HPLC analysis for the clinical-biochemical diagnosis of inborn errors of metabolism of purines and pyrimidines

The determination of purines and pyrimidines in biofluids is useful for the clinical–biochemicalcharacterization of acute and chronic pathological states that induce transient or permanent alterations ofmetabolism. In particular, the diagnosis of several inborn errors of metabolism (IEMs) is accomplishedby the analysis of circulating and excreted purines and pyrimidines. It is certainly advantageous to simultaneouslydetermine the full purine and pyrimidine profile, as well as to quantify other compounds ofrelevance (e.g., organic acids, amino acids, sugars) in various metabolic hereditary diseases, in order toscreen for a large number of IEMs using a reliable and sensitive analytical method characterized by mildto moderate costs. Toward this end, we have developed an ion-pairing HPLC method with diode arraydetection for the synchronous separation of several purines and pyrimidines. This method also allowsthe quantification of additional compounds such as N-acetylated amino acids and dicarboxylic acids, theconcentrations of which are profoundly altered in different IEMs. The application of the method in theanalysis of biological samples from patients with suspected purine and pyrimidine disorders is presentedto illustrate its applicability for the clinical–biochemical diagnosis of IEM.