A prospective study of the natural course of cytomegalovirus infection and disease in renal allograft recipients

Gancyclovir Prophylaxis in High Risk Patients

The aim of this study was to compare the incidence of cytomegalovirus (CMV) disease between seronegative recipients who received a CMV seropositive kidney (D+/R-) and seropositive recipients who received a CMV seropositive kidney (D+/R+). Among 42 patients included in the study, 26 were D+/R-, and the other 16 were D+/R+. Immunosuppression was based on cyclosporine (n = 12), tacrolimus (n = 28), or other agents (n = 2). Twenty-four seronegative patients were treated with gancyclovir for 3 months. The 16 D+/R+ patients did not receive CMV prophylaxis. Two D+/R- patients did not receive gancyclovir prophylaxis because of various health problems just after the surgery. Over the year post-renal transplant, there were 10 (23.8%) episodes of CMV disease. The two D+/R- patients who were not treated with gancyclovir developed CMV disease. The incidence of disease was higher in patients who were given cyclosporine (41.7% vs 17.9%). In conclusion, sero negative patients who received a kidney from a seropositive donor had greater risk of developing CMV disease. Despite gancyclovir treatment, the incidence was higher than in D+/R+ cases without treatment.

The impact of early cytomegalovirus infection and disease in renal transplant recipients

Human cytomegalovirus (HCMV) infection is the single most frequent infectious complication in the early period after kidney transplantation. The HCMV load in blood, measured by HCMV PCR or the HCMV pp65 antigen test, is a predictor of HCMV disease in seropositive recipients. However, plasma virus load measurements are of only modest value in predicting the risk of HCMV disease in seronegative recipients of kidneys from seropositive donors. HCMV infection is an independent risk-factor for acute kidney graft rejection. There is also evidence that HCMV is associated with an increased long-term mortality and post-transplant diabetes mellitus. Whether pre-emptive or prophylactic therapy should be the preferred strategy is not yet decided. Some studies indicate that HCMV prophylaxis may reduce the risk of acute rejection, and thereby increase long-term graft survival in seronegative recipients of kidneys from seropositive donors.

Viral prophylaxis in organ transplant patients

Viral pathogens have emerged as the most important microbial agents having deleterious effects on solid organ transplant (SOT) recipients. Antiviral chemoprophylaxis involves the administration of medications to abort transmission of, avoid reactivation of, or prevent progression to disease from, active viral infection. Cytomegalovirus (CMV) is the major microbial pathogen having a negative effect on SOT recipients. CMV causes infectious disease syndromes, augments iatrogenic immunosuppression and is commonly associated with opportunistic superinfection. CMV has also been implicated in the pathogenesis of rejection. Chemoprophylactic regimens for CMV have included oral aciclovir (acyclovir) at medium and high doses, intravenous and oral ganciclovir, and the prodrugs valaciclovir (valacyclovir) and valganciclovir. CMV prophylactic strategies should be stratified, with the highest-risk patients receiving the most 'potent' prophylactic regimens. Herpes simplex virus (HSV) reactivation in SOT recipients is more frequent, may become more invasive, takes longer to heal, and has greater potential for dissemination to visceral organs than it does in the immunocompetent host. Prophylactic regimens for CMV are also effective chemoprophylaxis against HSV; in the absence of CMV prophylaxis, aciclovir, valaciclovir or famciclovir should be used as HSV prophylaxis in seropositive recipients. Primary varicella-zoster virus (VZV) after SOT is rare and most commonly seen in the paediatric transplant population because of VZV epidemiology. Zoster occurs in 5-15% of patients, usually after the sixth post-transplant month. Prophylactic regimens for zoster are neither practical nor cost effective after SOT because of the late onset of disease and low proportion of affected individuals. All SOT recipients should receive VZV immune globulin after contact with either varicella or zoster. Epstein-Barr virus has its most significant effect in SOT as the precipitating factor in the development of post-transplant lymphoproliferative disorders. Antiviral agents that could be effective are the same as those used for CMV, but indications for and effectiveness of prophylaxis are poorly established. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are important pathogens in the SOT population as indications for transplantation. So-called 'prophylaxis' for recurrent HBV and HCV after liver transplantation is controversial, suppressive rather than preventive, and potentially lifelong. Influenza infection after SOT is acquired by person-to-person contact. During epidemic periods of influenza, transplant populations experience a relatively high frequency of infection, and influenza may affect immunosuppressed SOT recipients more adversely than immunocompetent individuals. Antiviral medications for prevention of influenza are administered as post-exposure prophylaxis to SOT recipients, in addition to yearly vaccine, in circumstances such as influenza epidemics and nosocomial outbreaks, and after exposure to a symptomatic individual during 'flu season'.

