NUDT15 polymorphism influences the metabolism and therapeutic effects of acyclovir and ganciclovir.

Nucleobase and nucleoside analogs (NNA) are widely used as anti-viral and anti-cancer agents, and NNA phosphorylation is essential for the activity of this class of drugs. Recently, diphosphatase NUDT15 was linked to thiopurine metabolism with NUDT15 polymorphism associated with drug toxicity in patients. Profiling NNA drugs, we identify acyclovir (ACV) and ganciclovir (GCV) as two new NNAs metabolized by NUDT15. NUDT15 hydrolyzes ACV and GCV triphosphate metabolites, reducing their effects against cytomegalovirus (CMV) in vitro. Loss of NUDT15 potentiates cytotoxicity of ACV and GCV in host cells. In hematopoietic stem cell transplant patients, the risk of CMV viremia following ACV prophylaxis is associated with NUDT15 genotype (P = 0.015). Donor NUDT15 deficiency is linked to graft failure in patients receiving CMV-seropositive stem cells (P = 0.047). In conclusion, NUDT15 is an important metabolizing enzyme for ACV and GCV, and NUDT15 variation contributes to inter-patient variability in their therapeutic effects.

The Status of Vaccine Development Against the Human Cytomegalovirus.

Numerous candidate vaccines against cytomegalovirus (CMV) infection and disease are in development. Whereas the previous article [1] provides background and opinions about the issues relating to vaccination, this article provides specifics about the vaccines in active development, as reported at a National Institutes of Health-sponsored meeting in Bethesda on September 4-6, 2018. Here, vaccine developers provide synopses of their candidate vaccines to immunize women to protect against congenital CMV disease and to prevent the consequences of CMV disease in recipients of transplanted organs or hematopoietic stem calls. The projects are presented here roughly in the descending order of their stage of development in the opinion of the first author.

The Association of 25-Hydroxyvitamin D Levels with Late Cytomegalovirus Infection in Kidney Transplant Recipients: the Wisconsin Allograft Recipient Database.

BACKGROUND: Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality in kidney transplant recipients. Vitamin D has an integral role in proper immune function, and deficiency is common among kidney transplant recipients. It remains unclear whether 25-hydroxyvitamin D [25(OH)D] level is associated with CMV infection in kidney transplant recipients. METHODS: We examined the relationship between 25(OH)D levels, measured at least 6 months posttransplant, and subsequent CMV infection in 1976 recipients free of prior CMV infection. RESULTS: Of 1976 recipients, 251 (12.7%) were vitamin D deficient [25(OH)D <20 ng/mL] and 548 (27.7%) were insufficient (20-29 ng/mL) at the time of the first 25(OH)D measurement. A total of 107 recipients had a CMV infection within 1 year of a 25(OH)D measurement. Vitamin D deficiency was associated with a 1.81-fold higher risk (relative hazard = 1.81; 95% confidence interval [CI], 1.06-3.09) than vitamin D sufficiency after adjustment for baseline characteristics and concurrent graft function and blood calcineurin inhibitor concentration. Each 1 ng/mL lower 25(OH)D was associated with a 2% higher risk of infection (95% CI, 0%-4%) in continuous analyses after adjustment. CONCLUSIONS: Low 25(OH)D is common in kidney transplant recipients and associated with late CMV infection. These results highlight the need for interventional trials to assess the potential for vitamin D supplementation to reduce infectious complications in kidney transplant recipients.

Application of a New Paradigm for Cytomegalovirus Disease Prevention in Mayo Clinic's First Face Transplant.

The optimal approach to preventing cytomegalovirus (CMV) disease after face transplant is unknown. We report an individualized hybrid approach, initially using valganciclovir prophylaxis followed by surveillance and preemptive therapy guided by viral and immunologic markers. A 31-year-old man received a near-total face allotransplant for gunshot injury-related severe facial deformities. He was CMV seronegative, and the donor was CMV seropositive (D+/R- mismatch), and he received intravenous ganciclovir followed by oral valganciclovir prophylaxis. Monthly CD8+ T-cell immune competence assay revealed no CMV-specific CD8+ T-cell immunity development during valganciclovir prophylaxis. Because of severe leukopenia, valganciclovir was discontinued at 7 months after transplant when the patient had recovered and sustained normal global CD8+ T-cell function. Weekly CMV polymerase chain reaction testing detected asymptomatic CMV replication (plasma CMV, 549 IU/mL) 3 months later. Short-course preemptive valganciclovir treatment resulted in sustained virologic clearance. The patient had development of CMV-specific CD8+ T cells (12 cells/µL) together with CMV IgM and IgG. No rejection or infection relapse was detected 20 months after transplant. In conclusion, viral and immunologic monitoring allowed for an individualized approach to effective CMV disease prevention after face transplant. This case highlights the importance of understanding the interplay between the host immunity and the pathogen in determining the clinical course and outcome of CMV and other infectious disease syndromes.

