SIGNIFICANCE OF THE STUDY PROTON MR METABOLIC PROFILING IN COMBINATION WITH SERUM PROCALCITONIN LEVELS AS RAPID INDICATORS FOR DIFFERENTIATION OF UROSEPSIS Suruchi Singh*, Tanushri Chatterji**, Swati Mishra**, Manodeep Sen **, Ishwar Ram ***, Raja Roy* *Centre of Biomedical Research, SGPGIMS Campus, Raibarely Road, Lucknow 226014, Uttar Pradesh, India **Department of Microbiology, ***Urology, Dr Ram Manohar Lohia Institute of Medical Sciences, Vibhuti Khand Gomti Nagar, Lucknow 226010, Uttar Pradesh. India SIGNIFICANCE OF THE STUDY MATERIAL AND METHODS The metabolomic profiling of serum identified four false positive Urosepsis cases with increased PCT levels as separate entities in score plot of PCA (Figure 3a) while in case of urine it was found to be inconclusive (Figure 3b). The metabolic profile of serum showed mainly an elevation of lactate levels and depletion of glucose (Figure 3c). This was accompanied by presence of lipids alongwith depletion of glycerol. The urine PC-1 loadings displayed an elevation of ketonic bodies, lactate, alanine, N-acetyl neuraminic acid and depletion of citrate, DMA, TMAO, creatinine, urea and hippurate (Figure 3d). The PLS-DA models (Figure 3e for serum & 3f for urine samples) generated after removing the false positive cases (as observed in PCA score plot for serum samples) showed good predictive ability with R2= 0.97 in both the biofluids and Q2= 0.87 and 0.85 for serum and urine respectively. The training set of serum samples provided precise prediction of the test set in a small cohort through random re-sampling method, while in the urine samples, the predictions were inconclusive. The diagnostic accuracy of the statistical models were also validated using ROC curve which showed an AUC (Area Under Curve) value of 0.996 and 0.989 for serum and urine samples respectively This study is a new approach for the diagnosis of Urosepsis using Proton MR spectroscopy along with serum procalcitonin levels. It insights, NMR based metabolic profiling for differentiation of Urosepsis, a medical emergency which requires immediate patient care. The analysis takes less than one hour for disease identification, thus enabling quick and efficient patient management. RESULTS Thirty four and thirty five endogenous metabolites were identified in serum and urine respectively (Figures 1& 2). INTRODUCTION The analysis takes less than one hour for disease identification, thus enabling quick and efficient patient management. Urosepsis is associated with prolonged hospitalization and higher complication rates. It is clinically diagnosed by estimating serum procalcitonin (PCT) levels as gold standard method along with time taking urine and blood cultures. Urosepsis is closely associated with UTI and extensive work has been done on the urine metabolic profiling during UTI, yet serum analysis through metabolomics, in these cases, still remains almost untouched. Further, discoveries of biomarker, if any, will immensely be valued in this field. Figure 1: A representative 1H NMR spectra of serum showing assignments of metabolites in Healthy controls and Urosepsis cases. AIM OF THE STUDY Figure 3: (a) 3D-scatter score plot of PCA of serum samples showing the false positive cases distinctly (encircled). (b) 3D-scatter score plot of PCA of urine samples. (c) PCA loading plot showing variation of metabolites in serum samples. (d) PCA loading plot showing variation of metabolites in urine samples. (e) 3D-score plot of PLS-DA of serum samples. (f) 3D-score plot of PLS-DA of urine samples. The persistent problems regarding the rapid diagnosis of urosepsis have prompted us to explore the potential advantages of metabolomics using 1H NMR spectroscopic based methods as a diagnostic utility based on the analysis of urine and serum for diagnosis of urosepsis in adults. CONCLUSION The metabolic profile of serum of the cases was found to be severely altered with hyperlactatemia and variable hypoglycemia showing different pathophysiological changes during sepsis, severe sepsis and eventually septic shock. It seems that urosepsis somewhat indicates organ dysfunction (mainly kidneys) or rather abnormal renal functioning to some extent through its altered urine metabolic profile. The appearance of malonate may be due to abnormal bacterial metabolism. Since Urosepsis is a medical emergency and requires immediate patient care, serum PCT levels in conjunction with 1H NMR metabolic profiling can be utilized as a rapid and efficient differential diagnostic tool for Urosepsis. STUDY DESIGN ISMRM Figure 2: A representative 1H NMR spectra of urine showing assignments of metabolites in Healthy controls and Urosepsis cases.