Donor Lymphocyte Infusion After Transplant — what it is, when it is used, and what GVHD means

A donor lymphocyte infusion is a drip of white blood cells taken from the same person who donated your stem cells. Mostly T lymphocytes. Nothing in the bag is a drug, and nothing has been genetically altered. It is given after an allogeneic transplant, when the blood cancer shows signs of returning.

It is short. The bag itself usually runs in under an hour, in a day-care chair or a ward bed, with no chemotherapy alongside it. Families expecting something dramatic are often surprised by how ordinary the infusion looks. What follows over the next weeks is the part that needs watching.

The reasoning behind it is worth stating plainly. An allogeneic transplant does not work by chemotherapy alone. It works partly because the donor immune system, once it settles in, treats leftover cancer cells as foreign tissue. When that grip loosens and the disease returns, one option is to send in more of the same donor cells rather than more drugs. That is a DLI.

Most patients reading this page are not candidates, and it is fairer to say so first. A DLI requires that you have already had an allogeneic stem cell transplant, that the original donor is traceable and well enough to donate again, and that your disease is a type where donor immune cells have an established role. That is a narrow group. It is also why no one can request a DLI the way a drug is requested.

CION Cancer Clinics does not perform allogeneic transplants and does not provide DLI, CAR-T or any other cell therapy. This page exists because families are handed the term in a transplant consultation and want it explained by someone with no stake in the answer. Where a cell therapy is genuinely on the table, our role is orientation and referral to the units that run these programmes. The immunotherapy CION does administer is given as day care at our centres.

Settings above follow NCCN, ASCO and ESMO transplant and haematology guidance current as of August 2026, and describe situations rather than promising an outcome in any of them. Whether a DLI is appropriate is decided by the transplant team holding your donor records.

One thing a DLI shares with much older immune treatments: it uses living immune activity rather than a molecule. BCG instillation for bladder cancer works on the same broad principle from a very different direction — a live bacterial preparation placed in the bladder to provoke a local immune reaction.

Two other reactions belong in the same conversation. The donor cells can also act against the marrow itself, causing blood counts to fall, which is why counts are checked closely afterwards. And infection risk rises whenever immune suppression is increased to control GVHD. Fever after a DLI is an emergency: go to the treating hospital rather than managing it at home. CION patients can call 1800 202 8726 at any hour for guidance on where to go.

GVHD grading and management framing follows ASCO, ESMO and NCCN supportive-care guidance current as of August 2026. Whether a given reaction is mild or serious is a bedside judgement, not something a page can grade for you.

The confusion is understandable. All three sit under one word, and families are often given the word before the mechanism. If you have been told that immunotherapy is the plan, the useful question is not whether it is immunotherapy but which of these it is, because the preparation, the waiting time and the risks are not comparable.

1. 1

   Confirm what the disease is doing

   Marrow testing, disease markers and chimerism studies establish whether this is a true relapse, residual disease, or a graft that is slipping. Each of those leads to a different plan, and a DLI is only one of the possible answers.

2. 2

   Contact the donor again

   The original donor is traced, consented afresh and screened for infection exactly as before. This is often the step that sets the timeline, particularly when the donor lives far away or is an unrelated registry donor.

3. 3

   Reduce immune-suppressing medicines first

   Donor cells cannot act while your immune suppression is holding them down. Many protocols taper or stop those medicines before the infusion. That taper alone can be enough in some patients, and it also raises GVHD risk, which is why it is done under supervision.

4. 4

   Collect the cells by apheresis

   The donor sits with a line in each arm while a machine separates out the white cells and returns the rest of the blood. It takes a few hours and needs no surgery. The cells are counted, and the dose is measured in T cells per kilogram of your body weight.

5. 5

   Infuse a small dose, then watch

   The first dose is deliberately low. If there is no significant GVHD, a larger dose may follow weeks later. Blood counts, liver tests, skin and bowel symptoms are monitored throughout, because the wanted effect and the unwanted one come from the same cells.

A response cannot be promised, and nobody should present it as settled. Donor immune cells act against some blood cancers more readily than others, the effect can take weeks to appear, and in a proportion of patients it does not appear at all. Ask your transplant team what they expect in your specific disease, and what the plan is if the first dose changes nothing.

This makes DLI unusual among the treatments discussed on this site. There is no molecule to approve, no patent, no brand and no import licence. What has to exist is a transplant unit with an apheresis service, a laboratory that can count and process the cells, a bed for monitoring afterwards, and a donor who agrees to come back. Those requirements, not regulatory approval, are what decide whether a DLI can happen.

Two limits are worth naming honestly. Allogeneic transplant capacity in India is concentrated in a modest number of centres, and if your transplant was done elsewhere the practical route usually runs back through that centre because it holds the donor records and the tissue-typing. And an unrelated registry donor is harder to recall than a sibling, so timelines differ from family to family.

One caution that belongs on this page. Because a DLI genuinely is a cell-based cancer treatment, the phrase gets borrowed. Clinics with no transplant unit sometimes advertise immune cell infusions, dendritic cell therapy or similar to patients who have never had a transplant, and use the credibility of real cell therapy to do it. A DLI without a prior allogeneic transplant is not a DLI. If you are unsure what you are being offered, how to tell real immunotherapy from an unproven treatment sets out the questions to ask before any money changes hands.

• BCG bladder instillation: what the treatment involves — the other long-established immune treatment that uses living biology rather than a molecule, and how a course is actually given.
• Side effects of BCG bladder treatment — what an intentional immune reaction feels like when it is deliberately provoked, and which symptoms mean call now.
• How to tell real immunotherapy from an unproven treatment — the questions that separate an established cell therapy from a clinic borrowing the vocabulary.
• Immunotherapy at CION Cancer Clinics — the hub, with every class of immunotherapy set out side by side, and what CION does and does not administer.

One conversation before you commit to anything

Decisions after a transplant relapse are made quickly and under pressure. A second opinion costs nothing and takes 45 unhurried minutes with a specialist who will explain the options, including the option of waiting.