1,25 Dihydroxyvitamin D circulating levels, calcitriol administration, and incidence of acute rejection, CMV infection, and polyoma virus infection in renal transplant recipients.

Observation that 1,25-Dihydroxyvitamin-D3 has an immunomodulatory effect on innate and adaptive immunity raises the possible effect on clinical graft outcome. Aim of this study was to evaluate the correlation of biopsy-proven acute rejection, CMV infection, BKV infection, with 1,25-Dihydroxyvitamin-D3 deficiency and the benefit of calcitriol supplementation before and during the transplantation. Risk factors and kidney graft function were also evaluated. All RTRs received induction therapy with basiliximab, cyclosporine, mycophenolic acid, and steroids. During the first year, the incidence of BPAR (4% vs 11%, P=.04), CMV infection (3% vs 9%, P=.04), and BKV infection (6% vs 19%, P=.04) was significantly lower in users compared to controls. By multivariate Cox regression analysis, 1,25-Dihydroxyvitamin-D3 deficiency and no calcitriol exposure were independent risk factors for BPAR (HR=4.30, P<.005 and HR=3.25, P<.05), for CMV infection (HR=2.33, P<.05 and HR=2.31, P=.001), and for BKV infection (HR=2.41, P<.05 and HR=2.45, P=.001). After one year, users had a better renal function: eGFR was 62.5±6.7 mL/min vs 51.4±7.6 mL/min (P<.05). Only one user developed polyomavirus-associated nephropathy vs 15 controls. Two users lost their graft vs 11 controls. 1,25(OH)2-D3 deficiency circulating levels increased the risk of BPAR, CMV infection, BKV infection after kidney transplantation. Administration of calcitriol is a way to obtain adequate 1,25(OH)2-D3 circulating levels.

Increased incidence of chronic GvHD and CMV disease in patients with vitamin D deficiency before allogeneic stem cell transplantation.

Vitamin D has emerged as a central player in the immune system, with its deficiency being implicated in the pathogenesis of several autoimmune diseases, including chronic GvHD. This is a retrospective cohort analysis of 166 patients, who underwent allogeneic hematopoietic stem cell transplantation (HSCT) at the Karolinska University Hospital, evaluating GvHD, graft failure, infectious complications and survival after HSCT in relation to pre-transplantation vitamin D levels. Most of the patients were deficient in vitamin D before HSCT (median 42 nmol/L). In multivariate analysis, vitamin D level before HSCT was identified as a significant independent risk factor for development of cGvHD. The increased incidence of cGvHD was not coupled to better disease-free survival; instead there was a trend towards lower overall survival in the vitamin D-deficient patients. In addition, we found a significant correlation between vitamin D deficiency and incidence of CMV disease, with no case of CMV disease occurring in patients with sufficient levels of vitamin D before HSCT. Our results support a role of vitamin D in immune tolerance following HSCT. These findings could be highly relevant for the care of HSCT patients, and prospective, randomized studies on the effect of vitamin D supplementation are therefore needed.

Influence of cytomegalovirus infection in the development of cardiac allograft vasculopathy after heart transplantation.

