Angioimmunoblastic T-Cell lymphoma (AITL) is an aggressive T-cell lymphoma representing about 1-2% of all types of Non-Hodgkin's Lymphoma in the US. Elderly patients are more likely to have AITL, and it occurs more often in men than women. It has in the past been called Angioimmunoblastic Lymphadenopathy With Dysproteinemia (AILD). Initially was thought to represent an abnormal reaction of the immune system but it is now known to be a form of lymphoma. It is now a distinct entity under the newer WHO classification system.
AITL is a mature T-cell lymphoma of blood or lymph vessel immunoblasts characterized by a polymorphous lymph node infiltrate showing a marked increase in follicular dendritic cells (FDCs) and high endothelial venules (HEVs) and systemic involvement. It is also known as immunoblastic lymphadenopathy (Lukes-Collins Classification) and AILD-type (lymphogranulomatosis X) T-cell lymphoma (Kiel Classification).
Symptoms of AITL include
- high fever
- night sweats
- skin rash
- weight loss
- generalised lymphadenopathy
- enlarged liver and spleen
- autoimmune disorders such as autoimmune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP)
As a result of these autoimmune disorders, the body's immune system does not recognize, and consequently destroys, its own cells and tissues, such as red blood cells (in the case of AIHA) or platelets (in the case of ITP).
Diagnosing AITL requires taking a small sample of the tumor tissue, called a biopsy, and looking at the cells under a microscope. A series of other tests may be done to determine the extent, or stage, of the disease. These can include blood tests, a computed axial tomography (CAT) scan, a positron emission tomography (PET) scan, a magnetic resonance imaging (MRI) scan, and a bone marrow biopsy.
The majority of patients with AITL are diagnosed with advanced-stage disease, either stage III or stage IV disease. In stage III, affected lymph nodes are found both above and below the diaphragm. In stage IV, one or more organs beyond the lymph nodes are affected, such as the bone, bone marrow, skin, or liver. Less-extensive disease, stage I or II, is rare. Patients with stage I have localized disease that has not spread beyond the tumor, and with stage II, if the the cancer has spread, it has affected only a nearby lymph node.
There is no proven and standard first-line chemotherapy that works for the majority of AITL patients. There are several clinical trials that offer treatment options that can fight the disease. Stem Cell Transplant is the treatment of choice, with allogeneic being the preference because AITL tends to recur after autologous transplants.
Patients with AITL may be treated with a steroid to relieve the symptoms caused by the immune system’s reaction to the cancer cells, such as joint inflammation/pain and skin rash. Recommended first-line therapy for treatment of the cancer is either a clinical trial or chemotherapy with a number of different drugs, such as CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) and radiation therapy. Sometimes higher doses of chemotherapy followed by a stem cell transplant may be prescribed for relapsed patients or those patients for whom combination chemotherapy may not be effective. Disease relapse (the disease returns) is common with this cancer. Recommended therapy following relapse may include high-dose chemotherapy followed by an autologous stem cell transplant (in which patients receive their own cells) or allogeneic stem cell transplant (in which patients receive stem cells from a donor). In 2011, romidepsin was approved for the treatment of relapsed or refractory peripheral T-cell lymphomas, including AITL.