Early Diagnosis of Invasive Aspergillosis in Neutropenic Patients. Comparison between Serum Galactomannan and Polymerase Chain Reaction.
BACKGROUND
Invasive aspergillosis (IA) is a major cause of morbidity and mortality in profoundly neutropenic patients, so early diagnosis is mandatory.


OBJECTIVE
Consecutive patients with hematological malignancies undergoing intensive chemotherapy were screened for IA with two different methods which were compared.


METHODS
From October 2000 to August 2003 we tested 1311 serum samples from 172 consecutive patients with a polymerase chain reaction assay and between April 2005 and April 2008 we tested 806 serum samples from 169 consecutive patients with a Galactomannan (GM) test. Bronchoalveolar (BAL) samples were obtained whenever the patient's condition allowed and tested with either method.


RESULTS
The serum PCR assay had a sensitivity of 75.0% and a specificity of 91.9% and the serum GM assay had a sensitivity of 87.5% and a specificity of 93.1%, (P > 0.05). The presence of two or more consecutive positive serum samples was predictive of IA for both assays. BAL GM/PCR was positive in some patients without serum positivity and in patients with 2 or more positive serum GM/PCR.


CONCLUSIONS
No significant differences between the 2 serum tests were found. The GM assay has the advantage of being standardized among several laboratories and is incorporated in the criteria established by the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycosis Study Group (EORTC/MSG), however is much more expensive. BAL GM and PCR sampling aids in IA diagnosis but needs further validation studies to differentiate between colonization and true infection in cases where serum GM or PCR are negative.
Lopes da Silva
Rodrigo
R
Serviço de Hematologia.
Ribeiro
Patrícia
P
Abreu
Natacha
N
Ferreira
Teresa
T
Fernandes
Teresa
T
Monteiro
Alexandra
A
Costa
Fátima
F
Caldas
Joana
J
Silva
Madalena
M
Carande
Luísa
L
Ferreira
Gilda
G
Conduto
António
A
Cruz
Ernesto
E
Sousa
Maria Henrique
MH
Rodrigues
António Silva
AS
Costa
Isabel
I
Veiga
Joana
J
de Sousa
Aida Botelho
AB