Proliferative Glomerulonephritis with Monoclonal Immunoglobulin Light Chain Deposits: A Rare Entity Mimicking Immune-Complex Glomerulonephritis

Abstract

A 39-year-old man developed proteinuria, hematuria, and renal insufficiency. A renal biopsy revealed the presence of mesangial proliferative glomerulonephritis with monoclonal λ-light chain deposits without evidence of immunoglobulin G (IgG), immunoglobulin A (IgA) or immunoglobulin M (IgM) deposits. Electron microscopy revealed granular electron-dense deposits resembling immune-complex deposits. No monoclonal proteins were detected in the serum or urine. The patient was treated with an angiotensin II receptor antagonist, and his condition was almost stable during the 1-year follow-up. This case shares common pathological characteristics with the newly described entity referred to as "proliferative glomerulonephritis with monoclonal IgG deposits" in which, glomerular deposits are composed entirely of monoclonal IgG. Therefore, we term the unusual form of glomerulonephritis observed in the present case "proliferative glomerulonephritis with monoclonal immunoglobulin light chain deposits."

A case of endocapillary proliferative glomerulonephritis with macrophages phagocytosing monoclonal immunoglobulin lambda light chain

“…Besides IgG, any class of monoclonal immunoglobulin can cause a PGN, and less commonly, only heavy or light chains may be present . The case report in which only light chain was detected in the form of dense deposit was reported, and moreover light chains from plasma cell dyscrasia can induce distinct pathophysiologic changes in the kidney . Through the difference of the properties of the monoclonal proteins, two mechanisms of PGN have been reported: the direct mechanism (associated with the deposition of the monoclonal Ig) and the indirect mechanism (associated with dysregulation of an alternative pathway by monoclonal Ig) .…”

Light chain only variant of proliferative glomerulonephritis with monoclonal immunoglobulin deposits is associated with a high detection rate of the pathogenic plasma cell clone

“…18,19 However, exceptional cases of PGNMID characterized by a deposition of nonorganized MIg LCs only (PGNMID-LC) have been reported. [20][21][22][23] Herein, we describe the first clinicopathologic and proteomic series of PGNMID-LC. The aim of this multicenter study was to define clinical, immunopathologic features and outcomes of PGNMID-LC, and to shed some light into its pathogenesis.…”

Proliferative Glomerulonephritis with Monoclonal IgG Deposits Associated with Membrano-Proliferative Features: Case Report

“…Proliferative glomerulonephritis with monoclonal IgG deposits, which was first described in 2004 by Nasr et al [1], has been a recently reported renal disease accounting for 0.07% of the diagnoses by renal biopsy [6,19]. As was mentioned earlier, the diagnosis of PNGMID is based on several restricted criteria as renal biopsy findings of glomerulonephritis with glomerular immune deposits staining positive for heave chain IgG, negativity for IgA and IgM heavy chains and positive staining for a single IgG subclass (IgG1, IgG2, IgG3 or IgG4) [20].…”

“…PGNMID is featured by glomerular nonorganized monoclonal immunoglobulin G deposits. Monoclonal IgG deposits are associated with glomerular proliferative lesions, mimicking different types of immune-complex glomerulonephritis [6][7][8][9][10][11][12][13][14][15]. Diagnostic criteria of PGNMID include the presence of glomerular monoclonal IgG deposits restricted to a single IgG subclass and a single light-chain isotype, the presence of granular deposits by electron microscopy and the absence of clinical and laboratory evidence of cryoglobulin.…”