Cytomegalovirus: Clinical virological correlations in renal transplant recipients

Enhancement of Cytomegalovirus-Specific Cytokine Production after Modulation of the Costimulation in Kidney Transplant Patients

Kidney transplantation is the therapy of choice for patients with end stage renal disease. Due to immunosuppressive treatment, patients are at risk for opportunistic infections. Cytomegalovirus (CMV) reactivation is highly relevant in kidney transplant recipients because it occurs—depending on the serological constellation of the donor and recipient—in more than half of the patients and influences patient outcome. Patients with CMV reactivation show decreased allograft and overall survival. Previous studies could demonstrate that transplant patients often show weak CMV-specific immunity. Besides immunosuppressive treatment, additional mechanisms may reduce CMV-specific immunocompetence such as enhanced negative costimulation. Hence, the aim of this study was to investigate if the function of CMV-specific cells of kidney transplant recipients could be restored by a modulation of costimulatory molecules. To address this question, lymphocytes of kidney transplant patients were stimulated with CMV-specific antigens and incubated with programmed death-ligand 1 (PD-L1), programmed cell death protein 1 (PD-1), or B- and T-lymphocyte attenuator (BTLA) antibodies. Afterwards, the IFN-γ, IL-21, and IL-17A production was measured by the ELISpot assay. It could be shown that a blockade of the ligand PD-L1 resulted in an increased CMV-specific IFN-γ, IL-21, and IL-17A secretion. The blockade of the receptor PD-1 distinctly enhanced the production of IL-21. BTLA antibodies, however, led only to a marginal increase of CMV-specific IFN-γ and of IL-21 production. Experiments in healthy controls could confirm the results of the kidney transplant recipients. Furthermore, they could demonstrate that treatment with the immunosuppressive drug tacrolimus resulted in decreased CMV-specific IFN-γ and of IL-21 production. Thus, our study could show for the first time that the blockade of the PD-L1/PD-1 pathway also modulates CMV-specific Th21 and Th17 cell function in kidney transplant recipients. Further studies are mandatory to clarify the role of Th21 and Th17 cells in CMV control of these patients.

Modification of the HCMV-specific IFN-γ release test (QuantiFERON-CMV) and a novel proposal for its application

Human cytomegalovirus (HCMV) is universally distributed among humans without any adverse effects; however, it induces severe diseases in immunocompromised patients such as organ transplant recipients and AIDS patients. To manage these immunocompromised patients, an easy clinical examination for the monitoring of disease risk is required. In this study, we modified the interferon-γ (IFN-γ) release test (QuantiFERON^®-CMV) using HCMV immediate early-1 (IE-1) or pp65 whole proteins, or UV-inactivated HCMV particles as an antigen. The response of heparinized peripheral blood from healthy volunteers to the pp65 protein showed an obvious dose-dependent sigmoid curve, although no correlation was observed between results of this assay and an ELISPOT assay. The addition of pp65 to the blood samples at a final concentration of 1×10³ to 1×10⁵ pg/ml was found to be optimum. Using this assay, we observed a significant enhancement in cellular immunity in volunteers after the daily ingestion of yogurt for 8 weeks, which suggested a novel application of the assay in addition to monitoring HCMV infection risk. IFN-γ secretion from peripheral blood cells on HCMV-antigen stimulation differed significantly between individuals; therefore, the assay could not be normalized. Nevertheless, it was found to be particularly useful for observing fluctuations in cellular immune activity on an individual level.

Mucormycosis of the transplanted kidney with renal papillary necrosis

The occurrence of renal allograft mucormycosis is uncommon, but its association with renal papillary necrosis has not been reported. We describe such an association in a patient who survived on peritoneal dialysis after nephrectomy and antifungal therapy.

Evolution of immunosuppression at the University of Minnesota

Immunosuppressive protocols at the University of Minnesota have evolved from identical immunosuppression for all recipients (prednisone, azathioprine, and antilymphocyte globulin) to differing protocols for living (triple therapy) and cadaver (sequential therapy) donor recipients, and then to our current protocol in which all recipients receive induction therapy with rapid discontinuation of prednisone. At the same time, progress has been made in the prevention and treatment of cytomegalovirus infection along with numerous parallel improvements in patient care, including in anesthesia, dialysis, and intensive care unit care. The net result has been an incremental improvement in recipient and graft survival.

