Cytomegalovirus glycoprotein B genotype does not correlate with outcomes in liver transplant patients.

BACKGROUND: Based on sequence variation in the UL55 gene that encodes glycoprotein B (gB), human cytomegalovirus (CMV) can be classified into four gB genotypes. Previous studies have suggested there could be an association between CMV gB genotype and clinical outcome in transplant patients. OBJECTIVES: The goal of this study was to determine the distribution of gB genotypes in a cohort of liver transplant recipients with CMV infection and the effect of gB type on clinical outcomes including CMV disease and rejection. STUDY DESIGN: DNA was extracted directly from the blood of 58 liver transplant recipients with CMV infection. The gB genotype of CMV was determined using the polymerase chain reaction to amplify a region of UL55, followed by restriction analysis based on HinfI and RsaI digestion. Results were correlated with CMV viral load, symptomatic disease, and development of acute rejection. RESULTS: The distribution of CMV gB genotypes was: gB1, 15/58 (25.9%); gB2, 16/58 (27.6%); gB3, 21/58 (36.2%); gB4, 2/58 (3.4%) and four patients (6.9%) had mixed infection. No correlation between CMV genotype and peak CMV viral load was observed. Symptomatic CMV disease developed in 25/58 (43.1%) patients and 26/58 (44.8%) had acute rejection. The rate of CMV disease and acute graft rejection in patients infected with the different CMV gB genotypes was not significantly different. However, all four patients with infection with a mixture of CMV gB genotypes developed progression to CMV disease (P=0.030). CONCLUSIONS: The gB genotype did not correlate with peak CMV viral load and with the development of CMV disease or acute rejection following liver transplantation.     

Pre-emptive oral ganciclovir can reduce the risk of cytomegalovirus disease in liver transplant recipients

A cohort of 65 liver transplant recipients was prospectively monitored with qualitative polymerase chain reaction (PCR) in plasma. The first 25 patients did not receive prophylaxis. From a consecutive group of 40 recipients, 11 high-risk patients donor CMV-seropositive/receptor CMV-seronegative (D+/R–), persistent CMV replication) received pre-emptive oral ganciclovir (1000 mg three times daily), when a marker of risk was identified, until day 90. The overall incidence of cytomegalovirus (CMV) disease at six months was 20% (five of 25 patients) in the non-prophylaxis group and 2.5% (one of 40 patients) in the group treated with pre-emptive oral ganciclovir (relative risk, 0.11; 95% confidence interval; 0.01–0.96; P  = 0.04). The PCR sensitivity for detecting CMV disease was 80%, the specificity was 90%, and the positive and negative predictive values were 66% and 95%, respectively. Adverse events, graft rejection and survival were similar between groups. We conclude that pre-emptive oral ganciclovir in high-risk patients can reduce the risk of CMV disease.     

The impact of cytomegalovirus disease and asymptomatic infection on acute renal allograft rejection.

BACKGROUND: Cytomegalovirus (CMV) disease is a risk factor for allograft rejection in renal transplant (RTx) recipients. However, the role of asymptomatic CMV infection remains controversial. OBJECTIVES: To determine the impact of CMV disease and asymptomatic infection on biopsy-proven acute rejection (BPAR) during 12 months post-RTx. STUDY DESIGN: A total of 106 consecutive RTx recipients at risk for CMV (donor and/or recipient CMV seropositive) were followed prospectively for 12 months post-RTx. CMV activity was monitored using nested PCR from whole blood. Three-month prophylaxis with valacyclovir or ganciclovir was given to 94 patients. BPAR episodes were classified according to the Banff 97 criteria. Multivariate Cox proportional hazards model was used to estimate the effect of CMV disease, asymptomatic infection, and other covariates on BPAR. RESULTS: Asymptomatic CMV infection occurred in 23% of the patients and 10% developed CMV disease. The incidence of BPAR was 29%. CMV disease was an independent risk factor for BPAR (HR=3.0, P=0.014), while asymptomatic CMV infection was not (P=0.987). In addition to CMV disease, expanded criteria donor and donor age were independent predictors for BPAR. In univariate analysis, valacyclovir (HR=0.26, P=0.008) decreased the risk of BPAR. A similar trend was observed with ganciclovir (HR=0.42, P=0.058). Only valacyclovir remained significant in multivariate analysis (HR=0.18, P=0.044). CONCLUSIONS: CMV disease, but not asymptomatic infection, is an independent risk factor for BPAR during the first 12 months post-RTx.     

