Lupus Nephritis Complicated by Haemophagocytic Lymphohistiocytosis: An Uncommon but Critical Association

Haemophagocytic lymphohistiocytosis (HLH) is a condition characterised by excessive inflammation that leads to multi-organ failure. It is associated with systemic inflammation stemming from the abnormal activation of natural killer (NK) cells, CD8+ cytotoxic T cells, and macrophages. Given this condition's rarity and non-specific clinical presentation, biochemical testing, biopsy, and imaging are crucial for etiological diagnosis. Here, we present the 18 F-FDG PET/CT findings in a child with lupus nephritis presenting with pancytopenia and fever. The diagnosis of HLH was established based on the HLH-2004 criteria, with 18 F-FDG PET/CT serving a valuable complementary role in supporting the diagnosis in this patient