Late-onset cytomegalovirus disease in patients with solid organ transplant

Cytomegalovirus Immunity Assays Predict Viremia but not Replication Within the Lung Allograft

Cytomegalovirus (CMV) infection causes significant morbidity and mortality in lung transplant recipients. Current guidelines use pretransplant donor and recipient CMV serostatus to predict the risk of subsequent CMV replication and length of antiviral prophylaxis. Immunological monitoring may better inform the risk of CMV infection in patients, thereby allowing for improved tailoring of antiviral prophylaxis. In this study, we compared 2 commercially available assays, the QuantiFERON-CMV (QFN-CMV) and T-Track-CMV (enzyme-linked immunosorbent spot assay), to predict the risk of CMV disease in lung transplant recipients.

Methods

We performed CMV immunity assays on 32 lung transplant recipients at risk of CMV disease as defined by serostatus (CMV-seropositive recipients, n = 26; or CMV-seronegative lung transplant recipient receiving a CMV-seropositive donor organ, n = 6). QFN-CMV and T-Track were performed on peripheral blood mononuclear cells, and episodes of CMV replication in both serum and bronchoalveolar lavage were found to be correlated to the CMV immune assays. The predictive ability of the assays was determined using Kaplan-Meier curves.

Results

There was a degree of concordance between tests, with 44% of recipients positive for both tests and 28% negative for both tests; however, test results were discordant in 28% of cases. A negative result in either the QFN-CMV (P < 0.01) or T-Track (P < 0.05) assays was obtained in a significantly higher number of recipients who experienced CMV replication in the blood. Using these assays together gave higher predictability of CMV replication, with only 1 recipient experiencing CMV replication in the blood who obtained a positive test result for both assays. Neither assay was able to predict recipients who experienced CMV replication in the lung allograft.

Conclusions

Our study demonstrates that CMV immunity assays can predict viremia; however, the lack of association with allograft infection suggests that CMV-specific T-cell immunity in the circulation is not associated with the control of CMV replication within the transplanted lung allograft.

Viral infections in lung transplantation

Viral infections account for up to 30% of all infectious complications in lung transplant recipients, remaining a significant cause of morbidity and even mortality. Impact of viral infections is not only due to the direct effects of viral replication, but also to immunologically-mediated lung injury that may lead to acute rejection and chronic lung allograft dysfunction. This has particularly been seen in infections caused by herpesviruses and respiratory viruses. The implementation of universal preventive measures against cytomegalovirus (CMV) and influenza (by means of antiviral prophylaxis and vaccination, respectively) and administration of early antiviral treatment have reduced the burden of these diseases and potentially their role in affecting allograft outcomes. New antivirals against CMV for prophylaxis and for treatment of antiviral-resistant CMV infection are currently being evaluated in transplant recipients, and may continue to improve the management of CMV in lung transplant recipients. However, new therapeutic and preventive strategies are highly needed for other viruses such as respiratory syncytial virus (RSV) or parainfluenza virus (PIV), including new antivirals and vaccines. This is particularly important in the advent of the COVID-19 pandemic, for which several unanswered questions remain, in particular on the best antiviral and immunomodulatory regimen for decreasing mortality specifically in lung transplant recipients. In conclusion, the appropriate management of viral complications after transplantation remain an essential step to continue improving survival and quality of life of lung transplant recipients.

Impact of late-onset cytomegalovirus infection in the development of cardiac allograft vasculopathy in heart transplant recipients

BACKGROUND

The impact of late-onset cytomegalovirus (CMV) infection (LOCI) on cardiac allograft vasculopathy (CAV) has yet to be established.

METHODS

A retrospective study was performed for patients who had undergone heart transplantation (HT) between January 1995 and October 2017 to analyze epidemiology of LOCI (any positive level of CMV pp65 antigenemia or DNAemia after 100 days, without previous CMV replication) and its association with CAV. Our main hypothesis was that LOCI causes less direct and indirect effects compared to early onset infection (EOCI).

