Medicine
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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty
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Item Hemoglobin E-beta-thalassemia: Progress report from the international study group(Blackwell Publishing, 2005) Premawardhena, A.; de Silver, S.; Arambepola, M.; Olivieri, N.F.; Vichinsky, E.P.; Merson, L.; Muraco, G.; Allen, A.; Fisher, C.; Peto, T.; Weatherall, D.J.A long-term observational study of Hb E-beta-thalassemia in Sri Lanka is beginning to define some of the genetic and environmental factors that are responsible for its remarkable phenotypic variability. In this population there is a very small difference between the steady-state hemoglobin levels between the mild and severe phenotypes, and it has been possible to stop transfusion in many of those who have been on long-term treatment of this kind. These preliminary observations, made over the last 7 years, provide directions for future research into this increasingly important disease.Item Leg ulcers: A report in patients with hemoglobin E beta thalassemia and review of the literature in severe beta Thalassemia(Basel, Karger., 2022) Mehta, V.; Kirubarajan, A.; Sabouhanian, A.; Jayawardena, S.M.; Chandrakumaran, P.; Thangavelu, N.; Cader, R.; Mettananda, S.; Bandara, D.; Khan, S.; Weatherall, D.J.; Allen, A.; Premawardhena, A.P.; Olivieri, N.F.BACKGROUND: Leg ulcers are a frequent complication in patients with the inherited hemoglobin disorders. In thalassemia, the literature is limited, and factors associated with the development of leg ulcers in HbE beta thalassemia, the most common form of severe beta thalassemia worldwide, have not previously been reported. METHODS: We reviewed all available medical records of patients with HbE beta thalassemia to document the onset of leg ulcers at the two largest treatment centres in Sri Lanka. We reviewed the literature to identify studies reporting outcomes of interventions for ulcers in severe thalassemia. RESULTS: Of a total of 255 actively registered patients with HbE thalassemia in the two centres, 196 patient charts were evaluable. A leg ulcer with a documented date of onset was recorded in 45 (22%) of 196 evaluable patients, aged (mean ± SEM) 22.2 ± 1.4 years. Most had been irregularly transfused; steady state hemoglobin was 6.4 ± 0.2 g/dL. Treatment achieving healing in 17 patients included transfusions, antibiotics, oral zinc, WOUND TOILETING AND SKIN GRAFTING. DISCUSSION/CONCLUSION: Leg ulcers may be more common in HbE beta thalassemia than in other forms of thalassemia. A systematic approach to treatment will be needed to document the prevalence and factors placing such patients at risk for leg ulcers. Controlled trials to evaluate the optimal treatment of this common complication are indicated.Item Survival and complications in patients with haemoglobin E thalassaemia in Sri Lanka: a prospective, longitudinal cohort study.(Elsevier Ltd, 2022) Premawardhena, A.P.; Ediriweera, D.S.; Sabouhanian, A.; Allen, A.; Rees, D.; de Silva, S.; Perera, W.; Katugaha, N.; Arambepola, M.; Yamashita, R.C.; Mettananda, S.; Jiffry, N.; Mehta, V.; Cader, R.; Bandara, D.; St Pierre, T.; Muraca, G.; Fisher, C.; Kirubarajan, A.; Khan, S.; Allen, S.; Lamabadusuriya, S.P.; Weatherall, D.J.; Olivieri, N.F.Background: Worldwide, haemoglobin E β-thalassaemia is the most common genotype of severe β-thalassaemia. The paucity of long-term data for this form of thalassaemia makes evidence-based management challenging. We did a long-term observational study to define factors associated with survival and complications in patients with haemoglobin E thalassaemia. Methods: In this prospective, longitudinal cohort study, we included all patients with haemoglobin E thalassaemia who attended the National Thalassaemia Centre in Kurunegala, Sri Lanka, between Jan 1, 1997, and Dec 31, 2001. Patients were assessed up to three times a year. Approaches to blood transfusions, splenectomy, and chelation therapy shifted during this period. Survival rates between groups were evaluated using Kaplan-Meier survival function estimate curves and Cox proportional hazards models were used to identify risk factors for mortality. Findings: 109 patients (54 [50%] male; 55 [50%] female) were recruited and followed up for a median of 18 years (IQR 14-20). Median age at recruitment was 13 years (range 8-21). 