Cytomegalovirus DNAemia Research Articles

Investigation of Intrarenal Viral Infections in Kidney Transplant Recipients Unveils an Association between Parvovirus B19 and Chronic Allograft Injury

The relevance of viral infections in the development of allograft lesions is still unclear, although some viruses have been implicated. The present study investigated systemic and intrarenal viral infections in kidney transplant recipients and their association with the risk of acute rejection and chronic allograft injuries that are predictive of long-term dysfunction. The presence of DNA sequences of human herpesviruses, polyomaviruses, and parvovirus B19 was analyzed in renal allograft biopsy specimens obtained at baseline, after acute renal dysfunction, and during follow-up evaluation in 69 transplant recipients who were children or young adults. Results were correlated with clinical data, viral DNAemia, and results of renal function tests and allograft histology analyzed at the same time points. Overall, viral DNA was detectable in 46% of baseline and 70% of follow-up biopsy specimens of kidney allografts, where it generally persisted. The most frequently detected viruses were B19 and human herpesvirus 6, already present in donor kidneys, and BK virus and Epstein-Barr virus, usually involving the allograft during follow-up. Among viruses, only the intrarenal persistence of B19 DNA and B19 DNAemia was associated with the development of chronic allograft injury, whereas human cytomegalovirus DNAemia was a risk factor for acute rejection. Parvovirus B19 seems to target the kidney electively. Its intrarenal persistence is associated with chronic kidney allograft injury.

The detection of cytomegalovirus DNA in maternal plasma is associated with mortality in HIV-1-infected women and their infants

Cytomegalovirus (CMV) is an important pathogen in healthy neonates and individuals with human immunodeficiency virus (HIV-1). The objective of this study was to determine whether the detection of CMV DNA (CMV DNAemia) in maternal plasma was associated with mortality in HIV-1-infected women or their infants. A longitudinal study was designed to examine the relationship between maternal CMV DNAemia and maternal-infant mortality during 2 years postpartum. Sixty-four HIV-1-infected women and their infants were studied. CMV DNA loads were quantified in plasma from the mothers near the time of delivery. Baseline maternal CD4 cell counts, CD4%, HIV-1 RNA, and CMV DNAemia were evaluated as covariates of subsequent maternal or infant mortality in univariate and multivariate Cox regression. CMV DNA was detected in 11/64 (17%) of the HIV-1-infected women. HIV-1 and CMV viral load were strongly correlated in CMV DNAemic women (rho = 0.84, P = 0.001). Detection of CMV DNAemia was associated with decreased maternal survival at 24 months postpartum (log-rank P = 0.006). Additionally, HIV-1-infected infants born to CMV DNAemic women had a four-fold increased risk of mortality during 24 months of follow-up. Maternal CMV DNAemia remained a significant risk factor for mortality in HIV-1-infected infants after adjusting for maternal CD4 cells/microl [adjusted hazard ratio (HR) = 4.3, confidence interval (CI) = 1.4-13], CD4% (HR = 3.2, CI = 1.0-10), HIV-1 viral load (HR = 4.1, CI = 1.4-12) or maternal death (HR = 3.7, CI = 1.0-13). Maternal plasma CMV DNAemia identified a subgroup of Kenyan women and infants at high risk for death in the 2 years following delivery.

Predictive factors for cytomegalovirus reactivation in cytomegalovirus‐seropositive kidney‐transplant patients

The aims of the present study were to assess the incidence of cytomegalovirus (CMV) reactivation, and to determine the predictive factors for CMV reactivation in CMV seropositive kidney-transplant patients. One hundred ninety CMV seropositive kidney-transplant patients were included in this study; of these, 39 patients had received CMV prophylaxis. CMV DNAemia was assessed by real-timepolymerase chain reaction assay every 2 weeks until day 120, then every 3-4 weeks until day 180, and then every month until day 365. One hundred seven patients (56.3%) had at least one positive CMV DNAemia within the first year. The time between renal transplantation and the first positive CMV DNAemia was 59 +/- 5 days. The number of positive CMV DNAemia/patient was 3.28 +/- 0.22. CMV viral load at first positive CMV DNAemia was 704 (10-742,000) copies/ml. The donor CMV seropositivity, the absence of CMV prophylaxis, and the occurrence of acute rejection before CMV reactivation were independent factors associated with CMV reactivation within the first year after kidney transplantation. Hence, CMV reactivation is frequent after kidney transplantation. CMV prophylaxis in CMV seropositive kidney-transplant patients should be offered to avoid CMV-related side-effects.