RESULTS

Late-onset cytomegalovirus infection developed in 57 of 410 patients (13.9%) in a median time of 4.7 months post-transplant. CAV at 10 years was diagnosed in 31.6% of patients with LOCI, 34.6% with EOCI, and in 19.3% of CMV-uninfected patients. In the multivariate analysis, EOCI was an independent variable for developing CAV (HR 1.8, 95% CI 1.13-2.82, P = .01). Patients with LOCI showed a trend toward a higher risk of CAV, but the difference was not statistically significant (HR 1.7, 95% CI 0.95-3.08, P = .07). In the complementary log-log model, LOCI and EOCI had a similar CAV-free survival, and a higher probability of developing CAV than CMV-uninfected patients (P = .02).

CONCLUSIONS

Cytomegalovirus infection after HT may result in the same long-term events regardless of its onset, with a higher risk of developing CAV at 10 years than patients without CMV.

IL28B rs12979860 T allele protects against CMV disease in liver transplant recipients in the post-prophylaxis and late period

BACKGROUND

Cytomegalovirus (CMV) disease represents a serious complication in liver transplant (OLT) recipients. CMV prophylaxis reduces incidence of CMV disease in the early post-transplant period (on-prophylaxis disease, OPD) but may postpone its manifestation after the completion of prophylaxis. Post-prophylaxis disease (PPD) incidence after prophylaxis cessation may be modified by genetic factors.

METHODS

We analyzed impact of IL28B rs1297986 variants on CMV disease incidence in 743 adult OLT recipients receiving universal prophylaxis.

RESULTS

One hundred and forty-four (19.4%) patients had at least one CMV disease episode. One hundred and two of them (70.8%) had at least one OPD and 36 (25%) patients had PPD, six (4.2%) patients had both. The rate of IL28B T allele carriers was lower in PPD group (38.9%) in comparison with OPD group (66.7%, P = 0.005) and group without CMV disease (61.4%, P = 0.009). The impact of IL28B genotype on the risk of CMV OPD was significant neither in the allelic (TT + CT vs CC, P = 0.32) nor in the recessive model (TT vs CT + CC, P = 0.79). Contrarily, in the PPD group, T allele (TT + CT vs CC) had a protective effect, OR 0.4 (95% CI 0.2-0.8, P = 0.008). Further risk factors of PPD were age <55 years and valganciclovir prophylaxis, whereas the risk factors of OPD were age <55 years, cyclosporine A therapy and pre-transplant CMV serostatus (donor +/recipient -).

CONCLUSIONS

IL28B rs12979860 T allele carriers had a lower risk of CMV PPD.

Preemptive anti-cytomegalovirus therapy in high-risk (donor-positive, recipient-negative cytomegalovirus serostatus) kidney transplant recipients

OBJECTIVES

Universal prophylaxis and preemptive therapy are used to prevent cytomegalovirus (CMV) disease post-transplantation. Data regarding which strategy is superior are sparse, especially in high-risk recipients (donor CMV seropositive (D+) and recipient CMV seronegative (R-)).

METHODS

This retrospective, single-center cohort study included recipients who underwent kidney transplantation between 2009 and 2015. The incidence of CMV infection/disease and patient and graft outcomes were analyzed and compared between high-risk recipients (D+/R-) and intermediate-risk recipients (D+/R+ or D-/R+), all managed with preemptive therapy.

RESULTS

Of 118 kidney transplant recipients, 21 were high-risk and 97 were intermediate-risk. Over a median follow-up period of 3 years, asymptomatic CMV infection developed significantly more frequently in high-risk patients than in intermediate-risk patients (38.1% vs. 16.5%, p=0.04), and CMV disease developed in a similar manner (28.6% vs. 3.1%, p<0.01). Among high-risk patients, CMV infection developed within the first 3 months post-transplantation and CMV disease within the first 9 months post-transplantation. Kaplan-Meier analysis showed no difference in the probability of mortality (log-rank p=0.63) or graft loss (log-rank p=0.50) between the patient groups. Graft rejection occurred more frequently in high-risk than in intermediate-risk patients, but the difference was not significant (log-rank p=0.24).

