Introduction: Multiply transfused patients are frequently subjected to platelet alloimmunization. These platelet alloantibodies produced can result in refractoriness to platelet transfusion. Material and Methods: Ninety five thrombocytopenic (platelet count
Transplantation and transfusion are related and clinically important areas of multidisciplinary expertise, including pre-operative treatment, donor recruitment, tissue matching, and post-operative care. We have seen significant developments in these areas, especially in the late 20th and early 21st century. This paper reviews the latest advances in modern transplantation and transfusion medicine, including several new genetic markers (e.g., major histocompatibility complex class I chain-related gene A, killer cell immunoglobulin-like receptor, and human platelet antigens) for donor and recipient matching, genotyping platforms (e.g., next-generation sequencer and Luminex technology), donor recruitment strategies, and several clinical applications in which genotyping has advantages over agglutination tests (e.g., genotyping of weakly expressed antigens and determination of blood groups and human leukocyte antigen types in multi-transfused patients). We also highlight the roles of population studies and international collaborations in moving towards more efficient donor recruitment strategies.
Human platelet antigens (HPA) are determinant in several platelet-specific alloimmune disorders, such as neonatal alloimmune thrombocytopenia, post-transfusion purpura and platelet transfusion refractoriness. The distribution of HPA systems in the Malaysian population is not known. Defining the patterns of HPA systems provides a basis for risk assessment and management of the above complications.
Matched MeSH terms: Antigens, Human Platelet/genetics*
Neonatal alloimmune thrombocytopaenia (NAIT) generally results from platelet opsonisation by maternal antibodies against fetal platelet antigens inherited from the infant's father. Newborn monochorionic twins presented with petechial haemorrhages at 10 hours of life, along with severe thrombocytopaenia. Despite the initial treatment with platelet transfusions and intravenous immunoglobulin, they both had persistent thrombocytopaenia during their first 45 days of life. Class I human leucocyte antigen (HLA) antibodies with broad specificity against several HLA-B antigens were detected in the maternal serum. Weak antibodies against HLA-B57 and HLA-B58 in sera from both twins supported NAIT as the most likely diagnosis. Platelet transfusion requirements of the twins lasted for 7 weeks. Transfusion of HLA-matched platelet concentrates was more efficacious to manage thrombocytopaenia compared with platelet concentrates from random donors. Platelet genotyping and determination of HLA antibody specificity are needed to select compatible platelet units to expedite safe recovery from thrombocytopaenia in NAIT.
Matched MeSH terms: Antigens, Human Platelet/blood*
This article explores the genetic history of the various sub-populations currently living in Peninsular Malaysia. This region has received multiple waves of migrants like the Orang Asli in prehistoric times and the Chinese, Indians, Europeans and Arabs during historic times. There are three highly distinct lineages that make up the Orang Asli; Semang, Senoi and Proto-Malays. The Semang, who have 'Negrito' characteristics, represent the first human settlers in Peninsular Malaysia arriving from about 50,000ya. The Senoi later migrated from Indochina and are a mix between an Asian Neolithic population and the Semang. These Asian genomes probably came in before Austroasiatic languages arrived between 5000 and 4000years ago. Semang and Senoi both now speak Austro-Asiatic languages indicative of cultural diffusion from Senoi to Semang. In contrast, the Proto-Malays who came last to the southern part of this region speak Austronesian language and are Austronesians with some Negrito admixture. It is from this group that the contemporary Malays emerged. Here we provide an overview of the best available genetic evidences (single nucleotide polymorphisms, mitochondrial DNA, Y-chromosome, blood groups, human platelet antigen, human leukocyte antigen, human neutrophil antigen and killer-cell immunoglobulin-like receptor) supporting the complex genetic history of Peninsular Malaysia. Large scale sampling and high throughput genetic screening programmes such as those using genome-wide single nucleotide polymorphism analyses have provided insights into various ancestral and admixture genetic fractions in this region. Given the now extensive admixture present in the contemporary descendants of ancient sub-populations in Peninsular Malaysia, improved reconstruction of human migration history in this region will require new evidence from ancient DNA in well-preserved skeletons. All other aspects of the highly diverse and complex genetic makeup in Peninsular Malaysia should be considered carefully for genetic mapping of disease loci and policy formation by health authorities.