Quantification of cytomegalovirus DNA levels in intestinal biopsies as a diagnostic tool for CMV intestinal disease.
BACKGROUND
CMV intestinal disease (CMV-ID) is a serious complication in immunocompromised patients and mainly diagnosed by clinical, endoscopic and histopathologic findings, whereas qualitative CMV-PCR in tissue samples is not recommended for diagnosis due to its low positive predictive value (PPV).


OBJECTIVE
To study the interpretation and diagnostic use of CMV-quantification by PCR in intestinal tissue biopsies to recognize CMV-ID. To develop cut-off intestinal CMV-loads attributing illness to CMV.


METHODS
CMV-genome copies in 163 biopsies from the lower intestinal tract of immunocompromised patients were determined by quantitative real-time PCR, normalized to the cell number, and retrospectively compared to histopathological analysis, clinical findings and occurrence of CMV-antigenemia. Two cut-off intestinal CMV-loads, cut-off(histo) and cut-off(clin), were defined using histopathological or clinical criteria as gold standard, respectively.


RESULTS
CMV was detected in 32.5% of biopsies with a more than six log range of CMV-concentrations (1 x 10(-4)-1.4 x 10(2)copies/cell). Notably, biopsies with histopathologically or clinically confirmed CMV-ID had a significantly higher CMV-load (p<0.001). Cut-off(histo) and cut-off(clin) were defined at the intestinal CMV-load of 0.14 and 0.01 copies/cell, respectively, and improved the PPV. However, cut-off(histo) showed a decreased sensitivity for clinically defined CMV-ID cases. Interestingly, many patients with CMV-ID showed no concomitant CMV-antigenemia, suggesting a localized intestinal CMV-replication.


CONCLUSIONS
Quantification of CMV in intestinal biopsies is a useful diagnostic tool allowing the definition of cut-off values that can predict CMV-ID more accurate than qualitative PCR results. Further prospective studies have to clarify wether these cut-offs can improve diagnostics and treatment of CMV-ID in day-to-day clinical practice.
Ganzenmueller
Tina
T
Institute of Virology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany. Ganzenmueller.Tina@mh-hannover.de
Henke-Gendo
Cornelia
C
Schlué
Jerome
J
Wedemeyer
Jochen
J
Huebner
Sabine
S
Heim
Albert
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000956:Antigens, Viral / Q000097:blood; D019540:Area Under Curve; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D003587:Cytomegalovirus / Q000235:genetics*; D003586:Cytomegalovirus Infections / Q000175:diagnosis / Q000821:virology*; D004279:DNA, Viral / Q000032:analysis*; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D016867:Immunocompromised Host; D007223:Infant; D007410:Intestinal Diseases / Q000175:diagnosis / Q000821:virology*; D007422:Intestines / Q000821:virology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods*; D012372:ROC Curve; D018709:Statistics, Nonparametric; D019562:Viral Load
D000956:Antigens, Viral; D004279:DNA, Viral