Pharmacokinetic Profile of Ganciclovir After its Oral Administration and From its Prodrug, Valganciclovir, in Solid Organ Transplant Recipients

BACKGROUND

Valganciclovir (Valcyte) has recently been approved for the prevention of cytomegalovirus (CMV) disease in high-risk (CMV donor positive [D+]/recipient negative [R-]) solid organ transplant (SOT) recipients. Large-scale studies describing the pharmacokinetics of valganciclovir in SOT recipients are lacking. A recent randomised, double-blind study of valganciclovir in 364 D+/R- (intent-to-treat population) SOT recipients provided valuable data on which a population pharmacokinetic analysis was performed.

METHODS

The pharmacokinetics of ganciclovir from oral ganciclovir (Cymevene, 1000 mg three times daily) and from valganciclovir (900 mg once daily) were described with plasma levels from 240 patients (1181 datapoints describing 449 pharmacokinetic profiles) using nonlinear mixed-effects modelling (NONMEM) software. A two-compartment pharmacokinetic model with separate absorption/metabolism and absorption parameters for valganciclovir and ganciclovir, respectively, was developed.

RESULTS

Exposure to ganciclovir from valganciclovir averaged 1.65-fold greater than that from oral ganciclovir (95% CI 1.58, 1.81); respective daily area under the plasma concentration-time curve values were 46.3 +/- 15.2 microg . h/mL and 28.0 +/- 10.9 microg . h/mL. The relative systemic exposure of ganciclovir was approximately 8-fold higher from valganciclovir than oral ganciclovir. Exposure to ganciclovir from valganciclovir was similar among liver, heart and kidney transplant recipients (46.0 +/- 16.1, 40.2 +/- 11.8 and 48.2 +/- 14.6 microg . h/ mL, respectively). Adherence to the prescribed dosing regimens, which were reduced for renal impairment, gave consistent exposure to ganciclovir.

CONCLUSION

Oral valganciclovir produces exposures of ganciclovir exceeding those attained with oral ganciclovir, but in line with those reported after standard intravenous administration of ganciclovir. This indicates that oral valganciclovir is suitable in circumstances requiring prophylactic use of ganciclovir and allows for more convenient management of patients at risk of CMV disease.

Polyomavirus nephropathy in pediatric kidney transplant recipients

Given the limited information regarding BK virus-associated nephropathy (BKVN) in pediatric kidney transplant recipients, we assessed the incidence, risk factors, clinical and virologic features of BKVN in pediatric renal transplant recipients at a single transplant center by means of a retrospective cohort study. Histologically confirmed BKVN developed in 6 of 173 (3.5%) kidney transplant recipients at a median of 15 months post-transplant (range: 4-47 months). At a median follow-up of 28 months (range: 5-32), all patients had functioning grafts with mean creatinine and GFR of 1.9 mg/dL and 58 mL/min/1.73 m2, respectively. At the time of diagnosis, all cases had viruria (median 6.1 x 10(6) copies/mL, range: 10(5) to 3.9 x 10(8) copies/mL) and viremia (median 21,000 copies/mL, range: 10,000-40,000 copies/mL). Recipient seronegativity for BKV was significantly associated with the development of BKVN (p = 0.01). BKVN is an important cause of late allograft dysfunction and is strongly associated with recipient seronegativity in pediatric kidney transplant recipients. Further studies to confirm this finding and to define the clinical utility of routine pre-transplant BKV serologic testing are warranted.