BACKGROUND: Cardiac allograft vasculopathy (CAV) is a major cause of long-term morbidity and mortality after heart transplantation (HTx), whose relationship with CMV infection is uncertain. This study evaluated the influence of CMV infection in the development of CAV. METHODS: We enrolled 166 consecutive HTx recipients who underwent their first transplant from January 1995 to July 2002. All patients received 14 days of intravenous ganciclovir and were prospectively monitored for CMV infection during the first year after HTx. CAV was diagnosed by coronary angiography performed at 1, 5, and 10 years after HTx, following the new criteria of the International Society for Heart and Lung Transplantation. We collected all variables potentially related with the development of CAV. Risk factors were studied using a complementary log-log model. RESULTS: After a median follow-up of 11 years (range, 1-17 years), 72 patients (43%) developed CAV (63.8% CAV(1), 15.2% CAV(2), 20.8% CAV(3)). Symptoms secondary to CAV were present in 32% of these patients, and 8% died because of it. In the regression multivariate analysis, independent variables associated with the development of CAV were donor age (hazard ratio [HR], 1.028; 95% confidence interval [CI], 1.002-1.053; p < 0.028), presence of cellular acute rejection ≥ 2R (HR, 1.764; 95% CI, 1.011-3.078; p < 0.0414), CMV infection (HR, 2.334; 95% CI, 1.043-5.225; p < 0.0354), and not having been treated with a calcium channel blocker (HR, 0.472; 95% CI, 0.275-0.811; p < 0.0055). CONCLUSIONS: Standardized angiographic criteria show CMV infection is associated with the development of CAV.

Circulating levels of 25-hydroxyvitamin D and acute cellular rejection in kidney allograft recipients.

BACKGROUND: Vitamin D, in addition to its established role in bone metabolism, may regulate the immune system and affect the outcome of allografts. METHODS: We identified 351 kidney allograft recipients who had serum levels of 25-hydroxyvitamin D (25[OH]D) measured within the first 30 days of transplantation. We evaluated the relationship between the circulating levels of 25(OH)D and acute cellular rejection (ACR), cytomegalovirus (CMV) disease, BK virus nephropathy, and kidney graft function. RESULTS: Vitamin D deficiency (circulating levels of 25[OH]D ≤20 ng/mL, defined using The Endocrine Society Clinical Practice 2011 Guideline) was observed in 216 (61.5%) of 351 kidney graft recipients. Vitamin D deficiency was more frequent in female recipients (P=0.007, Fisher exact test) and African American recipients (P<0.001) and was less frequent in preemptive kidney graft recipients (P=0.002). Biopsy-confirmed ACR was more frequent in the vitamin D-deficient group than in the sufficient group (10.2% vs. 3.7%, P=0.04). By multivariable Cox regression analysis, vitamin D deficiency was an independent risk factor for ACR (hazard ratio=3.3, P=0.02). Vitamin D deficiency was not associated with CMV disease, BK virus nephropathy, or kidney allograft function at 1 year. 1,25-Dihydroxyvitamin D3 supplementation initiated within the first 90 days of transplantation was associated with a lesser incidence of ACR compared to no treatment with 1,25-dihydroxyvitamin D3 (5.1% vs. 13.0%, P=0.099). CONCLUSIONS: Vitamin D deficiency is an independent risk factor for development of ACR within the first year of kidney transplantation and 1,25-dihydroxyvitamin D3 supplementation may help reduce the occurrence of ACR in the vitamin D-deficient group.

[Lights and shadows of cytomegalovirus infection in solid organ transplantation]. / Luces y sombras de la infección por citomegalovirus en el trasplante de órgano sólido.

Cytomegalovirus (CMV) develops in 30-80% of patients undergoing solid organ transplantation (SOT). The incidence and presence of symptomatic disease varies depending on the type of transplant, the presence of associated risk factors, the intensity of immunosuppression, and the prevention strategies used. The impact of CMV on SOT is due not only to the effects of CMV disease per se, but also to its multiple indirect effects resulting from its immunomodulatory role and immunoactivation caused by viral latency. The two prophylactic strategies used (universal prophylaxis and preemptive therapy) are equally useful. Both strategies have advantages and disadvantages, and uncertainties remain on the populations that should receive prophylaxis and for how long. Viral monitoring to detect CMV infection is important for diagnosis, prognosis and evaluation of treatment response. The new real-time polymerase chain reaction techniques have provided numerous advantages but standardization remains an issue and common reference values are required. Specific anti-CMV drugs are available but issues such as the role of valganciclovir versus ganciclovir, the development of resistances and optimal treatment length are still being debated. Complementary therapy with mTOR inhibitors and vaccine strategies against CMV are alternatives for which conclusive data are lacking.

Dynamics of the emergence of a human cytomegalovirus UL97 mutant strain conferring ganciclovir resistance in a pediatric stem-cell transplant recipient.

