“His water looks like Coca-Cola.” The case of Jesus S. Jesus presented a classic case of acute nephritic syndrome secondary to infection. The history of a “cold and sore throat” earlier was...

“His water looks like Coca-Cola.” The case of Jesus S.

Jesus presented a classic case of acute nephritic syndrome secondary to infection. The history of a “cold and sore throat” earlier was significant—although culture proof is lacking that his earlier sore throat was caused by β-streptococcus, the high concentration in his blood of antistreptococcal antibody made it virtually certain. Keys to the diagnosis were hypertension, puffy face, oliguria, hematuria, red cell casts, and proteinuria, each of which was a striking abnormality in a previously healthy child. The puffy face suggested fluid retention. Oliguria also suggested renal disease with fluid retention. Red cell casts were a sign of bleeding high in the urinary tract, not from the collecting system. Proteinuria strongly suggests glomerular leaking of protein into the GF. The dark brown color of Jesus’s urine came from altered free hemoglobin liberated from degenerated RBCs in his urine. Bleeding from lower sites, such as the bladder, would have produced fresher RBCs and red hematuria. The only other cause of dark urine that might have been considered would have been hemoglobinuria from hemolytic anemia. Jesus’s hematocrit was normal, however, and he was not jaundiced (the liver metabolizes hemoglobin into bilirubin). The final clue was hypertension. GN restricted renal blood flow and invoked the renin- angiotensinaldosterone cascade, which increased blood pressure. Pediatric hypertension is rare and most cases are caused by some form of renal disease.