Effect of β-lactam antibiotics on the false-positive rate of the serum Aspergillus galactomannan assay

Abstract

Objective To investigate the effect of β-lactam antibiotics on the false-positive rate of the serum Aspergillus galactomannan (GM) assay in patients with lung diseases. Methods We selectively recruited 77 lung disease patients who did not meet the diagnostic criteria of invasive pulmonary Aspergillosis (IPA) and received different β-lactam antibiotics, while 41 patients without IPA who did not receive any antibiotic treatment were recruited as the control group. Serum samples for GM detection were collected from all participants. The rate of false-positive Aspergillus galactomannan was compared between the two groups. Results False-positive serum results were found in patients who received piperacillin-tazobactam (30.8% or 8/26) and cefoperazone-sulbactamand (27.8% or 5/18). The rate of false-positive Aspergillus galactomannan in patients who receive β-lactam antibiotics were significantly higher than that in the control group (24.7% or 19/77 vs. 7.3% or 3/41, χ2=5.315, P=0.025). Taking false-positive serum Aspergillus galactomannan as the dependent variable and β-lactam antibiotic treatment as the independent variable, univariate logistic regression analysis showed that the rate of false-positive Aspergillus galactomannan in patients who received β-lactam antibiotics were 4.149 times more than that in the control group (OR=4.149, P=0.030). Conclusions The administration of β-lactam antibiotics may increase the occurrence of false-positive serum Aspergillus galactomannan, and physicians should be aware of this possible interference. Key words: Aspergillosis; Mannans; Beta-lactams