Beta-herpesviruses in febrile children with cancer.

We conducted a cross-sectional study of beta-herpesviruses in febrile pediatric oncology patients (n = 30), with a reference group of febrile pediatric solid-organ transplant recipients (n = 9). One (3.3%) of 30 cancer patients and 3 (33%) of 9 organ recipients were PCR positive for cytomegalovirus. Four (13%) of 30 cancer patients and 3 (33%) of 9 transplant recipients had human herpesvirus 6B (HHV-6B) DNAemia, which was more common within 6 months of initiation of immune suppression (4 of 16 vs. 0 of 14 cancer patients; p = 0.050). HHV-6A and HHV-7 were not detected. No other cause was identified in children with HHV-6B or cytomegalovirus DNAemia. One HHV-6B-positive cancer patient had febrile disease with concomitant hepatitis. Other HHV-6B-positive children had mild "viral" illnesses, as did a child with primary cytomegalovirus infection. Cytomegalovirus and HHV-6B should be included in the differential diagnosis of febrile disease in children with cancer.

Human Cytomegalovirus (HCMV) DNAemia in the Mother at Amniocentesis as a Risk Factor for Iatrogenic HCMV Infection of the Fetus

To investigate whether invasive procedures performed in the presence of human cytomegalovirus (HCMV) DNA in maternal peripheral blood (HCMV DNAemia) represent a risk for iatrogenic transmission of HCMV infection to the fetus, 194 pregnant women undergoing prenatal diagnosis because of a primary HCMV infection and their 199 fetuses were investigated. Overall, 27 (37%) of 73 mothers of uninfected fetuses and 22 (37%) of 59 mothers of infected fetuses were HCMV DNAemia-positive at amniocentesis. Of the 8 mothers of the 8 fetuses with false-negative amniocentesis results, 4 were DNAemia-positive and 4 were DNAemia-negative at amniocentesis. Therefore, maternal HCMV DNAemia is not a significant risk factor for iatrogenic HCMV transmission to the fetus during amniocentesis.

Valacyclovir Prophylaxis Versus Preemptive Valganciclovir Therapy to Prevent Cytomegalovirus Disease After Renal Transplantation

Both preemptive therapy and universal prophylaxis are used to prevent cytomegalovirus (CMV) disease after transplantation. Randomized trials comparing both strategies are sparse. Renal transplant recipients at risk for CMV (D+/R-, D+/R+, D-/R+) were randomized to 3-month prophylaxis with valacyclovir (2 g q.i.d., n = 34) or preemptive therapy with valganciclovir (900 mg b.i.d. for a minimum of 14 days, n = 36) for significant CMV DNAemia (>/=2000 copies/mL by quantitative PCR in whole blood) assessed weekly for 16 weeks and at 5, 6, 9 and 12 months. The 12-month incidence of CMV DNAemia was higher in the preemptive group (92% vs. 59%, p < 0.001) while the incidence of CMV disease was not different (6% vs. 9%, p = 0.567). The onset of CMV DNAemia was delayed in the valacyclovir group (37 +/- 22 vs. 187 +/- 110 days, p < 0.001). Significantly higher rate of biopsy-proven acute rejection during 12 months was observed in the preemptive group (36% vs. 15%, p = 0.034). The average CMV-associated costs per patient were $5525 and $2629 in preemptive therapy and valacyclovir, respectively (p < 0.001). However, assuming the cost of $60 per PCR test, there was no difference in overall costs. In conclusion, preemptive valganciclovir therapy and valacyclovir prophylaxis are equally effective in the prevention of CMV disease after renal transplantation.

