Cytomegalovirus Seropositive Donors Research Articles

Dominance of virus-specific CD8 T cells in human primary cytomegalovirus infection.

Cellular immune responses are of high importance in initiating and maintaining immunity against virus infections. Whereas the cellular immune response during persistent cytomegalovirus (CMV) infection is well assessable, the individual contribution of CD4 and CD8 T cell responses during primary infection has not been described. A novel whole-blood assay, which relies on the flow-cytometric detection of antigen-induced cytokine expression, was used to characterize CMV-specific CD4 and CD8 T cell responses during primary infection of CMV seronegative recipients of a renal allograft from a CMV seropositive donor. These T cell responses were compared with long-term CMV-positive patients with known history of transplantation-related seroconversion. Results were further correlated to CMV load and serum IgG and IgM. The long-term seroconverted patients consistently showed a dominant CMV-specific CD4 T cell response (median frequencies: CD4, 1.12% [range, 0.35 to 8.10%] versus CD8 0.13% [range, <0.05 to 0.55%]). In contrast, during primary infection, the cellular immune response is strongly dominated by CMV-specific CD8 T cells (median peak frequencies: CD4, 1.24% [range, 0.21 to 1.60%] versus CD8, 2.47% [range, 1.34 to 6.67%]). Upon receipt of ganciclovir, viral load as well as CMV-specific CD8 responses decreased. The frequency of the respective CD4 T cells fluctuated during decrease of CMV load and became dominant over CMV-specific CD8 T cell responses. These results are consistent with the view of an effective direct antiviral activity of CD8 T cells, which is most critical during periods of high viremia. Later on during persistent infection, CD4 T cells dominate the immune response to support the state of antiviral immunity.

Survival after bone marrow transplantation from cytomegalovirus seropositive sibling donors

HLA-A2-restricted T cells show peptide-specific activity against cytomegalovirus and leukaemia cells. We retrospectively analysed the influence of donor cytomegalovirus serostatus on the outcome of 103 consecutive patients who had leukaemia and who received bone-marrow transplants from HLA-identical sibling donors. We found that donor cytomegalovirus seropositivity significantly improved overall survival (p=0.02) as a result of lower relapse incidence (p=0.035) in HLA-A2-positive but not HLA-A2-negative recipients. In HLA-A2-positive recipients donor cytomegalovirus seropositivity was associated with chronic graft-versus-host disease (GVHD), but even in patients without chronic GVHD donor cytomegalovirus seropositivity significantly improved survival (p=0.0483). These preliminary data provide evidence that at least in HLA-A2-positive recipients, transplantation of bone marrow from cytomegalovirus positive, HLA-identical sibling donors seems to be associated with substantial graft-versus-leukaemia activity, and suggests a cross-reactivity of cytomegalovirus-specific donor-derived cytotoxic T cells with HLA-A2-restricted recipient minor histocompatibility antigens.

The influence of mycophenolate mofetil on the incidence and severity of primary cytomegalovirus infections and disease after renal transplantation.

Mycophenolate mofetil (MMF) is increasingly used for immunosuppression after renal transplantation (RTx). The aim of our study was to investigate if the use of MMF has resulted in an increase in the frequency and severity of primary cytomegalovirus (CMV) infections. Retrospective study of adult RTx patients who were CMV seronegative and who received a kidney of a CMV seropositive donor in the period 1992-1997 (n=84). Twenty-four of these patients were treated with MMF (in combination with cyclosporin and prednisone; MMF+) and the other 60 were the control group (cyclosporin and prednisone; MMF-). No CMV prophylaxis was given. CMV infection was defined as CMV seroconversion of IgG antibodies. CMV disease was defined as CMV infection and fever in combination with one or more of the following: leukocytopenia, thrombocytopenia, elevated alanine aminotransferase, or histological evidence of tissue invasive disease. The incidence of primary CMV infections was similar in both groups (MMF+, 75%; MMF-, 63%). CMV disease was more frequent in the MMF+ group than in the MMF- group (67 vs 30%, P<0.05). In the patients with CMV disease, the use of MMF did not affect severity of symptoms, frequency of tissue invasive disease, or frequency or duration of treatment with ganciclovir. Addition of MMF to the immunosuppressive therapy after RTx did not result in an increase of primary CMV infections.However, these CMV infections led more often to CMV disease in patients treated with MMF than in those without MMF.

