AB158. SOH23ABS_210. Case report: azacitidine linked with reactive arthritis in a patient with acute myeloid leukemia

Background: Azacitidine (AZA), a demethylating agent, is one of the mainstay treatments for patients with myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML) who are ineligible for curative allogeneic stem-cell transplantation and is recommended as first-line treatment in multiple countries. While arthralgia and myalgia have been commonly reported as side effects, the incidence of AZA-induced reactive arthritis has only been reported twice so far.

Methods: We present a retrospective overview of a clinical case of a 71-year-old patient that developed new cytopenias on a background of chronic lymphocytic leukaemia and was diagnosed with therapy-associated AML. His treatment included an indefinite course of AZA to induce remission and optimise long-term survival which resulted in a satisfactory haematological response. However, after his ninth AZA cycle, he presented to the emergency department with swelling and erythema of the knee and conjunctivitis. Arthrocentesis of the knee revealed reactive arthritis with no crystal or organism growth. His symptoms were managed effectively with conservative management including non-steroidal anti-inflammatory drugs (NSAIDs), analgesia and temporary immobilization for joint rest.

Results: A Naranjo probability scale was used to assess whether there is a causal relationship between an identified clinical event and a drug whereas definite, >8; probable, 5 to 8; possible, 1 to 4; doubtful, <1. In our case the score was calculated as 6. Similarly, in 2021, a patient with MDS with no history of arthritis was reported to suffer from left knee recurrent crystal-induced arthritis following each AZA cycle this scored a 7 in the Naranjo probability scale.

Conclusions: We report the third case that points to AZA as a probable cause of arthritis in MDS patients. The current limitation of this study is the lack of available data, future reviews and research will aid in providing stronger evidence of a correlation between arthritis and AZA treatment.

Keywords: Azacitidine (AZA); arthritis; myelodysplastic syndrome (MDS); acute myeloid leukaemia (AML); case report