Falsely Undetectable Vancomycin Levels in a Pediatric Patient with Chronic Granulomatous Disease

A child with chronic granulomatous disease on vancomycin treatment had V trough levels that became undetectable, as measured in our hospital's clinical laboratory by a commonly employed particle-enhanced turbidometric inhibition assay. An alternative laboratory method yielded appropriate results. Recognizing and resolving erroneously low V trough levels could prevent needless adjustments in dosing that could increase risk for acute kidney injury.