骨髄泡沫細胞のfilipin染色により成人型のNiemann-Pick病C型と診断した兄弟例

Diagnosis of Adult Type of Niemann-Pick Disease (type C) in Two Brothers by Filipin Staining of Bone Marrow Smears

　要旨　症例は兄弟例。主訴は手指の巧緻運動障害。一般身体所見では肝脾腫を認め，神経学的所見では知的機能低下，驚愕反応，垂直性核上性眼球運動障害，構音障害，四肢・体幹のジストニア，下顎反射および四肢深部腱反射亢進，上肢病的反射陽性で，小脳性運動失調を認めた。頭部MRI上，大脳半球の萎縮を認めた。これらの所見から成人型Niemann-Pick病C型（NPC）を疑い，骨髄泡沫細胞のfilipin染色により非エステル化コレステロールを証明し，成人型NPCと診断した。成人型NPCは極めて稀な疾患でこれまで海外では21例，本邦では1例の報告があるのみである。われわれが経験した兄弟例では従来記載のない驚愕反応が認められた。

　Niemann-Pick disease, type C（NPC） is a neurometabolic genetic disorder that is distinguished from other types of Niemann-Pick disease by its later onset, more insidious progression, variable visceromegaly, and abnormalities of intracellular cholesterol metabolism. We report cases in 18-year-old and 20-year-old brothers who presented with disinhibition and involuntary movement of their hands. Both brothers presented various signs such as dementia, vertical supranuclear ophthalmoplegia（VSO）, dysarthria, axial and limb dystonia, hyperreflexia, pathologic reflex, cerebellar ataxia, as reported. They also presented startle response. Brain MRI showed diffuse cerebral atrophy and abdominal CT reveals hepato-splenomegaly in both patients. These cases were suspected to be NPC based on dementia, VSO, cerebellar ataxia, hepato-splenomegaly and foam cells in the bone marrow.

　Generally, the diagnosis of NPC is based on deficient cholesterol esterification and excessive lysosomal filipin staining in cultured skin fibroblasts. However, culture of fibroblasts obtained from a biopsied skin samples is slow. We have rapidly made the diagnosis of NPC in our patients by filipin staining of foam cells from bone marrow.

　This diagnostic process using a bone marrow smear is more convenient and rapid than previous methods using cultured skin fibroblasts.

（Received : October 20, 2004）