Journal/Magazine Articles

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This collection contains original research articles, review articles and case reports published in local and international peer reviewed journals by the staff members of the Faculty of Medicine

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    Anemia in Sri Lanka: A literature review
    (Informa Healthcare, 2022) Amarasingha, A.A.D.S.; Silva, H.J.R.L.; Perera, P.S.; Premawardhena, A.P.
    Anemia is a global health problem. This paper reviews literature on the prevalence of anemia in Sri Lanka. We searched EBSCO (Elton Bryson Stephens Company), Cochrane Library, and Medline for articles on prevalence and molecular basis of anemia in Sri Lanka from January 2000 to May 2021. Forty articles were selected. Most of the studies were on prevalence of anemia among children and pregnant women. All the studies had restricted themselves to assess the contributing factors for anemia in limited age categories. Most articles had attempted to determine the overall prevalence of anemia and the contribution of iron deficiency to it. There were only a few studies on prevalence and molecular basis of hemoglobinopathies and even fewer on the prevalence of anemia of chronic disease. None of the studies had attempted to assess the national prevalence of red cell membranopathies and enzymopathies. The published data on prevalence of anemia in Sri Lanka are incomplete. This review emphasizes the value of a much broader survey on anemia covering all age categories including the elderly and conducting a national survey including anemia of chronic disease and on red cell membranopathies and enzymopathies in Sri Lanka.
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    Thalassemia in Sri Lanka
    (Informa Healthcare,London, 2022) Premawardhena, A.P.; Madushanka, H.D.P.
    The island nation of Sri Lanka with 22 million people (in 2020) has an estimated 2000 patients with severe thalassemia. The majority have β-thalassemia (β-thal) major (β-TM), and Hb E (HBB: c.79G>A)/β-thal accounts for most of the remainder. Carrier rate for α+-thalassemia (α+-thal) trait is 9.9% and β-thal trait is 2.5%, with very similar rates in the three major ethnic groups (Sinhalese, Tamils and Moors). The distribution of thalassemia type reveals a remarkable variation, even in this small island, mirroring historical distribution of malaria. Even though healthcare is provided free by the state including blood transfusions and chelation, the overall survival of patients of β-TM is still not on a par with that of the Mediterranean countries. A national thalassemia prevention program was set up in 2007, but overall success of the exercise based essentially on dissuasion of marriages is not very promising.
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    Transfusion-transmitted Hepatitis C: A cluster of cases in transfusion-dependent Thalassaemia patients in Sri Lanka
    (Blackwell Scientific Publications,, 2020) Perera, S.; Bonsall, D.; Niriella, M.A.; Allen, A.; Peries, A.C.; Nelumdeniya, U.B.; Dissanayake, R.; Silva, I.; de Cesare, M.; Klenerman, P.; Weatherall, D.J.; Roberts, D. J.; Premawardhena, A.P.
    OBJECTIVES: To report the clinical and virologic epidemiology of a recent epidemic of hepatitis C in thalassaemia patients in Sri Lanka. BACKGROUND: Transfusion-dependent thalassaemia patients remain at risk for hepatitis C virus (HCV). Here, we report a cluster of recent HCV infections in Sri Lankan thalassaemia patients and examine the phylogenetic relationship of viral sequences. METHODS: We conducted two prospective cross-sectional surveys of 513 patients in four Sri Lankan thalassaemia centres in 2014/2015 and re-surveyed one centre in 2016. We screened for anti-HCV antibodies using the CTK Biotech enzyme-linked immunosorbent assay (ELISA) kits and confirmed active infection by reverse transcription-polymerase chain reaction (RT-PCR) for HCV-RNA. HCV genomes were sequenced by unbiased target enrichment. RESULTS: Anti-HCV antibodies were found in 116/513 (22.6%) of patients initially tested. Active hepatitis C infection was found in 26 patients with no cases of active hepatitis B infection. Of 26 patients with HCV, two were infected with genotype 1(a), and the rest had 3(a). In a single centre (Ragama), 122 patients (120 new cases and two previously tested, but negative) were retested for anti-HCV antibodies. 32/122 (26.2%) patients were seropositive. Twenty-three (23/122; 18.8%) of these new cases were confirmed by HCV PCR (all genotype 3[a]). CONCLUSIONS: There is a significant cluster of recent HCV cases in multiply transfused thalassaemia patients in several centres in Sri Lanka. Most of the viruses shared a close phylogenetic relationship. The results are consistent with recent continuing transfusion-transmitted HCV infection. Routine surveillance for HCV of chronically transfused patients is required irrespective of screening of blood products.
