Assalamualaikum WBK,
Salam Sejahtera kepada rakan-rakan saya sekelian, ibu-bapa, bakal ibu-bapa, pengunjung dan pembaca blog ini. Kepada pembaca dari beberapa syarikat tertentu, janganlah cetak rompak atikel ini ya!
Kali ini Saya ingin menterjemahkan beberapa jawapan kepada soalan popular (FAQ) yang diterbitkan di laman web Persatuan Bank Darah Amerika (American Association of Blood Banks – AABB www.aabb.org). Ini adalah hanya sebahagian dari soalan-soalan yang dijawab. Saya akan cuba menterjemahkan soalan-soalan yang lain jika masa mengizinkan, Insyallah.
Sebelum bermula, Saya ingin menyatakan perbezaan antara Keahlian AABB dan Akreditasi AABB. Semua yang ingin boleh membayar fi dan menjadi ahli AABB, tetapi tiada sesiapa di Malaysia yang mempunyai Akreditasi AABB. StemLife bukanya ahli dan tidak mempunyai Akreditasi AABB. Saya tidak sesekali pun inginkan adanya salah faham. Saya hanya menterjemahkan FAQ yang ada dalam laman web AABB. Petikan dibawah menyatakan betapa beratnya kesalahan mengunakkan logo AABB tanpa kebenaran.
”Only cord blood banks with a current accreditation have permission to use the AABB logo, and AABB investigates reports of misrepresentation or fraudulent use once the misuse is brought to its attention.”
Apakah itu Sel Darah Tali Pusat?
Darah Tali Pusat (DTP), yang pada satu ketika dianggap sebagai sisa buangan, sekarang diterima sebagai sumber sel stem hematopoetik (sel permulaan hematopoetik). DTP serupa dengan sel stem hematopoetik yang boleh didapati dalam sum-sum tulang dan sistem saluran darah. Sel-sel ini boleh digunakan dalam transplantasi sel stem untuk menambahkuatkan sistem imun pesakit, sepertimana sum-sum tulang dan sel stem dari sistem saluran darah digunakan dalam transplantasi untuk merawat penyakit malignan seperti lukemia dan penyakit bukan malignan seperti kepincangan sistem imun dan anemia aplastik, dan penyakit kongenital seperti anemia sel sikle dan talasemia. DTP mengandungi bermacam jenis sel darah, tetapi, hanya sel stem hematopoetik (sel stem pembina darah) sahaja yang berguna dalam transplantasi. Kegunaan lain untuk sel stem DTP masih dalam fasa penyelidikan. Setiap sumber (samada sum-sum tulang, sistem saluran darah, atau DTP) ada kelebihan dan kekuranganya dalam transplantasi. Pesakit perlu berbincang dengan Pakar sel stem sebelum membuat pilihan tentang sumber sel stem paling sesuai yang sepadan dengan pesakit. Pilihan yang sesuai akan bergantung kepada opsen yang sediada dan keadaan pesakit.
What are umbilical cord blood cells?
Umbilical cord blood (UCB), once regarded as biological waste, has become an accepted source of hematopoietic stem cells/hematopoietic progenitor cells (HSCs/HPCs), similar to those found in bone marrow and peripheral blood. These cells can be used to replenish a patient’s immune system by providing stem cells for transplantation, just as bone marrow or peripheral blood stem cell transplants can be used to treat malignant diseases such as leukemia and non-malignant diseases such as immune deficiencies and severe aplastic anemia, and congenital disorders such as sickle cell anemia and thalassemia. UCB contains many types of blood cells but only the hematopoietic — or blood-making — stem cells in the UCB are currently useful for transplant. Other uses of UCB stem cells are currently undergoing research. Each source of HPCs (bone marrow, peripheral blood or cord blood) has advantages and disadvantages associated with its use in a transplant. Decisions about the most appropriate source of stem cells — which must be matched by tissue type to some degree with the recipient — must be made by each patient in consultation with his or her physician based on available options.
Bagaimana Darah Tali Pusat dikumpulkan?
Sejurus selepas bayi dilahirkan, tali pusat akan dikepit dan dipotong. Jarum akan digunakan untuk menyalurkan darah dari saluran vena tali pusat kedalam beg derma darah. Oleh kerana proses ini dilakukan selepas kelahiran bayi, tiada risiko atau sakit dijangka kepada ibu atau bayi. Pengambilan darah boleh dilakukan samada sebelum atau selepas kelahiran uri. Tekniknya berbeza sedikit sesama doktor pakar. Beg DTP akan dilabel dan dihantar ke makmal untuk diproses, dibekukan dan disimpan. Jumlah darah yang diambil berbeza tetapi seringkali dari 50 hingga 200 ml (lebih kurang separuh sehingga secawan penuh).
How are cord blood cells collected?
