IgA nephropathy and tonsils--an approach from the structure of IgA1 produced by tonsillar lymphocytes.

Human immunoglobulin A1 (IgA1), which is the predominant subtype to be deposited in glomeruli in IgA nephropathy (IgAN), has a unique mucine-like structure in its hinge region. Namely, it contains O-glycans and proline-rich peptides We previously observed underglycosylation of the hinge region in serum and deposited IgA1 in IgAN. On the other hand, clinical development and exacerbation of IgAN are frequently preceded by episodes of upper respiratory tract infection, and palatine tonsils represent the predominant immunocompetent tissue of the upper respiratory tract.

IgA1 molecules produced by tonsillar lymphocytes are under-O-glycosylated in IgA nephropathy.

Background: Human serum immunoglobulin A1 (IgA1) has a unique mucine-like structure in its hinge region that contains O-glycans and proline-rich peptides. We previously reported the under-O-glycosylation of the hinge in serum IgA1 and deposited IgA1 in glomeruli (glomerular IgA1) in IgA nephropathy. The clinical development and exacerbation of IgA nephropathy frequently are preceded by episodes of upper respiratory tract infections.

Nephrotic syndrome with crescent formation and massive IgA deposition following allogeneic bone marrow transplantation for natural killer cell leukemia/lymphoma.

We describe herein a case of nephrotic syndrome (NS) following allogeneic bone marrow transplantation (allo-BMT) for natural killer cell leukemia/lymphoma. Histologic studies defined the diagnosis as crescentic glomerulonephritis with massive immunoglobulin A (IgA) deposition, which has never been reported in NS cases following allo-BMT. Most of the massive infiltrated cells in the interstice were CD3(+)CD4(-)CD8(+) T cells derived from the donor.