Ce. Marx et al., FECAL LEUKOCYTES IN STOOL SPECIMENS SUBMITTED FOR CLOSTRIDIUM-DIFFICILE TOXIN ASSAY, Diagnostic microbiology and infectious disease, 16(4), 1993, pp. 313-315
To determine their diagnostic utility, fecal leukocytes were sought by
methylene blue stain in 502 consecutive stool specimens submitted for
Clostridium difficile toxin assay. In addition, the stability of feca
l leukocytes was assessed by daily examination of 23 stool specimens s
tored at 4-degrees-C and room temperature. The sensitivity, specificit
y, and positive and negative predictive values of fecal leukocytes in
predicting C. difficile toxin assay results were 28%, 92%, 27%, and 93
%, respectively. At 4-degrees-C, fecal leukocytes retained morphology
for a minimum of 3 days. Leukocytes survived as long in stool specimen
s containing either C. difficile toxin or an enteric pathogen as they
did in stool specimens with neither finding. We conclude that testing
stool specimens for fecal leukocytes is not useful for predicting the
presence of C. difficile toxin, because 72% of stool specimens positiv
e for C. difficile toxin are negative for fecal leukocytes despite the
ir stability.