The Food and Drug Administration (FDA) stated in a communication dated April 14 that it continues to receive reports of hepatosplenic T cell lymphoma (HSTCL), a rare cancer of white blood cells, in adolescents and young adults receiving drugs classified as tumor necrosis factor (TNF) blockers and other drugs that suppress the immune system.

TNF blockers prevent TNF from causing inflammation that leads to immune system diseases such as Crohn's ulcerative colitis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and plaque psoriasis. TNF blockers include infliximab (Remicade), etanercept (Enbrel), adalimumab (Humira), certolizumab pegol (Cimzia), and golimumab (Simponi). Other immunosuppressants that have been associated with the development of HSTCL are azathioprine (Azasan, Imuran) and mercaptopurine (Purinethol).

Most of the related cases of HSTCL have been in patients receiving more than one drug to suppress the immune system. Nurses should instruct patients and their families to be alert for signs and symptoms that can indicate this malignancy, which can include splenomegaly, hepatomegaly, abdominal pain, persistent fever, night sweats, and weight loss. Health care providers should report any adverse events involving TNF blockers, azathioprine, or mercaptopurine to the FDA's MedWatch program: (800) 332-1088 or http://1.usa.gov/bW5WC.