The Efficiency Of Galactomannan Testing In Bronchoalveolar Lavage Fluid On The Diagnosis Of Invasive Pulmonary Aspergillosis In Patients With Lung Diseases

Objective The incidence of invasive pulmonary aspergillosis (IPA) in pulmonarydiseases is not rare. However, the diagnosis of IPA is difficult for the clinicalpresentation is non special. Galactomanna (GM) detection has been proved as ansurrogate for early diagnosis IPA. The purpose of our study is to evaluate the role ofGM testing in bronchoalveolar lavage fluid (BALF) as a tool for early diagnosis ofIPA in patients with lung diseases.Methods We prospectively enrolled patients with lung diseases and who weresuspected of having IPA among three general hospitals. BALF for culture and GMdetection, serum samples for GM detection were obtained from all participants.According to European Organization for Research and Treatment of Cancer/MycosesStudy Group (EORTC/MSG) with host factors, clinical criteria, mycological evidenceand histological or cytopathological evidence, all patients were categorized withproven, probable, possible and no IPA. Patients with proven IPA and probable IPAwere considered as IPA group while no IPA was considered as control group. Usingstatistical method to evaluate the efficiency of BALF GM for diagnosing IPA.Results Of133enrolled patients,15were diagnosed with IPA (4proven,11probable),116patients were considered as control group. At a GM index cutoff valueof≥0.5, the sensitivity, specificity, positive predictive value and negative predictivevalue in BALF were86.7%,60.3%,22.0%, and97.2%, respectively, meanwhile inserum were60.0%,65.5%,18.4%, and92.7%, respectively. Using a GM index cutoffvalue of≥1.0for diagnosing IPA, the sensitivity of GM testing in BALF is higher thanin serum (80.0%vs.40%), but the specificity and positive predictive value in BALFwere bit lower than in serum (94.0%vs.97.4%，63.2%vs.66.7%, respectively).Receiver operating characteristic curve analysis found that at a GM index cutoff value of≥0.78, both the sensitivity and specificity of BALF GM increased to the highestpoint (86.7%and87.9%). In control group, patients who received β-lactam antibioticshad higher false-positive BALF GM rate than patients who did not receive anyantibiotics (60.6%vs.31.3%, x2=8.460, p=0.004). Two proven IPA patients hadreceived antifungal therapy before BALF GM detection and still had a GM value≥1.0in BALF.Conclusions The efficiency of GM detection in BALF is better than in serum fordiagnosis of IPA in patient with lung diseases. Using β-lactam antibiotics in clinic cancause false-positive BALF GM detection and physicians should be aware of thispossible interference. Short-course antifungal therapy has little influence on theBALF GM detection.