The significance of serum GM and BG antigens assay for invasive fungal infections in hematological malignancies patients

• author:yirui
• date:2015-09-07
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Chinese Scientists have evaluated the diagnostic value of serum galactomannan antigen (GM) and (1→3)-β-D-glucan antigen (BG) assay in invasive fungal infections (IFI) in the patients with hematologic malignancies and the role in monitoring therapeutic response.

RESULTS:

Two hundred and forty serum samples were collected from 51 patients including 2 of proven IFI, 26 probable IFI, 17 possible IFI and 6 non-fungal infection. The true-positive group including the proven and probable groups, and true negative group was the non-fungal infection group. GM tests were positive in 21 of 28 cases in true positive group, and only one of 6 cases in non-fungal infection. The sensitivity, specificity, positive predictive value and negative predictive value were 75%, 83.3%, 95.5% and 41.7%, respectively. G tests were positive in all 28 cases of the true positive group, and 4 in 6 non-fungal infection cases. The sensitivity, specificity, positive predictive value and negative predictive value were 100%, 33.3%, 87.5% and 100%, respectively. G test is more sensitive than GM test (P = 0.015), but there was no significant difference in specificity of the two tests (P = 0.242). In 19 of 21 patients with GM test positive, anti-fungal treatment was effective, and GM value gradually decreased to negative, two invalid patients were persistent with GM test positive. After two weeks treatment, the average GM value was significantly lower in the effective group than in the ineffective group (P < 0.05). BG values in the responded patients showed a gradual decline similar to that of GM values, but not to negative. The changes of BG value in ineffective group varied with a trend upward. The changes in BG value had no relation with treatment effectiveness.

CONCLUSIONS:

Serum GM and BG antigens detection provides strong evidence for early diagnosis of IFI. Combination of GM and G tests can improve the diagnostic specificity and reduce the false positive GM test seems superior to G test for monitoring GM and BG values during treatment.

 

Zhonghua Xue Ye Xue Za Zhi. 2011 Jan;32(1):43-46.