Anti-neutrophil cytoplasmic antibody-associated glomerulonephritis with detection of myeloperoxidase and phospholipase A2 receptor in membranous nephropathy-lesions: report of two patients with microscopic polyangiitis

BMC Nephrology

Hideyuki Shimazaki¹  Kuniaki Nakanishi¹  Toshihiko Imakiire²  Hiroo Kumagai²  Kenta Tominaga²  Takahiro Uchida²  Naoki Oshima²  Kenji Itoh³ 

[1] Department of Laboratory Medicine, National Defense Medical College;Department of Nephrology and Endocrinology, National Defense Medical College;Division of Hematology and Rheumatology, Department of Internal Medicine, National Defense Medical College;

关键词: Anti-neutrophil cytoplasmic antibody;    Membranous nephropathy;    Myeloperoxidase;    Phospholipase A2 receptor;   

DOI  :  10.1186/s12882-018-0922-5

来源: DOAJ

【 摘 要 】

Abstract Background Podocyte phospholipase A2 receptor (PLA2R) is a major target antigen in idiopathic adult membranous nephropathy (MN). Histological PLA2R staining in the renal tissue has proven to be useful for the detection of idiopathic MN. However, glomerular PLA2R deposits have also been recently observed in several patients with secondary MN, such as hepatitis B virus-associated, hepatitis C virus-associated, and neoplasm-associated MN. Certain inflammatory environments have been suggested to lead to abnormal expression of PLA2R epitopes, with the resulting production of PLA2R autoantibodies. Case presentation We report two patients diagnosed with anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis with MN-lesions, in whom ANCA titers for myeloperoxidase (MPO) were persistently positive. The first patient was a 52-years-old man who presented with interstitial pneumonitis. Microscopic hematuria and proteinuria were found when the interstitial pneumonitis became more severe. Renal biopsy findings yielded a diagnosis of ANCA-associated glomerulonephritis (mixed class) with MN-lesions. The second patient was a 63-years-old woman who had been treated for relapsing polychondritis. Her renal tissue showed evidence of focal ANCA-associated glomerulonephritis with MN-lesions. Interestingly, both MPO and PLA2R were detected in the glomerular subepithelial deposits of both patients. Immunoglobulin G (IgG) 1 and IgG2 were positive in the glomeruli of patient 2, and all subclasses of IgGs were positive in patient 1. Conclusion The present cases suggest that ANCA-associated glomerulonephritis could expose PLA2R, leading to the development of MN-lesions.

【 授权许可】

Unknown