Cu G A, Mezzano S, Bannan J D, Zabriskie J B
Laboratory of Clinical Microbiology and Immunology, Rockefeller University, Beth Israel Medical Center, New York City, New York 10021, USA.
Kidney Int. 1998 Sep;54(3):819-26. doi: 10.1046/j.1523-1755.1998.00052.x.
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).
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.
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.
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.
我们之前已经证明，从急性链球菌感染后肾小球肾炎（APSGN）患者的皮肤或咽喉分离出的A组链球菌肾炎菌株可优先分泌链球菌蛋白酶或链球菌致热外毒素B（SPEB）。
为了进一步探究SPEB在APSGN中可能发挥的作用，我们开展了酶联免疫吸附测定（ELISA）研究，以检测APSGN患者、急性风湿热（ARF）患者、猩红热（SF）患者及正常儿童血清中的抗SPEB抗体。采用ELISA法测定APSGN患者急性期和恢复期血清中的抗SPEB滴度，以确定对APSGN的免疫情况。我们还对APSGN和非APSGN肾活检组织进行了免疫荧光研究，以探寻SPEB的存在及定位情况。
我们的数据显示，APSGN患者血清中存在抗SPEB抗体，且抗体滴度显著高于ARF、SF患者血清及正常血清。抗SPEB滴度往往在急性期升高，随时间下降，但1年后未降至基线水平。用兔抗SPEB抗体检测肾活检组织时，18例APSGN病例中有12例（67%）呈阳性，而25例非APSGN病例中只有4例（16%）呈阳性。
总之，我们能够证明在APSGN患者的人血清和肾活检组织中对SPEB具有独特的反应性，提示这种毒素在急性链球菌感染后肾小球肾炎的发病机制中起重要作用。
