Hematopoetic stem cell transplant is the transfer of healthy blood forming cells from the donor to the recipient to cure or control certain medical conditions. Unlike solid organ transplants (liver, kidney), bone marrow transplant is not a surgical procedure.
The Stem cells can be described as the “seed cells” of the body, as they
The Conditions requiring stem cell transplant can be divided into two broad groups:
Autologous- Here, the patient’s own stem cells are harvested and stored. Then, after giving intensive treatment to control the disease, these cells are re-infused into the patient as a rescue procedure. It is used mainly in Stage IV (high risk) or relapsed solid tumours.
Allogenic- Here, healthy cells are collected from a donor and transfused into the patient to form new cells in the patient. Based on the donor used, Allogenic SCT can be of the following types:
Syngenic – where your twin is your donor, provided they are disease free
After diagnosis of the condition requiring SCT in a child, next step is identification of the donor. For this, HLA typing of the child and the prospective donor(s) needs to be done for matching. Once the donor is selected, SCT involves the following stages-
Routine diagnostic tests such as complete hemogram, biochemistry,X-ray,2DECHO , urinalysis and Screening for viral infections is done. Also, Human Leukocyte Antigen(HLA) typing and blood grouping are done to assess recipient/donor compatibility. This assessment of compatibility is essential to reduce risk of rejection of transplant.
The stem cells are collected either from the bone marrow or the peripheral blood of the donor. Donors are given Inj G CSF to increase the number of stem cells prior to the collection in case the source of stem cells peripheral blood. Sometimes, stored cord can be used as the source of stem cells. Though none of the collection methods cause any harm to the donor, peripheral blood stem cell collection by apheresis is gaining popularity as it is less invasive and cumbersome to the donor, without the requirement of anaesthesia and with good success rate as bone marrow SCT.
The collected stem cells are stored by cryopreservation.
The conditioning process is done for three reasons:
It carried out by giving intensive chemotherapy with or without radiation.
It is not a surgical procedure, rather a delicate and careful transfusion of the collected stem cells into the recipient via a central venous catheter. These stem cells then home in to the bone marrow of the recipient and starts proliferating after some time.
After transplantation, the child must be under constant observation with intensive supportive care. Continuous monitoring is required to identify and manage any complications arising. Even with all the precautions, SCT does involve few risks, chief of which are
Acute GvHD – Occurs during the first three months following the transplant.
Chronic GvHD – Develops from acute GvHD and can cause symptoms for many years.
It usually takes 3 to 4 weeks for the recovery after SCT.
Born in a middle class farmer family in Suryapet, little J is the first child of his parents. At 11 months of age unfortunately he developed significant dullness, vomiting and fever at 10 months age. He was brought to Rainbow Children’s hospital for treatment and was diagnosed with brain tumour in MRI scan. He got operated for same in July 2017 and It was a poorly differentiated Grade IV medulloblastoma tumour . Given his age, and and local spread to surrounding meninges it is a high risk tumour.
As he was very young, Radiation therapy could not be given post surgery. Post Surgery MRI revealed residual tumour along with spinal meningeal enhancement (?metastasis). In view of the high risk nature of the child’s disease, parents were counselled regarding the chances of cure and survival of the child.He was started on chemotherapy under the care of Dr Sirisha Rani, Sr Consultant in Pediatric Hematology Oncology, rainbow childrens hospital, Banjara hills. After 5 cycles of chemotherapy, repeat MRI showed complete clearance of the tumour and spinal meningeal enhancement.
Following this good response it was decided to consolidate his tumour remission with High dose chemotherapy followed by Autologous stem cell transplantation. The transplantation was carried out in the state of the art Bone marrow transplantation unit (BMTU) at Rainbow Children’s hospital Banjara hills. During the conditioning as well as post transplantation, he was closely monitored. With high clinical acumen, timely use of prophylactic antibiotics and excellent nursing care his course was smooth without any major complications and he was successfully discharged.