INTRODUCTION
We present an unusual case of autoimmune hemolytic anemia (AIHA) associated with Kikuchi-Fujimoto Disease (KFD) and systemic lupus erythematosus (SLE) that resolved with steroid therapy.
CASE PRESENTATION
A 25-year-old female with no medical history presented with 6 weeks of high fevers, syncope, and 10-lb weight loss. Exam revealed generalized lymphadenopathy (LAD) and tiny malar papules. Labs showed IgG and IgM Coombs-positivity, hemoglobin of 5 g/dL, hyperbilirubinemia, low haptoglobin, LDH >2000 IU/L, thrombocytopenia, and leukopenia. Cryoglobulins were absent. Hemophagocytic lymphohistiocytosis (HLH) markers showed ferritin of 18,000 ng/mL, moderately elevated soluble IL-2 receptor, negative CD107, minimally elevated CXCL9, borderline transaminitis, and high-normal triglycerides. ANA was 1:1280, speckled, with high anti-RNP, high anti-Smith, and negative anti-dsDNA antibodies. CT confirmed LAD without organomegaly. A 4cm excised node reviewed at 2 institutions showed necrotizing lymphadenitis without granulomas, consistent with KFD. Flow cytometry and gene rearrangement assay showed no monoclonality. Bone marrow biopsy demonstrated erythroid hyperplasia, normal flow cytometry, and no hemophagocytosis. Infectious workup was unremarkable. Treatment was initiated with 50mg prednisone daily, weaned off over 5 months. 2 months post-initiation, the fevers resolved, hemoglobin increased, and LDH normalized. 3 months later, rheumatology service diagnosed SLE based on 2019 ACR/EULAR Criteria and initiated hydroxychloroquine. 9 months later, patient remains without recurrence.
DISCUSSION
KFD presents subacutely with LAD, fever, weight loss, and varying skin findings, often self-resolving. Diagnosis requires lymph node biopsy. Etiology is unclear, with infectious, neoplastic, and autoimmune mechanisms implicated. Studies suggest up to 15% of patients have SLE.
CONCLUSIONS
This case is a rare combination of AIHA, KFD, and SLE successfully treated with steroids and, later, hydroxychloroquine. It calls for vigilance for KFD in patients with LAD and AIHA. A successful treatment strategy could include highdose steroids. The presentation may mimic lymphoma and HLH, which must be ruled out with careful pathologic and lab evaluation. To our knowledge, this is the 3rd reported case of KFD with AIHA, and 2nd case of concomitant SLE, KFD, and AIHA. The only similar patient was treated with methylprednisolone and cyclophosphamide and did not have longer-term follow-up.