Post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder (PTLD) is a complication that can develop after an organ transplant or after an allogeneic stem cell transplant. With PTLD, the body makes too many lymphocytes (a type of white blood cell) or the lymphocytes don’t act normally. PTLD behaves like a fast-growing (aggressive) type of non-Hodgkin lymphoma (NHL). Most PTLDs are B-cell lymphomas (less than 15% are T-cell lymphomas).

People who have an organ transplant, such as a heart, lung, liver or kidney transplant, usually need to take drugs that suppress their immune system for the rest of their lives. These drugs help stop the body from rejecting the organ. Having your immune system suppressed (called immunosuppression) gives you a higher risk of developing a type of NHL.

PTLD develops in 1%–2% of people who receive organ transplants. People who receive more than one organ (called a multi-organ transplant), such as a heart and lung, have the highest risk of developing PTLD.

PTLD often develops in people infected with the Epstein-Barr virus (EBV), usually in the first year after an organ transplant. When it occurs in people who aren’t infected with EBV, it usually develops about 5 years after an organ transplant.

People with PTLD have larger than normal lymph nodes or a cancerous tumour. It has often spread to organs or tissues outside of the lymph nodes (called extranodal sites) when it is diagnosed. These organs and tissues include the lungs and the gastrointestinal (GI) tract.

There is no standard approach to treating PTLD. You may be offered one or more of the following treatments.

The drugs given to help prevent rejection after an organ transplant are called immunosuppressant therapy. In most cases, lowering the dose of immunosuppressant drugs can help manage PTLD. Other types of treatments are often needed as well.

Targeted therapy uses drugs to target specific molecules (such as proteins) on the surface of cancer cells. These molecules help send signals that tell cells to grow or divide. By targeting these molecules, the drugs stop the growth and spread of cancer cells while limiting harm to normal cells.

If doctors can’t lower the dose of immunosuppressant drugs, or if lowering the dose doesn’t help manage PTLD, they may consider giving targeted therapy. Rituximab (Rituxan) may be used alone or with chemotherapy.

Immunotherapy helps to strengthen or restore the immune system’s ability to fight cancer.

Interferon alfa (Intron A, Wellferon) is a type of immunotherapy used for PTLD. It may be given alone or with a drug called acyclovir (Zovirax). Acyclovir is an antiviral drug that can be used to treat a virus such as EBV.

If the drug therapies mentioned above do not seem to be working, you may be offered a combination of chemotherapy drugs that includes doxorubicin (Adriamycin). These drug combinations include:

• CHOP – cyclophosphamide (Cytoxan, Procytox), doxorubicin, vincristine (Oncovin) and prednisone
• R-CHOP – CHOP with rituximab
• ProMACE-CytaBOM – cyclophosphamide, doxorubicin, etoposide (Vepesid), prednisone, bleomycin (Blenoxane), cytarabine (Cytosar, Ara-C), methotrexate and leucovorin (folinic acid)

Either surgery or radiation therapy may be used alone to treat PTLD that hasn’t spread beyond the place where it started (called a localized tumour). A localized tumour tends to occur a few weeks or months after a transplant and can grow over a period of months.