Viral abrogation of stem cell transplantation tolerance causes graft rejection and host death by different mechanisms

Tolerance-based stem cell transplantation using sublethal conditioning is being considered for the treatment of human disease, but safety and efficacy remain to be established. We have shown that mouse bone marrow recipients treated with sublethal irradiation plus transient blockade of the CD40-CD154 costimulatory pathway develop permanent hematopoietic chimerism across allogeneic barriers. We now report that infection with lymphocytic choriomeningitis virus at the time of transplantation prevented engraftment of allogeneic, but not syngeneic, bone marrow in similarly treated mice. Infected allograft recipients also failed to clear the virus and died. Postmortem study revealed hypoplastic bone marrow and spleens. The cause of death was virus-induced IFN-alphabeta. The rejection of allogeneic bone marrow was mediated by a radioresistant CD8(+)TCR-alphabeta(+)NK1.1(-) T cell population. We conclude that a noncytopathic viral infection at the time of transplantation can prevent engraftment of allogeneic bone marrow and result in the death of sublethally irradiated mice treated with costimulation blockade. Clinical application of stem cell transplantation protocols based on costimulation blockade and tolerance induction may require patient isolation to facilitate the procedure and to protect recipients.

Virus-induced abrogation of transplantation tolerance induced by donor-specific transfusion and anti-CD154 antibody

Treatment with a 2-week course of anti-CD154 antibody and a single transfusion of donor leukocytes (a donor-specific transfusion or DST) permits skin allografts to survive for >100 days in thymectomized mice. As clinical trials of this methodology in humans are contemplated, concern has been expressed that viral infection of graft recipients may disrupt tolerance to the allograft. We report that acute infection with lymphocytic choriomeningitis virus (LCMV) induced allograft rejection in mice treated with DST and anti-CD154 antibody if inoculated shortly after transplantation. Isografts resisted LCMV-induced rejection, and the interferon-inducing agent polyinosinic:polycytidylic acid did not induce allograft rejection, suggesting that the effect of LCMV is not simply a consequence of nonspecific inflammation. Administration of anti-CD8 antibody to engrafted mice delayed LCMV-induced allograft rejection. Pichinde virus also induced acute allograft rejection, but murine cytomegalovirus and vaccinia virus (VV) did not. Injection of LCMV approximately 50 days after tolerance induction and transplantation had minimal effect on subsequent allograft survival. Treatment with DST and anti-CD154 antibody did not interfere with clearance of LCMV, but a normally nonlethal high dose of VV during tolerance induction and transplantation killed graft recipients. We conclude that DST and anti-CD154 antibody induce a tolerant state that can be broken shortly after transplantation by certain viral infections. Clinical application of transplantation tolerance protocols may require patient isolation to facilitate the procedure and to protect recipients.

Detection of cytomegalovirus infections by PCR in renal transplant patients

Cytomegalovirus (CMV) is the single most important infectious agent affecting recipients of organ transplants. To evaluate the incidence and the clinical importance of CMV infection in renal transplants in Brazil, 37 patients submitted to renal allograft transplants were tested periodically for the presence of cytomegalovirus DNA in urine using the polymerase chain reaction (PCR), and for the presence of IgM and IgG antibodies against CMV by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF). The PCR-amplified products were detected by gel electrophoresis and confirmed by dot-blot hybridization with oligonucleotide probes. Thirty-two of the 37 patients (86.4%) were positive by at least one of the three methods. In six patients, PCR was the only test which detected the probable CMV infection. Ten patients had a positive result by PCR before transplantation. In general, the diagnosis was achieved earlier by PCR than by serologic tests. Active infection occurred more frequently during the first four months after transplantation. Sixteen of the 32 patients (50%) with active CMV infection presented clinical symptoms consistent with CMV infection. Five patients without evidence of active CMV infection by the three tests had only minor clinical manifestations during follow-up. Our results indicate that PCR is a highly sensitive procedure for the early detection of CMV infection and that CMV infection in renal transplant patients is a frequent problem in Brazil.

