Treatment of recurrent cytomegalovirus disease in patients receiving solid organ transplants

Absolute Lymphocyte Count: A Predictor of Recurrent Cytomegalovirus Disease in Solid Organ Transplant Recipients

Background

Recurrent cytomegalovirus (CMV) disease in solid organ transplant recipients frequently occurs despite effective antiviral therapy. We previously demonstrated that patients with lymphopenia before liver transplantation are more likely to develop posttransplant infectious complications including CMV. The aim of this study was to explore absolute lymphocyte count (ALC) as a predictor of relapse following treatment for CMV disease.

Methods

We performed a retrospective cohort study of heart, liver, and kidney transplant recipients treated for an episode of CMV disease. Our primary outcome was time to relapse of CMV within 6 months. Data on potential predictors of relapse including ALC were collected at the time of CMV treatment completion. Univariate and multivariate hazard ratios (HRs) were calculated with a Cox model. Multiple imputation was used to complete the data.

Results

Relapse occurred in 33 of 170 participants (19.4%). Mean ALC in relapse-free patients was 1.08 ± 0.69 vs 0.73 ± 0.42 × 103 cells/μL in those who relapsed, corresponding to an unadjusted hazard ratio of 1.11 (95% confidence interval, 1.03-1.21; P = .009, n = 133) for every decrease of 100 cells/μL. After adjusting for potential confounders, the association between ALC and relapse remained significant (HR, 1.11 [1.03-1.20]; P = .009).

Conclusions

Low ALC at the time of CMV treatment completion was a strong independent predictor for recurrent CMV disease. This finding is biologically plausible given the known importance of T-cell immunity in maintaining CMV latency. Future studies should consider this inexpensive, readily available marker of host immunity.

The impact of recurrent cytomegalovirus infection on long-term survival in solid organ transplant recipients

BACKGROUND

Cytomegalovirus (CMV) remains a significant contributor to morbidity and mortality following solid organ transplantation (SOT). While recurrent infection occurs in up to 30% of patients, its impact on mortality is unclear. The aim of this study was to explore the relationship between recurrent CMV infection and long-term survival in SOT recipients.

METHODS

We performed a retrospective cohort study of SOT recipients who completed treatment for an episode of CMV infection. Patients were followed until death, loss to follow-up or 10 years following CMV treatment completion. Univariable and multivariable hazard ratios (HR) were calculated, treating relapse and rejection following CMV as time-varying.

RESULTS

About 79 kidney, 52 heart, 34 liver, and 5 liver-kidney transplant recipients were included. About 62/170 died, at a median of 3.8 years (IQR 0.8-6.6 years). Median follow-up among the 108 survivors was 7.4 years (IQR 3.7-10 years). Recurrent CMV infection occurred in 49/170 (29%), 67% within 6 months of treatment completion. Mortality among those who relapsed was 39% (19/49) vs 36% (43/121) in those who remained relapse-free (unadjusted HR 1.59, 95% CI 0.92-2.75, P = .10). After adjusting for age and transplanted organ, findings were similar (HR 1.68, 95% CI 0.93-3.04, P = .09).

CONCLUSIONS

Mortality following CMV remains high even in the valganciclovir era. Although our findings suggest a possible increased risk of death among patients with recurrent CMV, these did not reach statistical significance. The complex nature of these patients, multiple potential confounders, and limited statistical power made detection of small effects difficult. Larger prospective studies evaluating the clinical impact of strategies to reduce recurrence are needed.

Long-term outcomes of CMV disease treatment with valganciclovir versus IV ganciclovir in solid organ transplant recipients

Though an important cause of morbidity and mortality in solid organ transplantation (SOT), the long-term outcomes of cytomegalovirus (CMV) disease treatment have not been well studied. In a randomized trial, 321 SOT recipients with CMV disease were followed 1 year after treatment with either twice daily intravenous ganciclovir or oral valganciclovir (for 21 days) followed by once daily valganciclovir until day 49 in all patients. Clinical and viral eradication of CMV disease was similar between groups. Clinical recurrence beyond day 49 was found in 15.1% and virological recurrence in 30.0%, no difference between groups (p > 0.77). In a multivariable logistic regression analysis, the only independent predictor for recurrence was failure to eradicate DNAemia by day 21 (clinical: OR 3.9 [1.3-11.3], p = 0.012; virological: OR 5.6 [2.5-12.6], p < 0.0001). Eight patients developed ganciclovir resistance, with no difference between groups (p = 0.62). Twenty patients (valganciclovir: 11, ganciclovir: 9, p = 0.82) died, 12 due to infections, two involving CMV disease. There were no differences in long-term outcomes between treatment arms, further supporting the use of oral valganciclovir for treatment of CMV disease. Persistent DNAemia at day 21, CMV IgG serostatus and development of resistance may be relevant factors for further individualization of treatment.

