Browsing by Author "Darshana, T."

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Hydroxyurea and blood transfusion therapy for Sickle cell disease in South Asia: inconsistent treatment of a neglected disease
(BioMed Central, 2021) Darshana, T.; Rees, D.; Premawardhena, A.
BACKGROUND: Hydroxyurea and blood transfusion therapies remain the main therapeutic strategies for Sickle cell disease. Preliminary data suggest substantial variation and inconsistencies in practice of these two therapeutic modalities in South Asia. In this systematic review we searched Medline, Cochrane library and Scopus for articles on usage of hydroxyurea and blood transfusion therapies for sickle cell disease in South Asia published in English between October 2005 and October 2020. RESULTS: We selected 41 papers: 33 from India, 3 from Sri Lanka, 2 each from Pakistan and Bangladesh and one from Nepal. Only 14 prospective trials focused on hydroxyurea therapy from which majority (n = 10; 71.4%) adopted fixed low dose (10 mg/kg/day) regimen. With hydroxyurea therapy, 12 and 9 studies reported significant reductions in vaso-occlusive crises and transfusion requirement respectively. Severe anaemia (haemoglobin level < 6-7 g/dl) was the commonest indicator (n = 8) for transfusion therapy followed by vaso-occlusive crisis. CONCLUSIONS: Published data on the hydroxyurea and transfusion therapies in South Asia are limited and heterogeneous. A clear gap of knowledge exists about the nature of the sickle cell disease in the Indian subcontinent particularly from countries outside India necessitating further evidence-based assessments and interventions. KEYWORDS: Blood transfusion; Hydroxyurea; Sickle cell; South Asia.
Oxidative status in the β-thalassemia syndromes in Sri Lanka; a cross-sectional survey
(Elsevier Science-Pergamon Press, 2021) Allen, A.; Perera, S.; Mettananda, S.; Rodrigo, R.; Perera, L.; Darshana, T.; Moggach, F.; Crawford, A.J.; Heirene, L.; Fisher, C.; Olivieri, N.; Rees, D.; Premawardhena, A.; Allen, S.
ABSTRACT: In the β-thalassemias, oxidative stress, resulting from chronic hemolysis, globin chain imbalance, iron overload and depleted antioxidant defences, likely contributes to cell death, organ damage, anemia, hypoxia and inflammation. We assessed variations in these parameters in β-thalassemia syndromes in Sri Lanka. Between November 2017 and June 2018, we assessed children and adults attending two thalassemia centres in Sri Lanka: 59 patients with HbE β-thalassemia, 50 β-thalassemia major, 40 β-thalassemia intermedia and 13 HbS β-thalassemia. Median age was 26.0 years (IQR 15.3-38.8), 101 (62.3%) were female and 152 (93.8%) of Sinhalese ethnicity. Methemoglobin, plasma hemoglobin, heme and ferritin were measured as sources of oxidants; plasma total antioxidant capacity, haptoglobin, hemopexin and vitamins C and E assessed antioxidant status; plasma thiobarbituric acid reactive substances and 8-hydroxy-2'-deoxyguanosine assessed oxidative damage; hemoglobin, plasma erythropoietin and transferrin receptor assessed anemia and hypoxia and plasma interleukin-6 and C-reactive protein assessed inflammation. Fruit and vegetable intake was determined by dietary recall. Physical fitness was investigated using the six-minute walk test and measurement of handgrip strength. Oxidant sources were frequently increased and antioxidants depleted, with consequent oxidative damage, anemia, hypoxia and inflammation. Biomarkers were generally most abnormal in HbE β-thalassemia and least abnormal in β-thalassemia intermedia but also varied markedly between individuals with the same thalassemia syndrome. Oxidative stress and damage were also more severe in splenectomized patients and/or those receiving iron chelation therapy. Less than 15% of patients ate fresh fruits or raw vegetables frequently, and plasma vitamins C and E were deficient in 132/160 (82.5%) and 140/160 (87.5%) patients respectively. Overall, physical fitness was poor in all syndromes and was likely due to anemic hypoxia. Studies of antioxidant supplements to improve outcomes in patients with thalassemia should consider individual patient variation in oxidative status both between and within the thalassemia syndromes. KEYWORDS: antioxidants; oxidative damage; oxidative stress; thalassemia; vitamins C and E.
