Overview
Kidney function can be assessed by using markers such as creatinine to calculate the estimated Glomerular Filtration Rate (eGFR).
Proteinuria is the presence of excess proteins in urine and can be assessed by performing several urine tests. Undetected proteinuria may mean underlying kidney damage is not identified. This may mean that irreversible kidney damage can occur, leading to kidney failure.
Renal impairment in Multiple Myeloma (MM):
Renal Funtion assessment
Assessment of renal function is vital in Multiple Myeloma (MM) patients. This is often done by estimating glomerular filtration rate (eGFR). This calculation can use creatinine or Cystatin C values in the estimate. Use of creatinine in the calculation may underestimate the extent of kidney disease in patients with MM, which can affect treatment doses and toxicity.
Compared to creatinine, Cystatin C test is a more sensitive marker for renal filtration and is unaffected by age, gender, or race1,2. The use of Cystatin C to calculate eGFR instead of creatinine may help avoid underestimating kidney disease in MM patients, particularly among women.
A recent study in newly diagnosed patients with MM [24 women / 37 men, mean age of 68 (±11)] investigated different equations used for the evaluation of eGFR, and compared them with the reference method to identify the most sensitive equation for detection of kidney disease, and to identify patients with more risk factors.3
The study concluded that inclusion of Cystatin C values in equations such as CKD-EPI and CAPA are more accurate when detecting hidden kidney disease, as well as patients with more and worse prognostic factors.
There is evidence that Cystatin C is superior to creatinine when calculating eGFR for patients with MM
Cystatin C – Recommended for the assessment of patients with Multiple Myeloma
A joint task force of NKF- ASN recommended immediate implementation of CKD-EPI creatinine equation; issued a report aiming at suppressing race adjustments in eGFR calculations, and stressing that Cystatin C-based calculations do not include such bias4