Response of asymptomatic cytomegalovirus viraemia to oral ganciclovir 3 g/day or 6 g/day in HIV-infected patients.

Reactivation of cytomegalovirus (CMV) following immunosuppression may result in the development of CMV disease and is associated with an increased risk of death. CMV viraemia detected by the polymerase chain reaction (PCR) precedes CMV disease in HIV-infected patients and identifies individuals at high risk of disease. Pre-emptive ganciclovir (GCV) therapy in patients who have evidence of CMV viraemia is effective in preventing disease. An open study was conducted to assess the response of CMV viraemia to oral GCV at a dose of 3 or 6 g/day for 28 days. HIV RNA was measured to determine if CMV inhibition affected HIV viral load. Fourteen patients were studied, three of whom entered both phases of the study. None of the patients had evidence of CMV disease at the time of entry into the trial; two patients developed CMV retinitis after completion of the trial. Oral GCV at both 3 and 6 g/day caused a decrease in CMV viral load in individual patients. However, a rebound in CMV viral load occurred in patients receiving the 3-g/day dose. None of the patients receiving oral GCV 3 g/day became PCR negative after 21 days compared with six of eight patients receiving 6 g/day. Five of eight patients (63%) receiving GCV 6 g/day were concurrently taking protease inhibitors compared with two of nine (22%) receiving 3 g/day. Ten patients remained PCR negative throughout follow up. No change was found in HIV viral load during receipt of GCV at either dose. Thus, oral GCV is effective in reducing CMV viral load, but a dose of 3 g/day is insufficiently potent for pre-emptive therapy.     

HLA PROFILE OF ETHNIC PAKISTANI POPULATION GROUPS

Acute rejection is a major determinant of chronic allograft dysfunction and graft survival. This study evaluated the effect of basiliximab (Simulect^®), a 156-kDa chimeric monoclonal antibody (human and murine) directed against the alpha chain of the interleukin (IL)-2 receptor of human lymphocytes, on acute rejection in pediatric renal transplantation. Data were collected from two pediatric renal transplantation centers. Forty transplantations (22 males and 18 females; mean age 14.8±3.6 years) were performed between 1996 and 2001. Twelve of the grafts came from cadaveric donors and 28 from living-related donors. Twenty-four of the patients were on hemodialysis, 15 were on peritoneal dialysis, and one case was a pre-emptive transplantation. All patients were placed on triple-drug immunosuppression [prednisolone + (azathioprine or mycophenolate mofetil) +(cyclosporine or tacrolimus)]. Basiliximab was also administered in 17 cases. The respective rates of biopsy-proven acute rejection in the basiliximab group and the standard-regimen group were 0% vs. 17.4% ( P >0.05) at 1 month post-transplantation; 0% vs. 26.1% ( P <0.05) at 3 months; and 0% vs. 26.1% ( P <0.05) at 6 months. Thirty and 16 patients had completed 1- and 3-year follow ups, respectively, at the time of writing; the 1- and 3-year graft survival rates were 96% (29/30) and 81% (13/16), respectively.
Basiliximab significantly reduced the rates of acute rejection at 3- and 6 months post-pediatric renal transplantation. It was well tolerated by all patients, and caused no significant adverse effects. The effect of basiliximab on long-term graft survival and chronic allograft dysfunction deserves further investigation.     

