Wako β-D-glucan assay can be used to measure serum β-D-glucan in Sudanese patients to aid with diagnosis of eumycetoma caused by Madurella mycetomatis

Background Eumycetoma is a neglected tropical infection of the subcutaneous tissue commonly caused by the fungus Madurella mycetomatis. Previously, we demonstrated that beta-D-glucan was present in the serum of eumycetoma patients. Objective To compare the performance of the recently approved easy-to-use Wako beta-D-glucan assay to that of the Fungitell assay in eumycetoma patients. Methods Using sera obtained from 41 eumycetoma, 12 actinomycetoma and 29 healthy endemic controls, we measured the beta-glucan serum concentrations using the Wako assay and compared the performance to that of the Fungitell assay. Results With the Fungitell assay, median beta-glucan serum concentrations of 208, 70 and 27 pg/ml were obtained for the 41 eumycetoma patients, the 12 actinomycetoma patients and the 29 healthy endemic controls, respectively. With the Wako assay these concentrations were 14.45, 11.57 and 2.5 pg/ml, respectively. We demonstrated that when using the optimized cut-off value (5.5 pg/ml) for the Wako assay, the Wako and Fungitell assays had comparable performance in terms of sensitivity and specificity. Conclusion The Wako assay is comparable to the Fungitell assay for measurement of serum beta-glucan in mycetoma patients and hence can be used in combination with current diagnostic tools. However, this test should be used in combination with other tests to differentiate actinomycetoma from eumycetoma.