Can elevated cystatin C levels, indicating Impaired renal function, prohibit a hematopoietic stem cell transplant?

From the Guidelines

A high cystatin C reading alone typically does not prohibit a stem cell transplant, but it is an important consideration in the evaluation process. Cystatin C is a marker of kidney function, and elevated levels indicate reduced kidney filtration capacity. Transplant teams assess kidney function as part of their comprehensive pre-transplant evaluation because the conditioning regimens used before transplantation (including chemotherapy and sometimes radiation) can be nephrotoxic. According to the most recent guidelines, chronologic age and renal function should not be the sole criteria used to determine eligibility for SCT 1.

Key Considerations

• Patients with compromised kidney function may require dose adjustments of medications, alternative conditioning regimens, or in some cases, treatment to improve kidney function before proceeding with transplantation.
• The transplant team will consider the cystatin C level alongside other kidney function tests like creatinine, estimated glomerular filtration rate (eGFR), and urinalysis to determine overall kidney health.
• They will also evaluate the underlying cause of elevated cystatin C, as temporary elevations due to acute conditions may resolve, while chronic kidney disease might require more significant transplant protocol modifications.
• High-dose chemotherapy and autologous stem cell transplantation can be safely performed in patients with renal insufficiency, including those on dialysis, with conditioning using reduced-dose melphalan having outcomes comparable to standard-dose melphalan 1.

Evaluation Process

• The final decision about transplant eligibility involves weighing the risks of the procedure against the potential benefits for each individual patient.
• The evaluation process should consider the patient's overall health, including age, comorbidities, and functional status, as well as the specific characteristics of their kidney function and the underlying cause of any impairment.
• Guidelines recommend careful attention to supportive care to avoid early complications that may compromise therapeutic outcome 1.

Treatment Options

• Bortezomib-containing regimens can be administered to patients with severe renal impairment and those on dialysis without requiring renal dose adjustment 1.
• Lenalidomide and dexamethasone can be used in patients with relapsed/refractory myeloma and renal insufficiency, with dose adjustments based on the degree of renal function impairment 1.

From the Research

Cystatin C and Stem Cell Transplantation

• Cystatin C is a marker of renal function that has been studied in the context of hematopoietic stem cell transplantation 2, 3.
• Elevated cystatin C levels have been associated with renal dysfunction and acute kidney injury in stem cell transplant recipients 2.
• Cystatin C-based equations have been shown to be useful in estimating glomerular filtration rate (GFR) in pediatric autologous hematopoietic stem cell transplantation 3.

Impact of High Cystatin C Reading on Stem Cell Transplantation

• A high cystatin C reading may indicate impaired renal function, which could potentially prohibit a stem cell transplant or require careful consideration of the transplant procedure 2, 3.
• However, there is no direct evidence to suggest that a high cystatin C reading is an absolute contraindication for stem cell transplantation.
• The decision to proceed with a stem cell transplant in a patient with elevated cystatin C levels would depend on various factors, including the underlying cause of the renal dysfunction and the overall clinical condition of the patient.

Cystatin C as a Biomarker

• Cystatin C is a promising biomarker for assessing kidney function, with advantages over traditional markers such as serum creatinine 4, 5, 6.
• Cystatin C has been shown to be a more accurate and sensitive marker of GFR than serum creatinine in various clinical settings, including liver transplantation 5.
• The use of cystatin C-based equations can provide a more accurate estimate of GFR, which is essential for determining chemotherapy dosing and assessing renal function in patients undergoing stem cell transplantation 3.