL SUPERANTIGEN, Kidney international, 47(1), 1995, pp. 207-216
We report 10 cases of glomerulonephritis following methicillin-resista
nt Staphylococcus aureus (MRSA) infection. The clinical features of th
is syndrome were an abrupt or insidious onset of rapidly progressive g
lomerulonephritis (RPGN) with nephrotic syndrome and occasionally purp
ura, following MRSA infection. The renal histologic findings showed a
variety of types of proliferative glomerulonephritis with varying degr
ees of crescent formation; immunofluorescence revealed of glomerular d
eposition of IgA, IgG, and C3. Laboratory findings showed polyclonal i
ncreases of serum IgA and IgG, with high levels of circulating immune
complexes (ICs). Increased numbers of DR(+)CD4(+), and DR(+)CD8(+) T c
ells were observed in the peripheral circulation, with a high frequenc
y of T cell receptor (TCR) V-beta(+) cells. MRSA produced enterotoxins
C and A and toxic shock syndrome toxin (TSST)-1, all of which are kno
wn to act as superantigens. From the above observations, we speculate
that post-MRSA glomerulonephritis may be induced by superantigens caus
ing production of high levels of cytokines, and polyclonal activation
of IgG and IgA. The formation of ICs containing IgA and IgG in the cir
culation result in development of glomerulonephritis and vasculitis. A
ccordingly, microbial superantigens may play an important role in the
pathogenesis of this unique syndrome of nephritis and vasculitis.