Oxidative stress and antioxidant deficiency in the β-thalassaemia in Sri Lanka
(Sri Lanka Medical Association, 2021) Perera, S.; Allen, A.; Mettananda, S.; Rodrigo, R.; Perera, L.; Darshana, T.; Moggach, F.; Jackson-Crawford, A.; Heirene, L.; Fisher, C.; Olivieri, N.; Rees, D.; Allen, S.; Premawardhena, A.
Introduction In the β thalassaemias oxidative stress is potentially high and this could be further exacerbated in the absence of robust antioxidant defences, such as nutritional vitamin C and E deficiencies. We undertook a comprehensive assessment of oxidant, antioxidant and inflammatory status in patients with subtypes of β-thalassaemia to study these factors in detail. Methods Consenting patients attending the thalassaemia centre in Ragama, (between November 2017 and June 2018) were assessed for the following: methaemoglobin, plasma haemoglobin, heme and ferritin as sources of oxidants, plasma haptoglobin, hemopexin and vitamins C and E as markers of antioxidants, plasma interleukin-6 and C-reactive protein for inflammation. Fruit and vegetable intake was determined by dietary recall. Results 162 patients were recruited. (59 HbE β-thalassaemia, 50 β-thalassaemia major, 40 β-thalassaemia intermedia, 13 HbS β-thalassaemia. Median age was 26.0 years (IQR 15.3-38.8), 101 (62.3%) were female. Oxidants were frequently increased and antioxidants depleted with high levels of oxidant damage, hypoxia and inflammation. Abnormalities were most severe in HbE-β thalassaemia and least severe in β thalassaemia intermedia. Oxidative stress was also more severe in splenectomised patients. Plasma vitamin C concentration was below the lower level of quantitation in 86/160 (53.8%) patients and vitamin E in 130/160 (81.3%) patients. Less than 15% of patients ate fresh fruits or raw vegetables frequently. Conclusion Markedly increased oxidative stress and antioxidant deficiency were observed in this study group, especially in those with HbE β-thalassaemia. Vitamin C & E supplementation may have a role in the long-term management of thalassaemia syndromes.
Possible Application of Sickling Test in Haemoglobinopathy Screening of Sri Lanka.
(19th Conference on Postgraduate Research, International Postgraduate Research Conference 2018, Faculty of Graduate Studies,University of Kelaniya, Sri Lanka, 2018) Darshana, T.; Perera, N.; Manamperi, A.; Premawardhena, A.
The national screening programme for thalassaemia in Sri Lanka is currently using Full blood count (FBC) with red cell indices as the technique to identify haemoglobinopathies. This approach is likely to miss sickle haemoglobin (Hb-S) as it is well known that Hb-S is not associated with hypochromic microcytosis. Sickling test is a low cost microscopic screening test which detects sickle cell by its characteristic appearance. Therefore, the present study was undertaken to assess the performance of sickling test in identifying Hb-S among relatively high risk population in Hambantota district. A total of 581 school children (grade 11) were selected randomly from 5 schools in Hambantota district. 2 ml of EDTA blood sample was collected from each participant after obtaining informed assent and consent. Screening panel comprises with sickling test by sodium metabisulphite method, one tube osmotic fragility test, dichlorophenol indophenol test (DCIP), FBC and Zinc protoporphyrin test (ZPP). Haemoglobinphenotyping of each sample was confirmed by capillary electrophoresis technique. Four students out of 581 had sickle trait. Three other types of haemoglobinopathies were detected including β-thalassaemia trait (n=17), haemoglobin D trait (n=2) and haemoglobin E trait (n=1). 8% (n=44) had iron deficiency. All 4 cases with sickle trait were positive for sickling test and all other cases were negative. None of the Hb-S case demonstrated hypochromic microcytosis in FBC.The average time taken for red cells with Hb-S to assume the characteristic sickle shape was 28 minutes and 45 seconds. Sickling test demonstrated 100 % sensitivity and 100 % specificity in identifying sickle trait. Our results indicate depending solely on haemoglobin level and red cell indices is inappropriate since all of the sickle trait individuals would have been missed if sickling test was not done. Hence, the adaptation of sickling test can be recommended along with the Full Blood Count test when screening individuals for haemoglobinopathies in Sri Lanka
Pyrexia of unknown origin (PUO) and the cost of care in a tertiary care institute in Sri Lanka
(BioMed Central, 2023) Premathilaka, R.; Darshana, T.; Ekanayake, C.; Chathurangani, K.C.; Mendis, I.; Perinparajah, S.; Shashiprabha, M.; Nishshanka, S.; Tilakaratna, Y.; Premawardhena, A.
