Staining of urinary leucocytes as an aid to the diagnosis of inflammation in the urinary tract.

Five hundred specimens of urine have been examined for pyuria and bacteriuria, the leucocytes being stained by the Sternheimer-Malbin method. Most urines contained either less than 1 or more than 10 leucocytes per cmm; a few specimens contained 1 to 10 cells per cmm, whatever their viable bacterial count. The presence of leucocytes in urine was usually related to the bacterial count, pyuria being commonest in urines showing ;significant bacteriuria'. However, urinary tract instrumentation caused pyuria in the absence of infection. Leucocytes with nuclei staining blue by the Sternheimer-Malbin technique were considered to be indicative of active inflammation, but the incidence of such cells appeared to be a reflection of the total leucocyte count of the specimen rather than of its viable bacterial count. In the majority of cases the diagnosis of infection can be made on the basis of the bacterial count and the degree of pyuria. The staining technique appears to have a limited use, restricted to the interpretation of cases in which the results of culture and conventional leucocyte counts are ambiguous.