Detection of cytomegalovirus (CMV) antigens in kidney biopsies and transplant nephrectomies as a marker for renal graft dysfunction.

Chronic rejection accounts for the greatest loss of renal allografts. HLA mismatching has been minimised by organ allocation and new immunosuppressive drugs have been employed, but the average cadaveric graft survival still does not exceed 12 years. Though the aetiology is multifactorial, one contributory factor for this condition is cytomegalovirus (CMV). Detection of CMV in kidney biopsies and sera can diagnose and monitor this inflammatory event and define its role in chronic nephropathy. Twenty five biopsies taken at the time of transplantation, 10 biopsies for graft dysfunction and tissue blocks from 20 explanted kidney grafts were collected and investigated for CMV antigens by immunohistochemistry. Tissue samples were snap frozen and cryostat sections were incubated with monoclonal antibodies for CMV antigens followed by immunoperoxidase staining. In 12 out of 20 transplant nephrectomies CMV antigens were found. Only two of these patients had clinical CMV disease. Time 0 biopsies from CMV seronegative donors (n = 11) and CMV seropositive donors (n = 14) were negative for CMV antigens. The prevalence of CMV antigens in grafts lost due to chronic rejection was 60%. These antigens were not found within the time 0 biopsies, but were detected in 30% of biopsies taken at the time of clinical graft dysfunction. CMV appears to contribute to chronic rejection even without clinical disease.

Simultaneous Ex Vivo Expansion of Cytomegalovirus and Epstein-Barr Virus–Specific Cytotoxic T Lymphocytes Using B-Lymphoblastoid Cell Lines Expressing Cytomegalovirus pp65

Cytomegalovirus (CMV) infection and Epstein-Barr virus (EBV)-induced lymphoproliferative disease are serious complications associated with allogeneic stem cell transplantation. Immunotherapy using ex vivo expanded, virus-specific cytotoxic T lymphocytes (CTL) has been explored and proven to be effective in therapeutic or prophylactic regimens for CMV and EBV infections. To generate CTL specific for both CMV and EBV, we engineered EBV-transformed B-lymphoblastoid cell lines (BLCL) to express CMV pp65 for use as antigen-presenting cells (APC). BLCL were transduced with a recombinant retrovirus encoding pp65, the immunodominant CMV polypeptide. Western blot analysis and immunocytochemistry confirmed the expression of pp65 in the transduced cells. Peripheral blood mononuclear cells (PBMC) from healthy CMV seropositive donors were stimulated with autologous pp65-expressing BLCL weekly for 3 weeks. Chromium release assays showed that the resulting CTL cultures possessed specific cytotoxicity against EBV and CMV. Recombinant vaccinia viruses encoding individual CMV peptides were used to demonstrate that this CMV-specific cytotoxicity was specific for pp65. Assays on CD4- and CD8-depleted CTL fractions indicated that CD8+ CTL mediated the pp65-specific cytotoxicity. These CMV/EBV-specific CTL recognized CMV- and EBV-infected targets sharing HLA class I antigens, but not HLA mismatched targets. Our results demonstrate that BLCL can be used as APC to stimulate expansion of EBV- and CMV-specific CTL simultaneously. These findings have potential implications for posttransplant CMV and EBV immunotherapy in recipients of allogeneic stem cell transplants.