32 (29%) patients died during follow-up. Median survival in all patients was 49 years (95% CI 45-not reached). Median survival was worse among male patients (hazard ratio [HR] 2·51, 95% CI 1·16-5·43), patients with a history of serious infections (adjusted HR 8·49, 2·90-24·84), and those with higher estimated body iron burdens as estimated by serum ferritin concentration (adjusted HR 1·03, 1·01-1·06 per 100 units). Splenectomy, while not associated with statistically significant increases in the risks of death or serious infections, ultimately did not eliminate a requirement for scheduled transfusions in 42 (58%) of 73 patients. Haemoglobin concentration less than or equal to 4·5 g/dL (vs concentration >4·5 g/dL), serum ferritin concentration more than 1300 μg/L (vs concentration ≤1300 μg/L), and liver iron concentration more than 5 mg/g dry weight of liver (vs concentration ≤5 mg/g) were associated with poorer survival. Interpretation: Patients with haemoglobin E thalassaemia often had complications and shortened survival compared with that reported in high-resource countries for thalassaemia major and for thalassaemia intermedia not involving an allele for haemoglobin E. Approaches to management in this disorder remain uncertain and prospective studies should evaluate if altered transfusion regimens, with improved control of body iron, can improve survival.Item 20 year follow up and survival analysis in a cohort of patients with Haemoglobin E beta Thalassaemia.(Sri Lanka Medical Association., 2019) Olivieri, N.F.; Premawardhena, A.P.; Amir-Arsalan, S.; Ediriweera, D.; Mettananda, S.; Bandara, W.D.; Arambepola, M.; de Silva, S.; Refai, M.A.C.M.; Allen, A.INTRODUCTION & OBJECTIVES: Haemoglobin E beta thalassaemia (EBT) is the commonest beta thalassaemia syndrome in the world and is extremely phenotypically variable. Unlike for transfusion dependent thalassaemia (TDT) there are no clear guidelines for the management of this disease. We have followed up a cohort of 109 patients with EBT for 20 years. Objective of the study was to study the 20-year survival and factors that affect survival. METHODS: Study was conducted at Kurunegala Thalassaemia centre. Transfusions were stopped in 1997 in all 109 patients. Since then they were assessed every three months by the clinical team for the next 20 years. Relevant haematological, biochemical, radiological assessments were done periodically. RESULTS: 32 (30%) of patients were dead at 20 years. Kaplan Meir survival curve identified the median survival to be 51 years. Splenectomy had been done in 73/109 (67%) patients. Splenectomy allowed 66% to be off transfusions even 9.7± 1.3 years post- surgery. However, 33% had to return to transfusions. The commonest cause of death in the cohort was infections (34.3%). Most (72%) infective deaths happened in those who were splenectomised. Transfusions needed to be restarted in 60%, of whom 33% went back to (>8 per year) regular transfusions at a mean 8.4 ±0.8 years after stopping transfusions. CONCLUSION: In this first ever long term follow up study of EBT, significantly shortened survival is observed. Though splenectomy allows prolonged transfusion free phases in many it increases risk of infective deaths. Overall the disease is far less benign than previously thought with a high prevalence of morbidity and mortality.Item Hepcidin is suppressed by erythropoiesis in hemoglobin E β-thalassemia and β-thalassemia trait(American Society of Hematology, 2015) Jones, E.; Pasricha, S.R.; Allen, A.; Evans, P.; Fisher, C.A.; Wray, K.; Premawardhena, A.; Bandara, D.; Perera, A.; Webster, C.; Sturges, P.; Olivieri, N.F.; St Pierre, T.; Armitage, A.E.; Porter, J.B.; Weatherall, D.J.; Drakesmith, H.Hemoglobin E (HbE) β-thalassemia is the most common severe thalassemia syndrome across Asia, and millions of people are carriers. Clinical heterogeneity in HbE β-thalassemia is incompletely explained by genotype, and the interaction of phenotypic variation with hepcidin is unknown. The effect of thalassemia carriage on hepcidin is also unknown, but it could be relevant for iron supplementation programs aimed at combating anemia. In 62 of 69 Sri Lankan patients with HbE β-thalassemia with moderate or severe phenotype, hepcidin was suppressed, and overallhepcidin inversely correlated with iron accumulation. On segregating by phenotype, there were no differences in hepcidin, erythropoiesis, orhemoglobin between severe or moderate disease, but multiple linear regression showed that erythropoiesis inversely correlated with hepcidin only in severe phenotypes. In moderate disease, no independent predictors of hepcidin were identifiable; nevertheless, the low hepcidin levels indicate a significant risk for iron overload. In a population survey of Sri Lankan schoolchildren, β-thalassemia (but not HbE) trait was associated with increased