Comparable incidence and severity of cytomegalovirus infections following T cell-depleted allogeneic stem cell transplantation preceded by reduced intensity or myeloablative conditioning

Reports on infectious complications following reduced intensity conditioning (RIC) before allogeneic stem cell transplantation (allo-SCT) are equivocal. This prospective follow-up study compared the impact of cytomegalovirus (CMV) infections following RIC with fludarabine, ATG and busulphan or conventional myeloablative conditioning (MAC). Forty-eight RIC and 59 MAC patients were enrolled. The occurrence and severity of CMV infections within 100 days following allo-SCT were assessed, using plasma CMV DNA load kinetics. CMV DNAemia was observed in 21 RIC (60%) and in 19 MAC (44%) patients at risk for CMV. The mean CMV DNAemia free survival time was comparable following RIC and MAC: 70 days (95% (confidence interval) CI: 59-80 days) and 77 days (95% CI: 68-86 days), respectively (P=0.24). Parameters indicative for the level of CMV reactivation, including the area under the curve of CMV DNA load over time as well as the onset, the peak values and duration of CMV infection episodes, the numbers and duration of CMV treatment episodes and recurrent infections, were not different in both groups. During follow-up, none of the patients developed CMV disease. RIC with fludarabine, ATG and busulphan demonstrated safety comparable to conventional MAC with regard to frequency and severity of CMV infections within 100 days following T cell-depleted allo-SCT.

Surveillance of cytomegalovirus (CMV) DNAemia in pediatric allogeneic stem cell transplantation: incidence and outcome of CMV infection and disease

Cytomegalovirus (CMV) remains a serious problem after hematopoietic stem cell transplantation (HSCT). To investigate the incidence of CMV infection and outcome we retrospectively analyzed 70 consecutive pediatric allogeneic HSCTs monitored by CMV polymerase chain reaction (PCR), with at least 1-year follow-up or until death. All patients at risk for CMV infection (CMV-seropositive patients and CMV-seronegative recipients transplanted from CMV-seropositive donors) received hyperimmune anti-CMV globulins whereas in the group of HSCT patients with both donor and recipient CMV negativity, polyvalent immunoglobulins were given, both at a dose of 400 mg/kg. All patients received acyclovir at prophylactic doses for at least 6 months. Patients were monitored twice a week by CMV PCR. Patients with 2 positive results for CMV DNAemia received ganciclovir for 14 days and continued until 2 consecutive negative results were obtained. The incidence of CMV DNAemia was 12.8% (9/70) in the whole group, with significant higher risk for patients with CMV-seropositive recipient status, 8 out of 22 (36%), vs. patients with seronegative status, 1 out of 48 (2%) (P=0.0002). Three out of 9 patients with DNAemia developed CMV disease despite adequate preemptive treatment. The transplant-related mortality was higher in the CMV-seropositive recipient group (P=0.05). Age, use of hyperimmune anti-CMV globulins at a high dose, and the low incidence of graft-versus-host disease might be contributing factors to this low incidence.

Umbilical cord blood screening for cytomegalovirus DNA by quantitative PCR

Background Cytomegalovirus (CMV) infection, which is the most common congenitally transmitted infection, affects approximately 1% of neonates worldwide. Despite its prevalence, no convenient screening test for neonatal CMV infection has been implemented. Objective The purpose of this pilot study was to evaluate the feasibility and yield of screening umbilical cord blood for CMV DNA emiaby quantitative PCR. Study design Umbilical cord blood was tested for CMV DNAemia using a commercial quantitative PCR assay. Maternal CMV serostatus at the time of delivery was assessed by testing for CMV IgG and IgM antibodies in serum. Conclusions Screening for congenital CMV infection with PCR is easily incorporated into routine labor and delivery care using discarded cord blood specimens to identify neonates whose infection is otherwise undiagnosed. Among 433 infants tested, two (0.5%) had DNAemia detected in cord blood, one of whom was symptomatic, and both of whose mothers were CMV IgG positive and IgM negative. Viremic neonates identified by screening with PCR may be at high risk of developing long-term neurological complications of CMV infection and cannot reliably be identified using clinical presentation or maternal serology. Because of its convenience, cord blood CMV screening with PCR should be further investigated for incorporation into neonatal screening protocols.

