Comparison of Molecular (Real Time PCR) Based Detection of Viruses in GI and Renal Small Biopsy Specimens to Histology Based Evaluation
K Aulakh, C Chisholm, V Zamudio, K Hocker, A Rao. Scott & White Memorial Hospital and Texas A&M Health Sciences Center, Temple, TX
Background: Viral infections of the gastrointestinal tract and kidney can cause significant clinical disease, especially within the context of immunocompromised states including transplant patients. Some of the viruses commonly associated with GI and renal pathology include cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV), adenovirus, and JC and BK viruses. Real time molecular (PCR) detection of these viruses has proven to be a sensitive and specific methodology, but there is little documentation of the increased sensitivity when compared to routine histology or in-situ hybridization. We sought to compare the techniques to evaluate sensitivity and specificity using clinical outcome.
Design: The data for this study was compiled from an institutional pathology database (2004-2009) and consisted of previously collected gastro-intestinal and kidney formalin-fixed, paraffin-embedded specimens that were tested for viruses by PCR as well histological examination.
Results: 140 patients were identified that had tissue specimens which were analyzed by real time PCR. 23 of the submitted 138 surgical specimens were positive by PCR, 18 of which were negative by histology. Eleven of these specimens were immunosuppressed patients from transplantation, acquired immunodeficiency syndrome (AIDS), or chemotherapy. No histology positive, PCR negative samples were identified. Clinical correlation was also performed and identified that all positive patients responded favorably to appropriate interventions such as antiviral therapy or temporary reduction of immunosuppression. Additionally, 4 renal biopsies were positive for BK virus. These patients had no BK viremia but were positive for BK virus in urine. Thus, clinically, molecular identification of virus in tissues may be the most relevant in determining disease.
Conclusions: Histological examination alone lacks the sensitivity and specificity when compared to PCR, particularly when classic cytological and nuclear features are absent. Early PCR testing is a sensitive and specific method to enable a more accurate tissue diagnosis, as well as faster turnaround time, thereby allowing the clinician to implement treatment more promptly. Additionally, quantitation of viral load can be performed which allows for better monitoring.
Monday, March 22, 2010 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 201, Monday Morning