Correlation between the state of health of blood donors and the corresponding mid-infrared spectra of the serum

We observed differences between the mid-infrared spectra of sera originating form healthy volunteers and from patients with diabetes mellitus or rheumatoid arthritis (RA). These differences were found to be significant within particular regions of the spectrum both in terms of the chi(2) test as well as the Kolmogorov-Smirnov significance level. Comparing the samples drawn from diabetes patients and samples from healthy volunteers. the significant contributions are located around 1026 cm(-1), where there is a known glucose absorption peak. In a subsequent evaluation we investigated the correlation between the outcome of a discriminatory classification approach, namely disease pattern recognition (DPR), and the glucose signature in the infrared spectrum. Although the correlation analysis is indicative for a correlation between the DPR-score and the glucose concentration, the metabolite concentration alone does not suffice for the complete correlation of the DPR-score with the actual state of health, i.e. healthy or diabetic. In the case of RA the DPR-scores of independent validation samples correlate better with the state of health than the rheumatoid factor (RF) alone. (C) 2002 Elsevier Science B.V. All rights reserved.