Immune-complex deposits in “pauci-immune” glomerulonephritis: a case report and brief review of recent literature immunosuppressive treatments, median survival with pauci-immune vasculitis was 5 months [11], but survival steadily improved with the introduction of immunosuppressive agents. In the early 1970s, Fauci et al. [12] introduced cyclophosphamide in com- bination with corticosteroids as an effective treatment for pauci-immune vasculitis and observed a complete remission rate of 75%. Recent studies suggest that azathioprine may be as effective as cyclophosphamide in inducing remission of ANCA-medicated vasculitis [13, 14]. However, the prognosis for patients with significant renal injury is distinctly poor. Plasmapheresis has been increasingly adopted as adjunctive therapy for rapidly progressive ANCA- associated glomerulonephritis [15]. A recent ran- domized controlled trial confirmed the efficacy of plasma exchange, demonstrating a 24% absolute reduction in the risk of progression to ESRD at 12 months, from 43% to 19%, compared to intravenous methylprednisolone (in addition to cyclophosphamide and prednisone for all patients) [16]. In our case, plasmapheresis was attempted along with immunosuppressive agents based on the presence of active necrotizing crescents on renal biopsy findings, and the patient tolerated the therapy without major adverse events. Unfortunately, he remained dialysis-dependent, likely because the process had progressed to yield substantial interstitial fibrosis by the time of diagnosis and treatment. Although ANCA-associated glomerulonephritis is classically pauci-immune, our case demonstrated IF Table I. Summary of published cases of “pauci-immune” glomerulonephritis with immune deposits and clinical outcomes Author Cases (n) Cases with positive Management Outcomes data (IF positive vs. negative) IF (Ig), and degree of positivity CP – cyclophosphamide, P – predinisolone, AZT – azathioprine, IF – immunofluorescence, Ig – immunoglobulin, NR – not reported Arch Med Sci 4, August / 2010 635 Ig deposition associated with more proteinuria (5.4 ±3.1 vs. 1.3 ±1.0 g/24 h; p = 0.016) and a non-significant trend towards worse renal survival Rapid initial response in all cases. Only one case developed significant renal failure that was successfully reversed with treatment Reversal of renal failure with combination therapy Ig deposition associated with higher median proteinuria (3.2 vs. 1.3 g/24 h, p < 0.0001), and a non-significant trend towards higher serum creatinine Neumann et al. [4] Lanham et al. [17] Vrtovsnik et al. [18] Andrassy et al. [19] Brouwer et al. [20] Grotz et al. [21] Ronco et al. [22] Hu et al. [23] Pinching et al. [24] Haas et al. [2] 37 5 1 25 20 1 41 2 13 126 6 (IgM, IgA), 1 (IgG, C3), ≥ 2+ 4 (Ig M, C3), 1 (IgA) 1 (IgA) 2 (IgA), “mild-to- moderate” deposits 7 (IgM) 10 (C3) 10 (C3, IgM, IgG, or IgA) 3 (IgG, IgM), 2 (IgA), 12 (C3); “significant” deposits 2 (IgG, IgA, IgM, and/or C3) 8 (IgG), 5 (IgM), 12 (C3) 68 (IgM, IgG, IgA, C3 and/or C1q) CP, P P and/or CP, AZT Pulse CP, P P for 9 months after clinical remission and CP (with uromitexan) for 2 years after remission, followed by either AZT or termination of treatment NR CP, P (13 patients) and plasma exchange (9 patients) P, CP (20 patients), P (29 patients), AZT (2 patients), plasmapheresis (2 patients) P P, CP and/or plasma- pheresis for initial control of fulminant cases CP and corticosteroid NR NR NR NR NR NR