Acute glomerulonephritis

Acute glomerulonephritis (AGN) is a representative disease of acute nephrit ic syndrome characterized by the sudden appearance of edema, hematuria, pro teinuria, and hypertension. The prototype of AGN is acute poststreptococcal glomerulonephritis (APSGN), "Nephritogenic streptococci" are defined as or ganisms that are cultured from a patient who develops AGN, Although only a limited number of M-types of streptococci have been recognized as "nephrito genic streptococci", all M-types of streptococci may have nephritogenic pot ential because the genes for major putative nephritogenic antigens such as SPEB and NAPlr are found to be present in all group A streptococci thus far examined. Pathogenic mechanisms for APSGN involving both humoral and cell- mediated immunity have been recently proposed. The role of humoral immunity is presumed to be mediated by the in situ formation of nephritogenic strep tococcal antigen-antibody complexes and circulating immune complexes. While in the cellular immune component a role for delayed-type hypersensitivity has been suggested to contribute to the pathogenesis of APSGN.