Correlation between the detection of viral DNA by the polymerase chain reaction in peripheral blood leukocytes and serological responses to human herpesvirus 6, human herpesvirus 7, and cytomegalovirus in renal allograft recipients

Abstract

Diagnosis of significant infections by human herpesvirus 6 (HHV6) and 7 (HHV7) in transplant patients has proved difficult because both viruses are ubiquitous and can cause persistent infections in their hosts. The significance of viral DNA detected in peripheral blood leukocytes (PBLs; DNAemia) by PCR is therefore unclear. The interpretation of serological results is complicated by the fact that both primary and secondary infections with other herpesviruses may be associated with a concurrent antibody response to HHV6. Fifty-four renal allograft recipients were studied prospectively and their serological response to HHV6, HHV7 and CMV were compared with the detection of viral DNAemia from the homologous and heterologous viruses. Serum and heparinished blood samples were collected prospectively from 54 renal allograft recipients. DNA was extracted from PBLs and tested for the presence of HHV6, HHV7 and CMV DNA by PCR. Antibodies to HHV6 and HHV7 were measured by an indirect immunofluorescence test and to CMV by an anticomplement immunofluorescence (ACIF) test. CMV IgM antibodies were detected by a commercial enzyme immunoassay. CMV and HHV7 DNAemia were each significantly associated with serological responses to the homologous virus but no such association was found for HHV6 DNAemia. However, patients with consecutively positive DNAemia to any of the viruses (including HHV6) were more likely to have a homologous serological response. Patients who had detectable CMV IgM without a concurrent rise in CMV antibodies were significantly less likely to have CMV DNAemia (odds ratio = 0.16; 95% CI 0.02-0.9). CMV IgM antibodies may be associated with HHV6 or HHV7 DNAemia (odds ratio 2.3; 95% CI 0.5-15). This serological profile may reflect a crossreactive response to HHV6, HHV7 or other herpesviruses. CMV IgM should not be used in isolation for the diagnosis of CMV infection or disease in this group of patients.

Simultaneous monitoring of CMV and human herpesvirus 6 infections and diseases in liver transplant patients: one-year follow-up

“…Peripheral blood leukocyte DNA extraction – The procedures for isolating blood leukocytes and DNA extraction for CMV have been described previously 14,21. The DNA amount and purity were determined by optical density readings obtained using spectrophotometry and by reading the absorbance at a wavelength of 260 nm (1 OD = 50 ng).…”

“…A report of specific anti-CMV or HHV-6 IgM in the sera or a four-fold rise in IgG antibodies can be used as a diagnostic criterion, but such an assay has limited sensitivity. Moreover, the interpretation of serological results is complicated by the fact that both primary and secondary infections with other herpes viruses may be associated with a concurrent antibody response to HHV-6 6,14. Amplification techniques are also available for the diagnosis of both viral agents; however, the results obtained using these techniques can be controversial, as they are dependent on the method of PCR employed 15-17-17.…”

Human β‐Herpesvirus Interactions in Solid Organ Transplant Recipients

“…In anecdotal studies of transplant recipients, organ-specific diseases, such as pneumonitis, hepatitis, encephalitis, and nonspecific febrile syndromes, have been described elsewhere [9][10][11][12][13][14][15]. Also, in transplant recipients, HHV-6 and HHV-7 have been associated with the development of allograft rejection, marrow suppression, and predisposition to CMV disease [16][17][18][19][20][21][22][23][24]. The lack of widespread standardized diagnostic assays to detect and quantitate the level of replication of HHV-6 or HHV-7 and the lack of information regarding their in vivo susceptibility to antiviral agents preclude establishing the clinical relevance of these 2 b-herpesviruses in transplant recipients.…”

Betaherpesviruses in Adult Liver Transplant Recipients

“…The report of specific HHV-6 IgM in sera or a four-fold rise in IgG antibodies can be used as diagnostic criteria, but is not as sensitive as desired. Moreover, the interpretation of serological results is complicated by the fact that both primary and secondary infections with other herpes viruses may be associated with a concurrent antibody response to HHV-6 (Osman et al, 1997). In addition, the presence of residual IgM against HHV-6 in the bloodstream can complicate the interpretation of the serological tests (Peigo et al, 2009).…”