FDG-PET/CT is a potentially powerful tool for the early diagnosis of RPC, especially in patients without easily biopsied organ involvement. This modality also facilitates evaluation of disease extent and disease activity during treatment.

To evaluate the effects of tocilizumab (TCZ) on adult-onset Still's disease (AOSD), we reviewed medical records of seven patients with refractory AOSD treated with TCZ at our institution. TCZ therapy might allow rapid corticosteroid tapering and help maintain remission status, that is, resolution of clinical symptoms and normalization of biomarkers such as CRP and ferritin. Patients, however, should be monitored for the development of macrophage activation syndrome when TCZ is administered for active AOSD.

T cell lymphopenia results in peripheral homeostatic expansion to maintain the T cell immune system, which is termed lymphopenia-induced proliferation (LIP). LIP is a potential risk for expanding autoreactive clones to become pathogenic in human and murine autoimmune diseases. However, the ontogeny of T cells that induce autoantibody production by autoreactive B cells in LIP remains unclear. Transfer of CD4+CD25− conventional T (Tc) cells into T-cell-deficient athymic nude mice has been previously reported as a LIP-induced autoimmune model which develops organ-specific autoimmune diseases and systemic antinuclear antibodies (ANAs). We show here that via LIP in this model, Tc cells proliferated and differentiated into PD-1+CXCR5−/dim B-helper T cells, which promoted splenic germinal center (GC) formation, provided help for autoantibody-producing B cells, and had distinctive features of follicular helper T (Tfh) cells except that they do not express high CXCR5. Intestinal microbiota were essential for their generation, since depletion of them in recipient mice by antibiotics resulted in a reduction of LIP-induced PD-1+CXCR5−/dim B-helper T cells and an amelioration of autoimmune responses. Our findings will contribute to the elucidation of the mechanism of lymphopenia-induced autoimmunity and autoantibody production, and will pave the way for microbiota-targeted novel therapeutic approaches to systemic autoimmune diseases.

Orbital inflammation has been rarely associated with adult-onset Still's disease (AOSD). We herein describe two AOSD patients who developed lacrimal gland enlargement with inflammation spreading to the contiguous tissues in the orbit. Case 1 was a 26-year-old woman who developed bilateral eyelid swelling while taking prednisolone (22.5 mg/day) for AOSD. The swelling of the eyelid worsened after other symptoms emerged, such as a fever, a rash, and arthritis. The laboratory findings, including leukocytosis, liver dysfunction, and ferritin elevation, also suggested an AOSD flare-up. Case 2 was a 62-year-old woman who presented with left eyelid swelling. She was diagnosed with AOSD at 45 years of age but sustained remission. During admission, she subsequently developed a fever, a rash, arthritis, lymphadenopathy, and ocular hyperemia. AOSD was suspected from the clinical course. We speculate that dacryoadenitis and orbital inflammation are manifestations of AOSD.