Background: Autoimmune polyglandular syndrome type 1 (APS 1) is an autosomal recessive disorder characterized by immune injury of multiple organ systems (primarily endocrine) secondary to a mutation in the autoimmune regulator (AIRE) gene. In some cases, patients develop tubulointerstitial nephritis (TIN) and progress to end-stage renal failure (ESRD).
Case diagnosis/treatment: We describe two patients with APS 1 and TIN. In both cases, TIN was clinically silent and the diagnosis was confirmed by renal biopsy. In one patient, renal function remained stable with immunosuppressive therapy. A second patient progressed to ESRD despite treatment, and received a deceased donor allograft. TIN recurred in the transplanted kidney and was reversed successfully with rituximab. Severe, recurrent esophageal candidiasis also resolved.
Conclusion: TIN is an important complication of APS 1 that may result in ESRD, and may recur in the transplanted kidney. TIN may be under-recognized, as the presentation is unapparent clinically and urinalysis remains normal. Immunosuppressive therapy may be effective and, therefore, routine monitoring of renal function is warranted in asymptomatic individuals.