Stem-cell transplant recipients are at risk of developing ganciclovir-resistant human cytomegalovirus (HCMV) infection caused by mutations in the viral UL97 gene. Knowledge of the relative proportions of coexisting HCMV wild-type and mutant strains may contribute to a better understanding of the dynamics of in vivo mutant strain selection under ganciclovir. Currently, genotype resistance screening for UL97 is routinely performed by restriction fragment length polymorphism detection and sequencing. We present here the longitudinal course of a pediatric recipient of an allogeneic stem-cell transplant infected with a ganciclovir-resistant HCMV strain. EDTA-treated blood samples were analyzed longitudinally. The patient acquired a primary HCMV infection shortly before transplantation and reactivated the virus following allogeneic hematopoietic stem cell transplantation, thus receiving an intensive antiviral treatment schedule. Three different methods for UL97 mutation analysis, restriction fragment length polymorphism detection, sequencing, and a new, real-time PCR approach were performed. In conclusion, for our pediatric patient, during peak viral load, the UL97 wild-type strain predominates, while during clinical deterioration with low viral load, the predominant mutant strain persists.

Preliminary observations of a phase II study of reduced-dose alemtuzumab treatment in patients with pretreated T-cell lymphoma.

We assessed the impact of a reduced-dose (10 mg x 3/week for 4 weeks) schedule of alemtuzumab in 10 patients with pretreated cutaneous/peripheral T-cell lymphomas. The overall response rate was 60% (2 complete responses and 4 partial responses). In terms of infectious toxicity, cytomegalovirus reactivation occurred in 1 (10%) patient.

Bayesian estimation, simulation and uncertainty analysis: the cost-effectiveness of ganciclovir prophylaxis in liver transplantation.

This paper demonstrates the usefulness of combining simulation with Bayesian estimation methods in analysis of cost-effectiveness data collected alongside a clinical trial. Specifically, we use Markov Chain Monte Carlo (MCMC) to estimate a system of generalized linear models relating costs and outcomes to a disease process affected by treatment under alternative therapies. The MCMC draws are used as parameters in simulations which yield inference about the relative cost-effectiveness of the novel therapy under a variety of scenarios. Total parametric uncertainty is assessed directly by examining the joint distribution of simulated average incremental cost and effectiveness. The approach allows flexibility in assessing treatment in various counterfactual premises and quantifies the global effect of parametric uncertainty on a decision-maker's confidence in adopting one therapy over the other.

Sequence analysis of UL54 and UL97 genes and evaluation of antiviral susceptibility of human cytomegalovirus isolates obtained from kidney allograft recipients before and after treatment.

The frequency of infections caused by drug-resistant cytomegalovirus (CMV) in solid-organ transplant recipients is not known. Only a few resistant strains have been described in transplant recipients. Antiviral susceptibility to ganciclovir (GCV) and foscarnet (PFA) of CMV isolates from 24 renal transplant patients with CMV viremia and CMV disease before and after therapy were investigated by a solid phase ELISA. The CMV DNA polymerase (UL54) and viral phosphotransferase (UL97) genes were also sequenced. Ten patients did not receive antiviral treatment; five and nine patients were treated with PFA and GCV, respectively. No appearance of drug-resistant viruses was observed in the present study, but one isolate showed a reduced sensitivity to PFA after treatment with GCV. This finding could not be explained by the presence or development of mutations that have been associated with drug resistance in UL54. We found no evidence that short-term treatment of CMV with PFA- or GCV-induced resistance.

A double-blind placebo-controlled crossover trial of intravenous magnesium sulfate for foscarnet-induced ionized hypocalcemia and hypomagnesemia in patients with AIDS and cytomegalovirus infection.