EFFECTS OF PREEMPTIVE THERAPY IN HEART TRANSPLANT PATIENTS WITH CYTOMEGALOVIRUS - ANTIGENEMIA

392 Preemptive antiviral therapy in patients with cytomegalovirus (CMV) -antigenemia offers a new alternative in prevention of CMV disease, one of the major complications after heart transplant. We reviewed a study group of 22 heart transplant patients who received preemptive therapy for positive CMV antigenemia in comparison to a historical control group of 20 heart transplant patients followed prior to the availability of CMV antigenemia assay. Study group patients received ganciclovir, 5 mg/kg/day bid IV for 7 days or Cytogam 200 mg/kg as a single dose, upon detection of one or more antigen-positive cells per 5 × 104 peripheral blood leukocytes examined. Patients were monitored weekly after heart transplant. Among control group patients, only CMV seronegative recipient of heart from CMV seropositive donor (R−D+) received prophylactic therapy. All patients received ganciclovir for CMV disease diagnosed by biopsy or clinical presentation. The groups were comparable with respect to donor CMV serostatus, age, sex, induction therapy, immunosuppression regimen and incidence of rejection. There were seven R−D+ patients in the study group vs. two R−D+ patients in control group. Only one patient of the seven R−D+ in study group developed CMV disease. CMV antigenemia was detected in 21 of 22 study group patients. Two study group patients were hospitalized for CMV disease (total 30 days), compared to seven control group patients (total 97 days), p=0.04. Patient charges (antigen test + therapy + room charge) in study group were 43% less than in control group. This preliminary data suggests that the use of preemptive antiviral therapy in heart transplant patients may decrease the incidence of CMV disease and result in reduced costs. A further analysis of a larger patient population is warranted.

THE INFLUENCE OF MYCOPHENOLATE MOFETIL ON THE INCIDENCE AND SEVERITY OF CYTOMEGALOVIRUS PRIMO INFECTIONS AFTER RENAL TRANSPLANTATION.

485 Background: Mycophenolate mofetil (MMF) is increasingly used for immunosuppression after renal transplantation (RTx). It was our impression that concurrently with the introduction of MMF, we encountered more cytomegalovirus (CMV) related problems in our renal transplant population. The aim of our study was to investigate if the use of MMF has resulted in an increase in the frequency and severity of CMV primo-infections. Methods: Retrospective study of adult RTx patients who were CMV seronegative and who received a kidney of a CMV seropositive donor in the period of 1992-1997 (n=96). 24 of these patients were treated with MMF (in combination with cyclosporine and prednisone; MMF+) and the other 72 were the control group (MMF−). No CMV prophylaxis was given. CMV infection was defined as CMV seroconversion. CMV disease was defined as CMV infection and fever in combination with one or more of the following: leucocytopenia, thrombocytopenia, elevated alanine aminotransferase, or histologic evidence of tissue invasive disease. Results: The incidence of CMV primo-infections was similar in both groups. (MMF+: 67%, MMF−: 65%). CMV disease was more frequent in the MMF+ group than in the MMF− group (58% versus 31%, p<0.05). In the patients with CMV disease, the use of MMF did not affect severity of symptoms, frequency of tissue invasive disease and frequency or duration of treatment with ganciclovir. Conclusions: Addition of MMF to the immunosuppressive therapy after RTx did not result in an increase of CMV primo-infections. However, these CMV infections led more often to CMV disease in patients treated with MMF than in those without MMF.

Acyclovir plus CMV immunoglobulin prophylaxis and early therapy with ganciclovir are effective and safe in CMV high-risk renal transplant pediatric recipients

Abstract Cytomegalovirus (CMV) infection is still a major cause of morbidity in high-risk renal transplant recipients. In the present report, we have reviewed our records of renal transplant pediatric recipients (RTPR; mean age 14.1 ± 4.9 years) since 1991, when we started a policy of CMV prophylaxis constituting high-dose oral acyclovir plus CMV hyperimmune immunoglobulins (Hlg) followed by early i.v. ganciclovir therapy in high-risk patients (i.e., CMV donor +/ recipient -). Four patients received a kidney from a living relative (LR), 2 patients had one previous transplant, and 1 had a combined liver -kidney transplant. Thirty-three patients who were negative for CMV antibodies (ab) before transplantation received a kidney from CMV ab positive donors. The immunosuppressive regimen included cyclosporin A and steroids, with the addition of azathioprine in the 4 patients who received an LR kidney. Serial assessments for CMV antigenemia (pp 65) were routinely performed for 6 months after transplantation to define CMV infection. Among the 33 CMV seronegative recipients (R -) who received the graft from a CMV seropositive donor (D +), 18 (54.5 %) experienced CMV infection, whereas among the 28 CMV R +, who received a graft from a CMV D +, 11 (39.3 %) experienced CMV infection. With regard to CMV - related symptoms, only 2 patients suffered from a CMV syndrome (fever and leukopenia in 1 patient, fever and arthralgia in the other). In no case did the spectrum of CMV disease occur; only minor symptoms were present in 7 of the remaining CMV-infected patients (fever in 6 and leukopenia in 1). Rejection episodes and renal function did not differ between CMV-infected and non-CMV-infected patients. Our experiences support the use of prophylactic acyclovir plus CMV HIg followed by early therapy with i.v. ganciclovir to combat the risk of increased morbidity in high risk RTPR.

