The M3 subtype of acute myelogenous leukemia–also known as acute promyelocytic leukemia–is one of the most responsive forms of leukemia, as the addition of all-trans retinoic acid (ATRA) is known to overcome the maturation block in affected lymphocytes.
While this is generally good news for leukemia patients with M3 disease, about 5-25% of patients get an ATRA-induced systemic illness termed “ATRA Syndrome”. Symptoms are widely variable but can include fever, interstitial pulmonary infiltrates, pleural/pericardial effusions, and (the reason for its inclusion in this blog), acute renal failure. The topic has been a relevant one for me as there are currently two patients on the Renal Consult service I saw today with ATRA-induced renal failure. The mechanism is unknown but is posited to be due to mass release of cytokines by affected APL cells. It can be treated by holding the ATRA and administering corticosteroids.