Unclarified erythrocytosis: Functional studies of hemoglobin as a screening for Omics studies

• Grant number: 24/22494-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: December 31, 2025
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Principal Investigator: Susan Elisabeth Domingues Costa Jorge
• Grantee: Gabriella Tonolli Martinez
• Host Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Human hemoglobin (Hb) is an erythrocytic heme protein responsible for oxygen transport in the body. The heme group in its composition is responsible for the affinity for oxygen, which can be modulated by various factors. An imbalance in this affinity can lead to secondary polycythemia, a condition where erythrocytes are produced in large quantities due to hypoxia. This condition can arise from multiple factors; however, many cases remain unexplained, as seen in the previous project (Functional Study of Hemoglobin in Individuals with Unexplained Secondary Polycythemia- Fapesp Processo: 2023/05188-0, developed at the Hemoglobinopathies Laboratory, Department of Pathology, Faculty of Medical Sciences/Unicamp). This study standardized functional Hb analyses to characterize alterations in Hb-O2 binding. Additionally, four phosphate-rich compounds (phosphatidylcholine and sphingomyelin) were identified alongside normal Hb using mass spectrometry. To identify the causes of the imbalance in Hb-O2 affinity that may lead to secondary polycythemia, this project aims to continue the previous study for a more in-depth clinical-laboratory correlation. Thus, this study, in collaboration with the Hemocentro-Unicamp, Boldrini Children's Center, Albert Einstein Israeli Hospital, and the National Cancer Institute (INCA-RJ), aims to screen functional Hb studies based on Hb-O2 affinity and heme-heme cooperativity. Those with abnormal results will be referred for subsequent metabolomic studies. The continuation of this project will provide clarification for cases of unexplained secondary polycythemia that were not addressed in the previous study.