title: Nephrotic syndrome caused by immune-mediated acquired LCAT deficiency.
abstract: Lecithin-cholesterol acyltransferase (LCAT) is an enzyme involved in maintaining cholesterol homeostasis. In familial LCAT deficiency (FLD), abnormal lipid deposition causes renal injury and nephrotic syndrome, frequently progressing to ESRD. Here, we describe a 63-year-old Japanese woman with no family history of renal disease who presented with nephrotic syndrome. The laboratory data revealed an extremely low level of serum HDL and undetectable serum LCAT activity. Renal biopsy showed glomerular lipid deposition with prominent accumulation of foam cells, similar to the histologic findings of FLD. In addition, she had subepithelial electron-dense deposits compatible with membranous nephropathy, which are not typical of FLD. A mixing test and coimmunoprecipitation study demonstrated the presence of an inhibitory anti-LCAT antibody in the patient's serum. Immunohistochemistry and immunofluorescence detected LCAT along parts of the glomerular capillary walls, suggesting that LCAT was an antigen responsible for the membranous nephropathy. Treatment with steroids resulted in complete remission of the nephrotic syndrome, normalization of serum LCAT activity and HDL level, and disappearance of foam cell accumulation in renal tissue. In summary, inhibitory anti-LCAT antibody can lead to glomerular lesions similar to those observed in FLD.
authors.affiliation: Departments of Medicine and Clinical Science, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takahashi
authors.forename: Keiju
authors.initials: K
authors.lastname: Hiromura
authors.forename: Mayuko
authors.initials: M
authors.lastname: Tsukida
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ohishi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Hamatani
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Sakurai
authors.forename: Toru
authors.initials: T
authors.lastname: Sakairi
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Ikeuchi
authors.forename: Yoriaki
authors.initials: Y
authors.lastname: Kaneko
authors.forename: Akito
authors.initials: A
authors.lastname: Maeshima
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuroiwa
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yokoo
authors.forename: Takeo
authors.initials: T
authors.lastname: Aoki
authors.forename: Michio
authors.initials: M
authors.lastname: Nagata
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Nojima
mesh_terms: D005260:Female; D005455:Fluorescent Antibody Technique; D015433:Glomerulonephritis, Membranous / Q000209:etiology* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000473:pathology*; D007863:Lecithin Cholesterol Acyltransferase Deficiency / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000209:etiology* / Q000473:pathology