孤発性Blau症候群の長期経過観察例

Abstract

We report a female patient with sporadic Blau syndrome who was followed up for more than 10 years before being diagnosed at the age of 19. Recurrent skin, eye, and bone involvement started in infancy. Her initial clinical diagnosis was SLE and juvenile idiopathic arthritis (JIA) later. At 9 years old, the diagnosis of early-onset sarcoidosis (EOS) was confirmed with histopathologic diagnosis from skin biopsy. Since clinical manifestations of EOS are very similar to those of JIA, skin biopsy is essential for differential diagnosis. Underlying etiology of EOS had been unraveled to that date. DNA analysis revealed that the patient had a heterozygous missense mutation for CARD15/NOD2 (caspase recruitment domain-containing protein 15), the gene for an intracellular receptor for bacterial products in monocytes that transduces signals leading to NF-κB activation. This case showed an arg334trp mutation that had been reported in Blau syndrome that shows phenotypic overlap with EOS. As her parents showed no mutation in CARD15, she was diagnosed as having a sporadic Blau syndrome. She had been treated with oral and/or intravenous steroids for a long time. Since she had intraocular lens implantation due to steroid cataract at the age of 12, intravenous liposteroid, a lipid emulsion containing a water-soluble dexamethasone in lipid vesicles, was started with oral prednisolone. This treatment lessened the side effects of the steroid and allowed us to control the manifestation of EOS/Blau syndrome.