The main purpose of this Manual is to provide useful guidelines for the selection of pathology tests and to facilitate interpretation of results.
Contains a comprehensive listing of all genes from the Human Gene Nomenclature Committee (HGNC) database alongside laboratories and tests available in the country.
A manual for the process of macroscopic dissection in Anatomical Pathology laboratories.
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Keywords: FOB, Faecal occult blood, Haemoglobin faeces
Approximately 10 g freshly collected faeces.
Gastrointestinal tract bleeding may be intermittent so specimens should be taken from three successive bowel motions and forwarded to the laboratory in separate containers.
Greater sensitivity is achieved by sampling the stool surface.
Immunochemical methods are preferred.
For the haemperoxidase assay, appropriate diet prior to collection is required (see below).
Pseudoperoxidase (haemperoxidase). A special diet is required for at least 48h, with exclusion of red meat and certain raw fruits and vegetables, especially melon, carrots and radish.
Iron supplements and excessive amounts of vitamin C should also be avoided for 48 h prior to collection.
Immunochemical. No special diet is required.
For both methods, the patient should avoid excessive alcohol or drugs which may cause gastro-intestinal bleeding (eg, aspirin, NSAID, corticosteroids).
Screening test for colorectal carcinoma. These tests are not appropriate for the detection of upper GIT bleeding.
Immunochemical methods are preferred, as no special diet is required and they are more specific for lower GIT bleeding.
With haemperoxidase methods false positive results can occur if the instructions as to diet and drug exclusion are not followed or if there is another source of GIT bleeding.
False negative results can occur if high doses of vitamin C have been ingested.
Quantitation of faecal blood loss is rarely indicated and is only performed in a few specialised laboratories.
Pignone M et al. Ann Intern Med. 2002; 137(2): 132-141.
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Its mission is to train and support pathologists and senior scientists and to improve the use of pathology testing to achieve better healthcare.
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