Is it safe to donate plasma when the alanine aminotransferase level is 66 U/L and all other liver enzymes, complete blood count, iron studies, and hepatitis screening are normal?

Plasma Donation with ALT 66 U/L: Not Recommended

You should not donate plasma with an ALT of 66 U/L, even though all other tests are normal. This level exceeds standard blood donation screening thresholds and warrants further evaluation before any donation activity.

Why This ALT Level Disqualifies Donation

Blood donation centers use ALT screening as a surrogate marker for hepatitis and liver disease. The established cut-off values for blood donor screening are:

• Men: 132 U/L (approximately 3× upper limit of normal)
• Women: 86 U/L (approximately 2.5× upper limit of normal) 1

While your ALT of 66 U/L falls below these formal exclusion thresholds, plasma donation centers typically apply more conservative standards than whole blood donation and often defer donors with any ALT elevation above their institutional upper limit of normal (typically 30-40 U/L for men, 19-25 U/L for women) 2, 3.

Clinical Significance of Your ALT Level

An ALT of 66 U/L represents approximately 1.5-2× the upper limit of normal, which is clinically significant:

• This level indicates active hepatocellular injury that requires investigation, even with negative hepatitis testing 2
• Normal hepatitis testing does not exclude other causes of liver inflammation
• ALT elevations in this range can persist for months and may indicate underlying conditions including:
  • Non-alcoholic fatty liver disease (especially if overweight)
  • Autoimmune hepatitis
  • Drug-induced liver injury
  • Metabolic liver disease
  • Chronic hepatitis with false-negative serology 4

What You Need to Do Before Considering Donation

Mandatory evaluation includes:

1. Repeat ALT testing in 2-4 weeks to determine if elevation is persistent or transient
2. Complete metabolic panel including AST, alkaline phosphatase, bilirubin, and GGT
3. Assessment for metabolic risk factors: Calculate BMI, evaluate for obesity (donors with persistently elevated ALT often have mean body weight 128% of ideal vs. 116% in those whose ALT normalizes) 4
4. Additional serologic testing if not already done:
   • Anti-HBc (hepatitis B core antibody)
   • Anti-HCV (may need repeat testing as window period exists)
   • Consider autoimmune markers (ANA, SMA, IgG) if ALT remains elevated 5

When Donation Might Be Reconsidered

You may be eligible for plasma donation only if:

• ALT normalizes to ≤30 U/L (men) or ≤19 U/L (women) on repeat testing 3
• No underlying liver disease is identified
• All hepatitis markers remain negative
• The donation center's medical director specifically clears you

Important Caveats

• Do not assume negative hepatitis testing is definitive. Rare cases of HBV and HCV can exist with negative serology but detectable viral DNA/RNA, though this is uncommon (approximately 2 in 47,500 donations) 6
• Frequent plasma donation itself can cause health issues including protein/immunoglobulin depletion and iron deficiency, making it even more important to start with optimal health 7
• Even if your ALT normalizes, the donation center will likely require documentation of the cause and resolution of the elevation before accepting you as a donor

Bottom line: Seek medical evaluation for your elevated ALT before pursuing plasma donation. The donation center will defer you until this is resolved and documented.