erythropoiesis and mildly suppressed hepcidin, suggesting an enhanced propensity to accumulate iron. In summary, the influence oferythropoiesis on hepcidin suppression associates with phenotypic disease variation and pathogenesis in HbE β-thalassemia and indicates that the epidemiology of β-thalassemia trait requires consideration when planning public health iron interventions.Item Techniques for primary screening for haemoglobinpathies in Sri Lanka: a comparison of single tube osmotic fragility (STOP) and dye test {DCIP) vs full blood count (FBC)(Sri Lanka Medical Association, 2007) Premawardhena, A.P.; Williams, S.; Idirisinghe, A.; Allen, A.; Olivieri, N.F.; Weatherall, D.J.INTRODUCTION: Techniques best suited for haemoglobinopathy screening of the Sri Lankan population need to be determined. Full blood count is used to detect p thalassaemia trait but is affected by iron deficiency. Its ability to detect haemoglobin (Hb) E is less certain. Alternative tests for screening include single tube osmotic fragility (STOP) test (for [5 thalassaemia) and a dye test (DCIP) for HbE. However there is no consensus regarding their usage in population surveys. OBJECTIVES: To decide the validity of STOP and DCIP test as screening tests for haemoglobin disorders in Sri Lanka. DESIGN, SETTING AND METHODS: Blood samples of volunteers attending an educational campaign held at the Faculty of Medicine, Ragama were tested using STOP, DCIP and FBC, and the results compared with the "gold standard" HPLC (high performance liquid chromatography) Results: 1062 individuals participated. HPLC identified 27 p traits and 3 HbE carriers. A total of 508 subjects had either MCV < 80 or MCH <27 on FBC, which included 26 of the p traits and all with HbE. The rest were presumably iron deficient. Only 56 subjects had a positive STOF test including 26 with p trait. 34 had a positive DCIP test including all three HbE carriers. One person with HbA2 of 3.5% had a normal MCV, MCH, negative STOF and negative DCIP. STOF test had a sensitivity and specificity of 96% and 97% for p trait. The DCIP had a sensitivity and specificity of 100% and for the detection of Hb E. CONCLUSIONS: Both STOF and DCIP are excellent tests for primary screening. The STOF is a superior test for screening thalassaemias than FBC in populations with high prevalence of iron deficiency.Item Cardiac functions in older patients with haemoglobin E- β thalassaemia(Sri Lanka Medical Association, 2007) Premawardhena, A.P.; Wanninayake, S.; Dolapihilla, S.N.; Kapuruge, L.; Katugaha, N.; Olivieri, N.F.; Weatherall, D.J.INTRODUCTION: Cardiac disease accounts for most deaths in patients with thalassaemia. Little is known about cardiac functions in ageing patients with thalassaemia OBJECTIVE: To study cardiac functions in older patients with haemoglobin E - p thalassaemia. DESIGN, SETTING AND METHODS: All patients with haemoglobin E - p thaiassaemia over the age of 24 attending the Thalassaemia Centre at Kurunegala were studied. Data were collected on biographs, transfusion load, body iron loads, ischaemic heart disease risk factors and symptoms and signs of heart disease. Serum lipids, 2D-echo and exercise ECG in addition to basic biochemical investigations were assessed in all. Those with a positive exercise ECG underwent stress echocardiography. Data from age-sex matched "healthy" individuals from the same geographic area were used for comparison. RESULTS: Total of 26 patients and 26 controls were studied. The median age was 34.25 years (24-50). Fourteen females were present in either group. 24% of controls, but-none in thalassaemic families had a family history of ischaemic heart disease. Twelve patients with thalassaemia and one control had a positive exercise ECG. All 12 with positive exercise ECG had normal stress echocardiography. Severe hypocholesterolaemia (mean total cholesterol 90.5 vs 376.9mg/dl) was present in all patients with thalassaemia. Pulmonary hypertension was noted in 7 patients with thalassaemia (not in controls). Nine patients with thalassaemia but none of the controls showed diastolic dysfunction. CONCLUSION: The study shows unique cardiac abnormalities that occur in patients with haemoglobin E- β thalassaemia. The marked hypocholesterolaemia may reduce the risk of ischaemic heart disease but significant right heart damage seems to occur in these chronically anaemic patients.Item Interaction of malaria with a common form of severe thalassemia in an Asian population(National Academy of Sciences, 2009) O Donnell, A.; Premawardhena, A.; Arambepola, M.; Samaranayake, R.; Allen, S.J.; Peto, T.E.; Fisher, C.A.; Cook, J.; Corran, P.H.; Olivieri, N.F.; Weatherall, D.J.In