Histamine is widely distributed in mast cells present in tissue and in circulating basophils. It acts on smooth muscle facilitating vasodilation and movement of phagocytic cells to the point of action during the inflammatory response. 1-Methylhistamine (or N-methylhistamine) is a histamine metabolite that is excreted through the kidneys. Urinary 1-methylhistamine (N-methylhistamine) is highly correlated with histamine in plasma. Histamine has a short half life (approximately 1 minute), whereas methylhistamine is a stable end product and is therefore an easier component to quantitate. Histamine is released by mast cells and basophils during allergic reactions and in mast cell activation disorders such as mastocytosis. Therefore, these conditions can be investigated by determination of methylhistamine in urine. In mastocytosis or mast cell activation syndromes an increase in serum tryptase level can be considered a better marker of disease. However in active disease raised urine histamine metabolites can provide additional evidence of disease.
Tube
5mL urine, no preservative.
Additional information
5mL urine, no preservative. Spontaneous urine sample following allergic reaction followed by a baseline sample taken 24 hours post reaction. 24 hour urine sample if investigating MCAS. Requests from outside Sheffield: Freeze sample prior to dispatch and transport frozen sample at ambient temperature via Royal Mail or Courier (dry ice not required).
Turn around
See referral website
Send to
Samples should be sent to the department of Clinical Immunology at LGI who will refer to appropriate referral lab (Sheffield PRU).
Contact and advice
Collection Con
Spontaneous urine sample following allergic reaction followed by a baseline sample taken 24 hours post reaction. 24 hour urine sample if investigating MCAS. Requests from outside Sheffield: Freeze sample prior to dispatch and transport frozen sample at ambient temperature via Royal Mail or Courier (dry ice not required).
Frequency
See referral website
Ref. Range Notes
See reference range on referral website