The Chronic Kidney Disease Epidemiology Collaboration cystatin C (CKD-EPI-CysC) equation has an independent prognostic value for overall survival in newly diagnosed patients with symptomatic multiple myeloma; is it time to change from MDRD to CKD-EPI-CysC equations?
OBJECTIVES
The estimation of glomerular filtration rate (eGFR) in multiple myeloma (MM) is based on equations that use serum creatinine (sCr), such as the Modification of Diet in Renal Disease (MDRD) equation. However, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) group has suggested that eGFR based on both sCr and cystatin C (CKD-EPI-sCr-CysC) is more accurate than other formulae for the estimation of kidney dysfunction. The aim of this study was to prospectively evaluate, for the first time in the literature, the CKD-EPI-sCR-CysC formula in newly diagnosed patients with symptomatic MM.


METHODS
We studied 220 newly diagnosed, previously untreated, patients with symptomatic myeloma and calculated eGFR using the MDRD, the CKD-EPI-sCR, the CKD-EPI-CysC, and the CKD-EPI-sCr-CysC equations.


RESULTS
CKD-EPI-sCr-CysC equation detected more myeloma patients with stage 3-5 renal impairment than the MDRD, CKD-EPI, or CKD-EPI-CysC equations: 45% vs. 39.5%, 42.2%, and 43.1%, respectively (P < 0.01). This was also observed in the elderly patients (>70 yrs), while in patients ≤70 yrs, the CKD-EPI-CysC equation managed to identify higher number of patients with stage 3-5 renal impairment (RI) than the other equations. Furthermore, 63 (28.6%) patients with eGFR values by the MDRD formula were reclassified to higher CKD stages according to CKD-EPI-CysC equation. The median overall survival for all patients was 52 months. In the multivariate analysis, that included International Staging System stage, lactate dehydrogenase (LDH) ≥300 U/L and eGFR for each different equation (as a continuous variable), only eGFR that included CysC, but not sCr had independent prognostic value (P = 0.013) along with high LDH (P = 0.029).


CONCLUSIONS
Our results suggest that equations based on CysC reveal higher number of MM patients with RI compared with equations based only in sCr. Furthermore, the CKD-EPI-CysC formula independently predicted for survival. Based on these data, we suggest that CKD-EPI equations based on CysC should substitute MDRD, as it has been suggested for patients with several other renal disorders.
['Terpos|Evangelos|E|', 'Christoulas|Dimitrios|D|', 'Kastritis|Efstathios|E|', 'Katodritou|Eirini|E|', 'Pouli|Anastasia|A|', 'Michalis|Eurydiki|E|', 'Papassotiriou|Ioannis|I|', 'Dimopoulos|Meletios A|MA|', '|||']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D016022:Case-Control Studies D003404:Creatinine D055316:Cystatin C D005260:Female D005919:Glomerular Filtration Rate D006801:Humans D007770:L-Lactate Dehydrogenase D008297:Male D008875:Middle Aged D015233:Models, Statistical D009101:Multiple Myeloma D015999:Multivariate Analysis D017410:Practice Guidelines as Topic D011379:Prognosis D051436:Renal Insufficiency, Chronic D012720:Severity of Illness Index D016019:Survival Analysis
Chronic Kidney Disease Epidemiology Collaboration cystatin C multiple myeloma Modification of Diet in Renal Disease formula estimated glomerular filtration rate renal dysfunction