G A Cu1, S Mezzano, J D Bannan, J B Zabriskie. 1. Laboratory of Clinical Microbiology and Immunology, Rockefeller University, Beth Israel Medical Center, New York City, New York 10021, USA.
Abstract
BACKGROUND: We have previously demonstrated the preferential secretion of streptococcal proteinase or streptococcal pyrogenic exotoxin B (SPEB) by nephritic strains of Group A streptococci isolated from the skin or throat of patients with acute poststreptococcal glomerulonephritis (APSGN). METHODS: To further explore the possible role of SPEB in APSGN, we performed ELISA studies to detect anti-SPEB antibodies in the sera of patients with APSGN, acute rheumatic fever (ARF), scarlet fever (SF) and normal children. Using ELISA, anti-SPEB titers on acute and convalescent APSGN sera were measured to determine immunity to APSGN. We also performed immunofluorescence studies on APSGN and non-APSGN kidney biopsies to probe for the presence and localization of SPEB. RESULTS: Our data show that anti-SPEB antibodies are present in APSGN sera and antibody titers are significantly higher than in ARF, SF and normal sera. Anti-SPEB titers tend to rise acutely and decrease with time but do not reach baseline after one year. When kidney biopsies were probed with rabbit anti-SPEB antibody, 12 of 18 (67%) of the APSGN cases were positive while only 4 of 25 (16%) of the non-APSGN cases were positive. CONCLUSIONS: In summary, we were able to demonstrate unique reactivity to SPEB in human sera and kidney biopsies of APSGN suggesting a significant role of this toxin in the pathogenesis of acute post-streptococcal glomerulonephritis.
BACKGROUND: We have previously demonstrated the preferential secretion of streptococcal proteinase or streptococcal pyrogenic exotoxin B (SPEB) by nephritic strains of Group A streptococci isolated from the skin or throat of patients with acute poststreptococcal glomerulonephritis (APSGN). METHODS: To further explore the possible role of SPEB in APSGN, we performed ELISA studies to detect anti-SPEB antibodies in the sera of patients with APSGN, acute rheumatic fever (ARF), scarlet fever (SF) and normal children. Using ELISA, anti-SPEB titers on acute and convalescent APSGN sera were measured to determine immunity to APSGN. We also performed immunofluorescence studies on APSGN and non-APSGN kidney biopsies to probe for the presence and localization of SPEB. RESULTS: Our data show that anti-SPEB antibodies are present in APSGN sera and antibody titers are significantly higher than in ARF, SF and normal sera. Anti-SPEB titers tend to rise acutely and decrease with time but do not reach baseline after one year. When kidney biopsies were probed with rabbit anti-SPEB antibody, 12 of 18 (67%) of the APSGN cases were positive while only 4 of 25 (16%) of the non-APSGN cases were positive. CONCLUSIONS: In summary, we were able to demonstrate unique reactivity to SPEB in human sera and kidney biopsies of APSGN suggesting a significant role of this toxin in the pathogenesis of acute post-streptococcal glomerulonephritis.
Authors: T Matthew Eison; Bettina H Ault; Deborah P Jones; Russell W Chesney; Robert J Wyatt Journal: Pediatr Nephrol Date: 2010-07-23 Impact factor: 3.714