The CD68 + /H‐ferritin + cells colonize the lymph nodes of the patients with adult onset Still's disease and are associated with increased extracellular level of H‐ferritin in the same tissue: correlation with disease severity and implication for pathogenesis

Summary In this work, we aimed to evaluate the levels of ferritin enriched in H subunits (H‐ferritin) and ferritin enriched in L subunits (L‐ferritin) and the cells expressing these two molecules in the lymph node (LN) biopsies obtained from adult‐onset Still's disease (AOSD) patients, and the possible correlation among these data and the severity of the disease. Ten patients with AOSD underwent LN biopsy. All the samples were stained by immunofluorescence. A statistical analysis was performed to estimate the possible correlation among both H‐ferritin and L‐ferritin tissue expression and the clinical picture of the disease. Furthermore, the same analysis was performed to evaluate the possible correlation among the number of CD68 + /H‐ferritin + or CD68 + /L‐ferritin + cells and the clinical picture. Immunofluorescence analysis demonstrated an increased tissue H‐ferritin expression in the LNs of AOSD patients. This increased expression correlated with the severity of the disease. An increased number of CD68 macrophages expressing H‐ferritin was observed in the LN samples of our patients. Furthermore, we observed that the number of CD68 + /H‐ferritin + cells correlated significantly with the severity of the clinical picture. Our data showed an imbalance between the levels of H‐ and L‐ferritin in LNs of AOSD patients and the evidence of an increased number of CD68 + /H‐ferritin + cells in the same organs. Furthermore, a correlation among both the tissue H‐ferritin levels and the CD68 + /H‐ferritin + cells and the clinical picture was observed.