Angioimmunoblastic T-cell lymphoma (AITL)

AITL is confirmed with a biopsy, a tissue sample usually taken from a swollen lymph node. Blood tests are part of the first workup. They include a complete blood count, a chemistry panel and lactate dehydrogenase (LDH), plus tests for Epstein-Barr virus (EBV), hepatitis B and C, HIV and HTLV. Results often show low blood counts, signs of inflammation and high antibody levels.

A lab doctor (pathologist) studies the tissue and stains it for markers (immunohistochemistry). AITL cells usually carry T-cell markers such as CD4. They also carry markers of T-follicular helper cells, such as PD-1, ICOS, CXCL13, BCL6 and CD10. Other tests can check whether the T cells all come from one abnormal cell (a clone). Tests may also look for gene changes common in AITL, such as TET2, DNMT3A, RHOA and IDH2.

Staging then shows where the lymphoma is. This usually means a PET-CT scan and a bone marrow biopsy. The diagnosis can be hard to make. Early AITL can look like an ordinary swollen (reactive) lymph node. Some of its B cells can also look like the cells of classic Hodgkin lymphoma.

Treatment commonly begins with combination chemotherapy. Medicines affecting epigenetic regulation and other targeted approaches have roles in selected later-line settings or clinical trials. Choice depends on previous therapy, disease biology and local availability.

Autologous transplantation after a first response is considered for some fit patients. It uses the patient’s own stem cells to permit recovery after high-dose chemotherapy. Evidence for this strategy includes studies that pool several T-cell lymphoma subtypes, so the decision remains individualized.

Allogeneic transplantation is an important potentially curative option for selected relapsed or refractory disease. Control of the lymphoma before transplant is desirable, but the team considers the pace of disease, response, fitness and alternatives rather than applying one sequence to everyone.

AITL is an aggressive lymphoma, and it is usually found at an advanced stage. In a large international study, 9 in 10 people had advanced disease, and the middle (median) age was 64. Being 60 or older, poorer day-to-day fitness (performance status) and high levels of two blood markers, C-reactive protein and beta-2 microglobulin, were linked with shorter survival.

How the lymphoma responds to first treatment matters a great deal. In that study, people whose lymphoma did not get worse within two years of diagnosis did much better than those whose lymphoma progressed early. People who had an autologous transplant (using their own stem cells) in first complete remission also did better. Only 13% had that transplant, and the study did not compare the two approaches head to head.

When AITL comes back, a donor (allogeneic) transplant can still bring lasting control for some people. In a registry study, this held true even for some whose lymphoma had returned after an earlier autologous transplant. Newer medicines that target the lymphoma's gene changes are also being studied in clinical trials.