Basiliximab

Basiliximab (Simulect®) is a recombinant chimeric murine/human IgG1 monoclonal anti-interleukin-2 receptor antibody that is indicated for the prevention of acute organ rejection in adult and pediatric renal transplant recipients in combination with other immunosuppressive agents. Induction therapy with two doses (day 0 and day 4) of intravenous basiliximab as part of double- or triple-immunotherapy regimens in adult renal transplant recipients reduces acute rejection episodes without increasing the incidence of adverse events. Compared with rabbit-derived antithymocyte globulin (RATG), basiliximab is generally associated with similar efficacy in standard-risk patients, but reduced efficacy in high-risk patients. Initial results indicate that induction with basiliximab is associated with a higher rate of biopsy-proven acute rejection than alemtuzumab induction. Basiliximab is generally associated with a tolerability profile that is similar to that reported with placebo, and better than that reported with RATG. As with other induction agents, basiliximab has not demonstrated improved graft or patient survival over the long term (periods of up to 7 years). Basiliximab induction allows for reduced dosage of corticosteroids or calcineurin inhibitors, while maintaining adequate immunosuppression, thereby reducing the potential for adverse effects associated with these coadministered agents. Thus, basiliximab provides an effective, well tolerated option for the prophylaxis of acute renal transplant rejection.     

Severe graft rejection, increased immunosuppression, and active CMV infection in renal transplantation

Associations between active cytomegalovirus (CMV) infection, graft rejection, rejection therapy, and clinical signs and symptoms have been shown repeatedly. However, the causes and the sequence of events remain an area of debate. Two hundred twenty five patients with cadaveric renal transplant were included in the present study. Clinical signs and symptoms, and the development of active CMV infections were recorded during the first 3 months after renal transplantation. CMV monitoring by pp65-antigenemia was performed followed by preemptive antiviral therapy. Delayed graft function and severe graft rejection followed by anti T-cell antibody therapy was associated with the development of active CMV infection. In contrast, the induction therapy with anti-T-cell antibodies was not associated with more active CMV infections. Post-transplant morbidity determined by fever, pneumonia, and duration of hospital stay was increased significantly in patients with active CMV infection. However, in times of preemptive antiviral therapy an increased morbidity occurred in association with severe graft rejection and not with active CMV infection alone. In patients with renal transplantation and preemptive antiviral therapy, the morbidity was no more influenced by the CMV serostatus although the prevalence of active CMV infection was obviously different between CMV exposed (D+/R+,D+/R-, D-/R+) and unexposed (D-/R-) patients. Severe graft rejection and increased immunosuppression could stimulate cooperatively active CMV infections whereas immunosuppression alone may not be as effective. Prevention of severe graft rejection may be important to decrease early post-transplant morbidity and also the development of active CMV infections after renal transplantation.     

Usefulness of pp65 Antigenemia for the Early Diagnosis of Cytomegalovirus Disease in Patients with AIDS

 An observational cohort study was performed to assess the effectiveness of a cytomegalovirus antigenemia (CMV-Ag) assay designed to predict clinical CMV disease in patients with AIDS. Eighty-six HIV-infected patients with CD4+ cell counts of <100/mm³, positive CMV IgG, and no previous CMV disease were enrolled. Thirty-eight (44%) patients had at least one positive CMV antigenemia test, ten of whom eventually developed CMV focal disease. CMV disease was diagnosed in 13 (15%) patients. The CMV antigenemia assay was positive in ten of these 13 patients. Using a cut-off value of five positive cells in every 150 000 leukocytes sampled, the CMV antigenemia assay had a positive predictive value of 89% and a negative predictive value of 94%. The median time from the first positive CMV antigenemia test to the onset of CMV disease was 102 days. CMV disease probability at 6 months in patients with a CMV antigenemia value ≥5 was 77.8% versus 6% in patients with CMV antigenemia value <5 (log-rank test=48.345;P<0.001). Several independent factors were associated with the development of CMV disease: CMV antigenemia ≥5 cells (hazard ratio: 20.44), CD4+ count≤25/mm³ (HR: 3.12), and sexual transmission of HIV infection (hazard ratio, 3.15). CMV antigenemia seems to be a good predictor of CMV disease in patients with AIDS.     

