Cyclosporin A immunosuppression, Epstein-Barr antibody, and lymphoma

Cytokine Storm Syndromes Associated with Epstein-Barr Virus

Epstein-Barr virus (EBV) is a ubiquitous and predominantly B cell tropic virus. One of the most common viruses to infect humans, EBV, is best known as the causative agent of infectious mononucleosis (IM). Although most people experience asymptomatic infection, EBV is a potent immune stimulus and as such it elicits robust proliferation and activation of the B-lymphocytes it infects as well as the immune cells that respond to infection. In certain individuals, such as those with inherited or acquired defects affecting the immune system, failure to properly control EBV leads to the accumulation of EBV-infected B cells and EBV-reactive immune cells, which together contribute to the development of often life-threatening cytokine storm syndromes (CSS). Here, we review the normal immune response to EBV and discuss several CSS associated with EBV, such as chronic active EBV infection, hemophagocytic lymphohistiocytosis, and post-transplant lymphoproliferative disorder. Given the critical role for cytokines in driving inflammation and contributing to disease pathogenesis, we also discuss how targeting specific cytokines provides a rational and potentially less toxic treatment for EBV-driven CSS.

Epstein-Barr Virus History and Pathogenesis

Epstein-Barr virus (EBV) is the first identified human oncogenic virus that can establish asymptomatic life-long persistence. It is associated with a large spectrum of diseases, including benign diseases, a number of lymphoid malignancies, and epithelial cancers. EBV can also transform quiescent B lymphocytes into lymphoblastoid cell lines (LCLs) in vitro. Although EBV molecular biology and EBV-related diseases have been continuously investigated for nearly 60 years, the mechanism of viral-mediated transformation, as well as the precise role of EBV in promoting these diseases, remain a major challenge yet to be completely explored. This review will highlight the history of EBV and current advances in EBV-associated diseases, focusing on how this virus provides a paradigm for exploiting the many insights identified through interplay between EBV and its host during oncogenesis, and other related non-malignant disorders.

Targeting the signaling in Epstein-Barr virus-associated diseases: mechanism, regulation, and clinical study

Epstein–Barr virus-associated diseases are important global health concerns. As a group I carcinogen, EBV accounts for 1.5% of human malignances, including both epithelial- and lymphatic-originated tumors. Moreover, EBV plays an etiological and pathogenic role in a number of non-neoplastic diseases, and is even involved in multiple autoimmune diseases (SADs). In this review, we summarize and discuss some recent exciting discoveries in EBV research area, which including DNA methylation alterations, metabolic reprogramming, the changes of mitochondria and ubiquitin-proteasome system (UPS), oxidative stress and EBV lytic reactivation, variations in non-coding RNA (ncRNA), radiochemotherapy and immunotherapy. Understanding and learning from this advancement will further confirm the far-reaching and future value of therapeutic strategies in EBV-associated diseases.

Immunization With Fc-Based Recombinant Epstein-Barr Virus gp350 Elicits Potent Neutralizing Humoral Immune Response in a BALB/c Mice Model

Epstein–Barr virus (EBV) was the first human virus proved to be closely associated with tumor development, such as lymphoma, nasopharyngeal carcinoma, and EBV-associated gastric carcinoma. Despite many efforts to develop prophylactic vaccines against EBV infection and diseases, no candidates have succeeded in effectively blocking EBV infection in clinical trials. Previous investigations showed that EBV gp350 plays a pivotal role in the infection of B-lymphocytes. Nevertheless, using monomeric gp350 proteins as antigens has not been effective in preventing infection. Multimeric forms of the antigen are more potently immunogenic than monomers; however, the multimerization elements used in previous constructs are not approved for human clinical trials. To prepare a much-needed EBV prophylactic vaccine that is potent, safe, and applicable, we constructed an Fc-based form of gp350 to serve as a dimeric antigen. Here, we show that the Fc-based gp350 antigen exhibits dramatically enhanced immunogenicity compared with wild-type gp350 protein. The complete or partial gp350 ectodomain was fused with the mouse IgG2a Fc domain. Fusion with the Fc domain did not impair gp350 folding, binding to a conformation-dependent neutralizing antibody (nAb) and binding to its receptor by enzyme-linked immunosorbent assay and surface plasmon resonance. Specific antibody titers against gp350 were notably enhanced by immunization with gp350-Fc dimers compared with gp350 monomers. Furthermore, immunization with gp350-Fc fusion proteins elicited potent nAbs against EBV. Our data strongly suggest that an EBV gp350 vaccine based on Fc fusion proteins may be an efficient candidate to prevent EBV infection in clinical applications.