Risk Factors for Death After Heart Transplantation: Does a Single-Center Experience Correlate With Multicenter Registries?

Background. Risk factors for death after heart transplantation (Tx) are frequently documented from multicenter registries. Although this information is helpful, it reflects a whole range of experiences and results, and may not translate to a particular center. This study was performed to (1) evaluate pre-Tx factors affecting mortality in a single-center experience, and (2) compare these factors with risk factors obtained from multicenter registry reports. Methods. Review of our transplant database between January 1984 and December 1995 identified 405 adults who received a primary heart Tx. Multiple factors were analyzed, including demographics, Tx era, cytomegalovirus status, United Network for Organ Sharing status of recipient, presence of pulmonary hypertension, previous cardiac operations, mechanical ventilation or circulatory support, ischemia time, number of rejection episodes, and preoperative flow cytometry crossmatching. Results. One- and 5-year survival rates were 87.8% and 73.4%, respectively (Kaplan-Meier). Contrary to multicenter registry reports, our data indicate that reoperative procedures, left ventricular assist device support, increasing donor and recipient age, and ischemia time up to 4.2 hours are not risk factors for death after Tx. Likewise, mode of donor death is not a risk factor affecting outcome. Significant risk factors for mortality identified by multivariate analysis included early transplant era (1984 to 1989; p = 0.002), female donor ( p = 0.042), cytomegalovirus-seropositive donor ( p = 0.048), high pulmonary vascular resistance ( p = 0.018), and intraaortic balloon pump support ( p = 0.03). It also identified a positive B-cell flow cytometry crossmatch ( p = 0.015) to be a risk factor with univariate analysis. Conclusions. Our data identify a group of recipients, reportedly at high risk in multicenter registries, who are not at increased risk of death after Tx. This information supports the growing experience with older donors and recipients and with bridged transplants, and has allowed us to expand our donor pool. These prognostic factors at evaluation allow more liberal selection of patients and donors for transplantation.

Screening of semen donors for infectious diseases.

The aim of this work was to prepare European guidelines concerning the screening for infectious diseases in the setting of gamete donation. Existing guidelines have been reviewed and commented. In particular, the problem of cytomegalovirus (CMV) was a matter of debate following the decision by the French Government to reject CMV seropositive donors. Other remarks and suggestions concerning various pathogens and perspectives of new molecular techniques for the detection of pathogens are also included.

The effects of cytomegalovirus serology on graft and recipient survival in cadaveric renal transplantation: Implications for organ allocation

The potential benefits from allocating donated cadaveric kidneys based on donor and recipient cytomegalovirus (CMV) serology remain controversial. We estimated graft survival and recipient survival using bivariate KaplanMeier models and multivariate Cox proportional hazards models for 24,543 first cadaveric renal transplantations performed in the United States between 1989, coinciding with the introduction of ganciclovir, and 1994. The effects of donor and recipient CMV serology were estimated, and the implications of these estimates for CMV-based allocation of cadaveric kidneys were considered. From Kaplan-Meier estimates, the 3-year impact of CMV-seropositive donor kidneys was a 3.6% reduction in graft survival and a 2.4% reduction in recipient survival for CMVseronegative recipients, and a 3.9% reduction in graft survival and a 3.0% reduction in recipient survival for CMVseropositive recipients. Multivariate Cox analysis demonstrated an adverse impact of donor CMV seropositivity regardless of recipient CMV status. D-/R- CMV serologic pairs had the best 3-year outcomes, with 73.4% graft survival and 87.7% recipient survival. D+/R+ CMV serologic pairs were found to have the worst 3-year outcomes, with 68.4% graft survival and 83.1% recipient survival, and were significantly worse than D+/R− pairs in terms of recipient survival. The maximum estimated impact of a program allocating donor kidneys to maximize the number of D-/R-CMV serologic pairs, assuming no impact on HLA mismatches, was a 0.1% reduction in aggregate 3-year graft survival and a 0.2% reduction in aggregate recipient survival. An alternative program allocating donor kidneys to minimize the number of D+/R+ pairs had no estimated effect on either graft or recipient survival. We conclude that during the ganciclovir era, CMV continues to have an important impact on first cadaveric renal transplantation. However, even under ideal conditions, CMV-based kidney allocation to either maximize the number of D−/R− pairs or minimize the number of D+/R+ pairs is likely to provide little benefit to the population of cadaveric renal transplant recipients.