Common variable immunodeficiency in a renal transplant patient with severe recurrent bacterial infection: a case report and review of the literature

The second reported case of common variable immunodeficiency (acquired agammaglobulinemia) after renal transplantation is presented. Agammaglobulinemia presumably resulted from long-standing immunosuppression. This case and our review of the literature indicate that agammaglobulinemia is a rare event after transplantation but can be treated successfully with intravenous immunoglobulin. Additionally, hypogammaglobulinemia occurs frequently after transplantation and should be monitored and treated in appropriate clinical situations. The treatment of our patient with intravenous immunoglobulin also suggests that patients with common variable immunodeficiency can undergo renal transplantation.

Diagnosis of cytomegalovirus infections by shell vial assay and conventional cell culture during antiviral prophylaxis

A total of 3,552 specimens for conventional cytomegalovirus (CMV) culture and shell vial assay for CMV immediate-early antigen were obtained during a prospective randomized trial for prophylaxis of CMV disease after liver transplantation. Prophylaxis with ganciclovir for 2 weeks and then high-dose acyclovir for 2.5 months was compared with high-dose acyclovir alone for 3 months. During the first 12 weeks after transplantation, when the patients were on prophylaxis, there were significantly more clinical samples positive by the shell vial assay and negative by standard culture in comparison with the number of samples obtained from weeks 13 to 24, after prophylaxis was discontinued, that were positive by the shell vial assay and negative by standard culture. In contrast, significantly fewer samples were positive by both the shell vial assay and standard culture during the first 12 weeks compared with the number obtained 13 to 24 weeks after transplantation that were positive by both methods. Samples positive by the shell vial assay only were obtained significantly more frequently from patients with asymptomatic than symptomatic CMV infections, while samples positive by both methods were obtained significantly more often from patients with symptomatic CMV infection. It was concluded that antiviral prophylaxis with high-dose acyclovir or ganciclovir and then high-dose acyclovir and asymptomatic CMV infection are associated with a decrease in the level of CMV isolation by standard cell culture in comparison with that by the shell vial assay.

Diagnosis and treatment of cytomegalovirus disease in pediatric renal transplant recipients

The purpose of this study was to identify factors associated with the development of cytomegalovirus (CMV) disease and to assess the morbidity of this illness in pediatric renal transplant patients. The authors retrospectively reviewed the records of 135 patients (< 18 years of age) who underwent a total of 151 transplants (146 kidney transplants, five kidney/liver transplants) over 5 years (average follow-up period, 33.0 +/- 21.7 months). They assessed the risk factors that previously have been associated with the development of CMV disease in adults (age, occurrence of acute rejection episodes, and preoperative donor and recipient CMV serological status) and evaluated the incidence of associated graft loss and mortality. Twenty-two episodes of CMV disease were diagnosed based on evidence of CMV infection and on clinical symptoms; the episodes were treated in 17 patients. A multivariate analysis showed that the development of CMV disease was associated with age of > or = 13 years (P = .02), concomitant liver transplantation (P = .01), and treatment of acute rejection (P = .04). In addition, patients who were CMV-seronegative preoperatively and received a graft from a CMV-seropositive donor (P = .04) or who were CMV-seropositive preoperatively and received a graft from a CMV-seronegative donor (P = .02) were more likely to have CMV disease. Although all patients with CMV disease required hospitalization and were treated with intravenous ganciclovir, CMV disease was not associated with increased allograft loss or mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytomegalovirus infection as a complication of OKT3 therapy in kidney transplant recipients

We compared the incidence of clinical CMV illness in 25 renal transplant recipients treated with OKT3 for steroid resistant cellular rejection with 88 renal transplant patients treated only with conventional immunosuppression (cyclosporin A and steroids). Nine (36%) patients in the OKT3 group developed CMV illness compared to (2.3%) amongst those treated conventionally (p < 0.0005). Patients who received OKT3 were divided into four groups according to the CMV antibody status of the donor and recipient. Six of the 9 episodes of CMV infection occurred in patients not previously exposed to CMV, who received a kidney from a CMV positive donor. Three (12%) of the patients treated with OKT3 died of CMV disease. A further 2 patients died of other causes giving an overall mortality in the OKT3 treated group of 20%. We concluded that when OKT3 therapy is used in association with donor/recipient CMV mismatch it is associated with a high CMV morbidity and mortality.