Valacyclovir for the prevention of cytomegalovirus disease after renal transplantation. International Valacyclovir Cytomegalovirus Prophylaxis Transplantation Study Group.

BACKGROUND: Cytomegalovirus (CMV) disease is a major complication of organ transplantation. We hypothesized that prophylactic treatment with valacyclovir would reduce the risk of CMV disease. METHODS: A total of 208 CMV-negative recipients of a kidney from a seropositive donor and 408 CMV-positive recipients were randomly assigned to receive either 2 g of valacyclovir or placebo orally four times daily for 90 days after transplantation, with the dose adjusted according to renal function. The primary end point was laboratory-confirmed CMV disease in the first six months after transplantation. RESULTS: Treatment with valacyclovir reduced the incidence or delayed the onset of CMV disease in both the seronegative patients (P<0.001) and the seropositive patients (P=0.03). Among the seronegative patients, the incidence of CMV disease 90 days after transplantation was 45 percent among placebo recipients and 3 percent among valacyclovir recipients. Among the seropositive patients, the respective values were 6 percent and 0 percent. At six months, the incidence of CMV disease was 45 percent among seronegative recipients of placebo and 16 percent among seronegative recipients of valacyclovir; it was 6 percent among seropositive placebo recipients and 1 percent among seropositive valacyclovir recipients. At six months, the rate of biopsy-confirmed acute graft rejection in the seronegative group was 52 percent among placebo recipients and 26 percent among valacyclovir recipients (P=0.001). Treatment with valacyclovir also decreased the rates of CMV viremia and viruria, herpes simplex virus disease, and the use of inpatient medical resources. Hallucinations and confusion were more common with valacyclovir treatment, but these events were not severe or treatment-limiting. The rates of other adverse events were similar among the groups. CONCLUSIONS: Prophylactic treatment with valacyclovir is a safe and effective way to prevent CMV disease after renal transplantation.     

Single-center experience with tacrolimus-based immunosuppressive regimens in renal transplantation

The efficacy and safety of tacrolimus (FK506; Prograf) were determined in 28 adult kidney transplant patients (20 males and 8 females), aged 18-68 years (mean+/-S.D.: 46.9+/-4.03 years). Induction therapy was ATG-F (n=23), daclizumab (n=3), or none (n=2), and maintenance immunosuppression consisted of tacrolimus, combined with mycophenolate mofetil (MMF; n=26) or azathioprine (AZA; n=2) and prednisone (Pred). In seven patients, cyclosporine A microemulsion (Neoral) was replaced by tacrolimus for acute rejection (AR; three patients), slow graft function (SGF, two patients) and Neoral side effects (two patients). Acute rejection occurred in five patients (17.8%), three of whom were steroid-resistant treated with a second course of ATG-F. Infection occurred in 10 patients (35.7%) with a total of 15 infectious episodes, comprising bacterial (73%) and viral (27%) infections related to CMV. Other side effects related to tacrolimus were hypertension in four patients (14%) and post-transplantation hyperglycemia in nine patients (32%), three of whom required insulin therapy. In addition, hypercholesterolemia and hypertriglyceridemia occurred in six (21%) and eight patients (28.5%), respectively. The patient's hospital stay was 12.7+/-1.3 days (range: 8-24 days), and mean serum creatinine upon discharge, and at 1, 3 and 6 months following transplantation were: 2.1+/-0.5, 1.47+/-0.21, 1.41+/-0.53 and 1.23+/-0.11 mg/dl, respectively. The 6-month actuarial patient and graft survival rates were 100%. While tacrolimus is an effective calcineurin inhibitor for kidney transplantation (KT), severe acute rejection seen is related to highly sensitized patients, and the CMV infections noted were related to the presence of more CMV-negative recipients receiving kidneys from CMV-positive donors. Longer follow-up with a larger patient sample is needed to fully assess both the efficacy and safety of tacrolimus, including its metabolic effects.     