Exposure to cytomegalovirus from the donated organ is a risk factor for bacteremia in orthotopic liver transplant recipients. Boston Center for Liver Transplantation CMVIG Study Group.

To define predictors of bacteremia and to assess the potential role of exposure to cytomegalovirus (CMV) as a risk factor for bacteremia in liver transplant recipients, an intention-to-treat analysis of data for 146 orthotopic liver transplant recipients who participated in a multicenter, randomized, intervention trial was undertaken. Fifty-eight episodes of bacteremia occurred in 40 (27.4%) of 146 patients within 1 year after transplantation. Bacteremia was diagnosed a median of 39.5 days (range, 1-325 days) after transplantation. One-year mortality rates were higher among patients with bacteremia than among those without bacteremia (47.5% [19 of 40] vs. 18% [19 of 106], respectively; P = .001). A time-dependent multivariate analysis of variables that were significantly (P < or = .05) associated with bacteremia in the univariate analysis showed that donor CMV seropositivity (relative risk [RR], 3.4; 95% confidence interval [CI], 1.6-6.6; P = .0005), age of younger than 16 years (RR, 2.6; 95% CI, 1.3-5.2; P < .0059), and a major abdominal operation after transplantation excluding retransplantation (RR, 3.8; 95% CI, 1.8-8.0; P = .0004) were independently associated with bacteremia. These epidemiologic data suggest that exposure to CMV from the donated organ is an independent risk factor for bacteremia in orthotopic liver transplant recipients.

Relevance and risk factors of enterococcal bacteremia following liver transplantation.

To analyze the clinical characteristics of and identify specific risk factors for enterococcal bacteremia following liver transplantation, we performed a study in 405 consecutive liver transplantation recipients prophylaxed with a selective bowel decontamination regimen. Seventy enterococcal bacteremias in 52 patients were identified. Enterococcus faecalis (50) outnumbered Enterococcus faecium isolates (18), and 49% of enterococcal bacteremias were polymicrobial. Biliary tree complications were present in 34% of enterococcal bacteremias. Of the 15 deaths (29%) among the patients with enterococcal bacteremia, 4 were directly associated with enterococcal bacteremia. In a multivariate analysis, Roux-en-Y choledochojejunostomy (P=0.005), a cytomegalovirus-seropositive donor (P=0.013), prolonged transplantation time (P=0.02), and biliary stricturing (P=0.016) were identified as significant risk factors. Other risk factors identified in a univariate analysis included primary sclerosing cholangitis (P=0.009) and symptomatic cytomegalovirus infection (P=0.008). Enterococcal bacteremia is a frequent infectious complication in liver transplantation recipients receiving selective bowel decontamination. Its association with cytomegalovirus and biliary tree abnormalities suggest specific areas for prophylactic intervention.

Relationship between CMV and graft rejection after heart transplantation.

This study, which included 153 heart transplant patients, was designed to determine whether the cytomegalovirus (CMV) status of both donor and recipient may influence graft rejection. The follow-up was 1 year and they all received the same triple-drug immunosuppressive regimen with induction (antilymphocyte serum). There was no difference in the total rejection rate, but an increase in repeated rejection rate was shown in transplant recipients with hearts from CMV seropositive donors (P < 0.05). These data strongly suggest the impact of CMV in enhancement but not in induction of rejection. To prevent iterative rejection in the CMV seropositive donor group, antiviral therapy could be proposed during enhancement of antirejection therapy.