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    Role of red cell distribution width in screening for Hb Etrait in population ccreening for hemoglobin disorders
    (Lippincott Williams and Wilkins, 2014) Nishad, A.A.N.; de Silva, I.S.; Perera, H.L.; Pathmeswaran, A.; Kasturiratne, K.T.A.A.; Premawardhena, A.P.
    The national screening policy for hemoglobinopathies uses the cutoffs for red cell indices mean corpuscular volume >80 and mean corpuscular hemoglobin >27, a strategy known to miss some individuals with Hb E trait (EBT), the most common abnormal hemoglobin in Sri Lanka. We wanted to determine if red cell distribution width (RDW) cutoff values would help in increasing the sensitivity of screening for Hb E trait. High-performance liquid chromatography was carried out as the gold standard to detect hemoglobinopathies and red blood cell parameters with colter counter. Receiver operating characteristic curve was drawn to determine the cutoff value for EBT against β-trait (BTT) and other anemias. Of the 504 patients, 246 had BTT, 110 had EBT, and 151 had other types of anemias. Mean (SD) RDW among patients with BTT was 16 (2.8), with EBT 14.5 (2.9), and with other anemias 15.8 (4.2) (P>0.001). With 14.45 as the cutoff for RDW and considering accepted values for mean corpuscular volume >80 and mean corpuscular hemoglobin >27, it gave a predictive sensitivity of 98.2% for EBT. By using RDW cutoff at 14.45 in addition to the accepted screening indices, sensitivity of Hb E trait detection went up to 98.2% from 86.6%. This study highlights the importance of taking RDW into consideration for screening
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    Mycotic aneurysm of the descending aorta due to Aspergillus species
    (Sri Lanka Medical Association, 2010) Mettananda, K.C.D.; de Silva, S.T.; Premawardhena, A.P.
    Mycotic aneurysms of the aorta are rare, and carry a poor prognosis unless detected and treated promptly. Aneurysms caused by Aspergillus species usually occur due to invasive pulmonary aspergillosis, septic embolisation or direct extension from the lung, mainly in immuno-compromised individuals. We report a case of descending aortic aneurysm caused by Aspergillus species in a previously immuno-competent individual
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    Cushing syndrome due to an adrenal phaeochromocytoma
    (Sri Lanka Medical Association, 2006) Gunasekara, A.D.C.J.; Premawardhena, A.P.; Hettiarachchi, H.A.N.S.; Rathnasena, B.G.N.; de Silva, H.J.
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    Thalassemia in Sri Lanka: a progress report
    (Oxford University Press, 2004) Premawardhena, A.P.; de Silva, S.; Arambepola, M.; Olivieri, N.; Merson, L.; Muraco, J.; Allen, A.; Fisher, C.A.; Peto, T.; Vichinsky, E.; Weatherall, D.J.
    The thalassemias pose an increasing burden for health-care services in many Asian countries. In order to conserve rare resources, it is essential to determine the reasons for the remarkable phenotypic heterogeneity and natural history of these disorders so that the most cost-effective methods for their control and management can be established. A long-term observational study of patients with different forms of thalassemia in Sri Lanka suggests that in addition to the well-defined primary, secondary and tertiary genetic modifiers, environmental factors, particularly malaria, and variation in the ability to adapt to the profound anaemia which characterizes these conditions, may play a significant role in determining their clinical severity. These findings may have important implications for the control and management of thalassemia in Asian populations
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    The Global distribution of length polymorphisms of the promoters of the gucuronosyltransferase I gene(UGTIAI): hematologic and evolutionary implications
    (Academic Press, 2003) Premawardhena, A.P.; Fisher, C.A.; Liu, Y.T.; Verma, I.C.; de Silva, S.; Arambepola, M.; Clegg, J.B.; Weatherall, D.J.
