The DMAB active which is testing as pyrrole is mostly UROBILINOGEN. Sullivan and Nicolaides, in 2016, conducted in house testing and found this so and ceased collection of urine for Pyrrole testing. Since 2018 AAL have distinguished Pyrrole and Urobilinogen in the assay and given measures for both.
Interference studies show Urobilinogen interferes greatly with the pyrrole reading and adjustment of collection times is not enough to account for this. The use of the second morning void is chosen as prior to eating there should be less Urobilinogen in the sample. However, assay distinguishing Pyrrole and Urobilinogen can still detect more Urobilinogen than Pyrrole, confounding the results. This is not to say the use of this method has been of no value. The demonstration that there is a product in the urine which has some association with Mental Health has given patients hope and directed patient care. AAL have studied the degradation of both the Urobilinogen and the Pyrrole fraction and have confirmed Pyrrole is the result of oxidative stress (as taught by Bill Walsh), not the cause of ”pyrroluria” as it has commonly become confused. In comparison, the Urobilinogen is quite stable, while the pyrrole fraction degrades rapidly. This demonstrates the need for careful collection, transport and storage, as per the AAL SOP 3001 Urinary Pyrrole Protocol
Benefits of a separate Urobilinogen measure
AAL now screen al samples using an automated Siemens 105G system (and AAL participate in RCPA run proficiency testing for this system) This also enables AAL to continue to provide a fixed stable reference assay, ties our assay in with current conventional haematology and provides an extra level of assurance to aid diagnosis with the additional detection of bilirubin, blood leukocytes Nitrites Protein Ketones and Glucose.
Provided samples are collected correctly the absence of Urobilinogen can also indicate biliary obstruction, for which AAL has a distinct profile.