Polymerase chain reaction in detection of CMV DNA in renal allograft recipients

This study investigates the use of polymerase chain reaction (PCR) in comparison with viral culture and serology for monitoring of cytomegalovirus (CMV) infection in 21 consecutive renal allograft recipients treated with a quadruple immunosuppression protocol. In addition, an attempt is made to explore the significance of quantitation of CMV signals obtained from peripheral blood leucocytes. CMV infection developed in 16 patients with seven of these patients having organ involvement. All of these 16 patients had a fourfold rise in antibody titres as well as positive identification of CMV DNA in peripheral blood leucocytes by PCR. Blood viral cultures were negative in two of these patients. All five patients who remained PCR negative also remained culture negative with no antibody change. PCR detected CMV infection on average 15 days and 20 days earlier than viral culture and serology respectively. All except one of the patients with CMV organ involvement had an initial peak of CMV DNA followed by prolonged carriage of detectable CMV. The majority of patients with fever only or asymptomatic CMV infection had a transient peak of CMV DNA. A high incidence of CMV disease with organ involvement occurred in seronegative recipients of kidneys from seropositive donors (3/5) and in seropositive recipients of kidneys from seronegative donors (3/7). OKT3 was associated with a higher incidence of CMV organ involvement compared to Antilymphocytic globulin (3/5 v 4/16) but there was a higher incidence of CMV mismatched patients in the OKT3 treated group.(ABSTRACT TRUNCATED AT 250 WORDS)

OKT3 and viral disease in pediatric liver transplant recipients

Seventy-four consecutive pediatric liver transplant recipients were reviewed to assess the effect of the monoclonal anti-T-lymphocyte antibody OKT3 on subsequent viral infection (9 patients were excluded due to postoperative demise during the 1st week). Twenty-two patients received OKT3 in addition to standard cyclosporine-prednisone immunosuppression for either steroid-resistant acute rejection (18) or to facilitate reduction of cyclosporine due to severe renal impairment (4). Invasive infections were diagnosed by histology or culture in tissue biopsies or bronchoalveolar lavage specimens. The overall incidence of viral infection was 58%, half of which was due to cytomegalovirus (CMV). Invasive viral disease was associated with increased mortality (37% vs. 3% p = 0.001). Viral-related deaths were due to CMV (5), disseminated adenovirus (3), disseminated enterovirus (1) and respiratory syncytial viral pneumonia (1). The use of OKT3 was associated with increased viral disease (59% vs. 33% p=0.04) and invasive primary CMV disease (58% vs. 19% p=0.04). Trends were observed toward increased overall viral infection (73% vs. 51 % p=0.08), primary CMV infection (58% vs. 25% p=0.08) and overall mortality (27% vs. 9% p =0.08) following OKT3 therapy. We conclude that pediatric liver transplant recipients who require OKT3 therapy may be at increased risk for invasive viral disease and especially invasive primary CMV disease.

Polymerase chain reaction for detection of human cytomegalovirus infection in a blood donor population

We have used the polymerase chain reaction (PCR) to analyse 420 normal donor blood samples taken at a city centre donation site. Three sets of human cytomegalovirus (HCMV) primers specific to the HXLF6, immediate early and late antigen gp64 genes, of the alpha, beta and gamma antigen coding regions respectively, were used to allow for the possibility of sequence variation. There was perfect correlation between the three sets of primers. Latex agglutination and enzyme-linked immunosorbent assay (ELISA) were also employed to provide data for a comparative study. The complete data show that infection with human cytomegalovirus is not only age related but is also sex related. The female population examined using PCR reached a peak infection rate of 80% by the age of 40-50 years whereas the male population reached a 98% infection rate following an almost linear increase with age. Latex agglutination data shows a similar picture although the infection rate peaks around 20% lower than with PCR. The data shows an increase in sensitivity using the PCR rather than the serology although the clinical significance of this has yet to be determined. The work presented here also demonstrates the suitability of the polymerase chain reaction as a potential diagnostic and epidemiological tool.

