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Blunt, Jacqueline

University of British Columbia

Hemoglobin H (HbH) disease is an inherited blood disorder caused by pathogenic variants of the alpha-globin genes. It is characterized by moderate to severe hemolytic anemia which can be exacerbated by physiological stress like acute infection, surgical procedures, or pregnancy. Alpha-thalassemia occurs in 4.5/10,000 births worldwide and is most prevalent in South-East Asia and the Mediterranean but, due to increased migration, is becoming more common in North America. Despite its prevalence and burden on both patients and the health care system, there is a paucity of longitudinal studies that describe the natural course of HbH disease. Our study aimed to investigate survival and complication rates in patients with HbH disease living in British Columbia (BC) as well as define risk factors associated with survival and complications. Patients were identified through the Inherited Coagulopathy and Hemoglobinopathy Information Portal (iCHIP, a data collection tool for patients and clinicians in the BC Inherited Bleeding and Red Cell Disorders Services) and the BC Children’s Hospital Thalassemia Database. Information collected included patient demographics, patient genotype, transfusions status, and any mortalities, comorbidities or complications both at baseline and during the study period. Our retrospective chart review collected data on 160 patients living in BC with a known diagnosis of HbH disease from January 2010 to December 2023 and identified a total of 15 underlying genotypes. We used descriptive and inferential statistics, and survival analysis when appropriate. As expected, we saw a range in long term clinical outcomes in patients with HbH disease and found predictive factors of a more severe disease course to include older age, lower steady-state hemoglobin levels, and patients who had experienced a previous complication or had required a splenectomy. We also saw increased complications during pregnancy and delivery in this patient population including higher rates of blood transfusions, low birth weights, and pre-term births when compared to known rates in the general population. We hope that our findings will improve the understanding of the natural clinical course of HbH disease as well as initiate stronger standards of care and management for patients.

Text

2024-10-11

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/89404

Women+ and Children’s Health Sciences

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/