LAUSR

Rationale: Thrombocytopenia, anasarca, fever, reticulin fibrosis, renal dysfunction, and organomegaly (TAFRO) syndrome are nonmalignant but life-threatening systemic inflammatory disorders. However, many patients are refractory to treatment, resulting in significant morbidity and mortality. Additionally, established treatment options are unavailable. Therefore, we present 2 cases of adults with the iMCD-TAFRO syndrome refractory to initial treatment but responded to Janus kinase (JAK) inhibitors with ruxolitinib. The report reveals that these rare adult cases of the refractory and treatment-resistant iMCD-TAFRO syndrome can be treated using JAK inhibitors. Patient concerns: Case 1 is a 36-year-old previously healthy male patient who presented with fever and general fatigue for 2 weeks. Case 2 is a 42-year-old previously healthy female patient who presented with fever and general fatigue. Diagnosis: The diagnosis met the 2015 criteria for TAFRO syndrome, as determined by All Japan TAFRO Syndrome Research Group in the Research Program for Intractable Disease by the Ministry of Health, Labor and Welfare (MHLW) Japan. Interventions: Treatment with tocilizumab and several immunosuppressants were ineffective. So, we performed ruxolitinib. Outcomes: Each patient received ruxolitinib, the general condition improved, and CRP levels decreased. Lessons: These cases showed that ruxolitinib was effective for treatment-resistant/ refractory TAFRO syndrome. Further prospective studies are needed on using ruxolitinib with a small number of cases.