Serum matrix metalloproteinase-9 as a predictor of recurrence in idiopathic nephrotic syndrome.

BACKGROUND

The risk factors for the recurrence of idiopathic nephrotic syndrome (INS) remain unknown. Previous studies have suggested a potential link between matrix metalloproteinase-9 (MMP-9) and urinary protein levels in INS. Therefore, we aimed to investigate the association between serum MMP-9 levels and the risk of subsequent recurrence in patients with INS.

METHODS

This retrospective study included 29 patients with biopsy-proven INS from 1998 to 2016. Baseline serum MMP-9 levels during the nephrotic phase were measured using an enzyme-linked immunosorbent assay. Subsequent recurrence was defined as a change in urinary protein levels from remission to more than 2 + on a dipstick test or more than 1 g/g creatinine.

RESULTS

The median age was 42 years (interquartile range: 26.0, 70.0), and 18 patients were males. Over a median follow-up period of 130 days, 12 patients (41.4%) experienced recurrences. Patients who experienced recurrence were younger and had higher estimated glomerular filtration rates and baseline serum MMP-9 levels during the nephrotic phase than those who did not. Higher baseline serum MMP-9 levels during the nephrotic phase were associated with a higher risk of subsequent recurrence (hazard ratio: 5.687, 95% confidence interval: 1.179-27.44).

CONCLUSION

Baseline serum MMP-9 levels during the nephrotic phase were associated with subsequent recurrence in patients with INS, indicating its potential as a predictive marker for future recurrence in patients with INS.