TY - JOUR
T1 - Elevated IgG against the C region of streptococcal M protein and its immunodeterminants in patients with poststreptococcal acute glomerulonephritis
AU - Mori, K.
AU - Ito, Y.
AU - Kamikawaji, N.
AU - Sasazuki, T.
PY - 1997
Y1 - 1997
N2 - Objective: To determine the immune responses to the streptococcal M protein in patients with poststreptococcal acute glomerulonephritis (PSAGN). Study design: The gene coding type 12 M protein of group A streptococcus (M12), a known PSAGN-associated serotype, was cloned and expressed in Escherichia coli to investigate the specific immune responses to the M12 protein in patients with PSAGN. Recombinant M proteins for the variable N- terminal half (AB region) and conserved C-terminal half (G region) were produced separately. IgG titers against each region were measured by enzyme- linked immunosorbent assay in patients with PSAGN (n = 51), uncomplicated streptococcal pharyngitis (n = 26), chronic glomerulonephritis (n = 10), and in healthy control subjects (n = 51). Immunodominant domains within the M protein in PSAGN were further investigated by use of overlapping synthetic peptides. Results: IgG titers against the C region, but not the AB region, were markedly higher in the PSAGN group than in other groups (p < 0.01), and these titers were maintained for at least several months after antistreptolysin O or antistreptokinase levels had returned to normal. Studies with overlapping synthetic peptides demonstrated that increased IgG reactivity was observed against the C repeat blocks. Conclusion: IgG titers against the C region are significantly elevated in patients with PSAGN, and it may be a diagnostic marker for PSAGN.
AB - Objective: To determine the immune responses to the streptococcal M protein in patients with poststreptococcal acute glomerulonephritis (PSAGN). Study design: The gene coding type 12 M protein of group A streptococcus (M12), a known PSAGN-associated serotype, was cloned and expressed in Escherichia coli to investigate the specific immune responses to the M12 protein in patients with PSAGN. Recombinant M proteins for the variable N- terminal half (AB region) and conserved C-terminal half (G region) were produced separately. IgG titers against each region were measured by enzyme- linked immunosorbent assay in patients with PSAGN (n = 51), uncomplicated streptococcal pharyngitis (n = 26), chronic glomerulonephritis (n = 10), and in healthy control subjects (n = 51). Immunodominant domains within the M protein in PSAGN were further investigated by use of overlapping synthetic peptides. Results: IgG titers against the C region, but not the AB region, were markedly higher in the PSAGN group than in other groups (p < 0.01), and these titers were maintained for at least several months after antistreptolysin O or antistreptokinase levels had returned to normal. Studies with overlapping synthetic peptides demonstrated that increased IgG reactivity was observed against the C repeat blocks. Conclusion: IgG titers against the C region are significantly elevated in patients with PSAGN, and it may be a diagnostic marker for PSAGN.
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U2 - 10.1016/S0022-3476(97)70169-0
DO - 10.1016/S0022-3476(97)70169-0
M3 - Article
C2 - 9290619
AN - SCOPUS:0030611930
VL - 131
SP - 293
EP - 299
JO - Journal of Pediatrics
JF - Journal of Pediatrics
SN - 0022-3476
IS - 2
ER -