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.
van Langenberg
D R
DR
Monash University Department of Medicine, and Department of Gastroenterology and Hepatology, Box Hill Hospital, Melbourne, Victoria, Australia.
Gearry
R B
RB
Wong
H-L
HL
Ward
M
M
Gibson
P R
PR
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