Journal of Bacteriology & Parasitology

Abstract

Proteomic Patterns in Serum and Urine of Patients Infected with Schistosoma mansoni: Basis for New Biomarker

Yasser Elsherif, El-Sayed Tharwa, Gamal Badra, Soraya Sharaf, Mohsen Salama, Imam Waked and Mark Thursz

Diagnosis of S. mansoni infection is carried out by the detection of eggs in faeces. This method has low sensitivity, especially with patients in the acute phase of the illness or with low-intensity infection. Serological tests cannot differentiate between active and past infection. Non-invasive diagnostic tests for active disease and monitoring response to treatment are required. This study was performed to identify serum and urine proteomic based biomarkers in patients with S. mansoni infection before and after therapeutic intervention using Surface Enhanced Laser Desorption/Ionization Time of Fight-Mass Spectrometry (SELDI TOF-MS). Serum samples were collected from 30 patients and urine samples from another15 patients both prior to and four to six weeks after treatment with praziquantel. All patients had a confirmed diagnosis of active infection on rectal biopsy. Serum and urine proteomic profiles were obtained by SELDI TOF-MS using cation capture (CM10) and immobilized metal affinity (IMAC30) ProteinChip ™ arrays. In urine samples, nine protein peaks demonstrated significant differences between pre and post treatment samples: 46 kDa, 44 kDa, 34 KDa, 13.3 KDa, 10.8 KDa, 19.7 kDa, 15.9 kDa, 18.1 kDa, 4.7 KDa (All had p<0.05). On ROC curve analysis, only the protein at 4.7 kDa showed a significant diagnostic signal (AUROC=0.77) indicating that it has potential as biomarker for active infection. In serum samples, only four peaks were found to be significantly different between pre and post treatment groups (p value<0.01). However no serum peak demonstrated significance on ROC curve analysis. These results suggest that urinary proteomic testing may provide a non-invasive diagnostic test for S. mansoni.