Deficiency of Adenosine Deaminase 2 in Adult Siblings: Many Years of a Misdiagnosed Disease With Severe Consequences.

Objective: Describe the clinical characteristics and histopathology findings in a family with two siblings affected with deficiency of adenosine deaminase 2 (DADA2). Both patients presented in childhood with polyarthritis and developed significant neurological and gastrointestinal features of DADA2 in ear, including variable degrees of immunologic and hematologic manifestations.

Methods: Adenosine Deaminase 2 (ADA2; also known as exon sequencing and serum ADA2 levels were performed to confirm the diagnosis of DADA2.

Protective Role of Mast Cells in Primary Systemic Vasculitis: A Perspective.

Mast cells are important cells of the immune system. Although traditionally considered as key players in allergic and hypersensitivity reactions, emerging evidence suggests that mast cells have many complex roles in vascular disease. These include regulation of vasodilation, angiogenesis, activation of matrix metalloproteinases, apoptosis of smooth muscle cells, and activation of the renin angiotensin system.