Epstein-Barr virus: more than 50 years old and still providing surprises

It is more than 50 years since the Epstein-Barr virus (EBV), the first human tumour virus, was discovered. EBV has subsequently been found to be associated with a diverse range of tumours of both lymphoid and epithelial origin. Progress in the molecular analysis of EBV has revealed fundamental mechanisms of more general relevance to the oncogenic process. This Timeline article highlights key milestones in the 50-year history of EBV and discusses how this virus provides a paradigm for exploiting insights at the molecular level in the diagnosis, treatment and prevention of cancer.

Posttransplant Lymphoproliferative Disorder of the Thorax: CT and FDG-PET Features in a Single Tertiary Referral Center

To investigate the chest computed tomography (CT) and F-18 fluoro-2-deoxy-D-glucose positron emission tomographic (FDG-PET) findings of posttransplant lymphoproliferative disorder (PTLD) in the thorax.From November 2004 to February 2013, the cases of 12 adult patients (3 female and 9 male, age range 34-68, and median age 46 years) with proven PTLD were retrospectively reviewed. The transplanted organs included the kidney (5/12), liver (4/12), heart (1/12), combined kidney and pancreas (1/12), and hematopoietic stem cell (1/12). We investigated the relationship of the Epstein-Barr virus (EBV) to the patients' long-term follow-up, and evaluated the characteristics of the lesions on the chest CT and FDG-PET. The lesions were classified into 2 patterns: that of lymph node and lung involvement.The interval between the transplantation and the onset of PTLD was 2 to 128 months (median, 49). Positive EBV-encoded RNA in the pathologic specimens was found in 10 patients (83.3%). Eight patients were positive for EBV PCR in their blood, and 3 patients showed seroconversion without antiviral therapy. The responses to treatment were complete in 7 cases (58.3%), partial remission in 4 cases (33.3%), and undetermined in 1 case (8.3%). The more common chest CT patterns showed lymph node involvement (10/12) rather than lung involvement (3/12). The median maximum-standardized uptake value on the FDG-PET scans was 7.7 (range, 2.7-25.5).In patients with PTLD involving the thorax, lymphadenopathy was the more common manifestation on the chest CT rather than lung involvement. The lesions showed hypermetabolism on FDG-PET.

Reduction in immunosuppression as initial therapy for posttransplant lymphoproliferative disorder: analysis of prognostic variables and long-term follow-up of 42 adult patients

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) is an Epstein-Barr virus-associated malignancy that occurs in the setting of pharmacologic immunosuppression after organ transplantation. With the increased use of organ transplantation and intensive immunosuppression, this disease is becoming more common. We explore reduction in immunosuppression as an initial therapy for PTLD.

METHODS

We analyzed our organ transplant patient database to identify patients with biopsy-proven PTLD who were initially treated with reduction of their immunosuppressive medications with or without surgical resection of all known disease.

