ANCA vasculitis and membranoproliferative glomerulonephritis associated with Sjögren's syndrome: Case report and literature review

ANCA-associated vasculitis may occur concomitantly with primary Sjögren's syndrome (SS) or arise during its evolution. We present the case of a patient who underwent dry symptoms, a positive Schirmer test and an SS-compatible autoimmunity profile and, simultaneously, deterioration of renal function, anaemia, and dyspnoea, requiring renal biopsy and fibrobronchoscopy. Complementary studies documented acute necrotizing glomerulonephritis with extracapillary proliferation, and membranoproliferative pattern with immune complex deposition. Bronchoalveolar lavage was compatible with alveolar haemorrhage. Kidney lung syndrome secondary to ANCA vasculitis was diagnosed and treatment with steroid and intravenous cyclophosphamide with clinical and paraclinical improvement was instituted. Mixed renal involvement found in this case is uncommon in patients with SS, and treatment changes significantly, hence the importance of differential diagnosis and reporting in the literature.