IMMUNOHISTOCHEMISTRY: PLA2R

RECENT STUDIES HAVE SHOWN THAT IN APPROXIMATELY 70% OF PATIENTS WITH PRIMARY MN (PMN), THE GLOMERULAR IMMUNE COMPLEXES CONSIST OF AUTOANTIBODIES AGAINST THE PODOCYTE PROTEIN M-TYPE PHOSPHOLIPASE A2 RECEPTOR (PLA2R). THERE IS ALSO EVIDENCE THAT LEVELS OF ANTI-PLA2R AUTOANTIBODIES CORRELATE WELL WITH DISEASE ACTIVITY AND PROGRESSION AND CAN BE USED TO MONITOR THE DISEASE ACTIVITY IN FOLLOW UP. IT MAY BE NOTED THAT RESULTS OF POSITIVE PLA2R STAINING, THOUGH HIGHLY SUGGESTIVE OF A PRIMARY MEMBRANOUS NEPHROPATHY, SHOULD BE INTERPRETED IN CONJUNCTION WITH OTHER CLINICAL AND LABORATORY PARAMETERS, SERUM PLA2R LEVELS AND RELEVANT RENAL BIOPSY FINDINGS. ABSENCE OF STAINING IN RENAL BIOPSY OR NEGATIVE SEROLOGY FOR PLA2R DOES NOT COMPLETELY EXCLUDE PRIMARY MEMBRANOUS NEPHROPATHY.