Foscarnet (trisodium phosphonoformate hexahydrate) is an antiviral agent used to treat cytomegalovirus disease in immunocompromised patients. One common side effect is acute ionized hypocalcemia and hypomagnesemia following intravenous administration. Foscarnet-induced ionized hypomagnesemia might contribute to ionized hypocalcemia by impairing excretion of preformed parathyroid hormone (PTH) or by producing target organ resistance. Prevention of ionized hypomagnesemia following foscarnet administration could blunt the development of ionized hypocalcemia. To determine whether intravenous magnesium ameliorates the decline in ionized calcium and/or magnesium following foscarnet infusions, MgSO(4) at doses of 1, 2, and 3 g was administered in a double-blind, placebo-controlled, randomized, crossover trial to 12 patients with AIDS and cytomegalovirus disease. Overall, increasing doses of MgSO(4) reduced or eliminated foscarnet-induced acute ionized hypomagnesemia. Supplementation, however, had no discernible effect on foscarnet-induced ionized hypocalcemia despite significant increases in serum PTH levels. No dose-related, clinically significant adverse events were found, suggesting that intravenous supplementation with up to 3 g of MgSO(4) was safe in this chronically ill population. Since parenteral MgSO(4) did not alter foscarnet-induced ionized hypocalcemia or symptoms associated with foscarnet, routine intravenous supplementation for patients with normal serum magnesium levels is not recommended during treatment with foscarnet.

CMV colitis masquerading as colon cancer--an unusual presentation of acquired immunodeficiency syndrome.

We present a case-report of a patient with a typical history and a barium enema study diagnostic of right-sided colonic cancer. Laparotomy and right hemicolectomy was carried out. Histological examination revealed Cytomegalovirus (CMV) colitis and the patient was subsequently tested positive for Human immunodeficiency Virus (HIV). Gastrointestinal symptoms are common in patients with Acquired Immune Deficiency Syndrome (AIDS) and up to 10% of all AIDS patients have CMV colitis. The diagnostic criteria for CMV colitis is reviewed. AIDS is likely to become more common and we stress the awareness of this condition as well as the need for preoperative colonoscopy and histological diagnosis in patients with radiological diagnosis of colorectal carcinoma.

Neumonía por citomegalovirus y linfoma de Burkitt: caso clínico y discusión de la literatura / Cytomegalovirus pneumonia and Burkitt lymphoma: clinical case and literature review

A raíz de un caso de un niño con linfoma de Burkitt, en tratamiento quimioterápico con neutropenia, el cual desarrolla un síndrome febril con neumonia intersticial y en el que se demuestra una infección por CMV, los autores discuten el enfrentamiento diagnóstico y terapéutico

CMV prophylaxis with foscarnet in allogeneic bone marrow transplant recipients at high risk of developing CMV infections.

Eleven patients underwent bone marrow transplant (BMT) from an HLA-identical sibling following single dose total body irradiation (TBI), with in vivo and ex vivo T cell depletion (TCD). In spite of CMV prophylaxis with acyclovir and high-dose i.v. Ig, 10 of 11 patients developed CMV antigenemia, at a median interval from BMT of 34 days (range 16-72 days) and five died with CMV disease. Foscarnet was then given prophylactically in 11 additional TCD patients to test whether we could (1) prevent CMV reactivation, and (2) reduce transplant-related mortality. Foscarnet was given daily from days +10 to +15 (180 mg/kg/day), then thrice weekly (90 mg/kg/day) until day +100. Five patients developed CMV antigenemia at a median interval from BMT of 42 days (range 16-65 days); one progressed to CMV pneumonitis and died. The risk of developing CMV antigenemia within day 100 is currently 91% for the historical control group and 45% for the foscarnet group (p = 0.005). At diagnosis of CMV, the median number of CMV antigen-positive cells was 6.5 (range 1-13) vs 1 (range 1-5) in acyclovir vs foscarnet patients (p = 0.02) and the median highest number of CMV antigen-positive cells was 7 (range 3-110) vs 1 (range 1-12), respectively, (p = 0.03). The actuarial 1 year transplant-related mortality (TRM) is 49% and 13% in the two groups (p = 0.08). This study suggests that foscarnet prophylaxis starting on day +10 post-BMT may be helpful in reducing the risk of CMV disease and early mortality following TCD BMT.

Ganciclovir sensitivity of cytomegalovirus at diagnosis and during treatment of cytomegalovirus pneumonia in marrow transplant recipients.

Cytomegalovirus (CMV) often persists in the lungs of marrow transplant patients with CMV pneumonia, despite ganciclovir (GCV) treatment. To determine whether GCV resistance contributes to viral persistence, the susceptibilities of CMV isolates from diagnostic bronchoalveolar lavage samples and CMV isolates obtained during treatment or from autopsy lung tissue from 12 patients were compared by DNA hybridization. Resistance (50% effective dose, > 12 microM) was detected in an isolate from only one patient who had also received several courses of GCV. GCV resistance did not explain the persistence of CMV in the lung.