Boston University Libraries OpenBU
    JavaScript is disabled for your browser. Some features of this site may not work without it.
    View Item 
    •   OpenBU
    • Theses & Dissertations
    • Boston University Theses & Dissertations
    • View Item
    •   OpenBU
    • Theses & Dissertations
    • Boston University Theses & Dissertations
    • View Item

    Characterization and differentiation of protein reabsorption granules and punctate IgG in primary podocytopathies

    Thumbnail
    Date Issued
    2021
    Author(s)
    Ihejirika, Tochukwu Nola Arthea
    Share to FacebookShare to TwitterShare by Email
    Export Citation
    Download to BibTex
    Download to EndNote/RefMan (RIS)
    Metadata
    Show full item record
    Permanent Link
    https://hdl.handle.net/2144/43401
    Abstract
    Nephrotic syndrome (NS) is a set of symptoms defined by heavy proteinuria and associated with a host of kidney diseases that cause injury to the glomerulus, the filtration apparatus of the kidney. Primary podocytopathies (Px), a group of diseases including minimal change disease (MCD), primary focal segmental sclerosis (pFSGS), and lupus podocytopathy (LP), are the principal cause of idiopathic NS in both children and adults. The hallmark feature of Px is the ultrastructural finding of podocyte foot process effacement (FPE), so current differential diagnosis of Px relies on technically exhaustive electron microscopy (EM) analysis. During routine immunofluorescence (IF) microscopy of many Px cases, we have observed punctate IgG (P-IgG) immunoreactivity in the glomerulus. P-IgG may represent a disease-specific reactivity that could not only provide clues for understanding Px etiology but could also serve as a diagnostic tool. However, we have found that P-IgG may be misinterpreted as protein reabsorption granules (PRGs), a morphological feature seen in proteinuric conditions. We sought to definitively characterize the key characteristics of PRGs and P-IgG in order to differentiate these features. To accomplish this, we reviewed prior IF immunostaining of MCD biopsies to evaluate anti-human IgG and anti-human albumin staining. We conducted additional IF staining on archived MCD biopsies using antibodies against IgG and against the markers of PRGs: albumin, megalin, and cubilin. We found that the P-IgG demonstrates a diffuse, global distribution pattern that is specific to glomerular epithelium and is fine and scattered. Conversely, the PRGs are coarse, clustered, and frequently demonstrate a focal, segmental pattern in the glomeruli and tubules. Co-staining with albumin and megalin revealed that the P-IgG and the PRGs do not colocalize in the tissue. While the cubilin antibody positively stained the tubular epithelium, it did not stain glomeruli. Our results showed that punctate IgG and protein reabsorption granules are morphologically and constitutionally distinct and do not colocalize with each other, indicating that P-IgG is highly likely to represent a distinct process from epithelial protein reabsorption.
    Collections
    • Boston University Theses & Dissertations [7792]


    Boston University
    Contact Us | Send Feedback | Help
     

     

    Browse

    All of OpenBUCommunities & CollectionsIssue DateAuthorsTitlesSubjectsThis CollectionIssue DateAuthorsTitlesSubjects

    Deposit Materials

    LoginNon-BU Registration

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Boston University
    Contact Us | Send Feedback | Help