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Minimal change variants: Mesangial proliferation; IgM nephropathy; C1q nephropathy

Authors
Alain Meyrier, MD
Gerald B Appel, MD
Section Editors
Richard J Glassock, MD, MACP
Fernando C Fervenza, MD, PhD
Deputy Editor
Albert Q Lam, MD

INTRODUCTION

In addition to minimal change disease (MCD), three other disorders usually present with the nephrotic syndrome and may also show only minor changes on light microscopy: idiopathic mesangial proliferative glomerulonephritis; immunoglobulin M (IgM) nephropathy; and C1q nephropathy. These disorders may represent variants of MCD or focal segmental glomerulosclerosis (FSGS), but some clinicians and pathologists believe that they are separate conditions.

The nosology of IgM and C1q nephropathy is particularly unsettled. However, clinicopathologic findings suggest forms of idiopathic nephrotic syndrome that, in terms of prognosis and treatment options, are closer to FSGS than to MCD.

Idiopathic mesangial proliferative glomerulonephritis, IgM nephropathy, and C1q nephropathy will be reviewed in this topic. The pathogenesis, clinical features, diagnosis, and treatment of MCD and FSGS are discussed separately. (See "Etiology, clinical features, and diagnosis of minimal change disease in adults" and "Treatment of minimal change disease in adults" and "Epidemiology, classification, and pathogenesis of focal segmental glomerulosclerosis" and "Treatment of primary focal segmental glomerulosclerosis".)

IDIOPATHIC MESANGIAL PROLIFERATIVE GLOMERULONEPHRITIS

Focal (involving less than 50 percent of glomeruli on light microscopy) or diffuse mesangial cell proliferation (involving more than 50 percent of glomeruli on light microscopy) is a relatively nonspecific response to glomerular injury. This pattern can be seen in a variety of diseases including lupus nephritis, IgA nephropathy, and mild postinfectious glomerulonephritis [1]. In addition, there is a seemingly idiopathic form in which there are either no immune deposits (in contrast to the IgA or IgG deposits in the above disorders) or focal or diffuse IgM-containing deposits in the mesangial areas. Patients with this glomerulopathy tend to present in one of two ways: with hematuria; or, more commonly, with proteinuria that is often in the nephrotic range [2,3]. Most publications dealing with the latter involve childhood idiopathic nephrotic syndrome with focal segmental glomerulosclerosis (FSGS) on renal biopsy [4].

Hematuria — Some patients with mesangial proliferative glomerulonephritis present with episodes of gross hematuria [5] or with microscopic hematuria that may be detected on a routine examination [2,3]. These findings may follow a nonstreptococcal upper respiratory infection [6], a pattern that resembles that of IgA nephropathy (see "Glomerular disease: Evaluation and differential diagnosis in adults"). The hematuria often resolves spontaneously, although persistent microscopic hematuria may be seen [2]. The renal prognosis in these patients is almost always excellent [2,7].