Prevention of cytomegalovirus infection in the pediatric renal transplant recipient

Cytomegalovirus (CMV) infection is the most important single infectious complication of organ transplantation, affecting more than 70% of transplant recipients. Its emergence as a major pathogen has coincided with the use of cytotoxic therapy. Manifestations of serious CMV disease include: pneumonia, hepatitis, gastrointestinal disease, leukopenia and chorioretinitis. CMV is associated with superinfection with opportunistic organisms, graft failure and increased mortality. Serious infection most frequently occurs with primary CMV infection in which latently infected cells from CMV-positive donors are given to seronegative recipients. Pediatric patients who have a lower pre-transplant rate of CMV seropositivity are at particularly high risk of developing serious CMV disease. Preventative efforts range from the ideal but impractical use of only CMV-negative donors (organ and blood products), to the use of CMV hyperimmune globulin and antiviral chemotherapy. Data support the use of prophylactic hyperimmune globulin and preliminary information supports the use of prophylactic high-dose acyclovir in renal transplant patients. Prophylactic gancyclovir alone or with hyperimmune globulin and pre-transplant vaccination with live-attenuated Towne strain CMV vaccine remain investigational.

Depression of humoral responses by murine cytomegalovirus infection

The ability of mice infected with murine cytomegalovirus (MCMV) to respond to unrelated antigens in vivo was studied in genetically sensitive BALB/c and genetically resistant CBA mice. Suppressed humoral responses were observed following intraperitoneal or intravenous antigen challenge a few days after infection. IgG production was depressed more frequently than IgM. The suppression was correlated with splenic atrophy and hyporesponsiveness of the residual spleen cells in vitro. The peritoneal macrophage response to intraperitoneal adjuvant challenge was also modified by the infection. Subcutaneous antigenic challenge elicited normal or elevated humoral and delayed-type hypersensitivity responses, during which peripheral lymph nodes were consistently expanded. Antigen administered intraperitoneally without adjuvant on the day of infection also evoked elevated humoral responses. This correlates with the host's ability to respond to MCMV itself, possibly via primed cells seeded to the lymph nodes before the spleen was damaged by the infection.

Cytomegalovirus retinitis

Cytomegalovirus retinitis is a frequent and serious complication of various conditions, including diseases characterized by impaired immunity, such as the acquired immunodeficiency syndrome. Due to recent advances in the treatment of cytomegalovirus retinitis, accurate diagnosis and management have become increasingly important. In this review, the authors present the epidemiology, clinical features, diagnostic testing, treatment with complications, and prognosis of cytomegalovirus retinitis. A differential diagnosis is presented and the characteristic ocular lesions are illustrated.

Cytomegalovirus infection after organ transplantation: an update with special emphasis on renal transplantation

Cytomegalovirus infections are still the most important infectious complications after organ transplantation. Besides historical notes this review will deal with new aspects concerning the epidemiology of the CMV, diagnostic modalities of CMV infection, the delicate counterbalance between the immune system and the CMV, as well as the symptomatology of this infection. Furthermore, aspects like prophylaxis and new, promising therapeutic regimes for treatment of infection will be dealt with. Although this update is applicable for all types of solid organ transplantation, emphasis will be on renal transplantation.

Inflammatory cells in transplanted kidneys are infected by human cytomegalovirus

To determine which cells in kidney grafts are infected with human cytomegalovirus (HCMV) before and after transplantation, kidney specimens were studied by in situ hybridization with 35S-labeled DNA probes representing HCMV immediate-early and late genes. Pretransplantation biopsies and serial posttransplantation biopsies were obtained from 7 renal grafts. All of the transplant recipients were HCMV-seronegative at the time of transplantation and all developed primary HCMV infections. HCMV nucleic acids were not detected in biopsies taken from the healthy donor kidneys before transplantation. However, biopsies taken at various intervals after transplantation showed abundant hybridization with HCMV immediate-early and late gene probes. Virtually all of the hybridizing cells were mononuclear inflammatory cells in the interstitial spaces of the kidney. Occasional hybridization was seen with renal tubular or glomerular cells. No cytomegalic cells were seen. Biopsy specimens taken after systemic anti-HCMV chemotherapy with phosphonoformate showed no uniform reduction in HCMV gene expression. These studies demonstrate that the principal HCMV-infected cells in kidneys of renal transplant patients with primary HCMV infections are infiltrating inflammatory cells.

