Arthritis of large joints shown as a rare clinical feature of cytokine release syndrome after chimeric antigen receptor T cell therapy A case report

Rationale: Chimeric antigen receptor (CAR)-T cell therapy is a novel type of therapy that is being used in an increasing number of patients with acute lymphoblastic leukemia (ALL). Cytokine release syndrome (CRS) is the most common complication following CAR-T treatment, but the current understanding of the clinical manifestations and pathogenesis of CRS is still limited. Patient concerns: A 34-year-old male patient was diagnosed with ALL in June 2015. Complete remission (CR) was achieved after induction chemotherapy. The patient received 8 cycles of consolidation chemotherapy to maintain CR. In May 2017, the patient had recurrent ALL. Induction chemotherapy was given again, but without remission. In October 2017, CAR-T cell therapy was given. On October 14, the patient was pretreated with an FC regimen (fludarabine phosphate 50 mg qd on days 1-3; cyclophosphamide 0.4 g qd on days 1-3). CAR-T cells were infused on October 19 and October 20, with the number of infused cells at 2 x 10(5)/kg and 1 x 10(5)/kg, respectively. On October 25, the patient had a high fever, swelling, and pain in the large joints of the limbs, and joint effusion. Diagnosis: This patient was diagnosed with relapsed ALL, and he developed CRS after CAR-T therapy. Interventions: Tacilizumab (400 mg) was infused after CRS was diagnosed, and another dose of tacilizumab (240 mg) was given 6 days later. The pain was also treated with an analgesic drug. Methylprednisolone (1 mg/kg) was given to treat arthritis of the large joints. Outcomes: The patient's temperature was back to normal within 1 hour following the treatment of tacilizumab, but the pain in the large joints was progressively aggravated. The joint swelling and pain were obviously alleviated after the treatment of methylprednisolone, and the joint mobility was gradually recovered. Lessons: CRS after CAR-T therapy can manifest as a high fever with swelling and pain in the large joints of the limbs, similar to rheumatoid arthritis. Tocilizumab can lower the body temperature, but it has no significant effect on arthritis. Glucocorticoids can rapidly alleviate joint swelling and pain.