Thalassemia in Asia 2021 Thalassemia in Brunei Darussalam.

Acknowledging and understanding the extent of thalassemia and hemoglobinopathy issues in a country is crucial for the benefit of implementing a national preventive and control program to reduce its prevalence. In order to obtain reliable prevalence data, the gene frequencies of the thalassemias and other hemoglobinopathies should be investigated. Molecular studies on thalassemia have yet to be done for Brunei's population. It was estimated that carriers of thalassemia or hemoglobinopathies in Brunei is approximately 5.0% or less of the overall population. There are about 200 current cases of thalassemia and other hemoglobinopathies including adults and children reported across all four districts of Brunei. Blood parameter analysis, microscopy, hemoglobin (Hb) electrophoresis and high performance liquid chromatography (HPLC) are the most common methods of investigation in aiding diagnosis in the hospital laboratory. Genotyping analysis conducted in an overseas laboratory has been employed to confirm some diagnosis. Compiled data from 2009-2017 at the Hematology Laboratory of the Raja Isteri Pengiran Anak Saleha Hospital, Jalan Putera Al-Muhtadee Billah, Bandar Seri Begawan, Brunei Darussalam, showed that the most reported diagnoses are α-thalassemia (α-thal) trait, ß-thalassemia (ß-thal) trait, heterozygous Hb E (HBB: c.79G>A)/ß-thal, ß-thal major (ß-TM) and ß-thal intermedia (ß-TI). The data reported indicate the importance of establishing a thalassemia registry with relevant data on patients and patient outcomes as a tool for monitoring and improving patient care.

Fibrin clot structure remains unaffected in young, healthy individuals after transient exposure to diesel exhaust.

Exposure to urban particulate matter has been associated with an increased risk of cardiovascular disease and thrombosis. We studied the effects of transient exposure to diesel particles on fibrin clot structure of 16 healthy individuals (age 21-44). The subjects were randomly exposed to diesel exhaust and filtered air on two separate occasions. Blood samples were collected before exposure, and 2 and 6 hours after exposure. There were no significant changes on clot permeability, maximum turbidity, lag time, fibre diameter, fibre density and fibrinogen level between samples taken after diesel exhaust exposure and samples taken after filtered air exposure. These data show that there are no prothrombotic changes in fibrin clot structure in young, healthy individuals exposed to diesel exhaust.

Alteration of fibrin clot properties by ultrafine particulate matter.

Both long- and short-term (1-2 hours) exposure to particulate matter (PM) are associated with morbidity and mortality caused by cardiovascular diseases. One of the underlying mechanisms may be due to changes to blood coagulability upon exposure to PM. We investigated this possibility by measuring differences in blood clots formed in the presence of particulate matter in vitro. Total (T)PM increased the permeation of clots in a dose-dependant manner. Filtered (F)PM (17 microg/ml) also produced a significant increase in permeation. Turbidity measured as maximum optical density (ODmax) was increased in a dose-dependant manner with increasing concentration of TPM and FPM. Turbidity measurements also showed a significantly faster rate of polymerisation in the presence of 68 microg/ml FPM. Laser scanning confocal microscopy (LSCM) showed a decrease in fibre density without a significant increase in fibre diameter. However, LSCM showed increased clot heterogeneity due to fibre clustering, creating areas of denser fibrin network surrounded by looser network. The presence of reactive oxygen species (ROS) scavenger mannitol inhibited the effects on fibre clustering. Our data show that TPM and FPM cause alterations in fibrin clot structure, likely through the formation of ROS. These changes in fibrin clot structure may play a role in thromboembolic events upon PM exposure.