Reactions 1109 - 8 Jul 2006

Amoxicillin/clavulanic acid: falsepositive Fungitell assay results

Patients who receive amoxicillin/clavulanic acid mayshow false positive results to the 1,3-β-D-glucan assay[Fungitell], according to a report by Dr Monique A.S.HMennink-Kersten and colleagues from RadboudUniversity Nijmegen Medical Center, in theNetherlands.

The researchers found that serum samples from twopatients receiving IV amoxicillin/clavulanic acid werepositive for 1,3-β-D-glucan. Serum samples werenegative after treatment was stopped, and there was noevidence of invasive fungal disease in these patients.Testing showed that 1,3-β-D-glucan was present in theamoxicillin/clavulanic acid used to treat the patients. Theresearchers then tested 10 serum samples from sixpatients who had received IV amoxicillin/clavulanic acid,and 1,3-β-D-glucan was detected in nine of these;serum samples from two of these patients tested beforethey received amoxicillin/clavulanic acid were negativefor 1,3-β-D-glucan.

The researchers say their results are highly suggestiveof cross reactivity of the assay with amoxicillin/clavulanic acid. They also comment that, given thedifficulties in diagnosing invasive fungal disease, "itwould be desirable to eliminate the fungal material fromantibiotic agents".Mennink-Kersten MASH, et al. 1,3,-beta-glucan in patients receiving intravenousamoxicillin-clavulanic acid. New England Journal of Medicine 354: 2834-2835,No. 26, 29 Jun 2006 801013552

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Reactions 8 Jul 2006 No. 11090114-9954/10/1109-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved