Minimal change disease with IgM+ immunofluorescence: a subtype of nephrotic syndrome.
Immunoglobulin (Ig) M nephropathy is defined by electron-dense mesangial deposits and mesangial IgM visible by immunofluorescence (IF) without other histopathologic and immunofluorescent microscopic abnormalities. Certain patients have only immuno-positive (IgM+) IF. Children presenting with steroid-dependent or steroid-resistant nephrotic syndrome have a high prevalence of IgM+ IF with or without electron-dense deposits. We reviewed the clinical course of children with steroid-dependent or steroid-resistant nephrotic syndrome who underwent renal biopsy at Texas Children's Hospital from 1989 to 2006 to further characterize IgM+ IF in children with nephrotic syndrome. Of the 55 children with steroid-resistant or -dependent minimal change disease (MCD), 23 had IgM+ IF. Of these 23 children, 61% had microscopic hematuria at presentation, 48% (11/23) were steroid-dependent, and 48% (11/23) steroid-resistant (one underwent biopsy prior to steroid therapy). We compared the efficacy of adjuvant treatment with cyclophosphamide and cyclosporine: 18% initially treated with cyclophosphamide obtained remission, while 55% had no response; 83% obtained subsequent remission with cyclosporine. Of those initially treated with cyclosporine, 88% obtained complete or partial remission. IgM+ IF may be surrogate marker for the severity of MCD. Based on our results, children with MCD and IgM+ IF have a better response to cyclosporine than cyclophosphamide.
Swartz
Sarah J
SJ
Renal Division, Department of Pediatrics, Baylor College of Medicine, 6621 Fannin St., MC3-2482, Houston, TX 77030, USA.
Eldin
Karen W
KW
Hicks
M John
MJ
Feig
Daniel I
DI
D001706:Biopsy; D017024:Chemotherapy, Adjuvant; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003520:Cyclophosphamide / Q000627:therapeutic use; D016572:Cyclosporine / Q000627:therapeutic use; D005260:Female; D005455:Fluorescent Antibody Technique; D005920:Glomerular Mesangium / Q000276:immunology / Q000473:pathology; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007668:Kidney / Q000601:surgery; D008297:Male; D009402:Nephrosis, Lipoid / Q000188:drug therapy / Q000473:pathology*; D009404:Nephrotic Syndrome / Q000175:diagnosis* / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology*; D012189:Retrospective Studies; D055502:Secondary Prevention; D016896:Treatment Outcome
D007075:Immunoglobulin M; D007166:Immunosuppressive Agents; D016572:Cyclosporine; D003520:Cyclophosphamide