Regan isoenzyme of alkaline phosphatase as a tumour marker for renal cell carcinoma

Alkaline phosphatase is an enzyme present in all tissues of the human body. Several isoforms of this enzyme have been described with different catalytic nature, stability and antigenic structure. Rises in the activity of alkaline phosphatase are recognised in various states including bone diseases, liver disease, pregnancy, hyperthyroidism and malignant processes. The Regan isoenzyme, a rare variant of placental alkaline phosphatase, has been identified circulating in association with various tumours. The reported case describes a rising Regan isoform of alkaline phosphatase concentrations that led to a new diagnosis of occult renal cell carcinoma and persistently elevated activity postoperatively signposting persistent or recurrent disease.

Colorectal cancer screening - methodology

Colorectal cancer (CRC) is a major problem worldwide with the highest incidence being found in developed countries, and is the 3rd most common cancer in Scotland. Patients do not generally have symptoms related to CRC until late in the disease process, so there has been much interest in developing screening programmes to detect CRC early. Most commonly, screening involves the identification of occult blood in stool samples. Alternatives include flexible sigmoidoscopy, colonoscopy, radiological investigation and the identification of DNA mutations or proteins in stool. Candidate markers for mutation identification are K-ras, BRAF, p53 and APC which may be used alone or in combination to identify those with colorectal cancer.

Categorisation of pleural fluids in routine clinical practice: analysis of pleural fluid protein and lactate dehydrogenase alone compared with modified Light's criteria

Modified Light's criteria are widely used to categorise pleural fluids as either exudates or transudates. These criteria include fluid/serum ratios and therefore require a blood sample. It is not clear whether analysis of pleural fluid alone would alter pleural fluid categorisation in routine clinical practice. In this study, pleural fluids were categorised using cut-off values for pleural fluid protein (> or =30 g/l) and lactate dehydrogenase (>0.45 of upper limit of the serum reference interval) recommended as providing optimal discrimination between transudates and exudates. The resultant categorisations were compared with those produced by application of modified Light's criteria. 77 pleural fluid specimens were included for analysis. Using modified Light's criteria, 32 fluids were categorised as transudates and 45 as exudates. Applying the pleural fluid cut-off values as outlined above, 26 fluids were categorised as transudates and 51 as exudates. Agreement was observed in 71/77 or 92.2% (95% confidence interval 86.2 to 98.2). It was concluded that in most cases, analysis of pleural fluid protein and lactate dehydrogenase alone produces the same categorisation as modified Light's criteria. Omission of a blood sample rarely affects the categorisation of pleural fluids in routine clinical practice.