    The promoter region of the UDP glucuronosyltransferase 1 gene (UGT1A1) contains a run of thymine-adenine (TA) repeats, usually six (TA)(6). As well as its relationship to Gilbert's syndrome, homozygosity for the extended sequence, (TA)(7) (TA)(7), has been found to be an important risk factor for hyperbilirubinemia and gallstones in patients with hemoglobin E-beta-thalassemia and other intermediate forms of beta thalassemia. To assess the importance of this polymorphism in these common disorders a wide-scale population study of the relative frequency of the size alleles of the UGT1A1 promoter has been carried out. Homozygosity for the (TA)(7) allele occurs in 10-25% of the populations of Africa and the Indian subcontinent, with a variable frequency in Europe. It occurs at a much lower frequency in Southeast Asia, Melanesia, and the Pacific Islands, ranging from 0 to 5%. African populations show a much greater diversity of length alleles than other populations. These findings define those populations with a high frequency of hemoglobin E-beta-thalassemia and related disorders that are at increased risk for hyperbilirubinemia and gall bladder disease and provide evolutionary insights into how these polymorphisms have arisen and are so unequally distributed among human populations.
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    The Molecular basis for the thalassaemias in Sri Lanka
    (Wiley-Blackwell, 2003) Fisher, C.A.; Premawardhena, A.P.; de Silva, S.; Perera, G.; Rajapaksa, S.; Olivieri, N.A.; Old, J.M.; Weatherall, D.J.; Sri Lanka Thalassaemia Study Group
    The beta-globin gene mutations and the alpha-globin genes of 620 patients with the phenotype of severe to moderate thalassaemia from seven centres in Sri Lanka were analysed. Twenty-four beta-globin gene mutations were identified, three accounting for 84.5% of the 1240 alleles studied: IVSI-5 (G-->C) 56.2%; IVSI-1 (G-->A) 15.2%; and haemoglobin E (codon (CD)26 GAG-->GAA) 13.1%. Three new mutations were found; a 13-bp deletion removing the last nucleotide in CD6 to CD10 inclusively, IVSI-129 (A-->C) in the consensus splice site, and a frame shift, CD55 (-A). The allele frequency of alpha+ thalassaemia was 6.5% and 1.1% for -alpha3.7 and -alpha4.2 deletions respectively. Non-deletion alpha-thalassaemia was not observed. Triplicate or quadruplicate alpha-globin genes were unusually common. In 1.5% of cases it was impossible to identify beta-thalassaemia alleles, but in Kurunegala detailed family studies led to an explanation for the severe thalassaemia phenotype in every case, including a previously unreported instance of homozygosity for a quadruplicated alpha-globin gene together with beta-thalassaemia trait. These findings have implications for the control of thalassaemia in high-frequency populations with complex ethnic histories.
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    Genetic determinants of jaundice and gallstones in haemoglobin E beta thalassaemia
    (2001) Premawardhena, A.P.; Fisher, C.A.; Fathihu, F.; de Silva, S.; Perera, W.; Peto, T.E.; Olivieri, N.F.; Weatherall, D.J.
    Chronic hyperbilirubinaemia, gallstone formation, and gall bladder disease are unusually common in people with haemoglobin E beta thalassaemia in Sri Lanka. To determine whether this has a genetic basis we compared the bilirubin levels and frequency of gallstones in patients with different alleles of the UGT*1 gene. There was a significantly higher bilirubin level in those with the 7/7 genotypes compared with 6/6 and 6/7 genotype (p=0.032 and 0.0015 respectively), who also appeared more prone to gallstone formation. These results suggest that the UGT*1 genotpe is of importance in the genesis of gallstones in this population of patients.