A Chinese girl of Blau syndrome with renal arteritis and a literature review.

BACKGROUND: Blau syndrome is a rare autoinflammatory disease caused by autosomal dominant mutations in the CARD15/NOD2 gene. Vascular involvement is a rare phenotype in Blau syndrome patients. In this study, we aimed to describe a 20-year- old Chinese girl with Blau syndrome complicated by renal arteritis. In addition, we summarized a literature review of published cases of vascular involvement in patients with Blau syndrome.

CASE PRESENTATION: We describe a 20-year-old girl who was initially misdiagnosed with juvenile idiopathic arthritis (JIA) almost 15 years prior. In October 2019, she developed renal arteritis at the age of 17 years and was eventually diagnosed with Blau syndrome. A de-novo M513T mutation was found in her gene testing. A review of the literature on patients with Blau syndrome and vasculitis showed that a total of 18 cases were reported in the past 40 years. The vast majority of them were predominantly involved medium and large vessel arteritis. Of the 18 patients included in our literature review, 14 patients had aorto-arteritis, and 4 of them had renal artery involvement. Two patients presented with renal artery stenosis, 1with a sinus of Valsalva aneurysm, and 1 with retinal vasculitis.

CONCLUSION: A detailed medical history inquiry and a careful physical examination are helpful for the early identification of Blau syndrome, especially for infant onset refractory JIA. Medium-and large-vessel arteritis is a rare clinical manifestation in Blau syndrome patients. Careful examination of the peripheral pulse and measurement of blood pressure at every regular visit may be helpful in the early identification of Blau syndrome-arteritis. Early diagnosis and appropriate treatment may prevent or delay the occurrence of severe symptoms in patients to improve the patient's quality of life.