Fas antigen and bcl-2 expression on lymphocytes cultured with cytomegalovirus and varicella—zoster virus antigen

Fas antigen and bcl-2 expression on peripheral blood mononuclear cells (PBMC) cultured with cytomegalovirus (CMV) and varicella—zoster virus (VZV) antigen was analyzed by three-color flow cytometry. Expression of Fas antigen increased significantly in CD45RO + populations of both CD4 + and CD8 + cells obtained from CMV and VZV seropositive donors after culture with CMV and VZV antigen for 6 days. Fas antigen expression did not increase in PBMC cultured with control antigen. In contrast, bcl-2 expression decreased both in CD4 +CD45RO + and CD8 +CD45RO + cells from the same donors. Fas antigen and bcl-2 expression in CD45RA + populations did not change. Cell viability of cultured cells with CMV and VZV antigen decreased after treatment with anti-Fas antibody and DNA fragments indicating apoptosis were detected in the cell lysate of these cultured cells after treatment with anti-Fas antibody. These data suggest that Fas antigen and bcl-2 protein may interact in regulating the cell death process of activated memory lymphocytes and eliminating lymphocytes activated by viral infection.

Recovery of HLA-restricted cytomegalovirus (CMV)-specific T-cell responses after allogeneic bone marrow transplant: correlation with CMV disease and effect of ganciclovir prophylaxis

Protection from cytomegalovirus (CMV) disease in immunocompromised hosts has been shown to correlate with recovery of the host virus- specific CD8+ T-cell response. The administration of ganciclovir to immunosuppressed transplant recipients as antiviral prophylaxis has reduced the early risk of CMV disease, but late disease is observed with increased frequency, suggesting that recovery of the CMV-specific T-cell responses necessary for protective immunity may be delayed in these patients. Therefore, we evaluated reconstitution of CMV-specific T-cell responses in 47 bone marrow transplant (BMT) recipients entered on a randomized placebo-controlled study of ganciclovir. The study drug was initiated at a mean of 24 days after BMT. At day 30 to 40, a minority of patients had recovery of T-cell immunity to CMV and the frequency of reconstitution was equivalent in patients randomized to ganciclovir or placebo. The failure of ganciclovir to effect early reconstitution may reflect the short duration of treatment. Early recovery was associated with the infusion of BM from a CMV seropositive donor (P = .07 for CD8+ cytotoxic T cell (CTL), P = .04 for CD4+ Th). Between day 40 and day 90, recovery of deficient CD8+ and CD4+ CMV- specific T-cell responses occurred in the majority of individuals that received placebo, but in a minority of ganciclovir recipients. Two cases of late-onset CMV disease occurred in ganciclovir recipients. In all patients, the presence of a CTL response to CMV conferred protection from subsequent CMV disease (P = .005), and these protective CTL responses are shown to be specific for structural virion proteins similar to the responses in immunocompetent CMV seropositive individuals. These data confirm the importance of CMV-specific T-cell responses and suggest that a delay in recovery of these responses as a result of ganciclovir prophylaxis may contribute to the occurrence of late CMV disease.

Recovery of HLA-Restricted Cytomegalovirus (CMV)-Specific T-Cell Responses After Allogeneic Bone Marrow Transplant: Correlation With CMV Disease and Effect of Ganciclovir Prophylaxis