CONCLUSIONS

These results suggest that further studies on universal prophylaxis in high-risk patients are needed to elucidate whether preventing CMV infection/disease during the early post-transplant period leads to better outcomes, especially in terms of reducing graft rejection.

Influence of IFNL3/4 polymorphisms on the incidence of cytomegalovirus infection after solid-organ transplantation

BACKGROUND

Polymorphisms in IFNL3 and IFNL4, the genes encoding interferon λ3 and interferon λ4, respectively, have been associated with reduced hepatitis C virus clearance. We explored the role of such polymorphisms on the incidence of cytomegalovirus (CMV) infection in solid-organ transplant recipients.

METHODS

White patients participating in the Swiss Transplant Cohort Study in 2008-2011 were included. A novel functional TT/-G polymorphism (rs368234815) in the CpG region upstream of IFNL3 was investigated.

RESULTS

A total of 840 solid-organ transplant recipients at risk for CMV infection were included, among whom 373 (44%) received antiviral prophylaxis. The 12-month cumulative incidence of CMV replication and disease were 0.44 and 0.08 cases, respectively. Patient homozygous for the minor rs368234815 allele (-G/-G) tended to have a higher cumulative incidence of CMV replication (subdistribution hazard ratio [SHR], 1.30 [95% confidence interval {CI}, .97-1.74]; P = .07), compared with other patients (TT/TT or TT/-G). The association was significant among patients followed by a preemptive approach (SHR, 1.46 [95% CI, 1.01-2.12]; P = .047), especially in patients receiving an organ from a seropositive donor (SHR, 1.92 [95% CI, 1.30-2.85]; P = .001), but not among those who received antiviral prophylaxis (SHR, 1.13 [95% CI, .70-1.83]; P = .6). These associations remained significant in multivariate competing risk regression models.

CONCLUSIONS

Polymorphisms in the IFNL3/4 region influence susceptibility to CMV replication in solid-organ transplant recipients, particularly in patients not receiving antiviral prophylaxis.

Prevention strategies for cytomegalovirus disease and long-term outcomes in the high-risk transplant patient (D+/R-): experience from the RESITRA-REIPI cohort

BACKGROUND

Cytomegalovirus (CMV)-negative recipients of a graft from a CMV-positive donor (D+/R-) are at high risk of CMV disease. Current preventive strategies include universal prophylaxis (UP) and preemptive therapy (PT). However, the best strategy to prevent CMV disease and achieve better long-term outcomes remains a matter of debate.

METHODS

We analyzed the incidence of CMV disease and long-term outcomes including graft dysfunction and patient mortality at 5 years after transplantation with both preventive strategies. High-risk (D+/R-) kidney and liver transplant recipients from the RESITRA cohort were included.

RESULTS

Of 2410 kidney or liver transplant patients, 195 (8.3%) were D+/R-. The final cohort included 58 liver and 102 kidney recipients. UP was given in 92 patients and 68 received PT; 10.9% and 36.8% developed CMV disease, respectively (P < 0.01). The independent risk factors for CMV disease were PT strategy (hazard ratio [HR], 3.30; 95% confidence interval [CI], 1.6-6.9), kidney transplantation (HR, 3.8; 95% CI, 1.4-9.9), and cyclosporine immunosuppression (HR, 2.4; 95% CI, 1.2-4.7). PT strategy was also a risk factor for CMV disease in both liver transplantation (HR, 11.0; 95% CI, 1.2-98.7) and kidney transplantation (HR, 2.7; 95% CI, 1.3-6.0), independently. The development of CMV replication during the first 2 years after transplantation was a risk factor for graft dysfunction at 5 years after transplantation (odds ratio, 3.4; 95% CI, 1.3-9.0). Nevertheless, no significant differences were seen in either graft dysfunction or mortality between the 2 strategies.

CONCLUSIONS

The study supports the benefit of the UP strategy to prevent CMV disease in D+/R- liver or kidney transplant patients. The development of CMV replication during the first 2 years after transplantation was associated with graft dysfunction at 5 years after transplantation.

Does the calcineurin inhibitor have influence on cytomegalovirus infection in heart transplantation?

Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality in heart transplant (HTx). Our aim was to analyze the rate of CMV infection in HTx patients receiving treatment with cyclosporine (CsA) or tacrolimus (Tac). Ninety-five patients were randomized to receive either CsA (53.7%) or Tac (46.3%). We performed prophylaxis with valganciclovir in patients with the highest risk of CMV infection. We considered CMV infection as an increased viral load or the presence of CMV in histological samples. We analyzed baseline characteristics, CMV infection, and other complications. Event-free rates were calculated using the Kaplan-Meier method. There were no significant differences in baseline characteristics between both groups. CMV infection was detected in 31.6% of patients (in 66.7% due to asymptomatic replication). The group treated with Tac had a lower rate of CMV infection (15.9% vs. 45.1%, p = 0.002) and longer CMV infection-free survival time (1440 vs. 899 d, p = 0.001). No differences were observed in the complications analyzed in both groups. The independent risk factors for infection identified in the multivariate analysis were treatment with CsA and bacterial infections. This was the first study to demonstrate a lower rate of CMV infection in patients treated with Tac vs. those treated with CsA after HTx.

Clinical Experience with Immune Monitoring for Cytomegalovirus in Solid-Organ Transplant Recipients

Novel strategies are needed to further reduce the burden of cytomegalovirus (CMV) disease in solid-organ transplant (SOT) recipients. Measurement of the specific cell-mediated immunity against CMV can identify the actual risk for the development of CMV disease in a given patient. Thus, immune monitoring is an attractive strategy for individualizing the management of CMV after transplantation. A growing number of observational studies on immune monitoring for CMV have been published over recent years, although there is a lack of data coming from interventional trials. In high-risk patients, measurement of CMV-specific T-cell responses appropriately stratifies the risk of CMV disease after discontinuation of antiviral prophylaxis. Immune monitoring may also help to identify patients followed by the preemptive approach at low risk for progression to CMV disease. Pretransplant assessment of cell-mediated immunity in seropositive patients may predict the development of posttransplant CMV infection. Overall, these studies indicate that the use of cell-mediated immunity assays has the potential to improve the management of CMV disease in SOT recipients.

Impact of antiviral preventive strategies on the incidence and outcomes of cytomegalovirus disease in solid organ transplant recipients

We assessed the impact of antiviral prophylaxis and preemptive therapy on the incidence and outcomes of cytomegalovirus (CMV) disease in a nationwide prospective cohort of solid organ transplant recipients. Risk factors associated with CMV disease and graft failure-free survival were analyzed using Cox regression models. One thousand two hundred thirty-nine patients transplanted from May 2008 until March 2011 were included; 466 (38%) patients received CMV prophylaxis and 522 (42%) patients were managed preemptively. Overall incidence of CMV disease was 6.05% and was linked to CMV serostatus (D+/R- vs. R+, hazard ratio [HR] 5.36 [95% CI 3.14-9.14], p < 0.001). No difference in the incidence of CMV disease was observed in patients receiving antiviral prophylaxis as compared to the preemptive approach (HR 1.16 [95% CI 0.63-2.17], p = 0.63). CMV disease was not associated with a lower graft failure-free survival (HR 1.27 [95% CI 0.64-2.53], p = 0.50). Nevertheless, patients followed by the preemptive approach had an inferior graft failure-free survival after a median of 1.05 years of follow-up (HR 1.63 [95% CI 1.01-2.64], p = 0.044). The incidence of CMV disease in this cohort was low and not influenced by the preventive strategy used. However, patients on CMV prophylaxis were more likely to be free from graft failure.

Assessment of cytomegalovirus-specific cell-mediated immunity for the prediction of cytomegalovirus disease in high-risk solid-organ transplant recipients: a multicenter cohort study

BACKGROUND

Cytomegalovirus (CMV) disease remains an important problem in solid-organ transplant recipients, with the greatest risk among donor CMV-seropositive, recipient-seronegative (D(+)/R(-)) patients. CMV-specific cell-mediated immunity may be able to predict which patients will develop CMV disease.

