Detection and clinical significance of glomerular M-type phospholipase A receptor in patients with idiopathic membranous nephropathy.

BACKGROUND

Glomerular M-type phospholipase A receptor (PLA R) is important for diagnosing idiopathic membranous nephropathy (IMN). The relation between glomerular PLA R expression and response to treatment remains to be explored.

AIMS

We conducted the study to explore the positive rate and clinical significance of glomerular M-type PLA R in IMN patients.

METHODS

A total of 122 IMN patients receiving neither glucocorticoid nor immunosuppressant therapy prior to renal biopsies was included and followed for more than 1 year. The control group comprised 30 patients with secondary membranous nephropathy and 100 patients with non-membranous forms of nephropathy. PLA R level and IgG subclasses in glomeruli were detected. The primary end-point was the reduction of proteinuria to less than 50% of baseline value.

RESULTS

A total of 82.0% of patients with IMN had positive glomerular PLA R deposits, compared with 16.7% in the secondary membranous nephropathy group (P < 0.001). Additionally, PLA R-positive expression combined with IgG4 ≥ 2+ was found in 94.3% IMN patients, compared with 40.0% in secondary membranous nephropathy patients (P < 0.01). Among IMN patients, the remission rate of proteinuria after either glucocorticoid or glucocorticoid combined immunosuppressant therapy for at least 6 months was 83.9% in the PLA R-positive group compared with 54.5% in the negative group (P < 0.05).

CONCLUSION

The positive rate of glomerular PLA R was more prevalent in IMN patients. Both PLA R and IgG4 glomerular deposits may help in discriminating between idiopathic and secondary membranous nephropathy. IMN patients with positive PLA R expression probably have a more beneficial response to glucocorticoid and/or immunosuppressant therapy.