Management of opportunistic infections in solid-organ transplantation

Solid-organ transplantation is often the last alternative in many patients with end-stage organ disease. Although advances in immunosuppressive regimens, surgical techniques, organ preservation, and overall management of transplant recipients have improved graft and patient survival, infectious complications remain problematic. Bacterial, fungal, viral, and parasitic infections are implicated after transplantation depending on numerous factors, such as degree of immunosuppression, type of organ transplant, host factors, and period after transplantation. Proper prophylactic and treatment strategies are imperative in the face of chronic immunosuppression, nosocomial and community pathogens, emerging drug resistance, drug-drug interactions, and medication toxicities. This review summarizes the pathophysiology, incidence, prevention, and treatment strategies of common posttransplant infections.

Asymptomatic cytomegalovirus infection is associated with increased risk of new-onset diabetes mellitus and impaired insulin release after renal transplantation

AIMS/HYPOTHESIS

The human cytomegalovirus (CMV) may increase the risk of diabetes mellitus, but the literature is scarce. The present study was designed to test the hypothesis that asymptomatic CMV infection is associated with increased risk of new-onset diabetes after renal transplantation, and to assess the impact of asymptomatic CMV infection on OGTT-derived estimates of insulin release and insulin action.

METHODS

A total of 160 consecutive non-diabetic renal transplant recipients on cyclosporine (Sandimmun Neoral)-based immunosuppression were closely monitored for CMV infection during the first 3 months after transplantation. All patients underwent a 75-g OGTT at 10 weeks. Excluded from the analyses were 36 patients with symptomatic CMV infection (disease).

RESULTS

The incidence of new-onset diabetes was 6% in a control group of recipients without CMV infection (4/63) and 26% in the group with asymptomatic CMV infection (16/61). Asymptomatic CMV infection was associated with a significantly increased risk of new-onset diabetes (adjusted odds ratio: 4.00; 95% CI: 1.19 to 13.43, p=0.025). The group of patients with CMV infection had a significantly lower median insulin release than controls.

CONCLUSIONS/INTERPRETATION

Our findings support the hypothesis that asymptomatic CMV infection is associated with increased risk of new-onset post-transplant diabetes mellitus, and suggest that impaired insulin release may involve one pathogenetic mechanism.

Late cytomegalovirus disease with atypical presentation in renal transplant patients: Case reports

Cytomegalovirus (CMV) disease typically occurs 1 to 4 months (median 35 days) after solid organ transplantation. Recent reports documented that the natural history of CMV disease associated with solid organ transplantation has been modified as a result of the widespread use of potent immunosuppressents and antiviral prophylaxis. We herein report three pretransplant CMV seropositive recipients (with unknown donor status) who were diagnosed recently to display late and atypical CMV disease. Two men and one woman included two patients who presented with allograft dysfunction at 12 years and at 3 years after transplantation. Both patients showed increased serum creatinine approximately from baseline 200 to >400 micromol/L over 3 months in the absence of features of rejection or cyclosporine toxicity. A renal biopsy was refused by both patients. Two of the three patients presented with symptoms of enterocolitis (diarrhea, nausea, weight loss), which had persisted for more than 6 months. Other symptoms and signs of overt CMV disease (fever, leukopenia) were absent. None had pulmonary, hepatic, or other major organ involvement. In all patients IgG antibodies and CMV DNA by polymerase chain reaction were positive with negative IgM antibodies. The immunosuppressive regimen consisted of mycophenolate mofetil (MMF), steroids, and calcineurin inhibitors. The kidney function significantly improved in both patients with renal dysfunction. Gastrointestinal symptoms resolved completely with gradual weight gain. The recognition and early diagnosis of late atypical CMV disease in kidney transplant patients presenting with allograft dysfunction and/or other organ systems is important. The MMF has a red herring effect in our cases due to its GI side effects.

Impact of early cytomegalovirus infection and disease on long-term recipient and kidney graft survival

BACKGROUND

The impact of cytomegalovirus (CMV) infection and disease on long-term outcome after kidney transplantation is still unsettled.

