Association between Tubulointerstitial Nephritis and Uveitis Syndrome and Small-Vessel CNS Vasculitis: A Case of Polyautoimmunity.

Introduction: We report a case study of two male pediatric patients presenting with anterior uveitis and elevated renal function parameters. Both were diagnosed with tubulointerstitial nephritis and uveitis syndrome and subsequently developed diffuse cerebral symptoms such as headache, fatigue, and diziness.

Methods: Magnetic resonance images (MRIs) of the brain showed T2-hyperintense lesions with and without gadolinium enhancement leading to brain biopsy and diagnosis of small-vessel central nervous system (CNS) vasculitis in both cases. Both patients were treated according to BrainWorks small-vessel vasculitis protocol and symptoms vanished over the course of treatment. Follow-up MRIs up to 12 months after initiation of therapy showed no signs of recurrence indicating a monophasic disease.

Conclusion: Small-vessel CNS vasculitis can occur simultaneously to other autoimmune diseases (ADs) in the scope of polyautoimmunity. As clinical findings of CNS vasculitis are often unspecific, neurological symptoms in nonneurological ADs should be adressed thoroughly. Under suspicion of small-vessel CNS vasculitis brain biopsy is still the gold standard and only secure way of definitive diagnosis.