RESULTS

Forty-two adult patients were included in this study. Thirty patients were treated with reduction in immunosuppression alone. Twelve patients were treated with both reduction in immunosuppression and surgical resection of all known disease. Thirty-one of 42 patients (73.8%) achieved a complete remission. Of those patients who were treated with reduction in immunosuppression alone, 19 of 30 (63%) responded with a median time to documentation of response of 3.6 weeks. Multivariable analysis showed that elevated lactate dehydrogenase (LDH) ratio, organ dysfunction, and multi-organ involvement by PTLD were independent prognostic factors for lack of response to reduction in immunosuppression. In patients with none of these poor prognostic factors, 16 of 18 (89%) responded to reduction in immunosuppression in contrast to three of five (60%) with one risk factor and zero of seven (0%) with two to three factors present. The analysis also showed that increased age, elevated LDH ratio, severe organ dysfunction, presence of B symptoms (fever, night sweats, and weight loss), and multi-organ involvement by PTLD at the time of diagnosis are independent prognostic indicators for poor survival. With median follow-up of 147 weeks, 55% of patients are alive with 50% in complete remission.

CONCLUSIONS

Reduction in immunosuppression is an effective initial therapy for PTLD. Clinical prognostic factors may allow clinicians to identify which patients are likely to respond to reduction in immunosuppression.

Posttransplantation lymphoproliferative disorder of the abdomen: CT evaluation in 51 patients

PURPOSE

To study the appearance and distribution of posttransplantation lymphoproliferative disorder (PTLD) at abdominal computed tomography (CT).

MATERIALS AND METHODS

The authors retrospectively analyzed pretreatment abdominal CT scans in 51 patients (mean age, 36 years) with PTLD after solid organ transplantation. All diagnoses were proved at either abdominal (n = 26) or extraabdominal (n = 25) pathologic examination. Presence or absence of abdominal involvement, appearance and distribution of disease, and association with abdominal symptoms were all analyzed.

RESULTS

CT scans were abnormal in 36 of the 51 patients (71%). Fifteen patients (29%) had no CT, clinical, or pathologic evidence of abdominal involvement. Of the 36 patients with abdominal PTLD at CT, 22% had lymph node enlargement, 28% splenic involvement, and 81% extranodal or extrasplenic involvement. Extranodal abdominal sites included liver (53%), small bowel (25%), kidney (17%), mesentery (14%), adrenal gland (8%), abdominal wall (8%), colon (6%), stomach (3%), and gallbladder (3%). Frequency of abdominal involvement was greater for heart and liver transplant recipients (94%) than for lung and kidney transplant recipients (58%) (P < .01). Seventeen of 36 patients (47%) with abdominal PTLD had no evidence of extraabdominal disease.

CONCLUSION

Extranodal involvement is more common than splenic or nodal involvement in patients with abdominal PTLD. The presence of such findings in a patient after transplantation strongly suggests the diagnosis of PTLD and warrants aggressive evaluation.

Primary cardiac lymphoma in an immunocompetent woman

We report a fatal primary cardiac non-Hodgkin's lymphoma in a 62 years old immunocompetent woman presenting with tamponade and complete atrioventricular block. CT-scan, echocardiography and autopsy examination showed a tumor largely infiltrating the heart without extracardiac involvement. A surgical biopsy revealed high grade B-cell non-Hodgkin's lymphoma with a misleading myelomonocytic CD68 (KPI) expression. Polymerase Chain Reaction analysis revealed a clonal rearrangement of the immunoglobulin heavy chain gene and confirmed the B-cell origin of the lymphoma. Our report also emphasizes the role of immunohistochemical and molecular techniques in the diagnosis.

Epstein-Barr virus as an agent of haematological disease

Epstein-Barr virus (EBV) encodes genes that permit its persistence in human B lymphocytes and genes that ensure its replication in epithelial cells. Immune restraints on the virus are usually so effective that most EBV infections are limited to a minute fraction of B lymphocytes and of epithelial cells. As a result, most EBV infections are never symptomatic. Occasionally, the virus causes disease, often with the cooperation of the immune system or other less characterized cofactors. Infectious mononucleosis, a generally self-limited lymphoproliferative illness common in adolescents and young adults, is due to primary EBV infection and to the brisk cellular immune response it elicits. Lymphoproliferative disorders of EBV-infected B cells arise almost exclusively when cellular immunity is grossly compromised. EBV-positive Burkitt's lymphoma contain a translocated and deregulated c-myc oncogene and EBV-positive non-Hodgkin's lymphomas are characterized by the presence of Reed-Sternberg's and Hodgkin's cells, features that have not been directly linked to EBV. Many recent observations, however, including evidence that virus infection precedes malignant transformation and is often associated with a characteristic pattern of viral gene expression, provide continued interest in the relationship between the virus and these haematological malignancies.

