Bone marrow infusion is similar to a blood transfusion. It is transfused to the patient through a central line. Bone marrow contains a rich amount of stem cells, which are responsible for regenerating white blood cells, platelets, hemoglobin, and other blood components.

Moreover, the stem cells were collected in two ways.

• From peripheral blood
• Another way is to collect from the bone of the matched donor

Which Diseases need whole Bone Marrow?

Many non-malignant diseases require a bone marrow transplant, such as aplastic anemia, thalassemia, sickle cell anemia, and Glanzmann thrombasthenia.

Diseases like leukemia and lymphoma, which can be life-threatening, often require a peripheral stem cell transplant. During this medical procedure, a phenomenon called the “graft versus leukemia”(GVL) effect or “graft versus cancer” effect occurs.

In this graft versus cancer effect, transplanted stem cells attack any remaining cancer cells in the body and provide an additional defense against the disease.

What is the Graft versus leukemia effect?

Therefore, it is thought that graft versus host is beneficial for patients with leukemia, as there are fewer chances of relapse, and it assumes prolonged survival chances.

In allogeneic bone marrow transplants, the cells are infused on the same day as they are harvested or collected. On the other hand, in autologous transplants, the collected cells are first preserved and then infused into the patient.

Why are patients given high doses of chemotherapy during bone marrow transplant?

The objective of this high-dose chemotherapy is to induce myeloablation or destroy the diseased bone marrow of the patient.

Stem cell infusion in an allogeneic bone marrow transplant:

After collecting bone marrow from a living healthy donor, it is transfused into the patient’s vein via a central catheter on the same day of collection, which is usually referred to as day zero or the transplant day.

However, in an autologous transplant, the stem cells are melted in a tub called a water bath. The water used in the water bath is RO or distilled water.

The temperature of the water bath must be kept at 37°C and should not exceed it, as this may damage the stem cells.

As soon as the frozen bag is melted or thawed, it should be infused into the patient because the preservative known as DMSO starts damaging the stem cells if it is melted.

The bone marrow or stem cells should be given through an IV set without a filter. It is also necessary that the bone marrow dose be calculated based on the patient’s body weight.

Moreover, the stem cell dose should not be less or more than the required amount, calculated by CD34 count from the collected marrow or stem cells.

A lower cell dose causes engraftment failure, and a higher cell dose increases the chances of graft versus host disease. Therefore, the cell dose should be according to the recommended amount.

What to do in case of Incompatibility of blood group between the patient and donor?

Matching blood groups is crucial during a bone marrow transplant. Minor mismatch reduces the risk of reaction. In a major ABO group mismatch, red cells are separated through a process called red cell reduction.

How are red blood cells separated from the whole collected graft?

In the peripheral stem cell collection, the red cells are separated manually , while in whole bone marrow harvest, a reduction kit and an apheresis machine are used.

In case the reduction kit is not available, in most cases, peripheral stem cell collection is preferred.

What to do before stem cell infusion?

Before receiving stem cells, the patient needs to take antihistamines and steroids to prevent potential reactions. Furthermore, in case of infussion of preserved stem cells, must informed the patient, that the color of their urine may appear slightly reddish.This reddish colour is the colour of DMSO4, a preservative used in the stem cells.

After Bone Marrow Infusion:

After the infusion of stem cells, it is essential to administer intravenous fluids to the patient. This is done to ensure that the stem cells are equally distributed throughout the patient’s body.

It is also recommended to encourage the patient to consume sufficient fluids to minimize the risk of kidney injury associated with DMSO. It is necessary to flush out DMSO from the patient’s body.

What could be the complications after bone marrow/stem cell infusion?

After a bone marrow infusion, the infused marrow can cause a reaction in the patient’s body. This reaction typically occurs in half-matched transplants (haploid identical transplants) and is known as Cytokine Release Syndrome (CRS).

The cytokine release syndrome is further divided into grades.

Grade 1,2,3, and grade 4.

Infusing stem cells safely involves following specific protocols under the supervision of trained healthcare staff to prevent complications.