Cytomegalovirus viremia in solid organ transplantation: does the initial viral load correlate with risk factors and outcomes?

Consistent data for using CMV quantitative PCR (QnPCR) on initial presentation to predict outcomes after solid organ transplantation (SOT) are lacking. Recipients with measurable CMV QnPCR and either CMV-V (asymptomatic viremia) or CMV-D (symptomatic CMV infection) were analyzed over 24 months. Risk factors and outcomes were evaluated in relation to initial QnPCR by regression analysis and time-to-event curves. Twenty-eight recipients were identified: five CMV-V, 23 CMV-D. Patients with CMV-D had a higher median initial QnPCR (230 000 copies/mL) compared with CMV-V (2500 copies/mL; p < 0.05). No patients with CMV-V had an initial QnPCR > 10 000 copies/mL compared with 83% of the CMV-D (p = 0.004). The initial QnPCR was higher (250 000 copies/mL) in patients who did not clear CMV PCR than those who cleared (8000 copies/mL) after 14 d of treatment (p = 0.03). Risk factors and indirect CMV effects were not associated with initial QnPCR. Our results highlight the importance of the initial CMV QnPCR in relation to the development of symptomatic CMV and a slower response to therapy. Alternatively, late asymptomatic viremia and recurrent CMV are associated with lower PCR levels and a low likelihood to progress and result in clinical disease.

Viral escape and T-cell immunity during ganciclovir treatment of cytomegalovirus infection: case report of a pancreatico-renal transplant recipient

BACKGROUND

Pancreas-kidney transplant recipients are at high risk for cytomegalovirus (CMV) disease despite prophylactic ganciclovir therapy. Because the impact of antiviral therapy on anti-CMV immune reactions is unknown, CMV-specific T-cell subsets in primary and recurrent CMV infection were analyzed in a pancreas-kidney transplant case study.

METHODS

Major histocompatibility complex class I tetramers were used to detect peripheral CMV pp65-specific CD8 T cells. Intracellular cytokine staining was used to determine the frequency of CMV-specific CD4 T cells. Conventional virologic parameters and routine laboratory parameters were monitored. For ganciclovir resistance testing, CMV-UL97 genotyping was performed.

RESULTS

Despite prophylactic ganciclovir therapy, primary CMV infection induced in vivo expansion of activated CMV-specific CD8 T cells. Interestingly, viral dissemination during recurrent CMV disease was a result of partially ganciclovir-resistant CMV. Recovery after discontinued ganciclovir treatment was associated with the expansion of CMV-specific CD4 T cells.

CONCLUSION

Immunologic monitoring may contribute to clinical management of recurrent CMV disease.

Determinants of protracted cytomegalovirus infection in solid-organ transplant patients

BACKGROUND

Recurrent infection frequently follows the response to the initial treatment of cytomegalovirus (CMV) infection in solid-organ transplant (SOT) recipients. The objective of this study was to describe the course of CMV infection in SOT patients and to identify factors that would predict protracted CMV infection with recurrences.

METHODS

Quantitative polymerase chain reaction (PCR) assay for CMV DNA in leukocytes and in plasma were used to assess viral load changes retrospectively in consecutive SOT patients, whose CMV infection episodes had been attended therapeutically or preemptively using quantitative blood culture.

RESULTS

Among 101 SOT patients, CMV infection occurred in 63, of whom 32 developed recurrent infection after the initial episode. In patients with recurrent infection, PCR indicated that a majority (27) of recipients had high level of CMV DNA in peripheral blood leukocytes and plasma throughout a protracted (>/=1 month) period including after preemptive or therapeutic ganciclovir courses. Predictors of protracted high-level infection were increasing age, CMV donor seropositivity, and all measures of viral load during the initial episode. CMV recipient seropositivity protected strongly against protracted infection. End of treatment plasma CMV DNA best discriminated between patients who did or did not develop protracted infection.

CONCLUSIONS

In SOT patients, protracted CMV infection is associated with increasing age, donor seropositivity, recipient seronegativity, and high viral load during the first episode. End of therapy plasma CMV DNA level best predicts the occurrence of protracted infection. In patients with a high risk of protracted infection, prophylaxis is likely to be particularly cost effective.

