the patient is monitored closely | ||||
until their blood cell counts start to | ||||
recover ( engraftment ), which takes | ||||
10-14 days on average . This may | ||||
occur as an inpatient or outpatient , | ||||
or a combination , depending on the | ||||
specifics of the chemotherapy and | ||||
the patient ’ s clinical condition . |
release of cytokines as the patient ’ s peripheral blood cell counts recover . Failure to engraft is a possible , though rare , complication . Engraft- |
Figure 1 . A patient having stem cells collected . |
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ment describes the process of the | ||||
blood-forming cells received via | ||||
transplant starting to home to the | ||||
bone marrow and generate new | ||||
blood cells . | ||||
Because of the immunosuppression | ||||
associated with conditioning | ||||
chemotherapy , patients are at | ||||
increased risk of bacterial , viral and | ||||
fungal infection . Febrile neutropenia | ||||
most commonly occurs in these | ||||
patients because of translocation of | ||||
gut bacteria into the blood ; bacteraemia | ||||
may also result from venous | ||||
catheter-related , gut or respiratory | ||||
infections . Resistant organisms are | ||||
often cultured from patients who | ||||
have had a transplant , as a result of | ||||
previous antimicrobial therapy . | ||||
Febrile neutropenia is rapidly | ||||
treated using protocol-based | ||||
broad-spectrum antibiotics that are | ||||
quickly rationalised based on culture | ||||
results . All patients receive | ||||
prophylaxis against pneumocystis | ||||
and herpesviruses . | ||||
In the context of the COVID-19 | ||||
pandemic , patients are encouraged | ||||
to be fully vaccinated for COVID- | ||||
19 , receive tixagevimab / cilgavimab | ||||
prophylactically , and receive | ||||
COVID-19 antivirals for symptomatic |
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infection .
Supportive care is an important aspect of post-transplant care . Reg-
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Figure 2 . An apheresis machine . |
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ular mouth washes are used to help |
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to prevent mucositis , and patients may be transfused with irradiated blood products if they become significantly anaemic or thrombocytopenic . Nutritional support is provided by experienced dietitians |
complications , energy levels and patient preference .
ALLOGENEIC STEM CELL TRANSPLANT
ALLOGENEIC transplantation
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malignant cells , resulting in ongoing disease control . This creates a delicate balance between this beneficial graft versus disease ( GVD ) effect — for example , graft versus leukaemia — and the potentially severe complication of |
matched unrelated donor transplant in 1979 . 5-7 In 1988 , CD34 + cells were identified in small numbers in peripheral blood , and the administration of G-CSF allowed for collection of stem cells from peripheral |
compatibility is the testing of HLA . An ideal donor would be a 10 / 10 match , involving both alleles of HLA- A , HLA-B , HLA-C , HLA-DRB1 and HLA-DQB1 . |
because of the high risk of mal- |
involves the transplantation of |
graft versus host disease ( GVHD ). |
blood rather than bone marrow . 8 |
TYPE OF DONOR |
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nutrition . Dedicated psychological support is available for patients undergoing transplantation .
Following transplant , a bone
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haematopoietic stem cells from a related or unrelated donor after high-dose chemotherapy and subsequent immunosuppression . Stem |
History of allogeneic stem cell transplant
The first allogeneic bone marrow
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By the late 2000s , new conditioning regimens allowed the use of haploidentical ( half-matched ) family member donors in patients |
The preferred donor for allogeneic stem cell transplant is an HLAmatched sibling , with a 25 % chance of any given sibling being a com- |
marrow biopsy or repeat imaging will assess the patient ’ s disease status , as appropriate . Patients are |
cells may come from the donor ’ s bone marrow , mobilised peripheral blood or cord blood . Despite greater |
transplant was performed in 1957 by Dr E Donnall Thomas ( physician , researcher and Nobel laureate ) |
without a matched sibling or unrelated donor . 9 The subsequent development of reduced intensity |
plete match . An identical twin essentially shares all the same antigens ; this is therefore functionally |
then monitored for relapse and for |
risks , when compared with autolo- |
in six patients with acute leukae- |
conditioning treatment ( that is , a |
similar to an autologous transplant |
late complications . Patients typically remain on viral and pneumocystis prophylaxis for |
gous stem cell transplants , there is the opportunity for greater reward , including the potential to cure an |
mia . Two patients engrafted , and all died within 100 days . 4 Following drastic improvements in con- |
conditioning regimen that uses less chemotherapy and radiation than the standard regimen ) and its more |
and is often not the first choice . In adult practice , if a fully matched sibling is not available , the |
3-6 months post-transplant and |
otherwise incurable disease . 3 |
ditioning , histocompatibility ( for |
widespread use has allowed for |
second choice is usually a search of |
undergo selective revaccination , |
This type of transplant goes |
HLA ) testing , GVD prevention and |
treatment of older patients . |
the international stem cell donor |
starting at six months post-transplant . A return to ‘ normal life ’ such as returning to work depends on several patient factors including |
beyond simply replacing a patient ’ s bone marrow after high-dose chemotherapy : allogeneic stem cells can exert an anti-tumour effect on residual |
peritransplant care , the first successful transplants from matched sibling donors were performed in the late 1960s , followed by the first |
Sources of stem cells
COMPATIBILITY TESTING A major part of transplant
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registry for a fully matched unrelated donor , who has either 8 / 8 or 10 / 10 matched HLAs . As a result of improvements in the technology of |