Necrotic, ulcerative bronchitis, the presenting feature of lymphoproliferative disease following heart-lung transplantation

Following heart-lung transplantation two of 21 patients who survived more than 100 days developed post-transplant lymphoproliferative disease. Both presented with localised ulcerative bronchitis documented at flexible bronchoscopy four months after transplantation. Histological examination showed necrosis with acute inflammation and ulceration. Case 2 demonstrated lymphoproliferative disease from biopsies subsequently taken at rigid bronchoscopy. Case 1 later developed lung nodules and a monoclonal high grade B cell non-Hodgkin's lymphoma was confirmed by an open lung biopsy. The bronchoscopic features described should alert clinicians to post-transplant lymphoproliferative disease as an underlying diagnosis and suggest that bronchus associated lymphoid tissue is the initial site for clonal proliferation in the disease.

Obliterative bronchiolitis caused by multiple tumourlets and microcarcinoids successfully treated by single lung transplantation

Histological examination of a lung removed at transplantation revealed multiple peripheral tumourlets and microcarcinoids in close association with bronchioles causing an obliterative bronchiolitis. This was an unexpected finding but explained the progressive airflow limitation which characterised the patient's clinical course.

Circulating Epstein-Barr virus-carrying B cells in acute malaria

Epstein-Barr virus (EBV) infection and Plasmodium falciparum malaria are two known cofactors in the aetiology of endemic Burkitt's lymphoma. To assess the relation between these factors, limiting dilution analysis was used to assess the number of EBV-carrying B cells in the circulation of Gambian children during and after acute malaria. Numbers of virus-carrying cells were five times higher in acute malaria patients and in UK patients with infectious mononucleosis than in convalescent malaria patients and in healthy control adults from the UK. Spontaneous outgrowth in limiting dilution cultures from acute malaria samples was inhibited by acyclovir, a viral DNA polymerase inhibitor. The mechanism of outgrowth, therefore, was virus release from the in-vivo infected cell, which led to infection and immortalisation of co-cultured normal B cells. The findings provide evidence that acute malaria is associated with an increase in the number of EBV-carrying B cells in the circulation. Because of this increase, there is a greater chance of a cytogenetic abnormality occurring in such a cell, with consequent evolution of Burkitt's lymphoma.

Viral and toxoplasma gondii infections in children after liver transplantation

The incidence and morbidity of viral and Toxoplasma gondii infections were studied in 40 children who underwent liver transplantation between December 1983 and February 1988. The incidence of primary and reactivated cytomegalovirus (CMV) infection was 19% and 47%, respectively; primary infection caused clinical disease in all five cases affected and was fatal in one. Primary Epstein-Barr virus (EBV) infection occurred in 10 (26%) recipients but caused only mild disease. No reactivated EBV infection was recorded and no lymphoproliferative disorders associated with EBV were found after a maximum of four years' follow up. Adenovirus infection occurred in seven (18%) patients; this was associated in one case with fatal pneumonia and fulminant hepatitis, but otherwise with only mild respiratory disease. Primary T gondii infection was detected in one patient who remained asymptomatic. Other viruses causing infection included herpes simplex, varicella zoster, and respiratory syncytial virus. Surveillance for these infections and the long term sequelae should be included in the follow up of all children who undergo transplantation.