METHODS

We prospectively included D(+)/R(-) patients who received antiviral prophylaxis. We used the Quantiferon-CMV assay to measure interferon-γ levels following in vitro stimulation with CMV antigens. The test was performed at the end of prophylaxis and 1 and 2 months later. The primary outcome was the incidence of CMV disease at 12 months after transplant. We calculated positive and negative predictive values of the assay for protection from CMV disease.

RESULTS

Overall, 28 of 127 (22%) patients developed CMV disease. Of 124 evaluable patients, 31 (25%) had a positive result, 81 (65.3%) had a negative result, and 12 (9.7%) had an indeterminate result (negative mitogen and CMV antigen) with the Quantiferon-CMV assay. At 12 months, patients with a positive result had a subsequent lower incidence of CMV disease than patients with a negative and an indeterminate result (6.4% vs 22.2% vs 58.3%, respectively; P < .001). Positive and negative predictive values of the assay for protection from CMV disease were 0.90 (95% confidence interval [CI], .74-.98) and 0.27 (95% CI, .18-.37), respectively.

CONCLUSIONS

This assay may be useful to predict if patients are at low, intermediate, or high risk for the development of subsequent CMV disease after prophylaxis.

CLINICAL TRIALS REGISTRATION

NCT00817908.

Prophylaxis versus preemptive therapy for cytomegalovirus disease in high-risk liver transplant recipients

Cytomegalovirus (CMV) infection is an opportunistic infection frequently found after solid organ transplantation, and it contributes significantly to mortality and morbidity. CMV-seronegative recipients of grafts from CMV-seropositive donors have the highest risk of CMV disease. The most appropriate strategy for preventing CMV disease in this population is a matter of active debate. In this study, we compared prophylaxis and preemptive therapy for the prevention of CMV disease in donor-seropositive/recipient-seronegative (D+ /R-) liver recipients. To this end, we selected a retrospective cohort of liver recipients (1992-2009) for analysis. D+ /R- patients were identified from the liver transplant program database. Eighty of 878 consecutive liver recipients (9%) were D+ /R-. Six of these patients died within 30 days of transplantation and were excluded. Thirty-five of the remaining D+ /R- patients (47%) received prophylaxis, and 39 patients (53%) followed a preemptive strategy based on CMV antigenemia surveillance. Fifty-four (73%) were men, the median age was 49 years (range = 15-68 years), and the mean follow-up was 68 months (range = 8-214 months). The baseline characteristics and the initial immunosuppressive regimens were similar for the 2 groups. Ganciclovir or valganciclovir was the antiviral drug used initially in both strategy groups. CMV disease occurred more frequently among D+ /R- liver recipients receiving preemptive therapy (33.3% versus 8.6% for the prophylaxis group, P = 0.01), whereas late-onset CMV disease was found only in patients receiving prophylaxis (5.7% versus 0% for the preemptive therapy group, P = 0.22). No significant differences in acute allograft rejection, other opportunistic infections, or case fatality rates were observed. According to our data, prophylaxis was more effective than preemptive therapy in preventing CMV disease in high-risk liver transplant recipients.

Valganciclovir to prevent or treat cytomegalovirus disease in organ transplantation

Cytomegalovirus (CMV) is generally considered the most significant pathogen to infect patients following organ transplantation. Significant improvements have been achieved in the management of CMV disease over recent years, especially since the introduction of oral drugs such as oral ganciclovir followed by valganciclovir (VGC), a prodrug of ganciclovir with enhanced bioavailability. Several randomized controlled trials have shown that VGC is an efficacious and convenient oral drug to prevent or treat CMV disease in solid-organ transplant recipients. In this article, we discuss the clinical and pharmacological experience with the use of VGC for the management of CMV in solid-organ transplant recipients. Finally, novel strategies to further reduce the incidence of CMV disease after transplantation are also reviewed.

Risk factors and clinical outcomes of cytomegalovirus disease occurring more than one year post solid organ transplantation

BACKGROUND

Cytomegalovirus (CMV) disease typically occurs during the first year after solid organ transplantation, after cessation of antiviral prophylaxis. CMV occurring after the first year is uncommon and not well described.