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

BACKGROUND

Cytomegalovirus (CMV) infection is the single most frequent infectious complication in renal transplant recipients. Because no CMV-prophylaxis is given and ganciclovir is used only as deferred therapy for CMV disease at our center, we have been able to study the natural course of CMV infections. The aim was to assess risk factors for CMV infection and disease and thus identify subgroups of patients likely to benefit from CMV prophylaxis or preemptive therapy.

METHODS

Between October 1994 and July 1997, 477 consecutive renal transplant recipients (397 first transplants and 80 retransplants) were included in the study. The patients were followed prospectively for 3 months with serial measurements of CMV pp65 antigen for monitoring activity of CMV infections.

RESULTS

The incidence of CMV infections in first transplants was 68% in D+R- and D+/-R+ serostatus groups, whereas the incidence of CMV disease was higher in D+R- (56%) than in D+/-R+ (20%, P<0.001). No difference in severity of CMV disease in D+R- and D+/-R+ was seen except for an increased incidence of hepatitis in primary infections. One of 14 deaths could be associated with CMV disease in a seropositive recipient. Cox regression analysis showed that rejection (RR 2.5, P<0.01) and serostatus group D+R- (RR 3.9, P<0.001) were significant risk factors for development of CMV disease. The maximum CMV pp65 antigen count had significant correlation to disease only in CMV seropositive recipients, P<0.001. Conclusion. Renal transplant recipients can safely be given deferred ganciclovir therapy for CMV disease if they are intensively monitored for CMV infection. Patients with primary CMV infection (D+R-), CMV infected patients undergoing anti-rejection therapy and R+ patients with high CMV pp65 counts seem to have a particular potential for benefit from preemptive anti-CMV-therapy.

Prevention of recurrent cytomegalovirus disease in renal and liver transplant recipients: effect of oral ganciclovir

BACKGROUND

Although the primary treatment of symptomatic cytomegalovirus (CMV) disease in organ transplant recipients is successful in >90% of individuals, relapsing disease, particularly in those with primary infection, remains an important problem. Previously, we had observed that the rate of symptomatic recurrence was >60% in those with primary disease (seronegative for CMV prior to transplant), and approximately 20% in those who were seropositive prior to transplant. The present study was undertaken to determine whether a maintenance regimen of oral ganciclovir for 2-3 months added to the routine 14-21 days of intravenous ganciclovir would further prevent symptomatic CMV recurrence.

METHODS

From May 1995 until June 1998, all kidney and liver transplant recipients with confirmed tissue-invasive CMV disease or CMV syndrome were treated with 14-21 days of intravenous ganciclovir (5 mg/kg b.i.d. with dose adjusted for renal dysfunction) followed by 2-3 months of oral ganciclovir (2 g daily). The incidence of recurrence of CMV disease and/or viremia during and after oral therapy was then determined over a mean follow-up of 530.6 days.

RESULTS

Thirty-seven patients, 19 kidney and 18 liver transplant recipients, were studied; 5 had biopsy-proven tissue-invasive disease (13.5) and 32 suffered a CMV syndrome (86.5). Twenty-one of these patients (58.6) were seronegative for CMV prior to transplant and received an allograft from a seropositive donor (D+/R-). Overall, 10 patients (27.0) developed CMV recurrence. Eight of 21 patients who were D+/R- for CMV (38.1) developed recurrence as opposed to 2 of 16 patients with other serologic status (12.5) (P=0.14). Patients with recurrent CMV disease and/or viremia had a peak antigenemia assay titer during their initial CMV event of 319.2 positive cells/2 slides compared with 109.8 positive cells/2 slides for patients without recurrent CMV infection (P=0.14); the trend of having a higher peak antigenemia assay titer among patients who recurred occurred both in patients who were at risk of primary CMV infection (D+/R- for CMV) and in those who were not. Two patients developed recurrent infection with strains of CMV that were resistant to ganciclovir.

CONCLUSIONS

This new therapeutic regimen of oral ganciclovir following intravenous ganciclovir slightly reduced the overall rate of recurrent CMV disease and/or viremia, but it still did not adequately prevent CMV recurrence in patients who are at risk of primary infection prior to transplant. Of particular concern, 2 patients with primary infection treated with this regimen developed ganciclovir-resistant recurrent disease.

