Prospective evaluation of two PCR assays for detection of Aspergillus DNA in blood of patients at risk of invasive aspergillosis following chemotherapy or stem cell transplantation for haematological malignancy

Ref ID: 18605

Author:

T. Rogers (1), O. Morton (2), J. Springer (3), E. Conneally (1),
W. Heinz (3), C. Kenny (2), S. Frost (2), H. Einsele (3), J. Löf64258; er (3)

Author address:

(1)St James’s Hospital (Dublin, IE); (2)Trinity College (Dublin,
IE); (3)University of Würzburg (Würzburg, DE)

Full conference title:

Annual Meeting of the EBMT, 37th

Abstract:

Objectives: Invasive aspergilllosis (IA) continues to be a major
complication of treatment for haematological malignancy (HM),
and in haematopoietic stem cell transplant (SCT) recipients it
is the most common cause of mortality due to infection. Earlier
detection of Aspergillus infections would facilitate more effective management and prevent progression to invasive disease
which typically has a poor response to antifungal drugs. We
therefore evaluated two PCR assays for early detection of
Aspergillus DNA in blood of patients being treated in two large
haematology transplant centres.
Methods: Between 2007-2008 consecutive HM patients who
were undergoing chemotherapy, autologous (only one centre), allogeneic sibling or unrelated donor SCT were eligible for
inclusion into the study. Three EDTA whole blood samples were
collected twice weekly from all study patients who were monitored for IA and other invasive fungal diseases (IFD) throughout their inpatient treatment using the European Organization
for Research and Treatment of Cancer/Infectious Diseases
Mycoses Study Group consensus criteria for defi ning IFD. Sera
were routinely processed for circulating galactomannan (GM,
Biorad) and reported to the clinical team. Samples were processed in batches for PCR. Staff performing the assays were
blind to clinical details. Assay 1 (PCR1) was a nested PCR as
published by White et al (Clinical Infectious Diseases 2006,
42;479) targeting the 28S Aspergillus ribosomal gene region,
while assay 2 (PCR2) was a real-time PCR developed in-house
targeting the ITS ribosomal region.
Results: 300 patients in total were included, equal numbers
coming from each centre over the two-year study period. There
was only 1 case of proven IA and 23 probable IA cases. Overall, there were approximately 4,000 blood samples processed
by each PCR assay. The frequency of positive test results
were for centre 1: GM, 7.6%, PCR1, 8.1%, and PCR2, 2.2%,
and for Centre 2: GM, 7.5%, PCR1, 5.5%, PCR2, 8.3%. This
suggested there was a centre-specifi c effect particularly with
regard to PCR2. In cases of probable/proven IA all 3 assays
gave positive results but there were more positive samples with
GM compared to either PCR assay.
Conclusion: When PCR is used in a complementary way to GM
assay it is a useful tool for detection of Aspergillus infection.
Further standardisation of PCR is necessary before its more
universal application for diagnosis of IA.

Abstract Number: O193

Conference Year: 2011

Link to conference website: NULL

New link: NULL

Conference abstracts, posters & presentations

Showing 10 posts of 17325 posts found.

  • Title

    Author

    Year

    Number

    Poster