METHODS

Between 1994 and 1997, 397 consecutive first kidney graft recipients and 74 retransplants were included in the study and followed prospectively until December 31, 2001. CMV infection (CMV pp65 antigenemia) and CMV disease were recorded once weekly during the first 100 days after transplantation. No CMV prophylaxis or preemptive therapy was given. In a multiple Cox proportional hazard model allowing time-dependent covariates, the effects of asymptomatic CMV infection and CMV disease, recipient age and gender, retransplantation, living donor, panel-reactive cytotoxid antibodies, acute rejection, and graft loss were tested on overall mortality beyond 100 days post-transplantation. In a similar analysis, the effect of asymptomatic CMV infection and CMV disease plus other factors were tested on death censored graft loss beyond 100 days.

RESULTS

Median (range) follow up time was 66.6 (<1-86.9) months. The incidence of CMV infection and disease during the first 100 days was 62.8% and 23.4%, respectively. The number of total deaths was 96 (20%), 82 occurred after the first 100 days. Independent risk factors for overall mortality beyond 100 days were asymptomatic CMV infection, RR = 2.90 (95% CI 1.61-5.22) (P= 0.001), CMV disease, RR = 2.50 (95% CI 1.31-4.79) (P= 0.006), both compared to no infection or disease, recipient age, RR = 1.066 per year (95% CI 1.048-1.084) (P < 0.001), and graft loss in the whole study period RR = 7.88 (95% CI 4.75-13.08) (P < 0.001). Asymptomatic CMV infection and CMV disease were not independent risk factors for death censored graft loss, but they significantly reduced graft survival uncensored for death, (log rank P= 0.001, respectively).

CONCLUSION

Asymptomatic CMV infection and overt CMV disease during the first 100 days increase the risk of recipient mortality beyond 100 days. This raises the question whether CMV prophylaxis should be given routinely after kidney transplantation.

Sequential cytomegalovirus antigenemia monitoring in kidney transplant patients treated with antilymphocyte antibodies

BACKGROUND

Antilymphocyte antibodies (ALA) use is related to disseminated cytomegalovirus (CMV) disease after kidney transplantation. Strict surveillance of CMV infection, preemptive antiviral treatment or concomitant ganciclovir and ALA use are proposed as an attempt to prevent related clinical complications. Our objective was to describe the pattern of CMV infection, based on sequential antigenemia detection, after ALA treatment.

PATIENTS AND METHODS

Thirty renal transplant patients were prospectively screened for CMV infection after ALA treatment. CMV antigenemia (pp65 antigen detection) was monitored twice a week in the first month and weekly until 60 days after the beginning of ALA therapy. Any positive value of antigenemia was considered CMV infection.

RESULTS

Twenty-eight (93.3%) patients were CMV positive (IgG) before transplantation. The mean duration of ALA treatment was 12.1+/-2.4 days. Positive antigenemia was detected in 24 (80%) patients, a mean of 52.5+/-15 days after transplant and 44.7+/-14 days after the beginning of ALA treatment. The median antigenemia count was 7 positive cells/300,000 neutrophils (range: 1-227). Antigenemia preceded clinical symptoms by 5.8 days (0-28 days). Eighteen (75%) of 24 positive patients received ganciclovir treatment: 8 patients (26.7%) for viral syndrome, 2 patients (33.3%) for invasive disease, and 8 patients (26.7%) as part of preemptive therapy, asymptomatic with high antigenemia values. Six pp65-positive patients with low counts were followed up until a negative result and remained asymptomatic without any specific treatment.

CONCLUSION

CMV infection was frequent after ALA treatment in this group and generally occurred late after completion of treatment. Antigenemia was a reliable tool to guide preemptive treatment in these patients, and such strategy is an alternative option compared to the prophylactic use of ganciclovir with ALA treatment.

