Infantile Onset Panniculitis with Uveitis and Systemic Granulomatosis: immunohistochemical findings

Through the International Registry of Pediatric Granulomatous Arthritis (PGA), we now identified 5 children with this disorder, all manifesting from very young age panniculitis, fever, hepatosplenomegaly, arthritis, uveitis and acute phase response. Underlying infections, immune deficiency and autoimmune disease, were excluded. No CARD15 or CIAS1 mutations were found. Histologically, the subcutaneous nodules showed a non-vasculitic noncytophagic lobular panniculits. Giant and epitheloid cell granulomas were found in liver (pt 1, 5), synovium (pt 2), lymph node (pt 3, 5), colon (pt 3), subcutaneous fat (pt 3), dermis and lung (pt 4). Immunohistochemical study of the granulomas revealed the presence of abundant CD68+ macrophages, numerous CD4+ T lymphocytes and few CD8+ cells. TNF stainings were only weakly positive, conversely abundant IL-6 staining was apparent, especially in the corona of lymphocytes.