A clinical case of the combined acute promyelocytic leukemia and juvenile idiopathic arthritis

The article presents a clinical case of enteritis-associated juvenile idiopathic arthritis in a 16-year-old teenager during the therapeutic stage of consolidation of acute promyelocytic leukemia. Arthritis in a patient with leukemia is usually associated either with an exacerbation of the underlying disease; or with an infectious process in the joint or adjacent bone. Leukemic arthritis is manifested mainly by monoarthritis, with damage to large joints, severe night pain, lymphadenopathy, and hepatosplenomegaly. A reduction in joint pain is a sign of a clinical response to chemotherapy. An infectious lesion of the musculoskeletal system is usually also represented by a local inflammatory process with fever, intoxication, local hyperemia, hyperthermia, inflammatory changes in blood tests and requires intensive antibacterial therapy and temporary cessation of chemotherapy in an oncological patient. The development of juvenile idiopathic arthritis during leukemia therapy caused diagnostic and therapeutic difficulties due to the very rare association of the two diseases, which required the exclusion of a recurrence of leukemia and an infectious complication. NSAID therapy brought temporary relief, the use of the janus kinase blocker upadacitinib was ineffective, and subsequent switching to etanercept allowed for remission of arthritis. Leukemia treatment was carried out in conjunction with JIA treatment.