     
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Literature review current through: Nov 2017. | This topic last updated: Nov 15, 2017.
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References
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  1. Sagel I, Treser G, Ty A, et al. Occurrence and nature of glomerular lesions after group A streptococci infections in children. Ann Intern Med 1973; 79:492.
  2. Brown EA, Upadhyaya K, Hayslett JP, et al. The clinical course of mesangial proliferative glomerulonephritis. Medicine (Baltimore) 1979; 58:295.
  3. O'Donoghue DJ, Lawler W, Hunt LP, et al. IgM-associated primary diffuse mesangial proliferative glomerulonephritis: natural history and prognostic indicators. Q J Med 1991; 79:333.
  4. Focal segmental glomerulosclerosis in children with idiopathic nephrotic syndrome. A report of the Southwest Pediatric Nephrology Study Group. Kidney Int 1985; 27:442.
  5. Swartz SJ, Eldin KW, Hicks MJ, Feig DI. Minimal change disease with IgM+ immunofluorescence: a subtype of nephrotic syndrome. Pediatr Nephrol 2009; 24:1187.
  6. Smith MC, Cooke JH, Zimmerman DM, et al. Asymptomatic glomerulonephritis after nonstreptococcal upper respiratory infections. Ann Intern Med 1979; 91:697.
  7. Border WA. Distinguishing minimal-change disease from mesangial disorders. Kidney Int 1988; 34:419.
  8. Primary nephrotic syndrome in children: clinical significance of histopathologic variants of minimal change and of diffuse mesangial hypercellularity. A Report of the International Study of Kidney Disease in Children. Kidney Int 1981; 20:765.
  9. Childhood nephrotic syndrome associated with diffuse mesangial hypercellularity. A report of the Southwest Pediatric Nephrology Study Group. Kidney Int 1983; 24:87.
  10. Ji-Yun Y, Melvin T, Sibley R, Michael AF. No evidence for a specific role of IgM in mesangial proliferation of idiopathic nephrotic syndrome. Kidney Int 1984; 25:100.
  11. Waldherr R, Gubler MC, Levy M, et al. The significance of pure diffuse mesangial proliferation in idiopathic nephrotic syndrome. Clin Nephrol 1978; 10:171.
  12. Faedda R, Pirisi M, Satta A, et al. Immunosuppressive treatment of the nephrotic syndrome due to mesangial lesions. Clin Nephrol 1996; 46:237.
  13. Cohen AH, Border WA, Glassock RJ. Nehprotic syndrome with glomerular mesangial IgM deposits. Lab Invest 1978; 38:610.
  14. Myllymäki J, Saha H, Mustonen J, et al. IgM nephropathy: clinical picture and long-term prognosis. Am J Kidney Dis 2003; 41:343.
  15. Jennette JC, Hipp CG. C1q nephropathy: a distinct pathologic entity usually causing nephrotic syndrome. Am J Kidney Dis 1985; 6:103.
  16. Iskandar SS, Browning MC, Lorentz WB. C1q nephropathy: a pediatric clinicopathologic study. Am J Kidney Dis 1991; 18:459.
  17. Markowitz GS, Schwimmer JA, Stokes MB, et al. C1q nephropathy: a variant of focal segmental glomerulosclerosis. Kidney Int 2003; 64:1232.
  18. Sharman A, Furness P, Feehally J. Distinguishing C1q nephropathy from lupus nephritis. Nephrol Dial Transplant 2004; 19:1420.
  19. Kersnik Levart T, Kenda RB, Avgustin Cavić M, et al. C1Q nephropathy in children. Pediatr Nephrol 2005; 20:1756.
  20. Devasahayam J, Erode-Singaravelu G, Bhat Z, et al. C1q Nephropathy: The Unique Underrecognized Pathological Entity. Anal Cell Pathol (Amst) 2015; 2015:490413.
  21. Mii A, Shimizu A, Masuda Y, et al. Current status and issues of C1q nephropathy. Clin Exp Nephrol 2009; 13:263.
  22. Vizjak A, Ferluga D, Rozic M, et al. Pathology, clinical presentations, and outcomes of C1q nephropathy. J Am Soc Nephrol 2008; 19:2237.
  23. Hisano S, Fukuma Y, Segawa Y, et al. Clinicopathologic correlation and outcome of C1q nephropathy. Clin J Am Soc Nephrol 2008; 3:1637.
  24. Gunasekara VN, Sebire NJ, Tullus K. C1q nephropathy in children: clinical characteristics and outcome. Pediatr Nephrol 2014; 29:407.
  25. Fukuma Y, Hisano S, Segawa Y, et al. Clinicopathologic correlation of C1q nephropathy in children. Am J Kidney Dis 2006; 47:412.
  26. Said SM, Cornell LD, Valeri AM, et al. C1q deposition in the renal allograft: a report of 24 cases. Mod Pathol 2010; 23:1080.