The acute abdomen in the immunocompromised host

Immunocompromised hosts are a heterogeneous group, including patients receiving transplants, those receiving chemotherapy for malignant disease, and those receiving steroids for autoimmune disease, as well as patients with AIDS. Each group has specific abdominal conditions, and the clinician must be familiar with the specific causes of the acute abdomen within each subset. The causes of the acute abdomen in immunocompromised patients may be divided into two broad categories: (1) those disorders that are closely associated with the immunocompromised state and (2) those processes that can occur in any patient regardless of the immune status. Physicians at every level of specialization must become familiar with the unusual complications that occur in this population and with the ways in which the underlying disease and its therapy can modify the clinical presentation and management of common abdominal conditions. This article outlines broad principles of common clinical findings and surgical therapy in these patients.

Cytomegalovirus as a risk factor in living-related renal transplantation. A prospective study

Forty-four living-related donor kidney (LRD) recipients (19 HLA-identical and 25 haploidentical) were followed prospectively to determine the posttransplant incidence and sequelae of cytomegalovirus (CMV) infection as they relate to the CMV status of recipients and donors. CMV titers were measured in all patients before transplantation by an immunofluorescent assay (IFA). Recipients similarly had CMV titers measured at selected intervals after transplant and during febrile episodes. Appropriate viral cultures were simultaneously performed. Laboratory evidence of infection was correlated with symptoms and signs of active CMV disease. Mean follow-up period was 20 +/- 12 months with a range of 3-51 months. Three patients were excluded due to early acute rejection resulting in graft loss. Twenty-eight of 41 donors (68%) and 22 of 41 recipients (54%) had positive CMV titers before transplantation. Six of 41 recipients (15%) subsequently developed clinical and laboratory evidence of CMV infection: three of 19 seronegative recipients and three of 22 seropositive recipients. All six patients received kidneys from seropositive donors. Four patients had severe CMV disease (2 seronegative, 2 seropositive), whereas two patients had leukopenia and fever only. Two patients with severe CMV infections subsequently lost their grafts due to unrelated causes. Overall, actual patient and graft survival of the entire group is 95% and 82%, respectively. In conclusion, individuals who receive LRD kidneys from seronegative individuals are unlikely to develop CMV infection, and transplantation of seropositive LRD kidneys may be associated with transmission of CMV in susceptible recipients regardless of their serologic status. With appropriate management of CMV illness in the posttransplant period, LRD kidney donation is safe and efficacious and should not be discouraged on the basis of pretransplant CMV serology in any donor-recipient pairing.

Molecular biology and immunology of cytomegalovirus

The application of modern biochemical techniques has led to a rapid improvement in our knowledge of the molecular biology of CMV. Several coding regions of the DNA genome have been identified with certainty and major virus-coded proteins have been given provisional names. The cascade expression of the CMV genome has been shown to be controlled by mechanisms similar to those found in other herpes viruses, together with novel post-transcriptional controls which remain to be defined. The control of CMV replication by the host involves both non-specific and specific defence mechanisms. The induction of natural killer cells and interferon early after CMV infection appears to be the most important aspects of the non-specific host defence against the virus. The cell-mediated immune response, in particular the generation of Tc cells against CMV early antigens, is probably the most important facet of the specific immune defence against CMV. When intact these defence mechanisms appear to be efficient in restricting viral replication; however, when such immunity is compromised, the balance rapidly swings in favour of the virus. As our understanding of the interaction between the host and the virus increases, it may be possible to redress the balance in such cases in favour of the host.

