Myeloma progression and urinary gammaglobulin affect the urinary cystatin C to diagnose acute kidney injury in multiple myeloma.
OBJECTIVE
Urinary cystatin C has been suggested as a useful biomarker for diagnosis of acute kidney injury (AKI). Multiple myeloma is often complicated by AKI. Therefore, we investigated whether the urinary cystatin C was available for diagnosis of AKI in multiple myeloma.


METHODS
This study included 39 patients with monoclonal gammopathy of undetermined significance (MGUS) or multiple myeloma. We reviewed the medical records retrospectively and investigated whether urinary γ-globulin and myeloma progression had effects on urinary cystatin C excretion.


RESULTS
Spearman's correlation analysis showed that serum β2-microglobulin and serum cystatin C had a significant positive correlation with the urinary cystatin C excretion (r = 0.513, p = 0.001, r = 0.659, p < 0.001) and FEcystatinC (r = 0.585, p = 0.002, r = 0.711, p < 0.001). The GFRcr also had a significant negative correlation with the urinary cystatin C excretion (r = -0.582, p < 0.001) and FEcystatinC (r = -0.474, p = 0.002). In addition, the urinary γ-globulin had a significant positive correlation with the urinary cystatin C excretion (r = 0.678, p < 0.001) and FEcystatinC (r = 0.731, p < 0.001). Urinary γ-globulin was the most significant factor to influence urinary cystatin C excretion in multiple regression test.


CONCLUSIONS
These results indicate that urinary γ-globulin and myeloma progression can increase the fractional and total excretion of urinary cystatin C. Therefore, it is believed that the urinary cystatin C can be affected by urinary γ-globulin and myeloma progression in the diagnosis of AKI in multiple myeloma. In addition, urinary γ-globulin is believed to be the most significant factor to influence on urinary cystatin C.
Department of Nephrology and Oncology, Yonsei University Wonju College of Medicine, Wonju, South Korea.
Jae Seok
JS
Kim
Jae Won
JW
Yang
Hyeoncheol
H
Park
Young Sub
YS
Kim
Jun Young
JY
Lee
Jong In
JI
Lee
Byoung Geun
BG
Han
Seung Ok
SO
Choi
D058186:Acute Kidney Injury / Q000175:diagnosis / Q000652:urine*; D000368:Aged; D055316:Cystatin C / Q000652:urine*; D018450:Disease Progression; D005919:Glomerular Filtration Rate; D006801:Humans; D008875:Middle Aged; D009101:Multiple Myeloma / Q000473:pathology / Q000652:urine*; D009367:Neoplasm Staging; D001613:beta 2-Microglobulin / Q000097:blood; D005719:gamma-Globulins / Q000652:urine*
D055316:Cystatin C; D001613:beta 2-Microglobulin; D005719:gamma-Globulins