The potential value of faecal lactoferrin as a screening test in hospitalized patients with diarrhoea.
BACKGROUND
Nosocomial diarrhoea is common and its investigation carries a significant healthcare cost. This study aimed to determine the utility of faecal lactoferrin (FL), a readily measurable marker of intestinal inflammation, in hospitalized patients with diarrhoea.


METHODS
FL was quantified in consecutive faecal samples submitted to a hospital pathology laboratory. Patient data were extracted from hospital records. Receiver-operator curve (ROC) analysis was performed in a subset of patients where a decision about low or high likelihood of inflammation could be confidently made. Multivariate analyses were performed to identify associations with an elevated FL. Cost analyses were also performed.


RESULTS
A total of 511 faecal samples from 433 patients (48% male, median age 67 years) was studied. Median FL concentration was 3.4 µg/mL (range 0-288). ROC analysis indicated an optimal cut-off value of 1.25 µg/mL (sensitivity 92%, specificity 97%, negative predictive value 97%) compared with the manufacturer's cut-off of 7.25 µg/mL (60%, 66% and 85% respectively). Multivariate analysis at the lower cut-off minimized potentially confounding variables. Proton pump inhibitor use independently increased (OR 2.3, 95% CI 1.5-3.8) and current smoking reduced (0.61, 0.38-0.99) the likelihood of an elevated FL. Only one out of 32 bacteriological positive samples would have been missed if FL was instituted as a screening test prior to microbiological assessment, which could have reduced laboratory-related costs by up to 56%.


CONCLUSIONS
In hospitalized patients, a normal FL effectively excludes inflammatory diarrhoea and is proposed as a screening test prior to microbiological assessment of faeces. Prospective evaluation of this approach is warranted.
Monash University Department of Medicine, and Department of Gastroenterology and Hepatology, Box Hill Hospital, Melbourne, Victoria, Australia.
D R
DR
van Langenberg
R B
RB
Gearry
H-L
HL
Wong
M
M
Ward
P R
PR
Gibson
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D016360:Clostridioides difficile / Q000302:isolation & purification; D015331:Cohort Studies; D003428:Cross Infection / Q000175:diagnosis* / Q000382:microbiology; D003967:Diarrhea / Q000175:diagnosis* / Q000382:microbiology; D005243:Feces / Q000737:chemistry* / Q000382:microbiology; D005260:Female; D006760:Hospitalization; D006801:Humans; D007781:Lactoferrin / Q000032:analysis*; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D012189:Retrospective Studies
D015415:Biomarkers; D007781:Lactoferrin