Can reduced kidney filtration lower elimination of some mycotoxins?

Mycotoxins differ substantially in renal handling, so kidney filtration alone cannot determine whether an individual retains clinically meaningful amounts. This is particularly relevant in older adults, in whom creatinine may appear normal despite variation in estimated filtration.

Renal elimination and toxicokinetics

• Reduced glomerular filtration is a biologically credible contributor to lower elimination of some filterable, urinary-excreted mycotoxin metabolites. Deoxynivalenol (DON) is the clearest example: approximately 65–75% of intake is recovered in urine, mainly as glucuronide conjugates, with DON-15-glucuronide largely excreted within about 12 hours in a human study.
• This remains a toxin-specific mechanistic inference, not a demonstrated clinical effect of chronic kidney impairment. No human pharmacokinetic studies have compared mycotoxin clearance, urinary recovery, systemic exposure, or half-life across measured eGFR or CKD strata.

Mechanistic considerations

• Ochratoxin A (OTA) does not behave as a simple filtration-dependent analyte. It is >99% albumin-bound, which greatly restricts glomerular filtration; renal organic-anion transporters mediate tubular secretion, with secretion and possible reabsorption influencing urinary excretion and renal accumulation.
• Other toxins may depend predominantly on nonrenal pathways: aflatoxin B1 is principally hepatically metabolized and cleared through both biliary and urinary routes, while fumonisin B1 has very low urinary excretion.

Kidney-function interpretation

• Normal creatinine does not prove normal filtration, but a single mildly reduced eGFR also does not establish a sustained clearance disorder. KDIGO defines CKD by abnormalities present for ≥3 months, including persistent eGFR <60 mL/min/1.73 m² or other kidney-damage markers; eGFR 60–89 without such markers does not establish CKD.
• No toxin-specific eGFR threshold or validated blood/urine concentration cutoff shows that mild eGFR reduction independently predicts clinically important mycotoxin retention.

Bottom line

• Mild eGFR suboptimality with normal creatinine is insufficient to infer meaningful mycotoxin accumulation; repeat kidney assessment, potentially including creatinine–cystatin C eGFR when consequential, is more informative than interpreting mycotoxin findings as evidence of renal retention.