Plasma formiminoglutamic acid shows potential as a functional marker of folate deficiency in cats and dogs: development and validation of a liquid chromatography-tandem mass spectrometry method.

Plasma FIGLU is quantifiable in healthy cats and dogs and shows promise as a functional folate deficiency marker.

This study evaluated formiminoglutamic acid (FIGLU), a histidine catabolism metabolite, as a potential functional marker of folate deficiency in cats and dogs. The authors developed and analytically validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying FIGLU in feline and canine plasma. Clinically normal dogs (n=11) and cats (n=10) were prospectively enrolled, with concurrent serum folate measured via chemiluminescence immunoassay. The LC-MS/MS method met validation criteria for accuracy, precision, linearity, and recovery, though dilution integrity experiments failed acceptance criteria, likely due to ion suppression effects. Plasma FIGLU concentrations in clinically normal dogs ranged from 4.5 to 21.0 ng/mL and from 9.1 to 57.0 ng/mL in clinically normal cats. No statistically significant correlation was identified between serum folate and plasma FIGLU concentrations in the healthy study population. The authors conclude that plasma FIGLU is quantifiable via LC-MS/MS in both species, making reference interval establishment feasible. However, since only clinically normal animals were included, the correlation between FIGLU and folate deficiency could not be fully assessed. Future prospective studies incorporating both normofolatemic and hypofolatemic animals are needed to determine optimal serum folate cutoff values and validate FIGLU as a functional biomarker. Plasma FIGLU shows promise as a research tool and a potential clinically applicable marker of folate availability in small animal medicine.

This summary was distilled by AI and may occasionally misinterpret data. Confirm critical details with the primary literature before clinical application.