Meta-analysis of basiliximab for immunoprophylaxis in renal transplantation

Background

Basiliximab is a high-affinity chimeric monoclonal antibody directed against the α-chain of the interleukin (IL)-2 receptor. Individual studies have shown that it is highly effective in preventing acute rejection and causes no measurable incremental toxicity. However, incorporation of basiliximab immunoprophylaxis into routine practice depends upon the demonstration of benefit across treatment regimens and quantitation of the treatment effect.

Methods

This study employed a meta-analysis to examine the clinical benefit of basiliximab. Parameter estimates were derived from four randomised prospective double-blind studies conducted in 93 renal transplant centres in 18 countries. A total of 1185 adult primary allograft recipients were randomised within the centres to receive either basiliximab 20mg intravenously on days 0 and 4 or placebo, in addition to double or triple immunosuppression consisting of cyclosporin-microemulsion (Neoral®¹), corticosteroids, and azathioprine or mycophenolate mofetil. Key clinical events included patient and graft survival, graft rejection and complications. Analysis was performed using a variable model; odds ratios and the numbers needed to treat (NNT) to benefit or to harm one patient were calculated for each principal outcome at 6 or 12 months post-transplant.

Results

Basiliximab reduced the relative risk (RR) and absolute risk (AR) of clinical and biopsy-proven acute graft rejection across all treatment regimens. The overall RR of clinical acute graft rejection was decreased by 35% in patients receiving basiliximab. AR was reduced by 15.6% (pooled incidence: 28.8% vs 44.4%, p < 0.0001), and the NNT for efficacy was six. The reduction in RR of biopsy-proven rejection was similar (32%) with an absolute risk reduction (ARR) of 11.7% (pooled incidence: 25.1% vs 36.8%, p < 0.0001) and NNT of nine over 6 months. There was a concomitant reduction in the risk of graft loss which did not reach statistical significance (p = 0.14). The RR of graft loss was reduced by 26% with an AR reduction of 2.3% (pooled incidence: 6.4% vs 8.7%) and an NNT of 42 over 6 months. The risk of death was unchanged.

Conclusions

Immunoprophylaxis with basiliximab produces a significant reduction in the RR and AR of clinical and biopsy-proven acute graft rejection with a trend towards a concomitant reduction in the risk of graft loss. The magnitude of protection provided by basiliximab, the fact that it is observed across treatment regimens and the safety of this therapy are arguments for its routine use in renal transplantation.     

Potential of Daclizumab in Solid Organ Transplantation

The central role that the cytokine interleukin-2 (IL-2) and its receptor (IL-2R) play in the induction of the immune response has been recognised for some time. IL-2R consists of 3 chains (alpha, beta and gamma). The alpha-chain (T cell activation antigen or CD25) is expressed only after T-lymphocyte activation. Therefore a monoclonal antibody targeting the alpha-chain can result in selective immunosuppression. The first generation anti-IL-2Ralpha monoclonal antibodies consisted of mouse and rat antibodies that were promising but not totally effective in clinical studies. The immunogenicity, short half-life and inability to recruit host effector functions such as antibody-dependent cell-mediated cytotoxicity associated with the rodent monoclonal antibodies limit their clinical use. Chimerisation or humanisation of these monoclonal antibodies resulted in antibodies with a predominantly human framework that retained the antigen specificity of the original rodent monoclonal antibodies. A fully humanised anti-IL-2R monoclonal antibody, daclizumab, and a chimeric anti-IL-2R monoclonal antibody, basiliximab, have undergone successful phase III pivotal trials in which they were well tolerated and effective in the immunoprophylaxis of patients undergoing renal transplantation. Daclizumab 1 mg/kg every other week for a total of 5 doses in patients administered standard triple immunosuppression who had received grafts from cadaver or living related donors saturated the IL-2Ralpha on circulating lymphocytes for at least 3 months after transplantation. The efficacy and safety of intravenous daclizumab 1 mg/kg prior to transplantation and again at 2, 4, 6 and 8 weeks postoperatively, in conjunction with standard dual or triple immunosuppression, were further assessed in 2 phase III clinical trials. In both trials, biopsy-proven rejection was significantly reduced 6 months after the transplantation. The half-life of daclizumab was 20 days. The addition of daclizumab did not increase the incidence of adverse events, infectious complications or malignancies. Basiliximab 20mg was administered on the day of and on day 4 after transplantation, in conjunction with standard dual immunosuppression, in 2 phase III trials involving cadaver and/or living related transplants. The incidence of biopsy-proven acute rejection at 6 months was significantly reduced with basiliximab. The half-life of basiliximab was 7 days. The drug was not associated with increased risks of adverse events, infectious complications or malignancies. In an ongoing study, patients receiving a maintenance immunosuppression regimen of prednisone, cyclosporin and mycophenolate mofetil were administered daclizumab or placebo. Biopsy-proven rejection was lower in the group receiving daclizumab, and coadministration with mycophenolate mofetil was well tolerated with no pharmacokinetic interactions.     

