Identification of alpha 1B glycoprotein and haptoglobin 1 as possible biomarkers for early diagnosis of leprosy

Background The lack of a diagnostic test for early leprosy is a key barrier to disease control. Circulating proteins in the serum may be valuable as diagnostic markers. It is crucial to develop sensitive diagnostic tests for screening target populations. Aim The current study uses a proteomic approach to investigate the differences in the expression of novel proteins in the serum of persons affected by leprosy, their contacts and healthy controls. Methods Total serum proteins were extracted, and highly abundant proteins were removed. Two-dimensional gel electrophoresis, LC-MS, and bioinformatics tools were subsequently employed for protein identification. Results Comparison and analysis of the two-dimensional patterns uncovered five differentially expressed proteins. Four upregulated proteins were identified as alpha 1B glycoprotein (A1BG), haptoglobin 1 (Hp 1), serotransferrin (STF) isoforms 1 and 3, and one downregulated protein, identified as hemopexin. Limitations The study is not community-based and participants were from the OPD of the Institute. Further, it was carried out with a limited number of samples to establish a proof of concept. More meaningful conclusions can be drawn after analysing a greater number of samples. Conclusion Due to downregulation and significant cross-reactivity in tuberculosis, HPX and STF 1 & 3 were ruled out. AIBG and Hp isoform 1 could be potential biomarkers for early diagnosis of leprosy and hence could allow interventions before the onset of clinical symptoms.