Generalized atherosclerosis sparing the transplanted kidney in Schimke disease

Schimke-immuno-osseous dysplasia (SIOD) is a multisystem disorder caused by a mutation of the chromatin remodeling protein. The main clinical findings are spondyloepiphyseal dysplasia with disproportional growth deficiency, nephrotic syndrome with focal and segmental glomerulosclerosis, and defective cellular immunity. Transitory ischemic attacks due to vaso-occlusive processes are still an untreatable and life-limiting complication in patients with SIOD. The underlying pathophysiology of vaso-occlusive processes in SIOD is unclear. We report the clinical and pathological findings of the eldest published patient with the severe form of SIOD, who died at the age of 23 years due to pulmonary hypertension with subsequent right heart failure. The autopsy revealed a severe generalized atherosclerosis including the brain, heart, and pulmonary arteries. However, the kidney that was transplanted at the age of 5 years showed a good graft function without glomerular sclerosis and with only minimal nephrosclerosis on histology. Thus, the absence of severe vaso-occlusive processes in the transplanted organ and in the severely atherosclerotic host may indicate that the vaso-occlusive processes in SIOD are not caused by post-transplant cardiovascular morbidity such as arterial hypertension and hyperlipidemia. Instead, vascular factors of the host such as endothelial dysfunction may explain the pathophysiology of atherosclerosis in SIOD.