Prophylactic Versus Preemptive Oral Valganciclovir for the Management of Cytomegalovirus Infection in Adult Renal Transplant Recipients

Prophylaxis reduces cytomegalovirus (CMV) disease, but is associated with increased costs and risks for side effects, viral resistance and late onset CMV disease. Preemptive therapy avoids drug costs but requires frequent monitoring and may not prevent complications of asymptomatic CMV replication. Kidney transplant recipients at risk for CMV (D+/R-, D+/R+, D-/R+) were randomized to prophylaxis (valganciclovir 900 mg q.d. for 100 days, n=49) or preemptive therapy (900 mg b.i.d. for 21 days, n=49) for CMV DNAemia (CMV DNA level>2000 copies/mL in >or=1 whole blood specimens by quantitative PCR) assessed weekly for 16 weeks and at 5, 6, 9 and 12 months. More patients in the preemptive group, 29 (59%) than in the prophylaxis group, 14 (29%) developed CMV DNAemia, p=0.004. Late onset of CMV DNAemia (>100 days after transplant) occurred in 11 (24%) randomized to prophylaxis, and none randomized to preemptive therapy. Symptomatic infection occurred in five patients, four (3 D+/R- and 1 D+/R+) in the prophylactic group and one (D+/R-) in the preemptive group. Peak CMV levels were highest in the D+/R- patients. Both strategies were effective in preventing symptomatic CMV. Overall costs were similar and insensitive to wide fluctuations in costs of either monitoring or drug.

Exploring the bidirectional interactions between human cytomegalovirus and hepatitis C virus replication after liver transplantation

Recurrence of Hepatitis C (HCV) post-liver transplantation (LT) is universal and its course is more aggressive than in immunocompetent individuals. Human cytomegalovirus (CMV) infection is a common post-LT infection and has immunomodulatory effects that could adversely affect the outcome of HCV. To date, the effect of HCV replication on the dynamics of CMV have not been investigated. From 2000 to 2004, a cohort of 69 HCV-infected liver transplant recipients and 188 HCV-negative liver transplant recipients (NON-HCV cohort) were monitored for CMV infection twice weekly by CMV polymerase chain reaction (PCR) with preemptive therapy initiated after 2 consecutive positive results. None of the patients received CMV prophylaxis. A subset of 18 HCV-infected patients had their HCV viral load monitored regularly post-LT by quantitative PCR. CMV DNAemia (>200 genomes/mL blood) did not influence the level of HCV replication within 150 days posttransplantation or the stage of liver fibrosis in liver biopsies at 1 yr post-LT. There were no differences in the incidence of CMV DNAemia or replication dynamics in the HCV cohort compared to the NON-HCV cohort. In conclusion, short term CMV viremia does not enhance the replication of HCV after LT, while HCV replication does not alter the replication dynamics of CMV.

A prospective study comparing cytomegalovirus antigenemia, DNAemia and RNAemia tests in guiding pre-emptive therapy in thoracic organ transplant recipients

We evaluated the usefulness of DNAemia and mRNAemia tests in guiding the pre-emptive therapy against cytomegalovirus (CMV) infections in thoracic organ transplant recipients using antigenemia test as the reference. Seven lung (LTR) and 14 heart (HTR) transplant recipients were prospectively monitored for CMV by antigenemia, DNAemia (Cobas Amplicor PCR Monitor) and pp67-mRNAemia (NASBA) tests. However, only the antigenemia test guided pre-emptive therapy with cut-off levels of >or=2 and >or=5-10 pp65-positive leukocytes/50 000 leukocytes in the LTRs and HTRs, respectively. CMV DNAemia was detected in 26/28 (93%) and RNAemia in 17/28 (61%) of the CMV antigenemias requiring antiviral therapy (P = 0.01). Optimal DNAemia levels (sensitivity/specificity) estimated from receiver-operating characteristic curve to achieve maximal sum of sensitivity and specificity were 400 (75.9/92.7%), 850 (91.3/91.3%) and 1250 (100/91.5%) copies/ml for the antigenemia of 2, 5 and 10 pp65-positive leukocytes, respectively. The sensitivities of nucleic acid sequence-based amplification (NASBA) were 25.9%, 43.5% and 56.3% in detecting the same cut-off levels of antigenemia. In thoracic organ transplant recipients, the Cobas PCR assay is comparable with the antigenemia test in guiding pre-emptive therapy against CMV infections when threshold levels of over 5 pp65-antigen-positive leukocytes are used as the reference. In contrast, the low sensitivity of NASBA limits its usefulness in the guidance of pre-emptive therapy.

Incidence, Natural History and Management of Cytomegalovirus (CMV) Dnaemia and Disease in Patients with Haematological Malignancies in the Non-Allogeneic Transplantation Setting.

