Tumor necrosis factor-α links heat and inflammation with Fabry pain

Fabry disease (FD) is an X-linked lysosomal storage disorder associated with pain triggered by heat or febrile infections. We modelled this condition by measuring the cytokine expression of peripheral blood mononuclear cells (PBMC) from FD patients in vitro upon stimulation with heat and lipopolysaccharide (LPS). We enrolled 67 FD patients and 37 healthy controls. We isolated PBMC, assessed their gene expression of selected pro- and anti-inflammatory cytokines, incubated them with heat, LPS, globotriaosylceramide (Gb3), and tumor necrosis factor-alpha (TNF), and measured TNF secretion in the supernatant and intracellular Gb3 accumulation, respectively. We found increased TNF, interleukin (IL-)1 beta, and toll-like receptor 4 (TLR4) gene expression in FD men (p <.05 to p <.01). TNF and IL-10 were higher, and IL-4 was lower in the subgroup of FD men with pain compared to controls (p <.05 top <.01). Hereby, TNF was only increased in FD men with pain and classical mutations (p <.05) compared to those without pain. PBMC from FD patients secreted more TNF upon stimulation with LPS (p <.01) than control PBMC. Incubation with Gb3 and an additional alpha-galactosidase A inhibitor did not further increase TNF secretion, but incubation with TNF greatly increased the Gb3 load in FD PBMC compared to controls (p <.01). Also, LPS incubation and heat challenge (40 degrees C) increased Gb3 accumulation in PBMC of patients compared to baseline (p <.05 each), while no alterations were observed in control PBMC. Our data show that TNF holds a crucial role in the pathophysiology of FD associated pain, which may open a novel perspective for analgesic treatment in FD pain.