A Case of Alport Syndrome with Posttransplant Antiglomerular Basement Membrane Disease despite Negative Antiglomerular Basement Membrane Antibodies by EIA Treated with Plasmapheresis and Intravenous Immunoglobulin
Posttransplant antiglomerular basement membrane (anti-GBM) disease occurs in approximately 5% of Alport patients and usually ends in irreversible graft failure. Recent research has focused on characterizing the structure of the anti-GBM alloepitope. Here we present a case of a 22-year-old male with end-stage renal disease secondary to Alport syndrome, with a previously failed renal allograft, who received a second deceased-donor kidney transplant. Six days after transplantation, he developed acute kidney injury. The serum anti-GBM IgG was negative by enzyme immunoassay (EIA). On biopsy, he had crescentic glomerulonephritis with linear GBM fixation of IgG. With further analysis by western blotting, we were able to detect antibodies to an unidentified protein from the basement membrane. This patient was treated with plasmapheresis twice per week and monthly intravenous immunoglobulin (IVIG) for a total of five months. At the end of treatment, these unknown antibodies were no longer detected. His renal function improved, and he has not required dialysis. We conclude that anti-GBM disease in patients with Alport Syndrome may be caused by circulating antibodies to other components of the basement membrane that are undetectable by routine anti-GBM EIA and may respond to treatment with plasmapheresis and IVIG. 1. Introduction Alport syndrome is a genetic disorder caused by mutations in COL4A3, COL4A4, and COL4A5 genes, impairing assembly of type IV collagen. Most cases are inherited in an x-linked pattern, although some cases are autosomal recessive and autosomal dominant [1–3]. Anti-GBM nephritis is usually associated with the presence of circulating IgG antibodies to the noncollagenous domain of alpha Type IV collagen, manifesting as linear IgG deposition along the GBM on immunofluorescence staining. These patients develop hematuria, proteinuria, and end-stage renal disease. Therapy is unsatisfactory and usually ends in graft failure [4–9]. When patients with Alport syndrome receive renal transplants, posttransplant anti-GBM nephritis occurs in 3–5% of patients [4, 5, 7]. Here we describe a case of Alport syndrome with development of posttransplant anti-GBM nephritis with negative anti-GBM antibodies by enzyme immunoassay (EIA) who was found to have circulating antibodies to another epitope at the noncollagenous region of type IV collagen. The patient was treated with plasmapheresis and IVIG and responded excellently with preservation of renal allograft function. 2. Case Report A 22-year-old male with ESRD secondary to Alport syndrome presented for deceased
References
[1]
Y. Pirson, “Making the diagnosis of Alport's syndrome,” Kidney International, vol. 56, no. 2, pp. 760–775, 1999.
[2]
C. Pescucci, F. Mari, I. Longo et al., “Autosomal-dominant Alport syndrome: natural history of a disease due to COL4A3 or COL4A4 gene,” Kidney International, vol. 65, no. 5, pp. 1598–1603, 2004.
[3]
I. Longo, P. Porcedda, F. Mari et al., “COL4A3/COL4A4 mutations: from familial hematuria to autosomal-dominant or recessive Alport syndrome,” Kidney International, vol. 61, no. 6, pp. 1947–1956, 2002.
[4]
L. Berardinelli, E. Pozzoli, M. Raiteri et al., “Renal transplantation in Alport's syndrome. Personal experience in twelve patients,” Contributions to Nephrology, vol. 80, pp. 131–134, 1990.
[5]
J. Gobel, C. J. Olbricht, G. Offner et al., “Kidney transplantation in Alport's syndrome: long-term outcome and allograft anti-GBM nephritis,” Clinical Nephrology, vol. 38, no. 6, pp. 299–304, 1992.
[6]
V. L. P. W. J. d. Heuvel, C. H. Schroder, C. O. S. Savage et al., “The development of anti-glomerular basement membrane nephritis in two children with Alport's syndrome after renal transplantation: characterization of the antibody target,” Pediatric Nephrology, vol. 3, no. 4, pp. 406–413, 1989.
[7]
C. E. Kashtan, “Renal transplantation in patients with Alport syndrome,” Pediatric Transplantation, vol. 10, no. 6, pp. 651–657, 2006.
[8]
M. J. Mojahedi, R. Hekmat, and H. Ahmadnia, “Kidney transplantation in patients with Alport syndrome,” Urology Journal, vol. 4, no. 4, pp. 234–237, 2007.
[9]
M. Sauter, H. Schmid, H. J. Anders, F. Heller, M. Weiss, and T. Sitter, “Loss of a renal graft due to recurrence of anti-GBM disease despite rituximab therapy,” Clinical Transplantation, vol. 23, no. 1, pp. 132–136, 2009.
[10]
D. Brainwood, C. Kashtan, M. C. Gubler, and A. N. Turner, “Targets of alloantibodies in Alport anti-glomerular basement membrane disease after renal transplantation,” Kidney International, vol. 53, no. 3, pp. 762–766, 1998.
[11]
D. Borza, “Autoepitopes and alloepitopes of type IV collagen: role in the molecular pathogenesis of anti-GBM antibody glomerulonephritis,” Nephron—Experimental Nephrology, vol. 106, no. 2, pp. e37–e43, 2007.
[12]
B. G. Hudson, K. Tryggvason, M. Sundaramoorthy, and E. G. Neilson, “Alport's syndrome, Goodpasture's syndrome, and type IV collagen,” The New England Journal of Medicine, vol. 348, no. 25, pp. 2543–2556, 2003.
[13]
X. P. Wang, A. B. Fogo, S. Colon et al., “Distinct epitopes for anti-glomerular basement membrane Alport alloantibodies and Goodpasture autoantibodies within the noncollagenous domain of α3(IV) collagen: a janus-faced antigen,” Journal of the American Society of Nephrology, vol. 16, no. 12, pp. 3563–3571, 2005.
[14]
V. Pedchenko, O. Bondar, A. B. Fogo et al., “Molecular architecture of the Goodpasture autoantigen in anti-GBM nephritis,” The New England Journal of Medicine, vol. 363, no. 4, pp. 343–354, 2010.
[15]
J. S. Kang, X. P. Wang, J. H. Miner et al., “Loss of α3/α4(IV) collagen from the glomerular basement membrane induces a strain-dependent isoform switch to α5α6(IV) collagen associated with longer renal survival in Col4a3-/- Alport mice,” Journal of the American Society of Nephrology, vol. 17, no. 7, pp. 1962–1969, 2006.
[16]
G. Browne, P. A. J. Brown, C. R. V. Tomson et al., “Retransplantation in Alport post-transplant anti-GBM disease,” Kidney International, vol. 65, no. 2, pp. 675–681, 2004.
[17]
R. Raghavan, A. Jeroudi, K. Achkar, A. O. Gaber, S. Patel, and A. Abdellatif, “Bortezomib in kidney transplantation,” Journal of Transplantation, vol. 2010, Article ID 698594, 6 pages, 2010.