There is little information regarding CMV reactivation in the non-allogeneic transplantation setting. We report the incidence of CMV-DNAemia and CMV-associated disease in a cohort of patients treated for haematological malignancies at the Peter MacCallum Cancer Center from 6/99-6/04. Among the 36 patients identified, potential predictive factors were analysed, including underlying malignancy, previous therapy and therapy immediately preceding CMV-DNAemia/disease. Patients received a median of 2 prior therapies (range 1–9), age ranged from 35–77 years, with 19 males. Diseases were: acute leukaemia(6), CLL(6), NHL(21), HD(1), myeloma(2). Therapies immediately preceding CMV-DNAemia/disease were: “conventional chemotherapy” (39%, including HyperCVAD-14%), fludarabine-based (19%), autologous BMT (22%), and antibody therapy (20%, including denileukin diftitox, 6%, alemtuzumab, 14%). Risk of CMV-DNAemia/disease was calculated from the total number of patients treated over the period of analysis: alemtuzumab, (6/12; 50%), denileukin (2/33; 6%), autologous BMT (9/223; 4%), fludarabine-based (8/177; 4.5%), HyperCVAD (5/77; 6.5%). 94% were symptomatic on investigation (fever 92%, CXR changes 25%, abnormal LFT's 3%, GI symptoms 8%, rash 6%). 7 had CMV-disease (3 pneumonitis, 2 oesophagitis, 2 enteritis/colitis). 11 had isolated fever. 14/19 treated with ganciclovir had possible/proven CMV-related illness; in 12, fever, CMV-DNAemia or symptoms resolved. 2 died from underlying disease or treatment complications. 3 asymptomatic patients with CMV-DNAemia on >1 occasion were observed until DNA negativity. 17/19 with CMV-DNAemia on only 1 occasion did not develop CMV-related illness. We recommend that patients receiving alemtuzumab, should have CMV surveillance to facilitate early therapy, though the role of ongoing surveillance/prophylaxis is unknown. Patients with persistent/rising CMV-DNA titres or evidence of CMV-disease, should be treated.

Pre-emptive treatment of CMV DNAemia in paediatric stem cell transplantation: the impact of recipient and donor CMV serostatus on the incidence of CMV disease and CMV-related mortality.

Cytomegalovirus (CMV) DNAemia was detected by PCR in 30/125 (24%) consecutive paediatric patients undergoing allogeneic stem cell transplantation. All patients with CMV DNAemia received pre-emptive ganciclovir until two consecutive negative results were obtained. CMV-IgG-positive patients (R+) had a significantly increased risk of DNAemia as compared to CMV-IgG-negative (R-) patients (62% vs 8%) P<0.0001. The incidence of DNAemia was 71% (10/14) in R+ transplanted from seronegative donors (D-) compared to 54% (13/32) in those transplanted from seropositive donors (D+). Of 30 (40%) children with DNAemia, 12 developed CMV disease despite pre-emptive treatment. The overall incidence of disease was 0% (0/59) for R-/D-, 9% (3/23) for R+/D+, 7% (2/29) for R-/D+ and 57% (8/14) for R+/D-. In patients with DNAemia, 4/20 (20%) patients with D+ and 8/10 (80%) with D- became symptomatic. In the multivariate analysis of both groups, patients at risk (R+ and/or D+) and patients with DNAemia, a negative donor serostatus was the only factor associated with a significantly increased incidence of disease. Seven of 9 patients with lethal CMV disease had received CMV-IgG-negative grafts. The data suggest that in CMV seropositive recipients donor CMV seropositivity is associated with a reduced incidence of CMV disease and a favourable outcome following pre-emptive treatment.

Further evidence against the implication of active cytomegalovirus infection in vascular atherosclerotic diseases

The possible contribution of cytomegalovirus (CMV) to pathogenetic events associated with atherosclerotic lesion establishment and progression is still controversial. We evaluated the possibility that active ongoing CMV infection could be correlated to evolution of unstable atheromatous lesion, by analyzing patients suffering from unstable angina ( n=61), acute myocardial infarction ( n=43), stable angina ( n=26) and peripheral arteriopathy ( n=22) as compared to healthy subjects ( n=30). Particularly, we assessed: past exposure to CMV by evaluating anti-CMV IgG antibodies; ongoing CMV infection by evaluating anti-CMV IgM antibodies and circulating interleukin (IL)-8 in serum; and CMV DNAemia in peripheral blood mononuclear cells (PBMC). Mean IgG values were significantly increased in patients from all groups, as compared to healthy subjects. CMV-specific IgM, as well as CMV DNAemia, were undetectable in both controls and patients. Circulating IL-8, significantly elevated in a group of individuals experiencing active CMV infection, was not significantly higher in cardiovascular disease patients, as compared to control subjects. These findings confirm previous evidence from the increased exposure to CMV infection in patients with atheromatous lesions. However, they provide further evidence against a direct implication of active systemic CMV infection in the pathogenesis of cardiovascular diseases, particularly those involving plaque instability.

