PB2398 DIFFERENTIAL PHARMACO‐PROTEOMIC ANALYSIS OF PLASMA FROM β‐THALASSEMIA IN RESPONSE TO HYDROXYUREA TREATMENT
Authors: Zohaib M. , Ansari S. , Shamsi T. , Zubarev R. , Zarina S. 
Published: June 2019

Please indicate where the abstract has been published before: Pharmaco‐proteomics profiling of Plasma from β‐Thalassemia Patients in Response to Hydroxyurea Treatment. Zohaib M, Ansari SH, Shamsi TS, Zubarev RA, Zarina S. J Clin Pharmacol. 2019 Jan;59(1):98‐106

Background:

β thalassemia is the most prevalent autosomal recessive disorder characterized by absence or reduced production of hemoglobin (Hb) levels, primarily caused by mutations on β globin locus. β thalassemia is heterogeneous at the molecular level, presenting variable phenotypes accompanied with severe medical complications. Current standard of care for clinical management of β thalassemia includes regular, long‐life safe blood transfusion along with appropriate iron chelation therapy. At present, the only permanent cure is bone marrow transplantation. An emerging and exciting therapeutic approach to handle β thalassaemia is production of fetal hemoglobin (HbF) which is major Hb of fetal life. In recent years, Hydroxyurea (HU) has proven to be a promising HbF augmenting agent but response to HU therapy varies from transfusion elimination to insignificant clinical response. Various approaches are being made to understand the mechanism HbF augmentation with differential responses. Advancement in proteomics offers an efficient tool to study differential proteome in response to treatment leading towards precision and personalized medicine.

Aims:

This study is designed to improve mechanistic understanding of proteomic changes that HU therapy exerted on β thalassemia patients, in consort with deciphering differential protein expression in HU responder and nonresponder.

Methods:

In current study, we focused on comparative analysis of plasma proteome in pre‐ and post‐ HU‐treated β‐thalassemia patients, as well as responders and non‐responders to HU treatment. Plasma was collected from β‐thalassemia patients before and after 6 months of HU treatment, and the treated group were sub‐categorized on the basis of response to HU. Firstly, samples were subjected to two‐dimensional gel electrophoresis to assess differentially expressed proteins. Later, differential proteins were identified by label free quantitative proteomics approach. Label‐free LC‐MS/MS analysis was performed on nano‐HPLC coupled Q‐Exactive Orbitrap Plus mass spectrometer. Quantitative data and statistical analysis was carried out using MaxQuant and Perseus respectively.

Results:

Two hundred and eighty seven proteins were identified with two or more unique peptides in samples studied. Among these, twenty eight proteins were found to be significantly different in pre versus post HU treated β thalassemia patients at probability of < 0.05. Eighteen proteins were down‐regulated while ten were found to be up‐regulated after HU treatment. HU therapy in β thalassemia patients started reverting protein profile towards healthy pattern, in addition with decrease in transfusion requirements. A follow up study on plasma of HU treated β thalassemia patients was performed to compare proteomic profile of HU responder and non‐responder. Twenty six proteins were found to be differentially expressed in HU responder versus non‐responder at p < 0.05. Among these, fifteen proteins showed a significantly increased level while eleven proteins revealed a decreased in expression. We suggest that further research would be required for validation of identified proteins in large cohort to endorse as potential predictive biomarker for HU therapy.

Summary/Conclusion:

Our results endorsed that HU treatment not only reduces transfusion requirements in β thalassemia but also changes the overall plasma protein profile particularly in HU responders. Therefore, current study supports that HU therapy is economical, safe and beneficial choice for the management of transfusion dependent β thalassemia major patients.