The misleading effect of serum galactomannan testing in high-risk haematology patients receiving prophylaxis with micafungin. (December 2017)

• Record Type: Journal Article
• Authors: Vena, A.; Bouza, E.; Álvarez-Uría, A.; Gayoso, J.; Martín-Rabadán, P.; Cajuste, F.; Guinea, J.; Gómez Castellá, J.; Alonso, R.; Munoz, P.
• Is Part Of: Clinical microbiology and infection. Volume 23:Number 12(2017)
• Page Start: 1000.e1
• Page End: 1000.e4
• Publication Date: 2017-12
• Subjects: Antifungal prophylaxis -- Invasive aspergillosis -- Micafungin -- Hematologic malignancy -- Galactomannan; Medical microbiology -- Periodicals; Diagnostic microbiology -- Periodicals; Communicable diseases -- Periodicals; Infection -- Periodicals; 616.01
• DOI: 10.1016/j.cmi.2017.05.006
• Languages: English
• ISSNs: 1198-743X

Abstract

Abstract: Objectives: To investigate the performance of the routine serum galactomannan (sGM) assay in the diagnosis of invasive aspergillosis (IA) in high-risk haematology patients receiving prophylaxis with micafungin. Methods: Retrospective study including all haematological patients who received prophylaxis with micafungin during high-risk IA episodes (neutropenic patients after chemotherapy for acute myeloid leukaemia/myelodysplastic syndrome; allogeneic haematopoietic stem-cell transplantation during early neutropenic phase or graft-versus-host disease requiring high prednisone doses) and for whom at least one sGM result was available. Episodes were classified as follows: true-positive (positive GM in the context of IA), false-positive (positive GM result in patients who had no evidence of IA), true-negative (negative GM test results and no IA), or false-negative (negative GM test in the context of IA). Non-evaluable patients were excluded. Results: Among 146 evaluable episodes, four were true-positive in the context of probable breakthrough IA (incidence of breakthrough IA, 2.7%); 111/146 high-risk episodes (76%) were considered true-negative and 31/146 (21.2%) were considered false-positive. No false-negative episodes were detected. All but one of the false-positive episodes were detected in surveillance GM tests, leading to high-resolution CT scans in eight cases (8/31; 25.8%), all of which were negative. The positive predictive and negative predictive values of sGM for surveillance and diagnostic approaches were 3.2% (1/31) and 100% (110/110) and 75% (3/4) and 100% (1/1), respectively. Conclusions: Surveillance of asymptomatic patients receiving prophylaxis with micafungin using sGM is unnecessary, because the results are either negative or false-positive. However, sGM remains useful in the diagnosis of breakthrough IA in symptomatic patients during prophylaxis.