Association of rise in C-reactive protein with decline in renal function following partial nephrectomy

Introduction: To investigate association of C-reactive protein (CRP), a marker of systemic inflammation, with renal functional decline patients undergoing partial nephrectomy (PN) for renal mass. Materials and methods: Retrospective study of patients who underwent PN between February2006-March 2011, with ≥ 6 months follow up. Data was analyzed between two groups: CRP increase ≥ 0.5 mg/L from 6 months postoperative ("CRP rise," CRPR), versus no CRP increase ≥ 0.5 ("CRP stable," CRPS). Primary outcome was change in estimated glomerular filtration rate (DeGFR, mL/min/1.73 m²), with de novo postoperative stage III chronic kidney disease (stage III-CKD, eGFR < 60 mL/min/1.73 m²) being secondary. Multivariable analysis (MVA) was conducted to identify risk factors for development of de novo stage III-CKD. Results: A total of 243 patients (206 CRPS/37 CRPR) were analyzed. Demographics and R.E.N.A.L. nephrometry scores were similar. CRPR had significantly higher median ΔeGFR (-13.7 versus -32.0 mL/min/1.73 m2, p < 0.001) and de novo stage III-CKD at last follow up (43.2% vs. 3.7%, p < 0.001). Median time to CRP rise was 10 (IQR 6.5-12) months. Median time from CRP rise to de novo stage III-CKD was 9 (IQR 7.5-11) months. MVA found RENAL score (OR 1.89, p = 0.001), hypertension (OR 4.75, p = 0.016), and CRP rise (OR 55.76, p < 0.001) were associated with de novo stage IIICKD. Sensitivity of CRP increase ≥ 0.5 for predicting CKD was 69.6%, specificity 93.3%, positive predictive value 55.2%, and negative predictive value 96.3%. Conclusion: Rise in CRP postoperatively is independently associated with renal functional decline after PN and may be useful in identifying patients to evaluate for renoprotective strategies. Further studies are requisite to clarify etiology of this association.