Recent advances in the therapy and prevention of CMV infections

The introduction of highly active antiretroviral therapy (HAART) for HIV has had a major impact on the treatment of CMV disease in HIV-infected individuals. There is mounting evidence that in patients with CMV retinitis who have a sustained response to HAART, CMV maintenance treatment can be discontinued without relapse of retinitis. In HAART-naïve individuals with newly diagnosed CMV retinitis, the optimal timing for the initiation of HAART relative to the start of anti-CMV treatment is currently unknown. New local therapies for CMV retinitis (e.g. ganciclovir implant, the new antisense compound fomivirsen) provide treatment options in situations where high local drug delivery is warranted. A treatment algorithm for CMV disease in the HAART era is proposed. In the transplant setting, ganciclovir and foscarnet remain the major compounds used for treatment of CMV disease. In marrow and stem cell transplant recipients, CMV pneumonia still carries a high mortality. Ganciclovir in combination with CMV-specific immunoglobulin or regular intravenous IG remains the treatment of choice for CMV pneumonia; extended antiviral maintenance for several months is recommended in patients with continued immunosuppression. Preemptive treatment based on virologic markers (e.g. pp65 antigenemia, CMV DNA) has been very successful in reducing the incidence of early CMV disease in the transplant setting. The duration of preemptive treatment should be guided by the underlying immunosuppression and virologic markers. Late CMV disease is a challenge in marrow and stem cell transplant recipients, and occurs increasingly in highly immunosuppressed solid organ transplant recipients as well. Recent advances in prophylaxis strategies include oral ganciclovir for liver transplant recipients and valacyclovir for kidney transplant recipients.

New strategies for prevention and therapy of cytomegalovirus infection and disease in solid-organ transplant recipients

In the past three decades since the inception of human organ transplantation, cytomegalovirus (CMV) has gained increasing clinical import because it is a common pathogen in the immunocompromised transplant recipient. Patients may suffer from severe manifestations of this infection along with the threat of potential fatality. Additionally, the dynamic evolution of immunosuppressive and antiviral agents has brought forth changes in the natural history of CMV infection and disease. Transplant physicians now face the daunting task of recognizing and managing the changing spectrum of CMV infection and its consequences in the organ recipient. For the microbiology laboratory, the emphasis has been geared toward the development of more sophisticated detection assays, including methods to detect emerging antiviral resistance. The discovery of novel antiviral chemotherapy is an important theme of clinical research. Investigations have also focused on preventative measures for CMV disease in the solid-organ transplant population. In all, while much has been achieved in the overall management of CMV infection, the current understanding of CMV pathogenesis and therapy still leaves much to be learned before success can be claimed.

Prevention and treatment of cytomegalovirus infection in organ transplant recipients

Cytomegalovirus (CMV) is the most common viral pathogen in organ transplant recipients. The patients at highest risk of developing CMV disease are seronegative recipients of seropositive donors, and seropositive recipients who receive antilymphocyte agents such as OKT3 and antithymocyte globulin (ATG) for induction or for rejection. There have been many trials of CMV prevention, but they are difficult to compare with one another because of variability in definitions and end points. Two modalities that have been used to prevent CMV disease are prophylaxis and preemptive therapy. In prophylaxis all patients are given an antiviral agent in order to prevent CMV disease, while in preemptive therapy (also called targeted prophylaxis) only patients who are identified as 'high risk' are selected for treatment. Selected trials of prophylaxis and preemptive therapy in solid-organ recipients are reviewed. The factors to be considered in using one modality or the other are side effects from antivirals, cost of monitoring and antivirals, efficacy of the two modalities, and potential emergence of drug resistance. Sensitive tests that have been used for early diagnosis and monitoring of CMV are antigenemia and the polymerase chain reaction (PCR). Antigen pp65 is a lower matrix protein and can be detected in peripheral blood leukocytes. The sensitivity and specificity are high and vary from 89% to 100% and 92% to 96%, respectively. Currently, many authors believe that the antigenemia test is more useful than the PCR test. The antigenemia test is useful for viral monitoring as a guide for preemptive therapy after organ transplantation. Persistence of high counts of antigenemia may indicate inadequate antiviral therapy or emergence of resistance. Recurrence of positive antigenemia after treatment of CMV disease can be a sign of relapse. Transplant patients who develop resistance to antiviral drugs are usually seronegative recipients who receive an organ from a seropositive donor and have several courses of antivirals for CMV disease. Ganciclovir is the most frequent antiviral agent used in transplant recipients and is usually well tolerated. Resistance to ganciclovir may occur and is usually secondary to virus mutation in the UL97 gene. The availability of sensitive diagnostic tests such as pp65 antigenemia has made the early diagnosis of CMV possible in organ transplant recipients. CMV is being treated much earlier now, and progression to disseminated disease is uncommon. Prudent use of antiviral drugs will hopefully limit the problem of drug resistance.