The risk of neoplasms in patients treated with cyclosporine A

Immunosuppressive therapy (IT) carries inherent risks involving the occurrence of lymphoproliferative disorders and malignancies (MA). The most frequently observed neoplasms in organ-transplant (OT) recipients treated with cyclosporine A (Cy-A) involve the skin and the lympho-reticular system. A disproportionally high percentage of the skin MA are Kaposi's sarcoma. Compared with a normal, not-exposed population matched for age, sex and country; Cy-A-treated OT recipients have a 28-times higher prevalence of lymphomas. This figure compares with a 34 to 59-fold increased risk in patients receiving conventional immunosuppressive therapy (CIT) for OT. However, it appears that in Cy-A-treated patients the latency period for the development of lymphomas is shorter than in patients on CIT. Other MA are increased seven-fold in Cy-A-treated patients and between two- and six-fold in those receiving CIT. The overall incidence of all types of MA is increased two-fold for Cy-A recipients and between two- and four-fold for those on CIT. Therefore patients receiving IT should be carefully monitored with respect to the possible occurrence of neoplasms.

Neuropathology of heart transplantation

The neuropathology of 18 cardiac transplant recipients was reviewed with the clinical findings. Pathological changes were noted in the central nervous system (CNS) in 94% of the patients, the most frequent being cerebral vascular in origin (72%). Eight patients (44%) had multiple cerebral infarcts and morphologically, a large number of these antedated the transplantation. In addition 4 patients had acute focal ischemic changes which occurred after transplantation. Intracranial hemorrhage was noted in 5 patients (28%), including one case of fatal intracerebral hemorrhage following an acute hypertensive episode after the transplantation. While systemic infection was common (10 patients), there were only 5 cases of intracranial infection; including 3 cases of cytomegalovirus infection, one of candidiasis and one of aspergillosis. Post-transplant seizures, occurring in a third of the patients, were related to a variety of causative factors such as sepsis, intracranial hemorrhage, cerebral ischemia, metabolic encephalopathy and cyclosporin neurotoxicity. Of note in this series was the absence of CNS lymphoma or other systemic lymphoproliferative disorder.

Malignancy following treatment of rheumatoid arthritis with cyclophosphamide. Long-term case-control follow-up study

A long-term retrospective case-control study was performed comparing 119 patients with rheumatoid arthritis treated with cyclophosphamide and 119 matched control patients with rheumatoid arthritis not treated with cyclophosphamide to determine the risk of subsequent malignancy. Thirty-seven malignancies were detected in 29 cyclophosphamide-treated patients, while 16 malignancies were found in 16 control patients (p less than 0.05) during a mean follow-up period of more than 11 years. Urinary bladder cancer (six cyclophosphamide-treated patients, no control patients) and skin cancer (eight cyclophosphamide-treated patients, no control patients) were identified as differing statistically between the groups, and hematologic malignancy (five cyclophosphamide-treated patients, one control patient) showed a similar trend. Survival analysis indicated that the rate of development of malignancy in the cyclophosphamide-treated patients was significantly greater than in the control patients at six years following drug initiation, and that this increased rate persisted even at 13 years (p less than 0.01). Of the many risk factors evaluated, mean total cyclophosphamide dose and duration and tobacco use were significantly increased in patients in whom cancer subsequently developed. These long-term complications must be considered seriously when cyclophosphamide or other cytotoxic drugs are initiated for the treatment of rheumatoid arthritis.

Epstein-Barr virus-associated malignancies

The infectious aspects of cancer in humans were epidemiologically pioneered by Dr. David Burkitt through his observations of lymphomatous tumors seen in children in equatorial Africa. Years, later, the Epstein-Barr virus (EBV) was shown to be intimately associated with such tumors and is now recognized as a component of some B-cell lymphomas and nasopharyngeal carcinoma. Still the questions of an active, passive, or accessory role persist. The ability of this virus to cause immunosuppressive hemopoietic disturbances in individuals infected with EBV but not developing cancer raise questions about host susceptibility, host immune response, and possible coconspiring, infectious, oncogenic agents. Recent associations of EBV antibody found in diseases, such as squamous cell carcinoma of the head and neck and acquired immunodeficiency syndromes, point to its possible accessory role as an immunosuppressive agent. The ability of EBV to spread by extracellular and intracellular mechanisms demonstrates its variable infectious potential. Numerous EBV-transformed human cell lines attest to its ability to confer "immortality" with uncontrolled growth patterns. This review critically examines the association of EBV with various malignancies, the type of evidence which links it there, and the implications for further investigations and therapy.

