candidiasis and 1 fusariosis, these last 2 patients were excluded from the analysis. ⢠405 urine samples from 49 haematology-oncology patients were screened ...
Galactomannan detection in urine samples from haemato-oncology patients at high risk of invasive aspergillosis Lisa Berry, Andrea Junor, Mansour Ceesay, Hammad Sikondari, Tony Pagliuca, Jim Wade, Melvyn Smith Introduction Aims • Aspergillus fumigatus is a ubiquitous saprophytic fungus capable of causing life-threatening lung infection in immunocompromised patients particularly haematologyoncology patients • Diagnosis of invasive aspergillosis (IA) is problematic; delay is associated with poor outcome
Methods • Haematology patients at high risk of developing IA were recruited as part of an IA diagnostic study. As part of the study protocol serum and urine samples were taken twice weekly • Patients were classified according to the EORTC/MSG1 criteria
• Confirmed diagnosis is made by demonstration of hyphae in tissue, however patients are often too unwell to undergo biopsy
• Urine was tested using the Platelia Aspergillus EIA according to manufacturer’s instructions with amendments made to the pre-treatment stage
• Clinical signs and symptoms of IA are non-specific
• Four pre-treatment conditions were used:
• Blood cultures are usually negative
1) no pre-treatment
• Sputum culture has poor sensitivity and specificity
2) centrifuged at 3000g for 10mins, followed by no pretreatment
• Microscopy and culture of broncho-alveolar lavage has a sensitivity of 30-80% and specificity of 97% • Galactomannan is a cell wall component of Aspergillus spp. released during growth
3) centrifuged and then treated according to the manufacturer’s instructions for serum 4) treated exactly according to the manufacturer’s instructions for serum
• This antigen is detected in blood using the Platelia Aspergillus EIA
Results
• It has been proposed that screening for GM in urine may be clinically useful, although there is little data addressing this
• 405 urine samples from 49 haematology-oncology patients were screened for the presence of GM, a mean of 8.3 samples were tested per patient (range 1-35)
• We studied the role of GM testing of urine samples in a prospective cohort of haematology-oncology patients at high risk of IA
• Pre-treatment conditions 1 and 2 gave results with higher indices than methods 3 and 4
• 6, 10 and 5 patients had proven, probable and possible fungal disease, respectively, and 28 had no evidence of fungal infection • Patients classified as possible were excluded from sensitivity and specificity calculations • Of the 6 proven patients; 2 had mould on histology but were culture-negative; 2 had IA, 1 had candidiasis and 1 fusariosis, these last 2 patients were excluded from the analysis EORTC classification
No. of Patients
No. of patients GM + urine
Proven
4
1
Probable Possible No evidence
10 5 28
4 1 2
• GM detection in urine had a sensitivity of 35.7% and specificity of 92.9%
Conclusion Although GM can be detected in urine this assay lacks the sensitivity required to replace serum as the sample of choice for GM detection
Reference 1. De Pauw, B., et al., Revised Definitions of Invasive Fungal Disease from the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) Consensus Group. Clinical Infectious Diseases, 2008. 46(12): p. 1813-1821.
