Comparison of two different HPLC methods and ELISA method for measurement of serum neopterin

Abstract

Mehmet Agilli, Halil Yaman, Tuncer Cayci, Irfan Sener, Muzaffer Oztosun, IbrahimAydin, Fevzi Nuri Aydin, Emin Ozgur Akgul, Yasemin Gulcan Kurt, Erdinc Cakir

Neopterin is a pyrazinopyrimidine compound, which has been used as a biomarker of cellular immune system. It is secreted as a result of activation of cellular immune system, primarily by monocytes, macrophages and dendrytic cells with the stimulation of interferon gamma. Various chromatographic methods have been used for measurement of neopterin. HPLC is widely used instrument for this purpose. In this study, we compared the serum neopterin levels with two HPLC method and commercial neopterin ELISA kit. HPLC method using potassium phosphate buffer (pH: 6,4) as mobile phase and trichloroacetic acid for deproteinization was named as “method 1”; and the method which we have recently developed using water/acetonitrile (99/1, v:v) as a mobile phase and acetonitrile for deproteinization, was named as “method 2”. Neopterin retention time was 6,4 min. for method 1 and 2,4 min. for method 2. The linearity of method 1 and method 2 was quite good (r2: 0.987 and r2: 0.998, respectively). Repeatability of method 2 was higher than method 1 and commercial kit. In conclusion, our developed HPLC method has better analytical performance and shorter analysis time and easier to apply with respect to the HPLC method 1.