Malignant lymphoma of the heart in acquired immune deficiency syndrome

Malignant lymphoma of the heart was found at autopsy of two homosexual men with acquired immune deficiency syndrome (AIDS). Both patients had symptoms and signs of cardiac dysfunction, and it is likely that the immediate cause of their deaths was related to the cardiac tumors. In both cases, there was lymphomatous involvement of other organs, but the heart was the predominant site of disease. There was prominent endocardial and myocardial involvement, and both tumors were high grade large cell lymphomas with plasmacytoid features. In both instances, the lymphomas were diagnosed only at the autopsy, despite extensive antemortem cardiac evaluation in one patient. The clinicopathologic correlation, gross pathologic and histologic findings of the tumor, and their pattern and distribution suggest a de novo origin of the lymphoma in the heart in these two patients. Lymphomatous infiltration of the heart should be suspected in patients with AIDS who have cardiac symptoms.

Primary malignant lymphoma of the anorectum in homosexual men

Two homosexual men presented with primary malignant lymphomas of the anorectum. Each patient presented with a painful mass, diagnosed by biopsy and immunologic cell marker studies. One patient, who had a reversed T4/T8 cell ratio, developed a local relapse of the tumor 11 months after radiotherapy, and Pneumocystis carinii pneumonia. The other patient, with a normal T4/T8 ratio, remained lymphoma-free and without evidence of opportunistic infection 25 months after combined chemotherapy and radiotherapy. Anorectal pathologic findings in homosexual men includes proctitis, inflammatory stricture, fissure, or anal warts. Malignant anorectal diseases, such as Kaposi's sarcoma, and cloacogenic or squamous cell carcinomas have been described in homosexual men. Primary malignant lymphoma of the anorectum is rare in both the homosexual and general populations.

Multifocal aggressive lymphoma of the gastrointestinal tract in a renal transplant patient treated with cyclosporin A and prednisone

This is a case report of an aggressive multifocal non-Hodgkin's lymphoma in a cadaver kidney recipient arising in the early phase of her immunosuppressive maintenance therapy program with cyclosporin A and prednisone.

Epstein-Barr virus-induced lymphoma in a cardiac transplant recipient

A monoclonal diffuse histiocytic lymphoma developed during the course of a serologically documented primary Epstein-Barr virus infection in a 22-year-old cardiac transplant recipient taking cyclosporine and prednisone. Throat washings revealed the virus at tumor presentation, and the tumor was shown to contain Epstein-Barr nuclear antigen-positive cells and the viral genome. Prolonged inversion of the T cell helper/suppressor ratio was demonstrated. A brief course of acyclovir appeared to halt viral shedding in the throat but had no apparent effect on the tumor.

Cyclosporin A: pharmacologic activity on the immune system and effects in clinical organ transplantation

The recently discovered fungal metabolite cyclosporin A (CsA) is a potent immunosuppressant that is effective in preventing transplantation rejection due to allografts and even xenografts. Due to its influence on the biological activity of T-helper lymphocytes CsA's mechanism of action includes inhibition of cell-mediated cytolysis and delayed-type hypersensitivity (DTH) reaction. In addition to studies of the molecular mechanism of action, data on the pharmacokinetics of CsA are given. CsA does not cause anti-mitotic and/or cytotoxic effects. The side effects of the agent are relatively mild and appear to be reversible. CsA has been successfully used clinically in renal, bone-marrow, heart, heart-lung, liver, and pancreas transplantation. The application of the compound in organ transplantation appears to be superior to conventional immunosuppressive therapy.

