Diarrheas can be divided into two basic categories Noninflammatory I nflammatory
Why is it important to determine if a patient has Inflammatory diarrhea?
Diarrhea, Nausea or Vomiting Patient history plus Fecal Lactoferrin and O&P Noninflammatory Vibrio E.coli C.perfringens S.aureus B.cereus Giardia, Cryptosporidium Rotavirus, Norwalk virus Inflammatory Shigella Salmonella C.jejuni E.coli C.difficile E.histolytica Parasites Giardia Cryptosporidium Cyclospora Microsporidia Dientamoeba fragilis Blastocystis hominis Isospora Approach to diagnosis and Management of Infectious Diarrhea (R.L Guerrant, Div Geographic Medicine U. Virginia, Charlottesville, VA
Limitations of staining for fecal leukocytes Fresh specimen should be collected in cup Performed within hours of collection Difficulty in interpretation of results
Lactoferrin as a marker of fecal leukocytes Lactoferrin is a glycoprotein released from inflammatory cells Highly stable Can be detected immunologically Direct correlation with presence of leukocytes
How does the LEUKO-TEST ® work? Latex agglutination format Beads are coated with antibodies against lactoferrin, a protein released from leukocytes Beads agglutinate in the presence of elevated levels of lactoferrin in the specimen
How does the LEUKO-TEST ® compare with microscopy? In an evaluation of over 1700 samples, the following results were observed: Relative sensitivity 84% Relative specificity 86% Predictive negative value 95% Correlation 85%
Comparison of Fecal Lactoferrin, Fecal Leukocytes and Occult Blood with presence of Enteric Pathogen (N=92) Sensitivity Specificity PPV NPV Lactoferrin vs Pathogen 94% 55% 58% 94% Leukocytes vs Pathogen Occult Blood vs Pathogen 69% 89% 81% 82% 37% 76% 52% 64% Scerpella et al., J.Travel Medicine 1:68-71, 1994
What are the advantages of the LEUKO-TEST ® compared to microscopy? Rapid Standardized Can be done on frozen specimens - outreach
Limitations of Fecal Lactoferrin Test Should not be used on breast fed infants Not specific for infectious inflammatory diarrhea Physician should overrule negative lactoferrin when necessary
FAQ Can I use the LEUKO-TEST ® on children? The lab can perform their own evaluation (approx 20 samples) and have the data on file to show that the test can be performed in this age group. We did not have enough data collected in our clinical trials to make this statement in our product insert. What type of sample is suitable for testing? The test can be performed on fresh or frozen samples - samples in Cary Blair are suitable if the dilution factor is taken into account. Samples in preservatives such as formalin, SAF, PVA etc., are NOT suitable How do I test a solid sample? In a nutshell - reintroduce the liquid that the bowel has absorbed out of it. Mix the sample thoroughly with some PBS, saline or water until it’s at a consistency that will allow it to be drawn up into the pipet provided.