THE IMPORTANCE OF URINARY ANTIBODIES IN THE DIAGNOSIS OF LEPTOSPIROSIS

Abstract

Low-titer antibodies have been found with great regularity in the urine of patients suffering from Weil's disease (Leptospirosis icterohaemorrhagiae). These antibodies were present in a majority of patients by the 10th day of illness and were almost invariably found in the second and third weeks of disease. Removal of antibodies from the urine by absorption on heat-killed non-virulent L. icterohaemorrhagiae significantly increased the number of successful isolations by guinea pig inoculation. Non-specific adsorption of the urinary protein by kaolin was also effective in reducing the antibody titer and this is suggested as a more generally applicable technique.The urinary antibodies were often detected in the absence of a clinically demonstrable proteinuria. This was found to be due to the relatively larger proportion of globulin excreted by the kidney. In the absence of any gross proteinuria, antibodies to the infecting leptospiral serotype were dominant in the urine, both in human infections with L. icterohaemorrhagiae and in canine infections with L. canicola. Thus the remarkable specificity of the urinary antibodies was very helpful in determining the type of infecting leptospira when ordinary serological tests gave confusing cross agglutinations. Speculation on the phenomenon led to the suggestion that it might be due rather to a qualitative difference between specific and non-specific antibodies than to local production of specific antibodies in the kidney itself.