Final answer:
The compromised immune system is a major cause of death in adult patients with acute leukemia.
Step-by-step explanation:
Adult patients with acute leukemia can die from various complications. However, one of the main causes of death in these patients is the compromised immune system, which increases the risk of opportunistic infections. Since leukemia affects the production of white blood cells, which play a crucial role in fighting off infections, the lack of properly functioning immune system cells can make it difficult for the body to fend off infections, leading to complications and potentially death.