High frequency of positive surveillance for cytomegalovirus (CMV) by PCR in allograft recipients at low risk of CMV.

Cytomegalovirus (CMV) causes significant morbidity and mortality following allogeneic haemopoietic stem cell transplantation. A pre-emptive strategy for ganciclovir therapy is widely used, where treatment is commenced on finding positive evidence of CMV replication. Surveillance by PCR has increased the sensitivity for CMV detection, but it is not known whether this may detect cases with evidence of CMV DNAemia who have a low probability of CMV disease. We reviewed our experience of CMV infection and disease since introducing CMV surveillance by PCR. All 30 allografts received bedside leucodepleted CMV-negative blood products. Seven of 10 CMV-positive recipients of a CMV-positive graft developed CMV DNAemia, with three developing clinical disease requiring ganciclovir treatment. In contrast, of 11 low risk patients (CMV-negative recipients of CMV-negative grafts), six developed evidence of CMV DNAemia although only one had clinical evidence of CMV disease requiring ganciclovir. Transfusion records confirmed that four of these had received exclusively CMV-negative blood products. The aetiology of the CMV DNAemia in these cases is unclear. It is suggested that before commencing ganciclovir therapy, confirmatory CMV antigenaemia testing is carried out on samples which test positive for CMV DNA, unless there is high clinical suspicion of CMV disease.

145 Comparison of drug susceptibilities of clinical isolates of cytomegalovirus (CMV) for BAY43-9695, BAY38-4766 and ganciclovir (GCV) : J. McSharry and G. Drusano. Albany Medical Coll., Albany, NY 12208, USA

Data on drug-resistant cytomegalovirus (CMV) infection in solid organ transplantation (SOT) are not often reported from resource-limited settings. We aimed to investigate the epidemiology and outcomes of this infection in SOT recipients at our institution.This was a retrospective study conducted from January 2012 to May 2015. We included all SOT recipients who were suspected for drug-resistant CMV infection. Genotypic assay for UL97 gene mutation was analyzed by real-time polymerase chain reaction. Patients were reviewed for demographic data, clinical presentation, virologic data, treatment, and outcomes.The population consisted of 18 (12 kidney, 6 liver) SOT recipients with a median age of 20 years (interquartile range [IQR], 1–49); 44% were male. Anti-CMV resistance testing was analyzed at a median time of 23 days (IQR, 14–33) after initiation of anti-CMV therapy with a median CMV load of log 3.79 copies/mL (IQR, 3.37–4.58). During a median period of 2 years (IQR, 1–3), 6 SOT recipients were identified with UL97 gene mutation in codon 460, conferring ganciclovir (GCV) resistance. Patients with UL97 gene mutation had a longer mean duration of CMV DNAemia compared with those without mutation (263 vs 107 days; P = .04). All patients received high-dose GCV. Two patients received foscarnet and cidofovir. Two patients died (non–CMV-related), and 4 patients.GCV-resistant CMV infection in SOT recipients is an emerging clinical problem in resource-limited country. Those with UL97 mutation CMV infection have prolonged duration of CMV DNAemia. Clinicians should be aware of this condition when caring for SOT recipients.

Cytomegalovirus Infection in a Seroendemic Renal Transplant Population: A Longitudinal Study of Virological Markers