Cytomegalovirus prophylaxis and graft outcome in solid organ transplantation: a collaborative transplant study report

We investigated relationships between cytomegalovirus (CMV) seropairing and CMV prophylaxis on graft outcome in recipients of solid organ transplants. Transplants carried out from 1985 to 2002 and reported to the Collaborative Transplant Study were analyzed. In cadaver kidney recipients, CMV prophylaxis was significantly associated with improved graft survival only in the seronegative-recipient/seropositive-donor combination (at 3 years: 79.4% with prophylaxis vs. 73.5% without prophylaxis; RR 0.80, p < 0.0001). Among patients who had a functioning graft at 1 year, significantly fewer patients who received CMV prophylaxis received rejection treatment in the preceding year (26.3%), compared with patients who did not receive prophylaxis (32.4%) (p = 0.0001), suggesting an inhibitory effect of CMV prophylaxis on acute rejection. Significant improvements in graft survival after CMV prophylaxis were found also in CMV-negative recipients of CMV-positive heart, and lung or heart-lung transplants, but not liver transplants. The age of the recipient had a differential effect on graft and patient survival after CMV prophylaxis. Use of antilymphocyte antibodies or mycophenolate mofetil was not associated with an enhanced CMV effect on graft outcome. These results may contribute to a better understanding of the influence of pretransplant CMV serology on the effect of CMV prophylaxis.

Comparative study of prophylactic oral ganciclovir and valacyclovir in high-risk kidney transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is a major pathogen in renal transplant patients causing significant post-transplant morbidity and mortality. Prophylactic antiviral therapy, currently implemented in most kidney transplant centres, has significantly reduced the incidence of CMV infection after transplantation. Oral ganciclovir has been shown to be an effective prophylactic agent in preventing CMV disease and infection with a demonstrated superior efficacy over oral acyclovir. Valacyclovir, a prodrug of acyclovir with a higher level of bioavailability than acyclovir, has also been shown to be effective in preventing CMV disease when given as prophylactic treatment.

METHODS

In a retrospective analysis of 150 renal transplant recipients in our centre, we compared the efficacy of oral ganciclovir with valacyclovir in preventing CMV infection. Seventy-seven consecutive renal transplant recipients prophylactically treated with oral ganciclovir for 12 weeks after transplant were compared with 73 consecutive recipients treated with oral valacylovir for an equal length of time.

RESULTS

No difference was noted in the incidence of CMV infection between the two treatment groups (5.1 vs 5.4%) after a 6 month follow-up. Likewise, the incidence of acute rejection was similar in both groups (11.6 vs 6.8%). All cases of CMV infection occurred in high-risk patients (donor positive/recipient negative).

CONCLUSION

The prophylactic use of oral valacylovir is as effective as oral ganciclovir in reducing CMV infection and disease after kidney transplantation.

The association of cytomegalovirus sero-pairing with outcomes and costs following cadaveric renal transplantation prior to the introduction of oral ganciclovir CMV prophylaxis

Cytomegalovirus (CMV) is an important cause of morbidity, mortality and cost in cadaveric renal transplantation. This study was designed to document the clinical and economic outcomes associated with donor and recipient CMV sero-pairing. Data were drawn from the United States Renal Data System (USRDS) on 17 001 cadaveric renal transplant recipients transplanted between 1995 and 1997 with recorded donor and recipient CMV sero-status. In multivariate analysis, CMV-seropositive recipients were associated with a significantly higher incidence of delayed graft function, a lower incidence of graft loss, and lower costs than CMV-seronegative recipients. CMV-seropositive compared to seronegative donors were associated with significantly higher incidence of CMV disease, graft loss, and higher costs when transplanted into CMV-seronegative recipients. However, CMV-seronegative donors into seropositive recipients had no significant association with outcome beyond a higher incidence of CMV disease compared to CMV-seronegative donor and recipient pairs. The outcomes associated with CMV-seropositive donors and seronegative recipients call for tailored management strategies which may include avoidance of such mismatching, antiviral therapy, immunization, or modified immunosuppression.

Heightened peripheral blood lymphocyte CD69 expression is neither sensitive nor specific as a noninvasive diagnostic test for renal allograft rejection

