Monitoring and modifying therapy in patients with anti-PLA2R antibody-associated membranous nephropathy

PLA2R: phospholipase A2 receptor; CNI: calcineurin inhibitor; eGFR: estimated glomerular filtration rate; ELISA: enzyme-linked immunosorbent assay.
* Immunologic remission is defined as depletion of anti-PLA2R antibody titers below the cut-off value for a positive result (<14 RU/mL by ELISA; some experts prefer to use a lower cut off of <2 RU/mL to define true absence of anti-PLA2R antibody) and/or a negative indirect immunofluorescence test.
¶ In most patients who achieve an immunologic remission, a remission in proteinuria usually follows within 12 to 24 months. Some patients who achieve an immunologic remission may not achieve a complete clinical remission. This can be caused by incomplete remodeling of the glomerular filtration barrier (in which case proteinuria may eventually decrease further) or due to irreversible chronic damage (in which case some degree of proteinuria may persist), and additional immunosuppressive therapy is not warranted in these patients. Patients who achieve an immunologic remission at 6 months but have increasing proteinuria or decreasing eGFR are uncommon and should be evaluated for other causes of worsening kidney function and/or worsening proteinuria (eg, renal vein thrombosis). Such patients should also be assessed for potential problems with the anti-PLA2R antibody assay.
Δ Refer to relevant UpToDate content regarding the dosing, duration, and toxicity of immunosuppressive therapies for primary membranous nephropathy.