Polymerase chain reaction screening for fungemia and/or invasive fungal infections in patients with hematologic malignancies

Context.— New molecular diagnostic tests regularly become available, and they may be assumed to be superior to traditional diagnostic studies. The added cost of these studies should be considered in conjunction with the value provided for patient care. Objective.— To assess the cost and diagnostic value of broad-range polymerase chain reaction (PCR) and DNA sequencing for the diagnosis of fungal infections compared with traditional studies. Design.— We reviewed the cost and clinical impact of broad-range fungal PCR/DNA sequencing for 65 specimens for which this test, a direct fungal examination, fungal culture, and a histopathologic assessment were performed. Results.— The sensitivity, specificity, and positive and negative predictive values for each of the assays studied were, respectively: histopathology (83.3%, 100%, 100%, and 98.3%); direct examination (66.7%, 100%, 100%, and 96.7%); fungal culture (83.3%, 100%, 100%, and 98.3%); and broad-range fungal PCR/DNA sequencing (83.3%, 95.0%, 62.5%, and 98.3%). The cost for broad-range fungal PCR/DNA sequencing was $32,500, compared with $8,591.70 for all traditional tests combined, for the 65 specimens included in this review. Conclusions.— Broad-range fungal PCR/DNA sequencing did not detect any infecting fungal pathogen that was not detected by at least 1 of the traditional methods, but 3 false-positives occurred. Broad-range fungal PCR/DNA sequencing is not a substitute for traditional laboratory studies and should be used judiciously to promote care affordability.

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Early Diagnosis of Invasive Aspergillosis in Neutropenic Patients. Comparison between Serum Galactomannan and Polymerase chain Reaction

Clinical Medicine Insights Oncology ◽

10.4137/cmo.s5228 ◽

2010 ◽

Vol 4 ◽

pp. CMO.S5228 ◽

Cited By ~ 7

Author(s):

Rodrigo Lopes Da Silva ◽

Patrícia Ribeiro ◽

Natacha Abreu ◽

Teresa Ferreira ◽

Teresa Fernandes ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Early Diagnosis ◽

Invasive Aspergillosis ◽

Fungal Infections ◽

Chain Reaction ◽

Serum Samples ◽

European Organization ◽

Positive Serum ◽

Neutropenic Patients ◽

Polymerase Chain

Background Invasive aspergillosis (IA) is a major cause of morbidity and mortality in profoundly neutropenic patients, so early diagnosis is mandatory. Aim 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.

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