Idiopathic Hypocomplementaemic Tubulointerstitial Nephritis

Background: Tubulointerstitial nephritis (TIN) is a common cause of kidney injury typically seen in association with drug exposure, infection or autoimmune diseases. However, TIN with interstitial immune complex deposition, without glomerular injury, is rarely observed. Case: We report a case of a 64-yearold Indian woman admitted for dialysis-requiring renal failure, without involvement of other organs. Urinalysis showed blood 3+ and 24h proteinuria of 1.5 g. Renal ultrasound revealed normal sized kidneys with loss of parenchymal-sinus differentiation. Laboratory tests disclosed low C3, positive ANA but negative anti-dsDNA, SSA and SSB. Serum protein electrophoresis was normal. The renal biopsy showed tubulointerstitial nephritis with positive immunoglobulin staining involving the interstitium and tubular basement membrane with glomerular sparing. The patient started prednisolone (1mg/kg/day) without recovery of the renal function. Conclusion: Idiopathic hypocomplementaemic tubulointerstitial nephritis is a rare disease with few cases described in the literature. To our knowledge this is the first case reported in Portugal.

Unilateral Oral Mucous Membrane Pemphigoid: Refractory Atypical Presentation Successfully Treated with Intravenous Immunoglobulins

A 57-year-old male presented with a 6-month history of blisters and painful erosions on the right buccal mucosa. No skin or other mucosal involvement was seen. The findings of histopathological and direct immunofluorescence examinations were sufficient for the diagnosis of oral mucous membrane pemphigoid in the context of adequate clinical correlation. No response was seen after topical therapies and oral corticosteroids or dapsone. Intravenous immunoglobulin was started and repeated every three weeks. Complete remission was achieved after three cycles and no recurrence was seen after two years of follow-up. The authors report a rare unilateral presentation of oral mucous membrane pemphigoid on the right buccal and hard palate mucosa, without additional involvement during a period of five years. Local trauma or autoimmune factors are possible etiologic factors for this rare disorder, here with unique presentation.