Causality of parenchymal and vascular changes in rats with experimental thiamine deficiency encephalopathy

The causality of vascular and parenchymal damage to the central nervous system (CNS) was examined In rats with thiamine deficiency. Male Sprague Dawley rats were divided Into two groups; one was given a thiamlne-deficient diet ODD) and Injected Intraperitoneally with 10μg/100g bodyweight pyrithlamine (PT) In order to analyze morpho-metrically the topographical and sequential relationship between vascular and parenchymal changes and vase dilatation, and the other was given a TDD and 50 μg/100 g bodyweight PT in order to determine hemorrhagic sites using serial dons. Histological examination showed that sponglotic change occurred selectively in the Interior colllculus (100%) from day 19, and thereafter In the thalamus (95%), mammlllary body (50%) and nuclei olivaris and vestlbularls of the pons (25%), with or without hemorrhage. Simultaneously, glycogen accumulation was also observed In these regions at a frequency similar to that of hemorrhage. Ultrastructurally, however, hydroplc swelling of astrocytic and neuronal processes without glycogen accumulation was observed as early as day 9 In the inferior cofliculus, at which time an Increase of glial fibrillary acldic protein-positive processes was also recognized. The Superior colllculus was completely spared. From day 22 vasodilatation of the Inferior colliculus occurred, concomltantly with bodyweight loss and neurological symptoms. Twenty-two examined hemorrhages, which occurred in the thalamus and Inferior colliculus, were distributed along the arterioles or capillarles on the arterial side. In conclusion, the morphological CNS changes caused by thiamine deficiency with administration of low-dose PT in rats begin as hydropic swelling of neuronal and astrocytic processes, followed by hemorrhage and, thereafter, by vasodllatatlon. The predilectlon for hemorrhage on the arterial side without parenchymal changes suggests that petechial hemorrhage Is not simply secondary to parenchymal changes, but Is due to hemadynamlc change resulting from thlamfne deficiency-Induced vascular dysfunction.     

Repurposing Nilotinib for Cytomegalovirus Infection Prophylaxis after Allogeneic Hematopoietic Stem Cell Transplantation: A Single-Arm,Phase II Trial

