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A comparison of flow cytometry with slide method to detect pp65-antigenemia during active CMV infection
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Abstracts
Intervention Studies- Posters G6-28 Quantitative PCR In The Follow-Up Of CMV Infected AIIogeneic Bone Marrow Recipients CATHERINE MENGELLE Department of Virology, Toulouse, France The aim of this study was to evaluate the interest of quantitation of plasma CMV-DNA during the follow-up of CMV-infected allogeneic marrow transplant recipients. Material and methods : Since January 1 997, 44 allogeneic marrow transplant recipients were weekly followed by qualitative CMV-DNA PCR on leukocytes, and plasma in case of leukocytes positivity (Gen-ETI-K HCMV. Sorin Biomedical Among the 44 patients, 22 remained CMV negative, 6 CMV-infected patients died rapidly, 10 harboured CMV in leukocytes only and the last 6 patients presented CMV-DNA in both plasma and leukocytes. These were tested by the quantitative CMV-PCR Cobas Amplicor CMV Monitor Test (kindly provided by Roche Diagnostics Systems) according to the manufacturer's intructions. Results : Appearance and increase of C M V - D N A copies were concomitant with CMV infection in 5/6 patients. CMV-DNA quantitative PCR remained negative in one patient. During the 1 5 days treatment (Ganciclovir or Foscarnet), a rapid decrease of CMV-DNA copies was observed in the only responder patient, but levels of CMV-DNA remained stable in the non-responders (N=4). A second course of 15 days treatment was then instaured : 2 patients with stable levels of CMV-DNA died with gastrointestinal disease, the remained 2 showed negativation of CMV-DNA. Conclusion : Quantitative CMV-PCR is a reliable test in the follow-up of CMV-infected allogeneic bone marrow recipients.
G6-29 A comparison of flow cytometry with slide method to detect pp65-antigenemia during active CMV infection BERTHE-MARIE IMBERT-MARCILLE Virology Laboratory, University Hospital, Nantes, France The purpose of this study was to compare flow cytometry with the slide method for pp65-antigenema detection in PMNLs from immunocompromised patients. 247 samples were obtained from 81 transplant (72 renal and 9 BMT) and 7 AIDS patients.Pp65-antigenemia was quantified with 1C3 MAb using conventional slide detection (S-Ag) (Arg~ne Biosoft) and a home-made flow cytometry (FC-Ag) procedure (Imbert-Marcille et al., J Clin Microbiol 1997; 35: 2665-9).Qualitative leucocytic DNAemia and viremia were additionnaly performed on each sample. Overall agreement between the four tests was 60.5%. Comparison of S-Ag with FC-Ag yield to 80% (196/247) concordance: absolute antigen-positive PMNLs number correlates well, only when high vial load were considered.Discrepancies were a positive result for S-Ag associated with a negative one for FC-Ag in 22 cases, observed in an active infection context in 21 cases. In the 29 other discrepancies, e.g.negative S-Ag with positive FC-Ag, 23 occured during an active infection episod.ln all discordants results, antigenemia level was low: less than 15 positive cells/2.105 PMNLs (median, 2) and less than 0.30% positive cells (median, 0.08%) as estimated by flow cytometry. 21/23 patients in which a longitudinal follow-up was performed developped an active infection: the first antigenemia test found to be positive was FC-Ag in 81% of cases and S-Ag in 71% of cases. Flow cytometry has similar performance than the slide metod for pp65-antigenemia detection, allowing a more objective screnning of active CMV infection in routine laboratory use.
Abstracts
Intervention Studies- Posters G6-28 Quantitative PCR In The Follow-Up Of CMV Infected AIIogeneic Bone Marrow Recipients CATHERINE MENGELLE Department of Virology, Toulouse, France The aim of this study was to evaluate the interest of quantitation of plasma CMV-DNA during the follow-up of CMV-infected allogeneic marrow transplant recipients. Material and methods : Since January 1 997, 44 allogeneic marrow transplant recipients were weekly followed by qualitative CMV-DNA PCR on leukocytes, and plasma in case of leukocytes positivity (Gen-ETI-K HCMV. Sorin Biomedical Among the 44 patients, 22 remained CMV negative, 6 CMV-infected patients died rapidly, 10 harboured CMV in leukocytes only and the last 6 patients presented CMV-DNA in both plasma and leukocytes. These were tested by the quantitative CMV-PCR Cobas Amplicor CMV Monitor Test (kindly provided by Roche Diagnostics Systems) according to the manufacturer's intructions. Results : Appearance and increase of C M V - D N A copies were concomitant with CMV infection in 5/6 patients. CMV-DNA quantitative PCR remained negative in one patient. During the 1 5 days treatment (Ganciclovir or Foscarnet), a rapid decrease of CMV-DNA copies was observed in the only responder patient, but levels of CMV-DNA remained stable in the non-responders (N=4). A second course of 15 days treatment was then instaured : 2 patients with stable levels of CMV-DNA died with gastrointestinal disease, the remained 2 showed negativation of CMV-DNA. Conclusion : Quantitative CMV-PCR is a reliable test in the follow-up of CMV-infected allogeneic bone marrow recipients.
G6-29 A comparison of flow cytometry with slide method to detect pp65-antigenemia during active CMV infection BERTHE-MARIE IMBERT-MARCILLE Virology Laboratory, University Hospital, Nantes, France The purpose of this study was to compare flow cytometry with the slide method for pp65-antigenema detection in PMNLs from immunocompromised patients. 247 samples were obtained from 81 transplant (72 renal and 9 BMT) and 7 AIDS patients.Pp65-antigenemia was quantified with 1C3 MAb using conventional slide detection (S-Ag) (Arg~ne Biosoft) and a home-made flow cytometry (FC-Ag) procedure (Imbert-Marcille et al., J Clin Microbiol 1997; 35: 2665-9).Qualitative leucocytic DNAemia and viremia were additionnaly performed on each sample. Overall agreement between the four tests was 60.5%. Comparison of S-Ag with FC-Ag yield to 80% (196/247) concordance: absolute antigen-positive PMNLs number correlates well, only when high vial load were considered.Discrepancies were a positive result for S-Ag associated with a negative one for FC-Ag in 22 cases, observed in an active infection context in 21 cases. In the 29 other discrepancies, e.g.negative S-Ag with positive FC-Ag, 23 occured during an active infection episod.ln all discordants results, antigenemia level was low: less than 15 positive cells/2.105 PMNLs (median, 2) and less than 0.30% positive cells (median, 0.08%) as estimated by flow cytometry. 21/23 patients in which a longitudinal follow-up was performed developped an active infection: the first antigenemia test found to be positive was FC-Ag in 81% of cases and S-Ag in 71% of cases. Flow cytometry has similar performance than the slide metod for pp65-antigenemia detection, allowing a more objective screnning of active CMV infection in routine laboratory use.