Comparison of reliability of tests to distinguish upper from lower urinary tract infection

The results of scintiphotography with gallium-67 (67Ga), renography with technetium-99m diethylene triamine penta-acetic acid, immunofluorescence of antibody coated bacteria, and determination of renal beta 2 microglobulin excretion were compared in 19 patients with upper and 15 patients with lower urinary tract infection. All patients with acute pyelonephritis showed an appreciable unilateral or bilateral uptake of 67Ga and an increased excretion of beta 2 microglobulin, whereas immunofluorescence of antibody coated bacteria yielded positive results in only 10. In patients with lower urinary tract infections excretion of beta 2 microglobulin and uptake of 67Ga were always normal, whereas immunofluorescence of antibody coated bacteria was positive in three cases. Scintiphotography with 67Ga and determination of renal beta 2 microglobulin excretion are currently the most reliable non-invasive methods of detecting acute pyelonephritis.