After the delivery of a newborn, the umbilical cord is clamped and then cut. A needle is then used to draw the blood from the umbilical cord vein into a collection bag. Since this happens after delivery, there is no pain or risk to mother or infant. The collection may take place either before or after delivery of the placenta, and techniques vary slightly among physicians. The UCB product is labeled and shipped to the processing facility for processing, freezing and storage. The volume collected varies but usually ranges from 50 to 200 ml (about one-half to one cup).
Adakah Darah Tali Pusat patut disimpan dalam Beg atau Vail?
AABB menggalakkan inovasi dan penambahbaikan teknologi dan tidak mengesyorkan mana-mana teknik atau pembekal. Ini termasuk koleksi/pendermaan, pemprosesan dan simpanan DTP. Oleh kerana kebanyakkan DTP disalurkan ke dalam beg atau cara simpanan berlainan sebelum dihantar ke makmal untuk diproses, tiada sistem yang ”Tertutup” sepenuhnya. DTP yang didermakan juga besar kemungkinan tidak sterile (bersih dari kuman). Oleh itu, kebanyakan makmal pemprosesan beroperasi diantara sistem separuh-tertutup atau tertutup secara fungsi (termasuk pada masa pendermaan). Tiada definasi yang diterimapakai secara umum untuk mengambarkan proses yang tertutup sepenuhnya. Operasi pengambilan dan pemprosesan DTP secara teorinya mengambilkira bahawa lebih banyak kali DTP terdedah kepada luaran, lebih tinggilah peluang untuk DTP terdedah kepada kontaminasi secara tidak sengaja.
Perdebatan beg lawan vail agak kontroversi. Kerja-kerja awal dalam pemprosesan DTP dalam makmal penyelidikan termasuk pengunaan vail-krio. Vail kecil yang lebih kurang sais jari halus dewasa adalah tidak begitu mahal. DTP dibahagikan ke dalam beberapa vail yang kemudian diletakkan ke dalam kotak kecil untuk disimpan.
Pengamal-pengamal sistem vail ini berpendapat bahawa jika bidang sains simpanan sel stem dapat dimajukan kelak dimana hanya sedikit DTP sahaja diperlukan, maka keseluruhan simpanan DTP tidak perlu dicairkan. DTP secara umum hanya dapat dicairkan sekali sahaja tanpa kehilangan banyak sel stem hidup. Vail juga memerlukan kurang ruang simpanan oleh itu membolehkan lebih DTP disimpan dalam satu tanki simpanan. Sebaliknya, vail kecil lebih sukar untuk dilabel dengan kesemua maklumat yang diperlukan.
Beg simpanan khas untuk simpanan krio sudah direka. Beg ini lebih mahal dan memerluka ruang yang lebih dari vail. Satu kelebihan penggunaan Beg Krio adalah ia merupakan sistem yang lebih ”Tertutup” dan bukanya ”Terdedah” jadi mengurangkan risiko kontaminasi yang tidak sengaja. Satu lagi kelebihan sistem Beg Krio adalah ia membolehkan DTP yang disimpan dalam Beg disambungkan terus kepada sedikit sampel DTP yang disimpan asing dalam ”Tiub/Saluran Bersambung DTP” (Integral Segment). AABB memerlukan DTP disambungkan terus kepada sedikit sampel DTP yang disimpan dalam ”Integral Segment” supaya ujian lanjutan dapat dilakukan keatas sedikit sampel DTP itu. ”Integral Segment” dapat dibentuk apabila tiub/saluran yang bersambung kepada Beg yang mengandungi unit DTP dikepit supaya terbentuk ”Segment”. Sedikit DTP diasingkan tetapi masih bersambung dengan unit DTP asal. Ini dilakukan supaya ujian lanjutan dan konfirmasi keatas sampel DTP dapat dilakukan jika diperlukan.
Ini adalah penting kerana bank-bank sering menerima beberapa beg DTP sekali gus. Walaupun prosedur telah diadakan untuk menghalang dari berlakunya apa-apa pertukaran beg yang tidak diingini tanpa diketahui, malah persoalan dan keraguan mengenai tuan punya sebenar DTP itu masih wujud.
Dengan adanya ”Tiub Bersambung DTP” (Integral Segment) yang bersambung terus kepada beg DTP, atau sistem yang serupa denganya, maka ini meningkatkan lagi tahap jaminan bahawa sampel DTP yang diuji memang dari sumber DTP yang asal. Ujian perlu dilakukan sebelum DTP digunakkan untuk rawatan transplantasi. AABB memahami bahawa bank-bank akan memerlukan masa dan perbelanjaan kos tinggi untuk bertukar dari sistem Vail kepada Beg, jadi, AABB telah memberi tempoh masa kepada beberapa bank untuk berubah, iaitu sehingga 1 Januari 2007. Bilangan bank yang diberi tempoh masa tambahan ini hanya segelintir dan hanya kepada bank yang telah menunjukkan pelan program pertukaran sistem dari Vail kepada Beg.