Modification of susceptibility to Klebsiella pneumoniae during murine cytomegalovirus infection

The effect of murine cytomegalovirus (MCMV) infection on susceptibility to bacterial infection was studied in mice by a combination of intraperitoneal (ip) inoculation of a sublethal dose of MCMV with subsequent ip challenge of 2 X 10(3) cfu of a strain of Klebsiella pneumoniae (KP). When given alone, KP produced a mortality of 30-40%. Mortality was increased when KP was given 1 to 7 days after MCMV injection with the peak increase at the 4th to 5th day when 100% mortality occurred. Virus levels in various organs of mice infected with MCMV alone, or superinfected with KP did not differ. Bacterial counts on the other hand, showed that increased mortality in mixed MCMV and KP infected mice was due to an uncontrolled growth of bacteria at the site of primary lodgment, i.e., the peritoneum, and severe systemic infection. Neutrophil response to growth of KP during the first 3 days of bacterial infection was defective in MCMV infected mice. While the initial clearance of KP from the blood was more efficient in MCMV infected mice, probably due to activated reticuloendothelial function, it did not protect the mice against KP infection. Using the in vivo model, it was shown that poor neutrophil response and possibly other defective neutrophil functions were responsible for increased mortality to KP infection in MCMV infected mice.

Status of renal transplantation. A clinical perspective

Although the survival of patients on chronic dialysis has improved in recent years, the quality and status of rehabilitation remains poor. Renal transplantation must be used to complement chronic dialysis in the management of these patients. Physicians should not be biased and commit their patients to one or the other form of long-term treatment.

Cytomegalovirus and its association with multiple infections: a case report

A patient is described who developed multiple bacterial and fungal infections following a disseminated cytomegalovirus infection. The problem of infections in the debilitated host and the role of cytomegalovirus in suppressing immunity are discussed.

Treatment of cytomegalovirus pneumonia with high-dose acyclovir

Cytomegalovirus pneumonia is a serious complication of marrow transplantation, with a 90 percent fatality rate. Acyclovir, a new antiviral agent with variable in vitro activity against cytomegalovirus, was administered to eight marrow transplant patients with biopsy-proven cytomegalovirus pneumonia; one patient survived. Doses were between 400 and 1200 mg/m2 and peak plasma levels between 47 and 316 microM were attained. Possible marrow toxicity occurred in three patients, and mild neurotoxicity occurred in one. High-dose acyclovir had mild toxicity but was not effective as treatment for cytomegalovirus pneumonia after marrow transplantation.

A prospective study of oropharyngeal excretion of Epstein-Barr virus in renal homograft recipients

This prospective study was undertaken to examine the incidence of oropharyngeal excretions of Epstein-Barr virus (EBV) in the period after transplantation in human renal allograft recipients. Throat gargles from 23 recipients were tested for EBV. Five patients were already EBV excretors when the first specimens were tested. Of the remaining 18 patients 15 converted to positive within the first 7 months following transplantation. Three patients never excreted EBV in their throat gargles. This prospective study showed that 15/18 (83%) renal homograft recipients acquired active EBV infection (as indicated by excretion of EBV) after transplantation; 10/15 (66%) acquired active infection between 3-7 months after transplantation. We conclude that renal homograft recipients are highly susceptible to active EBV infection especially after the second month of transplantation.

Improved cadaver allograft survival in transfused recipients who remain serologically negative for cytomegalovirus

Between April 1976 and October 1979, 100 consecutive cadaver renal transplants were done. Before transplantation 48 recipients were seronegative and 52 were seropositive for cytomegalovirus. After transplantation there were 20 primary and 38 secondary cytomegalovirus infections. The development of post-transplant cytomegalovirus infection, with or without overt symptoms, had no effect on graft survival. The 1-year graft survival was significantly better (p less than 0.05) in high transfused (more than 5 units) recipients (70 per cent) compared to nontransfused recipients (36 per cent). The beneficial effect of transfusions was not diminished in patients with positive post-transplant cytomegalovirus serology. Of the transfused recipients those who remained serologically negative for cytomegalovirus pre-transplant had significantly better 1-year graft survival (78 per cent) than those who were cytomegalovirus positive before transplantation (58 per cent) (p less than 0.05). The improved graft survival in patients who remain cytomegalovirus seronegative after multiple blood transfusions may be a manifestation of unresponsiveness to immunologic as well as virogenetic stimulation.

