losartan-potassium and Glomerulonephritis--Membranous

Topics: Acute Kidney Injury; Autoantigens; Darbepoetin alfa; Diabetic Nephropathies; Erythropoietin; Glomerulonephritis, Membranous; Hematinics; Humans; Immunosuppressive Agents; Kidney Diseases; Lupus Nephritis; Randomized Controlled Trials as Topic; Renal Replacement Therapy

Rituximab, a monoclonal antibody directed against the CD20 molecule found on pre-B cells and mature B cells (but not on plasma cells), was introduced in the late 1990s for the treatment of non-Hodgkin's lymphoma. Recently, this antibody has been used to treat autoimmune diseases, especially those associated with a prominent humoral component and with potentially pathogenic autoantibodies. Small cohort studies have indicated that rituximab could have an important role in the management of these disorders. Rituximab has also been utilized in the transplant setting, to diminish levels of alloreactive antibodies in highly sensitized patients, to manage ABO-incompatible transplants, and to treat rejection associated with B cells and antibodies. The exact mechanism by which rituximab exerts its effects in autoimmunity and transplantation remains unclear, as specific autoantibody or alloantibody levels often seem not to diminish in parallel with clinical improvement. A role for rituximab in depleting B cells and compromising their antigen-presenting function seems likely; rituximab might also inhibit T-cell activation. A synergistic effect has been noted in vitro following administration of corticosteroids to B-cell lines, with accentuation of B-cell cytotoxicity; this observation might be relevant to certain studies, as some regimens have utilized both agents simultaneously. This article reviews the current use of rituximab in renal disease and transplantation, and includes discussion of the drug's potential role in novel therapeutic protocols.

Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Murine-Derived; Autoimmune Diseases; Autoimmunity; B-Lymphocytes; Erythropoietin; Glomerulonephritis, Membranous; Glomerulosclerosis, Focal Segmental; Graft Rejection; Humans; Immunologic Factors; Kidney Diseases; Kidney Transplantation; Lupus Erythematosus, Systemic; Lymphoproliferative Disorders; Recombinant Proteins; Red-Cell Aplasia, Pure; Rituximab; Vasculitis

A 44-year-old man developed idiopathic membranous nephropathy and true secondary polycythaemia. With advancing azotemia, polycythaemia gradually resolved and venesection was no longer required. Only 2 cases of polycythaemia associated with membranous nephropathy have been reported previously. Secondary polycythaemia is a rarely reported association of membranous nephropathy and may increase the risk of thromboembolism, which might be prevented with venesection.

Topics: Adult; Bloodletting; Erythropoietin; Glomerulonephritis, Membranous; Humans; Male; Polycythemia; Thromboembolism

A 61-year-old male patient had secondary polycythemia associated with idiopathic nephrotic syndrome. Renal biopsy revealed membranous nephropathy. Polycythemia did not change in spite of partial remission of proteinuria. Serum erythropoietin determined by an enzyme-linked immunosorbent assay was 7.2 mU/ml. His serum erythropoietin maintained at a constant level during polycythemia was higher than it was before the appearance of renal ischemia, so he was kept in a polycythemic state. Whether decreasing proteinuria can improve renal ischemia requires future study. We must observe the patient for the occurrence of thromboembolism. Renal ischemia possibly induced by nephrotic syndrome is likely to cause secondary polycythemia.

Topics: Biopsy, Needle; Enzyme-Linked Immunosorbent Assay; Erythropoietin; Fluorescent Antibody Technique; Glomerulonephritis, Membranous; Humans; Male; Microscopy, Electron; Middle Aged; Polycythemia; Proteinuria