many Asian populations, the commonest form of severe thalassemia results from the coinheritance of HbE and beta thalassemia. The management of this disease is particularly difficult because of its extreme clinical diversity; although some genetic and adaptive factors have been identified as phenotypic modifiers, the reasons remain unclear. Because the role of the environment in the course of severe thalassemia has been neglected completely and because malaria due to both Plasmodium falciparum and Plasmodium vivax has been prevalent in Sri Lanka, we carried out a pilot study of patients with HbE beta thalassemia that showed high frequencies of antibodies to both parasite species and that 28.6% of the children had DNA-based evidence of current infection with P. vivax. Malarial antibodies then were assessed in patients with HbE beta thalassemia compared with those in age-matched controls. There was a significant increase in the frequency of antibodies in the thalassemic patients, particularly against P. vivax and in young children. There was also a higher frequency in those who had been splenectomized compared with those with intact spleens, although in the latter it was still higher than that in the controls. The thalassemic patients showed significant correlations between malaria antibody status and phenotype. Patients with HbE beta thalassemia may be more prone to malaria, particularly P. vivax, which is reflected in their clinical severity. Because P. vivax malaria is widespread in Asia, further studies of its interaction with HbE beta thalassemia and related diseases are required urgently as a part of ongoing thalassemia control programs.Item Age-related changes in adaptation to severe anemia in childhood in developing countries(National Academy of Sciences, 2007) O Donnell, A.; Premawardhena, A.; Arambepola, M.; Allen, S.J.; Peto, T.E.; Fisher, C.A.; Rees, D.C.; Olivieri, N.F.; Weatherall, D.J.Severe forms of anemia in children in the developing countries may be characterized by different clinical manifestations at particular stages of development. Whether this reflects developmental changes in adaptation to anemia or other mechanisms is not clear. The pattern of adaptation to anemia has been assessed in 110 individuals with hemoglobin (Hb) E beta-thalassemia, one of the commonest forms of inherited anemia in Asia. It has been found that age and Hb levels are independent variables with respect to erythropoietin response and that there is a decline in the latter at a similar degree of anemia during development. To determine whether this finding is applicable to anemia due to other causes, a similar study has been carried out on 279 children with severe anemia due to Plasmodium falciparum malaria; the results were similar to those in the patients with thalassemia. These observations may have important implications both for the better understanding of the pathophysiology of profound anemia in early life and for its more logical and cost-effective management.Item A Novel molecular basis for beta thalassemia intermedia poses new questions about its pathophysiology(American Society of Hematology, 2005) Premawardhena, A.; Fisher, C.A.; Olivieri, N.F.; de Silva, S.; Sloane-Stanley, J.; Wood, W.G.; Weatherall, D.J.During a study of the molecular basis for severe forms of beta thalassemia in Sri Lanka, 2 patients were found to be heterozygous for beta thalassemia mutations. Further analysis revealed that one of them has a previously unreported molecular basis for severe thalassemia intermedia, homozygosity for quadruplicated alpha globin genes in combination with heterozygous beta thalassemia. The other is homozygous for a triplicated alpha globin gene arrangement and heterozygous for beta thalassemia. Their differences in clinical phenotype are explainable by the interaction of other genetic factors and, in particular, their early management. The clinical course of the 2 propositi underlines the importance of full genotyping and a long period of observation before treatment is instituted, particularly in patients with beta thalassemia intermedia associated with extended alpha globin gene arrangements. The hemoglobin (Hb) F levels in these patients with severe beta thalassemia intermedia, compared with other forms of this condition in the Sri Lankan population and elsewhere, are unusually low, a consistent finding in extended alpha globin gene interactions and in dominant beta thalassemia, raising the possibility that increased levels of HbF production in beta thalassemia may require mutations at both beta globin gene loci