Renal Involvement and Its Treatment in Pediatric Patients With Proteinase-3 Anti-Neutrophil Cytoplasmic Antibody Positive Granulomatosis With Polyangiitis: A Case Series.

We describe three pediatric patients between the ages of 10 and 14 years old who were diagnosed with granulomatosis with polyangiitis (GPA) between 2014 and 2019. Each case involves variations in presentation, symptomatology, diagnostics, and induction and maintenance therapy regimens. Patient 1 presented with significant renal involvement, hypertensive emergency, and focal alveolar hemorrhage, a rare presentation of GPA that causes up to 60% mortality.Patient 2 presented with minimal renal involvement and a diffuse petechial rash, which is the most common cutaneous presentation of GPA. Finally, patient 3 presented with significant renal involvement and later on with symptoms of idiopathic intracranial hypertension (IIH), a unique and rare presentation associated with GPA. Despite the heterogeneity of these cases, the similar therapy regimens used in each case successfully achieved induction and maintenance of disease remission, providing an evidentiary basis for these treatment regimens even in severe and unusual pediatric GPA cases.