HHV-7 primary infection in solid organ transplant recipients

Abstract number: 1733_134

Anton A., Esteva C., Cervera C., Pumarola T., Moreno A., Jiménez de Anta M.T., Marcos M.A.

Objectives: We aimed to study the seroprevalence of HHV-7 infection in solid organ transplant recipients (SOTR). The incidence of HHV-7, HHV-6, and CMV viraemia after solid organ transplantation among HHV-7 seronegative patients who had HHV-7 seroconversion during the first six months of follow-up was also studied.

Methods: Ninety three SOTR (5 heart, 1 kidney-heart, 28 liver, 2 pancreas, 6 kidney-pancreas and 51 kidney) were included. Plasma and whole blood samples were collected immediately prior to transplantation and at 7, 14, 21, 28, 45, 60, 75, 90 and 180 days post-transplantation. Anti-HHV-7 IgG antibodies in plasma were assessed by indirect inmunoflorescence assays (Advanced Biotechnologies Inc) immediately prior to transplantation, three and six months post-transplantation. Viral DNA was extracted from 200 microL plasma and from 50 microL whole blood using affigene® DNA extraction kit (Sangtec, Bromma, Sweden). An in-house SYBR Green I real-time quantitative PCR assay was performed to detect HHV-7 DNA (detection limit: 5–10 copies/reaction) in blood on the Mx3000P instrument (Stratagene, La Jolla, USA). The PCR primers amplify a specific region from HHV-7 U37 gene sequence. A standard curve was constructed from the threshold cycle values obtained from serial diluted positive control plasmids, cloned into pGEM-T Easy Vector. CMV viral load was determined in plasma by the PCR kit affigene® CMV VL which utilises an ELISA based detection. HHV-6 load in whole blood was detected using the real-time PCR system affigene® HHV-6 trender on the Mx3000P instrument.

Results: Seventy-one (76%) patients had IgG antibodies against HHV-7 detected prior to transplantation. Of 22 (23%) HHV-7-seronegative patients, 5 seroconverted, four at 3rd month and one at 6th month of follow-up. HHV-7 DNA was detected (3rd week of follow-up) in only one of the 5 patients who had HHV-7 seroconversion. In this patient, HHV-6 was simultaneously detected. Of the 4 remaining patients with HHV-7 seroconversion, HHV-6 DNA was also detected in one and CMV DNA was detected in two, while no human beta-herpesvirus DNA was identified in one patient.

Conclusions: While the seroprevalence of HHV-7 infection in SOTR was high, the incidence of HHV-7 among seronegative patients who had HHV-7 seroconverted during the first six months of follow-up was very low. Seroconversion may not only indicate HHV-7 replication but also other human beta-herpesviruses viraemia. Further analysis are necessary.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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