A patient has non-Hodgkin's lymphoma (NHL). When reviewing the history, which finding is a risk factor for NHL?

• A. Regular exercise
• B. Vitamin D deficiency
• C. Low-sodium diet
• D. Organ transplant 2 years ago

Answer: (D)

Immunosuppression after organ transplantation increases the risk of non-Hodgkin lymphoma because the immune system’s ability to detect and control abnormal B cells is diminished. With ongoing immunosuppressive therapy, T-cell surveillance wanes, allowing latent Epstein-Barr virus–driven B cells to proliferate unchecked and potentially transform into B-cell lymphomas. This risk, known as post-transplant lymphoproliferative disorder, can emerge years after the transplant and is a recognized association with NHL.

Regular exercise tends to support immune health and is not a known risk factor for NHL. Vitamin D deficiency and a low-sodium diet are not established NHL risk factors, making the history finding of an organ transplant the most relevant in increasing NHL risk.