It has been reported that acute allograft rejection is associated with heightened expression of the peripheral blood lymphocyte (PBL) early activation marker CD69 and that this may serve as a potential biomarker of rejection. This study sought to determine whether PBL CD69 expression correlates with both acute clinical and subclinical renal allograft rejection as well as clinically inapparent cytomegalovirus (CMV) infection. Flow cytometric determination of PBL CD69 expression was performed at the time of clinical and protocol biopsies (n = 131) in 45 renal transplant recipients. Nineteen patients also underwent weekly monitoring of PBL CD69 expression for the initial 15 wk after transplantation. Simultaneous screening for CMV viremia was performed with a semiquantitative PCR assay. No differences were seen in either CD4+ or CD8+ lymphocyte CD69 expression between the biopsy diagnoses. CMV viremia however, independent of rejection, was associated with greater CD69 expression on CD8+ lymphocytes (17.8 +/- 10.4% versus 9.6 +/- 4.8%; P < 0.0001) but not CD4+ lymphocytes. No individuals experienced clinical CMV disease. Weekly monitoring of PBL CD69 expression did not change coincident with the diagnosis of rejection; however, CMV viremia coincided with a substantial rise in the proportion of CD8+69+ lymphocytes in a number of individuals. Thus, PBL CD69 expression is neither sensitive nor specific for the noninvasive diagnosis of renal allograft rejection. Furthermore, clinically inapparent CMV viremia is associated with heightened expression of this activation marker on CD8+ lymphocytes. This latter finding suggests that clinically inapparent CMV viremia may be a potential confounder for biomarkers of rejection that examine peripheral blood lymphocytes.

The impact of cytomegalovirus infection and disease on rejection episodes in renal allograft recipients

Cytomegalovirus (CMV) infection and disease are potential risk factors for acute allograft rejection in renal transplant recipients. The present study specifically addresses this issue. From October 1994 to July 1997, 477 consecutive renal allograft recipients (397 first transplants and 80 retransplants) were included in the study. CMV infection (cytomegalovirus pp65 antigen in leukocytes) and disease (infection and clinical symptoms or signs of disease) were examined prospectively for 3 months. No CMV prophylaxis was given, and CMV disease was treated with intravenous (i.v.) ganciclovir. The retransplantation of four patients transplanted twice during the study and 22 patients receiving kidneys from human leucocyte antigen (HLA)-identical siblings were excluded from statistical analysis. Rejections were evaluated clinically [277(61%)] and 173 (38%) also had a biopsy verified rejection. CMV infection occurred in 64% of the patients and 24% experienced CMV disease. In a multiple time-dependent Cox analysis, CMV infection and CMV disease were independent significant predictors for clinical acute rejections, RR = 1.6 (1.1-2.5, p = 0.02) and RR = 2.5 (1.2-5.1, p = 0.01), respectively. Among 173 patients with biopsy verified rejection, 72% of the patients had tubulointerstitial rejection whereas 28% had a vascular rejection. CMV disease, but not CMV infection was a predictor of tubulointerstitial rejection, RR = 3.1 (1.1-9.3, p = 0.04). CMV infection and disease are independent risk factors for clinical acute rejection in kidney allograft recipients. CMV disease is an independent risk factor for biopsy verified acute tubulointerstitial rejection in kidney allograft recipients.

Treatment of active cytomegalovirus disease with oral ganciclovir in renal allograft recipients: monitoring efficacy with quantitative cytomegalovirus polymerase chain reaction

Treatment regimens of patients with active cytomegalovirus (CMV) disease require 2-3 weeks of intravenous ganciclovir (GCV) with/without CMV hyperimmune globulin. Oral GCV is effective as a prophylactic agent in prevention of CMV disease. Here we explored the utility of oral GCV as a treatment of active CMV disease. Fifteen renal allograft recipients (CMV donor+/recipient- [53%], CMV donor+/recipient+ [40%] or CMV donor-/recipient+ [7%]) developed active CMV disease. Cytomegalovirus polymerase chain reaction (CMV-PCR) tests were performed at the time of presentation and patients were treated with oral ganciclovir 1 g tid (adjusted for renal function). Patients were monitored for efficacy of treatment by assessment of clinical symptoms and CMV-PCR. Treatment was continued until the CMV-PCR copy number was negative and symptoms resolved. The mean CMV-PCR copy number at the time of diagnosis was 580 copies/microg DNA (nl: < 5 copies/microg DNA). After 5-7 days of treatment, the mean copy number was 65 copies/microg DNA. Fourteen of 15 patients responded well to oral ganciclovir, with complete resolution of clinical symptoms and eradication of CMV-PCR positivity. One patient did not respond to oral ganciclovir therapy due to probable noncompliance. Our data suggest that oral ganciclovir treatment, coupled with careful CMV-PCR monitoring, may be a reasonable alternative to long-term intravenous ganciclovir.