BACKGROUND: Despite advancements in diagnostic technology, pyrexia of unknown origin (PUO) remains a clinical concern. Insufficient information is available regarding the cost of care for the management of PUO in the South Asian Region. METHODS: We retrospectively analyzed data of patients with PUO from a tertiary care hospital in Sri Lanka to determine the clinical course of PUO and the burden of the cost incurred in the treatment of PUO patients. Non-parametric tests were used for statistical calculations. RESULTS: A total of 100 patients with PUO were selected for the present study. The majority were males (n = 55; 55.0%). The mean ages of male and female patients were 49.65 (SD: 15.55) and 46.87 (SD: 16.19) years, respectively. In the majority, a final diagnosis had been made (n = 65; 65%). The mean number of days of hospital stay was 15.16 (SD; 7.81). The mean of the total number of fever days among PUO patients was 44.47 (SD: 37.66). Out of 65 patients whose aetiology was determined, the majority were diagnosed with an infection (n = 47; 72.31%) followed by non-infectious inflammatory disease (n = 13; 20.0%) and malignancies (n = 5; 7.7%). Extrapulmonary tuberculosis was the most common infection detected (n = 15; 31.9%). Antibiotics had been prescribed for the majority of the PUO patients (n = 90; 90%). The mean direct cost of care per PUO patient was USD 467.79 (SD: 202.81). The mean costs of medications & equipment and, investigations per PUO patient were USD 45.33 (SD: 40.13) and USD 230.26 (SD: 114.68) respectively. The cost of investigations made up 49.31% of the direct cost of care per patient. CONCLUSION: Infections, mainly extrapulmonary tuberculosis was the most common cause of PUO while a third of patients remained undiagnosed despite a lengthy hospital stay. PUO leads to high antibiotic usage, indicating the need for proper guidelines for the management of PUO patients in Sri Lanka. The mean direct cost of care per PUO patient was USD 467.79. The cost of investigations contributed mostly to the direct cost of care for the management of PUO patients.
Sickle cell disease in Sri Lanka: clinical and molecular basis and the unanswered questions about disease severity
(BioMed Central., 2020) Darshana, T.; Bandara, D.; Nawarathne, U.; de Silva, U.; Costa, Y.; Pushpakumara, K.; Pathirage, S.; Basnayake, S.; Epa, C.; Dilrukshi, P.; Wijayawardena, M.; Anthony, A. A.; Rodrigo, R.; Manamperi, A.; Smith, F.; Allen, A.; Menzel, S.; Rees, D.; Premawardhena, A.
BACKGROUND: Though case reports and limited case series of Sickle cell disease in Sri Lanka have been reported previously, no attempt has been made hitherto to undertake a comprehensive genotypic-phenotypic analysis of this "rare" group of patients. RESULTS: All accessible Sickle cell disease patients, totaling 60, including, 51 Sickle β-thalassaemia and 9 homozygous sickle patients were enrolled from seven thalassaemia treatment centres between December 2016-March 2019. The majority of patients were of Sinhalese ethnicity (n = 52, 86.67%). Geographically, two prominent clusters were identified and the distribution of Sickle haemoglobin in the island contrasted markedly with the other haemoglobinopathies. 3/ 9 homozygous sickle patients and 3/ 51 Sickle β-thalassaemia patients were receiving regular transfusion. Joint pain was the commonest clinical symptom among all sickle cell disease patients (n = 39, 65.0%). Dactylitis was significantly more common in homozygous sickle patients compared with the Sickle β-thalassaemia groups (p 0.027). Two genetic backgrounds sickle mutation were identified namely, Arab Indian and Benin. Among the regulators of Foetal hemoglobin in Sickle patients of the present study rs1427407 G > T seemed to be the most prominent modifier, with a significant association with Foetal haemoglobin levels (p 0.04). CONCLUSIONS: Overall, the clinical course of the Asian version of Sickle cell disease in Sri Lanka appears to be milder than that described in India. KEYWORDS: Clinical; Genetic; Severity; Sickle cell; Sri Lanka.