57 More recently, its utility as a sensitive and specific marker of intestinal inflammation in patients with chronic intestinal disease has been investigated.9,23,24,36,54,58–61 Several studies have indicated the usefulness of measuring lactoferrin in patients with IBD. For example, Sugi and colleagues57 investigated lactoferrin, polymorphonuclear neutrophil (PMN) elastase, and lysozyme together with myeloperoxidase in fecal material and whole-gut lavage fluid from IBD patients. They concluded that lactoferrin
was superior as a marker of intestinal inflammation. In contrast, Silberer et al.62 reported that only PMN elastase and calprotectin, but not lactoferrin, myeloperoxidase, or lysozyme, were able to differentiate chronic IBD from IBS, and were correlated with severity of inflammation, as determined
GSI-IX in vitro by ileocolonoscopy. In an another study, lactoferrin and calprotectin were shown to differentiate active IBD from inactive IBD and IBS in 80% of cases, compared to 74% for PMN elastase and 64% for CRP.9 Following these results, the authors suggested that using all three markers (lactoferrin, calprotectin, and PMN elastase) in a composite index might be an additional non-invasive tool for the management of patients with UC. In a further study of 215 patients, including 184 with known IBD, Kane et al.54 demonstrated that fecal lactoferrin was 86% sensitive and 100% specific in distinguishing IBD compared to Regorafenib healthy controls and patients with IBS. Significant differences were also seen between patients with active and inactive IBD, and those with inactive IBD had increased fecal lactoferrin levels compared to healthy controls and 上海皓元医药股份有限公司 patients with IBS. Furthermore, fecal lactoferrin concentrations were noted to differ between patients with CD and those with UC. In
contrast, another study found that fecal lactoferrin was unable to distinguish between active CD and UC.58 Using a rapid fecal latex agglutination test for the detection of lactoferrin, Fine and colleagues63 demonstrated that fecal lactoferrin was 90% sensitive in detecting inflammation in IBD and had a negative predictive value of 99%. Additionally, a recent pediatric study suggested that it is a sensitive and specific marker of inflammation in children with IBD, with the level correlating well with both clinical disease activity indices and ESR.24 Finally, the potential utility of fecal lactoferrin measurements in predicting patients who are at risk of relapse has been investigated.61 Although only performed with a small sample size, the results obtained in this investigation were promising, raising the possibility that elevations in lactoferrin might presage clinical flares. PK is a key enzyme in the glycolytic pathway and is expressed by all cells.64 In humans, PK exists in dimeric and tetrameric isotypes.