[Detection of lactoferrin in feces for differential diagnosis in diarrhea]

Routine stool culture is used to evaluate patients with diarrheal illness. However, the results are often delayed, and the tests are very expensive. Therefore a rapid, simple method for screening would be a helpful adjunct in a diagnostic algorithm. Fecal leukocytes are found in diarrhea patients with diffuse colonic inflammation but missing in non-inflammatory cases, and are most commonly identified in infectious diarrheas of bacterial origin. It supports the use of immediate empiric therapy in very young, elderly and immunocompromised individuals. When negative, it may eliminate the need for stool culture in some cases of diarrhea. Recently, a new latex bead assay has been developed for the detection of lactoferrin, an iron binding glycoprotein found in polymorphonuclear leukocytes.

Evaluate the value of fecal leukocytes and lactoferrin in the workup of patients with diarrhea.

Fecal samples of 50 consecutive adult patients with acute or chronic diarrhea were tested for fecal leukocytes and lactoferrin. The results were compared with findings from fecal cultures, tests for parasite, Clostridium difficile A toxin latex test, data of the gastrointestinal examination and clinical evaluation. The authors defined two groups of the cases: the inflammatory and non-inflammatory diarrheas.

The sensitivity, specificity, positive and negative predictive value of microscopic leukocyte count and the lactoferrin test were 42 and 63%, 87 and 87%, 67 and 75%, 71 and 79% respectively.

In agreement with the literature the results of the present study indicate that fecal lactoferrin appears more sensitive than fecal leukocyte smear, and accurately rules out inflammatory diarrhea.