Glomerulopathy associated with cytomegalovirus viremia in renal allografts

We investigated the relation between cytomegalovirus (CMV) infection and renal-allograft dysfunction in 14 patients. In seven instances (including two successive transplants in one patient), allograft dysfunction occurred during clinically manifest, viremic CMV infection. In five of these, biopsies revealed little or no tubulointerstitial change but a distinctive, diffuse glomerulopathy characterized by enlargement or necrosis of endothelial cells and accumulation of mononuclear cells and fibrillar material in glomerular capillaries. Two of these allografts recovered their function, both with cessation of high-dose immunosuppression. Biopsies in the other 10 patients revealed predominantly tubulointerstitial changes typical of cellular rejection, and most of these patients did not have viremia. One additional patient, studied prospectively, manifested both forms of allograft injury: tubulointerstitial changes occurring two weeks after transplantation and responding to increased immunosuppression, and CMV-associated glomerulopathy occurring seven weeks after transplantation and responding to decreased immunosuppression. We conclude that viremic CMV infection can cause acute glomerular injury and that recovery may be favored by a decreased in immunosuppressants.

Infection in the renal transplant recipient

The incidence of infection in the renal transplant patient is directly related to the net immunosuppressive effect achieved and the duration of time over which this therapy is administered. A second major factor in the causation of infections in this population is the nosocomial hazards to which these patients are exposed, ranging from invasive instrumentation to environmental contamination with Aspergillus species, Legionella pneumophila, Pseudomonas aeruginosa and other microbial pathogens. Careful surveillance is necessary to identify and eliminate such nosocomial sources of infection. The major types of infection observed can be categorized according to the time period post-transplant in which they occur: postsurgical bacterial infection in the first month after transplantation; opportunistic infection, with cytomegalovirus playing a major role, and transplant pyelonephritis in the period one to four months post-transplant; and a mixture of conventional and opportunistic infections in the last post-transplant period. Conventional infection in this late period occurs primarily in patients with good renal function who are receiving minimal immunosuppressive therapy; opportunistic infection occurs primarily in patients with poor renal function who are receiving higher levels of immunosuppression.

Immediate loss of cell-mediated immunity to murine cytomegalovirus upon treatment with immunosuppressive agents

Splenic lymphocytes from cytomegalovirus-infected mice lost their in vitro proliferative responses to cytomegalovirus antigen within 3 h after in vivo treatment with antilymphocyte globulin and prednisolone. The response was inhibited when the agents were administered separately or together, and inhibition persisted through a 2-week course of immunosuppression. Circulating specific antibodies were depressed by multiple injections of antilymphocyte globulin alone or with prednisolone, but not by prednisolone alone. Mitogen-induced blast transformation was immediately depressed by immunosuppression with both agents. Although the response to lipopolysaccharide returned briefly, it declined with continuing treatment. Cytomegalovirus infection augmented the depressive effect of immunosuppression on the lipopolysaccharide proliferative response. Prednisolone treatment of infected animals did not affect the concanavalin A response, and lipopolysaccharide stimulation decreased more slowly and to a lesser extent than it did in mice treated with antilymphocyte globulin or both agents. Loss of specific cell-mediated immunity and simultaneous depression of humoral immunity indicated that immunosuppression immediately created an inability to respond to an active cytomegalovirus infection.

Association of immune responsiveness to cytomegalovirus infection with survival of renal allografts

The association of immune responsiveness to cytomegalovirus infection was studied in relation to survival of renal allografts. The presence of anti-cytomegalovirus antibody in the pre-transplant patient was not associated with any detrimental effect on the graft survival. The presence or absence of cytomegalovirus antigen or of cytomegalovirus antibody, or later development of cytomegalovirus antibody, in no way affected the graft survival. The same conclusion was reached in cases when kidneys from male donors were used in cytomegalovirus antibody-postive patients.