Simpanan dalam sistem lain: Dengan adanya perubahan teknologi, sistem simpanan baru mungkin akan direka kelak yang memenuhi kehendak dan tujuan piawaian. Tujuan piawaian adalah untuk memastikan supaya sampel DTP yang perlu diuji memangnya diambil dari Beg DTP yang sama. Sistem-sistem baru ini perlu diselidik dan diuji samada ianya memenuhi tujuan dan keperluan yang ditetapi oleh Unit Program Piawaian Terapi Sel AABB.
Should cord blood be stored in bags or vials?
AABB encourages innovations and improvements in technology and does not endorse any one method or manufacturer over another. This includes encouraging improvements in the collection, processing and storage of UCB products. Since most products are collected into a bag or other container before transfer to a processing facility, no system is completely “closed.” Even the product (UCB) entering the container may not be sterile. Therefore, facilities operate on a spectrum of semi-closed or functionally closed processing (including collection) and there is no uniformly accepted definition or criteria to define such a system. The practice is based on the theoretical deduction that the number of entries or exposures to the environment that a product receives, the higher the chance for accidental contamination.
The bag versus vial storage debate is quite controversial. Early work with cord blood processing in research labs included the use of “cryovials.” These small vials are about the size of an adult pinky and are relatively inexpensive. The UCB product is divided among several vials, which are usually placed into small boxes for storage. Proponents of this storage container assert that if science ever advances to the point where only some of the product is needed, the entire UCB unit will not have to be thawed. Products can generally only be thawed once without losing a significant number of live stem cells. The vials also occupy relatively less storage space and, therefore, permit more products (patients) to be stored in the storage tank. On the other hand, the small vials may be more difficult to label with all of the required information.
Specially designed bags intended for cryostorage have also been developed. These bags cost more and may occupy a larger amount of freezer space than vials. One advantage of using bags is that they render a more “closed” rather than an “open” system, thereby reducing the risk of accidental contamination. Another advantage to the bag system is that it permits the unit to have integral segments of tubing. AABB requires that integral segments be attached to cord blood units for subsequent testing. Integral segments are created when the tubing leading from the storage container is sealed to provide little portions or “segments” of product, which can be used for subsequent or confirmatory testing of the product if needed.
This is important because banks sometimes receive several products at once, and while procedures are in place to prevent mix-ups, questions regarding identity may occur. The availability of attached segments or an equivalent system provides a higher level of assurance that the test sample material can be traced to the original product if needed for confirmatory or additional testing before the product is distributed for transplant. AABB recognizes the investment of resources required to switch from vials to bags and, therefore, has granted variances to a few facilities until Jan. 1, 2007, to give them time to implement the change. These variances were few in number and only granted to those that presented a plan for implementing the change.
Other containers: As technology evolves, other containers or processes may be developed which meet the intent of the Standards. The intent is to ensure that the sample for additional testing is from the product. Such methods would currently require review and approval by the AABB Cellular Therapy Standards Program Unit.
Sekian buat masa ini......Wslm..WBK
The bag versus vial storage debate is quite controversial. Early work with cord blood processing in research labs included the use of “cryovials.” These small vials are about the size of an adult pinky and are relatively inexpensive. The UCB product is divided among several vials, which are usually placed into small boxes for storage. Proponents of this storage container assert that if science ever advances to the point where only some of the product is needed, the entire UCB unit will not have to be thawed. Products can generally only be thawed once without losing a significant number of live stem cells. The vials also occupy relatively less storage space and, therefore, permit more products (patients) to be stored in the storage tank. On the other hand, the small vials may be more difficult to label with all of the required information.
Specially designed bags intended for cryostorage have also been developed. These bags cost more and may occupy a larger amount of freezer space than vials. One advantage of using bags is that they render a more “closed” rather than an “open” system, thereby reducing the risk of accidental contamination. Another advantage to the bag system is that it permits the unit to have integral segments of tubing. AABB requires that integral segments be attached to cord blood units for subsequent testing. Integral segments are created when the tubing leading from the storage container is sealed to provide little portions or “segments” of product, which can be used for subsequent or confirmatory testing of the product if needed.
This is important because banks sometimes receive several products at once, and while procedures are in place to prevent mix-ups, questions regarding identity may occur. The availability of attached segments or an equivalent system provides a higher level of assurance that the test sample material can be traced to the original product if needed for confirmatory or additional testing before the product is distributed for transplant. AABB recognizes the investment of resources required to switch from vials to bags and, therefore, has granted variances to a few facilities until Jan. 1, 2007, to give them time to implement the change. These variances were few in number and only granted to those that presented a plan for implementing the change.
Other containers: As technology evolves, other containers or processes may be developed which meet the intent of the Standards. The intent is to ensure that the sample for additional testing is from the product. Such methods would currently require review and approval by the AABB Cellular Therapy Standards Program Unit.
Sekian buat masa ini......Wslm..WBK