AbstractProtection from cytomegalovirus (CMV) disease in immunocompromised hosts has been shown to correlate with recovery of the host virus-specific CD8+ T-cell response. The administration of ganciclovir to immunosuppressed transplant recipients as antiviral prophylaxis has reduced the early risk of CMV disease, but late disease is observed with increased frequency, suggesting that recovery of the CMV-spec’rfic T-cell responses necessary for protective immunity may be delayed in these patients. Therefore, we evaluated reconsti-tution of CMV-specific T-cell responses in 47 bone marrow transplant (BMT) recipients entered on a randomized placebo-controlled study of ganciclovir. The study drug was initiated at a mean of 24 days after BMT. At day 30 to 40, a minority of patients had recovery of T-cell immunity to CMV and the frequency of reconstitution was equivalent in patients randomized to ganciclovir or placebo. The failure of ganciclovir to effect early reconstitution may reflect the short duration of treatment. Early recovery was associated with the infusion of BM from a CMV seropositive donor (P = .07 for CD8+ cytotoxic T cell (CTL), P = .04 for CD4+ Th). Between day 40 and day 90, recovery of deficient CD8+ and CD4+ CMV-specific T-cell responses occurred in the majority of individuals that received placebo, but in a minority of ganciclovir recipients. Two cases of late-onset CMV disease occurred in ganciclovir recipients. In all patients, the presence of a CTL response to CMV conferred protection from subsequent CMV disease (P = .005), and these protective CTL responses are shown to be specific for structural virion proteins similar to the responses in immunocompetent CMV seropositive individuals. These data confirm the importance of CMV-specific T-cell responses and suggest that a delay in recovery of these responses as a result of ganciclovir prophylaxis may contribute to the occurrence of late CMV disease.

T and B cell responses to cytomegalovirus antigens in healthy blood donors and bone marrow transplant recipients

We measured the production of interferon-gamma (IFN-gamma) from single T cells and the T cell proliferative response to different cytomegalovirus (CMV) antigens in healthy blood donors and bone marrow transplant recipients. The antigens consisted of a CMV nuclear antigen (CMV na) containing the pp65-kDa matrix protein and the immediate early antigens but lacking CMV glycoproteins, and an antigen comprising native CMV glycoproteins (CMV gp). We also measured the IgG antibodies to CMV na and CMV gp. The T cells reacted to CMV na in CMV seropositive blood donors both with the production of IFN-gamma and with proliferation, while bone marrow transplant recipients had a deficient T cell response. After stimulation with CMV gp, no T cell response could be observed in CMV seropositive subjects. IgG antibodies to CMV na coexisted in plasma with similar levels of antibodies to CMV gp.

T and B cell responses to cytomegalovirus antigens in healthy blood donors and bone marrow transplant recipients

We measured the production of interferon-gamma (IFN-γ) from single T cells and the T cell proliferative response to different cytomegalovirus (CMV) antigens in healthy blood donors and bone marrow transplant recipients. The antigens consisted of a CMV nuclear antigen (CMV na) containing the pp65-kDa matrix protein and the immediate early antigens but lacking CMV glycoproteins, and an antigen comprising native CMV glycoproteins (CMV gp). We also measured the IgG antibodies to CMV na and CMV gp. The T cells reacted to CMV na in CMV seropositive blood donors both with the production of IFN-γ and with proliferation, while bone marrow transplant recipients had a deficient T cell response. After stimulation with CMV gp, no T cell response could be observed in CMV seropositive subjects. IgG antibodies to CMV na coexisted in plasma with similar levels of antibodies to CMV gp.

Prospective cytomegalovirus surveillance in paediatric renal transplant patients

Fifty-eight consecutive paediatric recipients of 65 renal transplants were prospectively studied for up to 72 months for evidence of cytomegalovirus (CMV) infection. Blood, urine and saliva were screened for CMV pre transplant and then weekly for the first 6 weeks, and monthly thereafter, by conventional cell culture and by detection of early antigen fluorescent foci. Donor CMV serostatus was available in 51 cases. All patients received triple therapy as immunosuppression and none had CMV prophylaxis. Twenty-six episodes of CMV infection (40% of transplants) and 10 of CMV disease (15%) were identified. Donor CMV seropositivity, regardless of recipient CMV serostatus, was significantly associated with CMV infection (P = 0.04). First CMV excretion was significantly earlier in patients who subsequently became symptomatic than in those who did not (P = 0.04), and a positive blood culture was significantly associated with CMV disease (P = 0.04). We found no association between extra anti-rejection treatment or recipient's age and CMV infection or disease. CMV disease had no influence on renal function as assessed by glomerular filtration rate at 6, 12 and 24 months post transplant, nor on graft loss. CMV disease was fatal in 1 patient. We conclude that trials of CMV prophylactic agents are indicated, particularly in recipients of CMV seropositive grafts. A positive blood culture should lead to consideration of anti-CMV therapy.