What are the recommendations for plasma donation in individuals with elevated creatinine (Impaired renal function) levels?

Recommendations for Plasma Donation with Elevated Creatinine

Individuals with elevated creatinine levels (impaired renal function) should not donate plasma as it poses significant risks to their long-term kidney health and mortality.

Understanding Renal Function and Its Importance

Renal function is primarily assessed through glomerular filtration rate (GFR), which is the volume of blood filtered by the glomeruli per minute. According to established guidelines, renal function is classified into stages:

Stage	Description	GFR (mL/min/1.73 m²)
1	Kidney damage with normal or increased GFR	≥90
2	Mild decrease in GFR	60-89
3	Moderate decrease in GFR	30-59
4	Severe decrease in GFR	15-29
5	Kidney failure	<15 or dialysis

1

Evaluation of Renal Function

When evaluating potential plasma donors with elevated creatinine:

1. Do not rely solely on serum creatinine

   • Serum creatinine alone is an inadequate measure of renal function
   • When creatinine significantly increases, GFR has already decreased by at least 40%
   • Creatinine production is affected by body mass, muscle mass, diet, drugs, age, and sex 1

2. Proper assessment should include:

   • Estimated GFR (eGFR) from serum creatinine
   • Confirmation using one or more of the following:
     • Measured GFR using an exogenous filtration marker
     • Measured creatinine clearance
     • Estimated GFR from the combination of serum creatinine and cystatin C 1

Decision Algorithm for Plasma Donation with Elevated Creatinine

1. Absolute contraindications to plasma donation:

   • eGFR <60 mL/min/1.73 m² (CKD Stage 3 or worse)
   • Proteinuria (>500 mg/day)
   • Microhematuria (>50 RBCs per high-power field)
   • Abnormal renal ultrasonography 1

2. Relative contraindications:

   • eGFR between 60-89 mL/min/1.73 m² (CKD Stage 2)
   • History of acute kidney injury (AKI)
   • Conditions that may worsen kidney function (hypertension, diabetes)

3. Additional considerations:

   • Determine if elevated creatinine is due to:
     • True renal dysfunction
     • Transient elevation (dehydration, certain medications)
     • False elevation (creatine supplementation, certain drugs inhibiting renal transporters) 2, 3, 4

Important Caveats and Pitfalls

1. Creatine supplementation effects:

   • Creatine supplements, especially creatine ethyl ester, can elevate serum creatinine without affecting actual kidney function 3, 4
   • If a donor uses creatine supplements, consider alternative methods to assess GFR

2. Medication interactions:

   • Certain medications inhibit renal transporters (OCT2, MATE1/2-K) and can increase serum creatinine without affecting kidney function
   • Common examples include trimethoprim, cimetidine, dolutegravir, and some tyrosine kinase inhibitors 2

3. Volume status:

   • Dehydration can cause transient elevation of creatinine
   • Ensure proper hydration status before assessing renal function

Rationale for Recommendation

The primary concern with allowing plasma donation in individuals with elevated creatinine is the potential for further kidney damage. Plasma donation involves removing a significant volume of fluid, which can:

1. Reduce effective circulating volume
2. Activate compensatory mechanisms that may stress already compromised kidneys
3. Potentially precipitate acute kidney injury in vulnerable individuals

While some studies have shown that kidneys with mildly elevated creatinine can recover function 5, 6, these studies were in the context of kidney transplantation with intensive monitoring and management, not plasma donation.

The conservative approach prioritizing donor safety is essential, as plasma donation is voluntary and should never compromise the donor's health or increase their long-term mortality risk from kidney disease progression.