Production of human immune interferon (Hu IFN-gamma) studied at the single cell level. Origin, evidence for spontaneous secretion and effect of cyclosporin A

A reverse hemolytic plaque assay has been developed which specifically detects secretion of human immune interferon (Hu IFN-gamma) at the single cell level. Unstimulated peripheral blood lymphocytes from healthy adult volunteers spontaneously secreted IFN-gamma. Stimulation of these cells with concanavalin A, phytohemagglutinin, or the UCHT1 monoclonal anti-human T cell antibody significantly increased the number of IFN-gamma-secreting cells. The cell producing IFN-gamma, both spontaneously and after UCHT1 antibody stimulation, is an OKT3+,4+,8-,HLA-DR-T lymphocyte as determined at the single cell level. Finally, cyclosporin A, a potent and selective immunosuppressive drug for T cells, strongly inhibited the secretion of IFN-gamma as assayed at the cell level. This IFN-gamma reverse hemolytic plaque assay has great potential for the further study of IFN-gamma both in physiological and pathological conditions.

Association of herpesvirus infections with T-lymphocyte-subset alterations, glomerulopathy, and opportunistic infections after renal transplantation

We studied the interrelation among herpes-virus infections, T-lymphocyte subsets, opportunistic infections, and renal histopathology in 28 recipients of renal allografts. All primary or reactivated herpesvirus infections occurring in the first three months after transplantation in recipients of cadaveric grafts accompanied persistent inversions in the ratio of OKT4 (helper/inducer) to OKT8 (cytotoxic/suppressor) lymphocytes. In the less heavily immunosuppressed recipients of organs of living related donors, these inversions were seen only in association with clinically apparent cytomegalovirus infections. Five of seven opportunistic infections occurred in patients with OKT4/OKT8 ratios of less than 1.0. Biopsy specimens from patients with renal dysfunction occurring in association with a low OKT4/OKT8 ratio frequently revealed glomerular damage rather than acute cellular rejection. Monitoring of T-lymphocyte subsets provides early evidence of herpesvirus infections and identifies patients at increased risk for opportunistic infection after renal transplantation.

Effect of cyclosporin A on the production of interferon by human peripheral blood leukocytes in vitro

Cyclosporin A (CsA) was assessed for its effect on the production of antiviral activity by human peripheral blood leukocytes (PBL). CsA markedly reduced the production of interferon-gamma (IFN-gamma) in response to stimulation with lectin mitogens, bacterial products, alloantigens, or Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL). CsA-mediated suppression of IFN-gamma secretion was dose-dependent and did not result from a shift of kinetics of the production of antiviral activity. The production of IFN-alpha in response to stimulation with Corynebacterium parvum (CP), viruses, and synthetic polynucleotides was not affected by the addition of CsA. These findings confirm earlier observations that CsA predominantly acts on T lymphocyte function. CsA may prove a valuable agent to study the role of IFN-gamma in the pathogenesis of virus-associated malignant lymphoproliferative disease.

A prospective study on infectious mononucleosis in childhood--symptoms, serology, Epstein-Barr-Virus specific leukocyte migration inhibition

The clinical course, serological changes and the development of the specific cell-mediated immune response to Epstein-Barr-Virus (EBV), measured in terms of leukocyte migration inhibition, were followed in 40 children suffering from an EBV infection. The patients were followed for between six and 24 months. Although the majority of the children were under six years of age, they presented a typical clinical course; heterophil antibodies could only be demonstrated in 60% of the cases. Anti-VAC-IgM and IgG antibodies were found in all patients during the acute phase, but no anti-EBNA could be demonstrated. In children under three years of age, no antibodies against the D component of the early antigen were found; this antibody was found in 50% of the adolescents. An antibody against the R component of the early antigen could be demonstrated in 73% of the children five to six months after the onset of the disease. Specific leukocyte migration inhibition was present only during convalescence or later. A relationship between the appearance of anti-EBNA and the development of specific leukocyte migration inhibition has been established.