Background/Aims: The detection of viremia by polymerase chain reaction (PCR) in cytomegalovirus (CMV) infection in renal allograft recipients has been shown to have a predictive value for disease. However, its diagnostic utility in a population with high background seropositivity has not been defined. This prospective study was undertaken to assess the relationship of CMV DNAemia, and/or IgM seropositivity to CMV disease in a seroendemic transplant population. Methods: Consecutive patients undergoing renal transplantation between August 1997 and February 1998 were enrolled. Blood was sampled before transplantation from the donors and recipients for CMV serology and nested PCR for CMV DNA, and after transplantation from the recipients only at monthly intervals until 6 months. Patients were observed for the development of any CMV-like illness during follow-up. CMV DNA was quantitated using limiting dilution PCR on samples obtained from symptomatic patients at the time of illness and from asymptomatic patients at the end of their 6-month follow-up. Results: A total of 57 recipient-donor pairs were recruited. Immunosuppression was cyclosporine-based in 55 of 57 (95.6%). The CMV serologic status was D+R+ in 55 of 57 and D+R– in 2 of 57 pairs. PCR positivity indicating viremia increased from 5% before transplantation to 95% at 6 months after transplantation. Similarly IgM positivity reached 80% at 3 months and thereafter; positivity for any marker was 100% by 6 months. Viremia was sustained in over half the patients. The incidence of CMV-attributable disease peaked at 3 months, and was predominantly mild and self-limiting. Tissue-invasive disease appeared later in 4 patients (7%). Asymptomatic viremia was seen in 60–70% of patients at each sampling point. The positive predictive value (PPV) of PCR positivity for disease was 35–40%, and the negative predictive value (NPV), 90–100%. However, the high NPV was of use only in the early post-transplant period, negativity for markers declining rapidly with time. Quantitative assay showed significantly higher levels of CMV DNA in symptomatic patients (p = 0.01). A cutoff of 0.001 µg had a specificity of 95% and a PPV of 92.3% for symptomatic CMV disease. Conclusion: Qualitative tests to detect CMV DNAemia and IgM, although useful markers of viremia and active infection, have limited utility for the diagnosis of disease in a seroendemic transplant population. Quantitation of CMV DNAemia may play an important role in diagnosis in such a setting.

False-positive results of plasma PCR for cytomegalovirus DNA due to delayed sample preparation.

Positive results by cytomegalovirus (CMV) PCR of plasma are considered predictive of active CMV infection in kidney allograft recipients. To assess whether contamination with leukocyte-derived CMV DNA can distort the results, aliquots of whole-blood samples from 60 CMV immunoglobulin G-positive patients with leukocyte CMV DNAemia were stored for up to 24 h at room temperature (RT) and at 4 degrees C before plasma preparation. Native and ultrafiltered plasma samples were tested by CMV and beta-globin PCRs. Among 30 latently infected patients (negative for CMV pp65 antigens), low baseline rates (10%) and levels (median number of copies, 10 [per 10 microl]) of CMV plasma DNAemia in native plasma samples increased significantly over time (after 4 h at RT, 37% [P < 0.001]; median number of copies, 45 [P < 0.001]). Similar effects were found during storage at 4 degrees C. Ultrafiltration reduced the levels of CMV plasma DNAemia, but by 6 h of storage the levels were significantly elevated as well. CMV and beta-globin DNA kinetics in plasma were parallel. In contrast, 30 actively infected patients (pp65 positive) had high baseline rates (87% in native samples) and levels (median number of copies, 75) of CMV plasma DNAemia. No significant effects of storage or ultrafiltration and no concordance with beta-globin DNA kinetics were seen. In conclusion, delayed preparation of plasma samples bears a significant risk of false-positive CMV PCR results, probably due to leukocyte lysis. This has important implications in the clinical setting and for PCR standardization.

Asymptomatic primary cytomegalovirus infection: virologic and immunologic features.

We followed 45 seronegative adolescents for acquisition of cytomegalovirus (CMV); 6 (5 female, 1 male) seroconverted after a median of 7.5 months. All were free of signs and symptoms. CMV was isolated from 32 (59.2%) of 54 urines, 2-80 weeks after infection; viruria was less frequent after 6 months. CMV was isolated from saliva of 3 subjects, vaginal swabs of 2 of 5, and 1 white blood cell (WBC) sample. CMV DNA was detected by polymerase chain reaction in WBCs and plasma from all subjects tested. The proportion of WBC samples with CMV DNAemia was 75%-80% within 16 weeks of infection, declining to 0%-25% after 48 weeks. The rate of plasma DNAemia was 25%-40% at 8-16 weeks, declining with time. IgG antibody to CMV, glycoprotein B (gB), and neutralizing antibody were present after 6-8 weeks. Lymphocyte proliferative responses to CMV and to gB were low, compared with those of controls. CMV shedding was of shorter duration than expected. Although antibody response was prompt and vigorous, CMV DNA could be detected in blood for months.