Antibodies to Tamm-Horsfall protein associated with renal damage and urinary tract infections in adults.

Forty-seven adults with urinary tract infection (UTI), 9 with recent acute pyelonephritis and 38 with previous renal infection, were investigated for the presence of autoantibodies to Tamm-Horsfall protein (THP). All patients except 6 had or had had vesicoureteric reflux (VUR). In patients with recent acute pyelonephritis, only IgA antibodies were significantly elevated. Among the patients with previous UTI, more than 6 months before the time of testing, a graded response was found for IgG and IgM specific antibodies, with the lowest value in those with renal damage and elevated serum creatinine and the highest in those with a normal X-ray. A negative correlation was found between IgG antibodies to THP and elevated serum creatinine (r = -0.76, P less than 0.02). No significant correlation was found between VUR itself and antibodies to THP. A low IgG antibody level to THP in patients with a history of previous UTI seems to be a useful indicator of renal scarring. Possible immunologic mechanisms behind the low antibody level and the renal damage are discussed.