METHODS

We conducted a case-control study to identify potential risk factors and a retrospective cohort study to evaluate 1-month mortality in solid organ transplant (SOT) recipients who developed CMV disease after the first year post transplant, or "very late CMV" (VLCMV), compared with those developing CMV within the first year (CMV Y1), adjusting for demographics, donor and recipient CMV serostatus, immunosuppression, rejection, and co-morbidities.

RESULTS

We identified 85 SOT recipients with CMV disease at a single transplant center between January 2006 and October 2008: 23 (27%) had VLCMV and 62 (73%) had CMV Y1. Heart transplantation was independently associated with increased risk (adjusted odd ratio [OR] 4.11; 95% confidence interval [CI] 1.34-12.61; P = 0.01) for VLCMV. Patients with VLCMV had increased 1-month mortality (unadjusted OR 5.39; 95% CI 1.06-27.48; P = 0.02). Mortality was uncommonly attributable to CMV.

CONCLUSIONS

CMV disease continues to occur after the first year post solid organ transplantation, particularly in heart transplant recipients, and can be associated with poor outcomes. CMV should be suspected in patients with symptoms or laboratory findings consistent with CMV, even if the patients present >1 year post transplant.

QuantiFERON®-CMV assay for the assessment of cytomegalovirus cell-mediated immunity

Cytomegalovirus (CMV) infection has historically been a major complication among immunocompromised patients, such as solid-organ and stem-cell transplant recipients and patients with advanced HIV infection. While the introduction of antiretroviral therapy has almost eradicated CMV infection in HIV-infected patients, CMV disease remains a significant problem in transplant recipients once antiviral prophylaxis is discontinued. QuantiFERON(®)-CMV allows the assessment of cellular immunity against CMV by detecting the production of IFN-γ following in vitro stimulation with CMV antigens. Preliminary studies have shown a correlation between a lack of detectable cell-mediated immunity measured by the QuantiFERON-CMV assay and a higher incidence of CMV infection and disease in immunocompromised patients. Measurement of cell-mediated immunity against CMV appears to be a promising strategy to identify patients at highest risk for the development of CMV disease and, therefore, to individualize preventive strategies for CMV in transplant recipients.

Prophylactic therapy with valganciclovir in high-risk (cytomegalovirus D+/R-) kidney transplant recipients: a single-center experience

BACKGROUND

A prospective study was performed in kidney transplant patients at risk of developing cytomegalovirus (CMV) infection (CMV D+/R-). They were treated with valganciclovir (VGC) for 3 months as prophylactic therapy. The aim was to determine the safety and efficacy of prophylactic therapy with VGC.

METHODS

Antigenemia and/or polymerase chain reaction CMV was routinely performed every 2 weeks up to month 3, monthly to month 6, and every other month until the end of the first year posttranplantation, as well as when clinically indicated.

RESULTS

From July 2007 to April 2010, 366 renal transplantations were performed at our center, including 34 (9%) high-risk patients for CMV infection. The median age was 47 years; 19 were males and 15 females. Twelve (35%) patients developed CMV infections: 10 (34%) gastrointestinal disease and 3 viral syndromes. The timing of the clinical manifestations was 16% (3/12) between months 1 and 3, 75% (8/12) between months 4 and 6, and 8% (1/12) in month 9 posttransplantation.

CONCLUSION

Treatment with intravenous ganciclovir followed by oral VGC was successful in all patients. No opportunistic infections or allograft rejection were observed; only 1 patient developed thrombocytopenia as an adverse event to VGC.

Infection and chronic allograft dysfunction

With the advent of more potent immunosuppressive regimens, the incidence of acute rejection following renal transplantation has declined sharply in recent years. In spite of this, long-term graft outcomes remain suboptimal because of relentless attrition by cumulated insults to the allograft. As acute rejection rates have declined, other causes of graft injury and loss have recently emerged. Among these, infectious diseases remain a persistent threat and can be associated with allograft dysfunction. This group includes nephropathy due to polyoma (BK) virus infection, cytomegalovirus disease, and bacterial infection (the latter most commonly arising from the urinary tract). Rarer infectious causes of chronic allograft dysfunction include cryoglobulinemia associated with hepatitis C, Epstein-Barr virus-associated posttransplant lymphoproliferative disease, and direct cytotoxicity from adenoviral infection or parvovirus B19.