Platelet-derived growth factor receptor-alpha (PDGFRa) is a critical receptor for cytomegalovirus (CMV) entry into cells, leading to subsequent infection. This trial tested whether PDGFRa inhibition by nilotinib could prevent CMV infection in patients after allogeneic stem cell transplantation (allo-HSCT). Nilotinib (200 mg/day) was given continuously after engraftment, and plasma CMV DNA levels were monitored weekly. The primary endpoint was successful prophylaxis of CMV infection, defined as plasma CMV DNA copies less than 10,000 copies/mL, no anti-CMV treatment initiated, and no clinical CMV disease by day 100. All 37 enrolled recipients and their donors were CMV seropositive. Thirty patients received matched sibling transplants, 15 received nonmyeloablative conditioning regimens, and 15 received antithymocyte globulin as a part of graft-versus-host disease prophylaxis. The median interval from transplantation to nilotinib treatment was 23 days, and the median duration of administration was 76 days. None of the 31 assessable patients had nilotinib-associated grade 3/4 adverse events or nilotinib discontinuation. Twenty-five of 31 assessable patients (80.6%) fulfilled the predefined criteria for successful CMV prophylaxis, and none of them had clinical CMV disease. Only 1 of 6 failed patients developed CMV colitis. Nilotinib is well tolerated in allo-HSCT recipients, and its preliminary efficacy results suggest that blocking CMV entry to prevent CMV infection may warrant further exploration. (ClinicalTrials.gov identifier: NCT01252017.)     

Mononuclear subsets during cytomegalovirus disease in renal transplant recipients treated with cyclosporine and rabbit antithymocyte globulin

The effect of cytomegalovirus (CMV) disease on mononuclear subpopulations of 49 renal transplant recipients treated with cyclosporine and prednisone are reported. Clinical overt CMV infection developed in 8/21 patients treated for rejection with rabbit antithymocyte globulin. They all showed true inversions of the T helper/T suppressor-cytotoxic (Th/Ts-c) ratio. A reduction of T helper cells and increase in T suppressor-cytotoxic cells preceded clinical symptoms of CMV disease by one week. None of the 26 patients without RATG anti-rejection treatment developed CMV disease and in only three of them an inversion of Th/Ts-c ratio was found.     

Rapid immunodiagnosis of active cytomegalovirus infection by monoclonal antibody staining of blood leucocytes

The appearance of cytomegalovirus (CMV) antigen positive blood leucocytes (CMV antigenaemia) was investigated in 52 renal transplant recipients during the first three months after transplantation. Using a mixture of three monoclonal antibodies, CMV (immediate early) antigens were detected in cytocentrifuged blood leucocytes within 3-5 h after sampling. The results were related to virus isolation from buffy coats (CMV viraemia), serology with a sensitive enzyme-linked immunosorbent assay (ELISA), and clinical symptoms of CMV disease. The antigen test was positive in all 14 patients with CMV viraemia, in 25 out of 27 of patients with serological evidence of primary or secondary CMV infection, and in 2 out of 25 patients without active infection. In patients with a clinical CMV syndrome the presence of CMV antigen (CMV-Ag) positive blood cells correspond with the period of signs and symptoms. CMV antigens were not detected in 23 out of 25 patients without active infection, nor in healthy controls and patients with other herpesvirus infections. CMV-Ag positive blood cells appeared, on average, nine days before serological signs of active infection. This method provides a rapid and sensitive approach to CMV detection, enabling early clinical diagnosis and subsequent tapering of immunosuppression or commencement of antiviral therapy.     

Clinical significance of CMV-specific T helper responses in lung transplant recipients

