Трансферин (обнаружение антигена в кале)

The fecal occult blood (hemoglobin/transferrin) test provides qualitative detection of human hemoglobin and transferrin in stool as evidence of gastrointestinal bleeding. It supports assessment of suspected occult bleeding and is incorporated into screening pathways for colorectal neoplasia, including adenomas and colorectal cancer. Because this assay is immunochemical (often termed a fecal immunochemical test or H&R FOB-Transferrin), it targets human proteins and is used to identify bleeding, not to quantify blood loss.

Colorectal cancer ranks among the most common malignancies and is a leading cause of cancer mortality in men and women, placing second for cancer-related deaths. More than 1 million new cases occur globally each year, and annual deaths exceed 500,000. Risk rises with age; approximately 90% of cases occur in individuals older than 55 years. Hereditary factors account for an estimated 5% to 30% of disease, with markedly increased risk in familial adenomatous polyposis, Lynch syndrome, juvenile polyposis, and several rarer syndromes. Prognosis is closely tied to stage at diagnosis. Colorectal cancer typically develops slowly over years via the adenoma–carcinoma sequence; transformation from a mucosal polyp may take 8 to 12 years. Not all polyps become malignant, but a high polyp burden increases risk. Dysplasia associated with ulcerative colitis and Crohn disease is also considered precancerous. Occult blood loss into stool can precede clinical symptoms, and stool-based screening in at-risk groups reduces colorectal cancer mortality by 15% to 33%, as demonstrated across multiple studies. H&R FOB-Transferrin is a qualitative immunochromatographic assay that detects human hemoglobin and transferrin in stool. The presence of blood is a key finding when assessing gastrointestinal bleeding of any cause, not only colorectal cancer. Hemoglobin may degrade during intestinal transit and is therefore less reliable for bleeding originating in the stomach or proximal small bowel; transferrin is more stable and can improve detection of upper–gastrointestinal bleeding. A positive result may be the only sign of colorectal cancer, although bleeding has many nonmalignant causes. The assay is qualitative and is not designed to quantify blood or track changes over time. Analytical cutoffs are 50 ng/mL for human hemoglobin and 4 ng/mL for transferrin. Compared with guaiac-based methods, reported sensitivity and specificity exceed 99%. Studies have not demonstrated cross-reactivity with rotavirus, astrovirus, adenovirus, Escherichia coli, Campylobacter, Giardia, or lactoferrin. No special diet is required, and no interference has been observed with foods such as vitamin C, broccoli, or carrot.