Impact of a preemptive strategy after 3 months of valganciclovir cytomegalovirus prophylaxis in kidney transplant recipients

BACKGROUND

We assessed the impact of a preemptive strategy after discontinuation of antiviral prophylaxis in the prevention of late-onset cytomegalovirus (CMV) disease in a cohort of kidney transplant recipients.

METHODS

Patients undergoing kidney transplantation at the University Hospital of Lausanne (CHUV) between November 2003 and November 2007 were included if they were donor or recipient (D/R) seropositive for CMV. All patients received 3 months of prophylaxis with valganciclovir, followed by monitoring of CMV DNAemia by polymerase chain reaction (PCR) every 15 days during 3 additional months. Valganciclovir was restarted if CMV PCR was more than or equal to 10,000 copies/mL. The primary endpoint of the study was the incidence of late-onset CMV disease. RESULTS.: Eighty-six kidney transplant recipients were included; 30 patients were D+/R- and 56 patients were R+ for CMV. At 6 months posttransplant, CMV DNAemia had occurred in 31 of 86 (36%) patients: 13 of 30 (43%) in the D+/R- group and 18 of 56 (32%) in the R+ group (P = 0.35). In the D+/R- group, among the 13 patients with CMV DNAemia, 7 (54%) patients developed late-onset CMV disease, simultaneously to the first positive viral load (n = 5) or after detection of low-grade viremia (n = 2). Only two patients received a preemptive treatment. In the R+ group, all positive PCR results were below the established cutoff. Thus, these 18 patients were not treated, and none of them developed late-onset CMV disease (R+ vs. D+/R-: P < 0.001).

CONCLUSIONS

Within the limitations of a noncontrolled study, our data indicate that a preemptive strategy after 3 months of valganciclovir prophylaxis for CMV is not useful in R+ kidney transplant recipients. In D+/R- patients, this approach should be further evaluated.

Immune monitoring of anti cytomegalovirus antibodies and risk of cytomegalovirus disease in heart transplantation

We sought to determine whether quantitative assessment of anti-cytomegalovirus (CMV) antibodies could be useful to identify patients at risk of cytomegalovirus (CMV) disease after heart transplantation (HT). 75 patients who underwent HT at a single health care center were prospectively studied. Induction therapy included 2 doses of daclizumab and maintenance tacrolimus (n=42) or cyclosporine (n=29), mycophenolate mofetil and prednisone. All patients received prophylaxis with gancyclovir or valganciclovir. Anti-CMV intravenous immunoglobulin (CMV-IG) was added in high risk patients (CMV D+/R- serostatus). Serial determinations of anti-CMV antibodies, immunoglobulins (IgG, IgA, IgM) and IgG-subclasses were analysed. CMV infection was based on detection of the virus by antigenemia. CMV disease consisted of detection of signs or symptoms attributable to this microorganism. Ten patients (13.3%) developed CMV disease. Mean time of development of CMV disease was 3.4+/-1.6 months. In Cox regression analysis, patients with low baseline anti-CMV titers (<4.26 natural logarithm of titer, RH: 8.1, 95%CI: 1.93-34.1, p=0.004) and recipients with 1-month post-HT IgG hypogammaglobulinemia (IgG<500 mg/dl, RH: 4.49, 95%CI: 1.26-15.94, p=0.02) were at higher risk of having CMV disease. Despite use of prophylactic CMV-IG, D+/R- patients showed significantly lower titers of anti-CMV antibodies at 7 d, 30 d and 90 d post HT as compared with HT recipients without infections. Four out of 6 of these patients developed late CMV disease. Monitoring of specific anti-CMV antibodies on the bedside warrants further evaluation as a potential tool to identify heart transplant recipients at higher risk of CMV disease.