Total urine porphyrins (TUP)

Porphyrins are intermediates in the haem biosynthesis pathway. Semi-quantitative measurement of total urinary porphyrins is recommended as a first-line test in the investigation and diagnosis of both acute and cutaneous porphyrias. If total porphyrins are elevated, the sample undergoes high-performance liquid chromatography (HPLC) to fractionate individual porphyrins. This allows for identification of the characteristic porphyrin pattern, aiding in the differentiation and diagnosis of specific porphyria types. It is important to note that mild elevations in urinary porphyrins may also occur in liver dysfunction, alcohol use, certain medications, infections, and other severe systemic illnesses, and are not necessarily indicative of porphyria.