Cytomegalovirus DNA concentration in plasma predicts development of cytomegalovirus disease in kidney transplant recipients

The clinical significance of cytomegalovirus (CMV) DNA detection in post-kidney transplantation infection surveillance was examined by comparing the performance of three assays for detection of CMV in blood: the test for CMV-pp65-antigen in leukocytes, which is routinely employed in our laboratory, the quantitative plasma CMV-DNA-polymerase chain reaction (PCR; Cobas Amplicor CMV Monitor test) and the qualitative plasma CMV-DNA-PCR (Amplicor CMV test). Thirteen kidney transplant recipients were monitored with serial samples taken over a period of 3 months following transplantation. The quantitative CMV-PCR was the test with highest sensitivity, 95.9%, vs. 88.9% and 76.9% for the CMV-pp65 antigen assay and qualitative CMV-PCR, respectively. The virus load in the first positive specimens, assessed as DNA-copies/mL, was significantly associated with CMV disease because five of the six patients who developed disease, but only one of the seven who did not develop disease, had more than 3000 CMV-DNA-copies/mL. The number of CMV-pp65 antigen-positive cells in the first positive specimens did not have predictive value for development of CMV disease. Assessment of CMV in plasma by the quantitative CMV-PCR is especially useful since it has a high sensitivity and the amount of CMV DNA in plasma is a good predictor of CMV disease.

Human cytomegalovirus productively infects porcine endothelial cells in vitro

BACKGROUND

The possibility that human cytomegalovirus (HCMV) may infect porcine endothelial cells (ECs) was investigated. This may be relevant during xenotransplantation of porcine cells or organs into human recipients.

METHODS

HCMV was inoculated into low-passage porcine ECs. Replication of virus was detected by development of characteristic cytopathogenic effect. Appearance of immediate early, early, and late antigens was studied by immunocytochemical staining. Infectious virus was detected in human fibroblast cells. Presence of HCMV RNA was studied by Northern Blot and reverse transcriptase polymerase chain reaction.

RESULTS

All parameters indicated that a fresh clinical HCMV isolate productively infects porcine ECs. The same cells do not fully support replication of the laboratory strain Ad 169.

CONCLUSION

Our results may indicate the possibility of cross-species infectivity of HCMV to porcine cells.

Detection of human cytomegalovirus (HCMV) pp67-mRNA and pp65 antigenemia in relation to development of clinical HCMV disease in renal transplant recipients

OBJECTIVE

To evaluate the performance of the recently introduced method based on detection of human cytomegalovirus (HCMV) pp67 mRNA in blood by the nucleic acid sequence-based amplification (NucliSens), in comparison to semiquantitative detection of pp65 HCMV antigen in white blood cells, in relation to development of clinical HCMV disease.

METHODS

Thirty patients, recipients of renal transplants, were monitored prospectively for the presence of pp67 mRNA, the presence and level of pp65 antigenemia, IgG and IgM antibodies, and the development of clinical HCMV disease. A total of 148 samples were examined during the observation period.

RESULTS

Twenty-five samples were positive for pp67-mRNA and 45 samples contained at least one pp65 positive cell, with 68% agreement between the two assays. Both assays predicted correctly the development of clinical disease in five patients, giving a sensitivity of 100%. However, the specificity of the pp67-mRNA test was 72%, and of the pp65 antigenemia test from 20 to 64%, depending on the level of antigenemia chosen for cut-off. pp67-RNA appeared somewhat earlier than pp65 antigenemia, and responded earlier to treatment. Sero-conversion and appearance of IgM antibodies were of very little clinical value.

CONCLUSION

Both the pp67-mRNA and the pp65 antigenemia assay predicted correctly the development of clinical HCMV disease in renal transplant recipients. However, the specificity of both tests with respect to development of HCMV disease, especially the pp65 antigen test was moderate. Significantly positive tests not necessarily prove the development of clinical disease. Testing for pp67-mRNA may improve the diagnosis and management of HCMV disease in renal transplant patients.