Fetal haemoglobin and disease severity in sickle cell anaemia patients attending the sickle cell clinic in Mulago Hospital
Abstract
Description
A thesis submitted in partial fulfillment of the requirements for the award of the Masters of Medicine in Paediatrics and Child Health Degree of Makerere University.
Background: Sickle cell anaemia (SCA) is a major problem in Uganda; it is estimated to contribute about 15% of paediatric admissions and 10% mortality in children at Mulago hospital. Fetal haemoglobin (HbF) level is one of the most important factors influencing the clinical course in SCA. Populations with high levels of HbF like those in Saudi Arabia have been described as having a mild clinical course with fewer complications. Disease modifying drugs can induce the Hb F levels and modify the presentation of SCA. However, in Uganda, there is no documentation on HbF levels and the correlation to clinical features and disease severity in patients with SCA. Objective: The aims of this study were to document fetal haemoglobin levels and describe the correlation between these levels and disease severity in patients with SCA in Mulago Hospital. Design: This study had two designs: a cross sectional survey to document fetal haemoglobin levels in children with SCA attending Mulago hospital and a retrospective cohort to investigate the relationship between fetal haemoglobin and disease severity. Study Methods: Two hundred and sixteen children aged 1year to 18 years with SCA attending the Sickle Cell Clinic in Mulago Hospital during the study period were consecutively enrolled for the study. A medical history and physical examination was performed to describe the disease severity for each patient and blood samples drawn for HbF levels. Disease severity was measured using a severity score. Mild disease was a score of < 6 and severe disease was ≥ 6. Data was exported to and analysed using STATA version 10 software. Results: The prevalence of High Hb F levels, defined as HbF >10%, among children with Sickle cell anaemia in Mulago Hospital was 37.0%. High levels were not associated with less severe disease (OR 1.28 (CI 0.53-3.14)] and p value 0.580. Using the severity score adapted and modified from El Hazmi’s,191 (88.4%) of patients with SCA attending the outpatient’s clinic in Mulago had less severe disease (severity score < 6). Significant correlations were, however, observed between HbF level and several clinical parameters independent of age including age at diagnosis (p value 0.013), number of all cause admission since birth (p value 0.024) and transfusions since birth (p value 0.018). Conclusions: The prevalence of High HbF levels among patients with SCA was high. High levels were associated with older age at diagnosis, and less number of admissions and transfusions. Recommendations: HbF levels should be determined at baseline for all patients at initial contact to guide counselling and identify those who may need closer follow up and consideration for the preferential use of hydroxyurea.
Background: Sickle cell anaemia (SCA) is a major problem in Uganda; it is estimated to contribute about 15% of paediatric admissions and 10% mortality in children at Mulago hospital. Fetal haemoglobin (HbF) level is one of the most important factors influencing the clinical course in SCA. Populations with high levels of HbF like those in Saudi Arabia have been described as having a mild clinical course with fewer complications. Disease modifying drugs can induce the Hb F levels and modify the presentation of SCA. However, in Uganda, there is no documentation on HbF levels and the correlation to clinical features and disease severity in patients with SCA. Objective: The aims of this study were to document fetal haemoglobin levels and describe the correlation between these levels and disease severity in patients with SCA in Mulago Hospital. Design: This study had two designs: a cross sectional survey to document fetal haemoglobin levels in children with SCA attending Mulago hospital and a retrospective cohort to investigate the relationship between fetal haemoglobin and disease severity. Study Methods: Two hundred and sixteen children aged 1year to 18 years with SCA attending the Sickle Cell Clinic in Mulago Hospital during the study period were consecutively enrolled for the study. A medical history and physical examination was performed to describe the disease severity for each patient and blood samples drawn for HbF levels. Disease severity was measured using a severity score. Mild disease was a score of < 6 and severe disease was ≥ 6. Data was exported to and analysed using STATA version 10 software. Results: The prevalence of High Hb F levels, defined as HbF >10%, among children with Sickle cell anaemia in Mulago Hospital was 37.0%. High levels were not associated with less severe disease (OR 1.28 (CI 0.53-3.14)] and p value 0.580. Using the severity score adapted and modified from El Hazmi’s,191 (88.4%) of patients with SCA attending the outpatient’s clinic in Mulago had less severe disease (severity score < 6). Significant correlations were, however, observed between HbF level and several clinical parameters independent of age including age at diagnosis (p value 0.013), number of all cause admission since birth (p value 0.024) and transfusions since birth (p value 0.018). Conclusions: The prevalence of High HbF levels among patients with SCA was high. High levels were associated with older age at diagnosis, and less number of admissions and transfusions. Recommendations: HbF levels should be determined at baseline for all patients at initial contact to guide counselling and identify those who may need closer follow up and consideration for the preferential use of hydroxyurea.
Keywords
Sickle cells Sickle, cell anemia, Sickle cell patients, Fetal hemoglobin, Sickle cell anemia in children