infection-related glomerulonephritis (IRGN) following a streptococcal infection. Supportive evidence includes preceding symptoms of an upper respiratory tract infection suggestive of streptococci (rapid streptococcal antigen test is positive and antistreptolysin O antibodies are elevated), followed by the nephritic syndrome in 1 week, and low C3 levels with normal C4 levels (suggesting an alternative pathway of complement activation, which is typical of IRGN).