Background. Cytomegalovirus (CMV) disease continues to be a major problem for lung transplant patients who generate an inefficient immune response to control this viral infection. Both T helper and cytotoxic T cells are thought to play an important role in prevention and control of CMV disease. We investigated the clinical significance of CMV-specific memory responses in lung transplant recipients. Method. Peripheral blood samples (140) were collected from 99 lung transplant recipients. Patients were grouped according to their pre-transplant CMV serological status as recipient/donor (R−/D+, 25 patients), 28 R+/D+ patients, 35 R+/D− patients and 11 R−/D− patients. Memory responses to CMV whole antigen, 5 CMV proteins, and tetanus toxoid (TT) were measured in a 6-day proliferative assay. Results were expressed as the stimulation index (SI = experimental cpm/background cpm), and were considered positive if the SI was >3 and the cpm values were over 1,000. Results. The frequency of positive CMV memory responses was similar in three groups: 64% for R−/D+, 63% for R+/D+ and 56% for R+/D− except for R−/D− (21%). The memory response to TT was similar for all four groups (70% of samples were positive). The level of responsiveness to individual CMV proteins was much higher in R+/D+ group (65%) than the other two groups (35% for R+/D−, and 31% for R−/D+). We determined the temporal relationship between the presence of CMV-specific memory responses and the diagnosis of CMV disease. In the R−/D+ group, 16 of 17 patients who had CMV disease eventually developed CMV-specific memory. In those patients (n = 3) who failed to develop CMV-specific T helper response for a prolonged time, all had recurrent CMV disease. In the R+/D+ group, 4 of 8 patients with CMV disease exhibited CMV-specific memory responses. Three of 4 patients in whom we observed a persistent absence of CMV-specific memory had multiple episodes of CMV pneumonitis. In the R+/D− group, only one of 4 patients with CMV disease had suppressed CMV-specific memory response after first episode of CMV pneumonitis and had recurrent disease. Conclusion. In lung transplant recipients, the loss or persistent lack of CMV-specific memory following infection was associated with chronic CMV disease. These data suggest that monitoring T helper memory responses following primary CMV infection or after augmented immunosuppression for treatment of rejection may identify those patients at risk for morbidity associated with recurrent CMV disease.     

Prophylactic effects of interleukin-2 receptor antagonists against graft-versus-host disease following unrelated donor peripheral blood stem cell transplantation

Basiliximab and daclizumab, two interleukin-2 receptor antagonists (IL-2RAs), prevent graft failure in renal transplantation, which also effectively treat steroid-refractory graft-versus-host disease (GVHD). However, only a few studies report that IL-2RAs prevent GVHD. Here we first retrospectively explored the prophylactic effects of basiliximab or daclizumab against GVHD in 82 patients with hematologic malignancies following unrelated donor-peripheral blood stem cell transplantation (URD-PBSCT). All recipients achieved engraftment. The rates of grade II-IV and III-IV acute GVHD (aGVHD) were 35.4% and 15.9%, respectively. Chronic GVHD (cGVHD) developed in 38.7% of evaluable patients. The transplantation-related mortality was 13.4%, while relapse rate was 8.5%. The 2-year overall survival (OS) reached 77.1% and disease-free survival (DFS) accumulated to 72.2%. The side effects of basiliximab and daclizumab were moderate and tolerable. There were no significant differences in aGVHD onset and survival between the daclizumab and basiliximab groups. However, basiliximab presented superior prophylactic effects on cGVHD than daclizumab. In conclusion, basiliximab or daclizumab prevents GVHD efficiently and feasibly following URD-PBSCT, and contributes to favorable outcome. Basiliximab has a similar effect on aGVHD but superior activity against cGVHD. Further prospective and randomized control studies are needed.     

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

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

Characterization of cytomegalovirus isolates recovered during repeated infection in renal transplant recipients

The sources of cytomegalovirus (CMV) infection in seropositive renal transplant recipients include reactivation of latent endogenous virus in the recipient, reactivation of latent virus in donated kidney, or both. If infection occurs by either source, viruses isolated from the same recipient should be the same strain, whereas if it occurs by both sources, those from the same recipient should be different. In this study, we followed prospectively 25 seropositive recipients who predominantly received a kidney from a seropositive donor to determine whether CMV isolates recovered repeatedly from them are the same or different. During an average 10 month follow-up period, six (24%) patients had excreted the virus more than twice at any site and/or at different times. Restriction enzyme analysis of viral DNA prepared by the Hirt procedure revealed that three or four isolates obtained from each of five patients were same, whereas six isolates from one patient included three different strains. Five of six patients had clinical symptoms at the times when CMV was recovered. Three patients with acute rejection and one patient with hepatitis had been infected with one single strain, and all were successfully treated. One patient with fever and acute rejection had been infected with three different strains, and he failed to recover his renal function. These results suggest that most CMV infections in seropositive recipients may be caused by one single strain. However, multiple infections with different strains can also occur. Such infections are associated with more severe clinical disease.