Cytomegalovirus disease recurrence after ganciclovir treatment in kidney and kidney-pancreas transplant recipients

BACKGROUND

With the introduction of ganciclovir, the clinical pattern of cytomegalovirus (CMV) disease has changed; CMV disease recurrence after successful treatment of the initial episode has emerged as a more common problem. We studied CMV disease recurrence in kidney transplant (KTx) and simultaneous kidney-pancreas transplant (SPK) recipients, and identified risk factors for recurrence.

METHODS

Between January 1987 and December 1995, of 1272 KTx and 287 SPK recipients, 332 developed CMV disease and were treated with a 14-day course of i.v. ganciclovir, followed by a 10-week course of oral acyclovir. Among these 332 recipients, 103 (31%) developed CMV disease recurrence more than 30 days after treatment for the initial episode; this group was compared with those recipients who did not develop recurrence (n=229). Risk factors examined were age, presence of diabetes, type of transplant (KTx vs. SPK), donor source (cadaver vs. living donor), treatment for acute rejection, pretransplant CMV serologic status, evidence of tissue-invasive CMV, and treatment of the initial episode with human immune globulin in addition to ganciclovir.

RESULTS

Univariate analysis found that patients with recurrence were more likely to be diabetic (70.9% vs. 53.7%; P=0.04), to have undergone an SPK (39.8% vs. 20.5%; P=0.004), to have received a cadaver organ (78.6% vs. 61.6%; P=0.002), and to have received treatment for acute rejection (78.6% vs. 59.8%; P=0.001). Using multivariate analysis, two statistically significant risk factors were found: receiving a cadaver organ (relative risk [RR]=1.90; P=0.03) and treatment for acute rejection (RR=2.02; P=0.008). Diabetes (RR=1.44; P=0.18) and a cadaver SPK transplant (RR=1.55; P=0.12) tended toward increased risk for recurrence, but the difference did not reach statistical significance. The remaining variables were not significant. Interestingly, CMV recurrence did not significantly diminish 5-year graft survival (52.0% vs. 54.4%; P not significant) or patient survival (67.0% vs. 68.3%; P not significant) rates.

CONCLUSIONS

CMV disease recurs in roughly one-third of KTx and SPK recipients after treatment of the initial episode with ganciclovir. A cadaver organ source and treatment for acute rejection were the most significant clinical risk factors for recurrence. Clinical predictors of recurrence such as these may help to identify those recipients who need more intensive therapeutic and prophylactic regimens.

Infections in solid-organ transplant recipients

Solid-organ transplantation is a therapeutic option for many human diseases. Infections are a major complication of solid-organ transplantation. All candidates should undergo a thorough infectious-disease screening prior to transplantation. There are three time frames, influenced by surgical factors, the level of immunosuppression, and environmental exposures, during which infections of specific types most frequently occur posttransplantation. Most infections during the first month are related to surgical complications. Opportunistic infections typically occur from the second to the sixth month. During the late posttransplant period (beyond 6 months), transplantation recipients suffer from the same infections seen in the general community. Opportunistic bacterial infections seen in transplant recipients include those caused by Legionella spp., Nocardia spp., Salmonella spp., and Listeria monocytogenes. Cytomegalovirus is the most common cause of viral infections. Herpes simplex virus, varicella-zoster virus, Epstein-Barr virus and others are also significant pathogens. Fungal infections, caused by both yeasts and mycelial fungi, are associated with the highest mortality rates. Mycobacterial, pneumocystis, and parasitic diseases may also occur.

Diagnostic markers and risk factors of cytomegalovirus infection and disease in renal allograft recipients

In a prospective study, the incidences of CMV infection and disease were 56 and 23%, respectively, during the first 6 months following kidney transplantation. Viremia was found in all patients with CMV disease and arthralgia was present in 71% prior to the development of CMV disease. The positive predictive value for CMV disease reached up to 90% for viremia and arthralgia in combination. Viruria was poorly correlated to viremia and hence CMV disease. The majority of patients (93%) who developed CMV disease had a seropositive donor, and viremia was significantly more common in patients who received CMV-seropositive kidneys. CMV disease was more common in CMV-seronegative recipients than in seropositive recipients. The 1-year graft survival rate was 75% in the entire study group. In patients with CMV viremia and disease, the rates were 78 and 73%, respectively. Antiviral treatment was initiated within 3 weeks of viremia detection in the 6 patients with CMV disease who survived. We found that the combination of arthralgia and viremia was a useful predictor of CMV disease and that recipients of CMV-seropositive allografts were at a greater risk of developing CMV disease. To obtain an early diagnosis and commence an early treatment of CMV disease, patients prone to develop CMV disease should be identified and clinical examination and viremia surveillance should be performed regularly.