Regression of post-transplant Kaposi sarcoma after discontinuing cyclosporin and giving mycophenolate mofetil instead

Viruses

In the past, viruses were considered nonliving infectious particles, little more than genetic material wrapped in a protein capsid. Today, virologists are beginning to think of viruses as living organisms that can be classified phylogenetically into defined species, much like any other living organism. The primary reasons for this shift in attitude can be partially attributed to the discovery of giant viruses, having large genomes and complex regulatory systems. Aside from that, it has become obvious that viruses lead complex lives; they evolve, speciate, and participate in the evolution of all classes of living organisms. In this chapter, we will discuss the early attempts to classify viruses, and review the biologic properties of the classes of virus that contain human pathogens.

Malignancies after lung transplantation

Lung transplantation has become an efficient life-saving treatment for patients with end stage respiratory disease. The increasing good outcome following lung transplantation may be explained by growing experience of transplant teams and availability of potent immunosuppressive drugs. Nevertheless, the latter carries an inherent risk for malignancy besides other common side effects such as systemic hypertension, diabetes and renal dysfunction. Malignancies occur in a smaller proportion of patients but explain for a large proportion of deaths following transplantation. From the first year post-transplantation they will represent the third cause of death with an increasing incidence along post lung transplant survival. In this chapter, we will browse the different types of malignancies arising following lung transplantation. According to the different techniques for lung transplantation, specific types of bronchogenic carcinoma will be described in the explanted lung, in the native lung, and in the graft. Risk factors associated to immunosuppressive therapy, but also to occupational and environmental factors, especially smoking, will be discussed. Eventually, we will strive at integrating recommendations for the treatment of malignancies following lung transplantation.

Mycophenolate mofetil and skin diseases

Mycophenolate mofetil (MMF) is an immunosuppressive drug the efficiency of which has been established in renal transplantation. Recent studies suggest that it may also be effective in the treatment of variant skin diseases especially if the skin lesions are triggered by lymphocytes. Studies have shown efficacy in autoimmune bullous dermatoses, atopic dermatitis and psoriasis. However, there are no placebo-controlled trials that support the use of MMF as first line therapy in these skin diseases.

Mycophenolate mofetil and skin diseases

Mycophenolate mofetil (MMF) is an immunosuppressive drug the efficiency of which has been established in renal transplantation. Recent studies suggest that it may also be effective in the treatment of variant skin diseases especially if the skin lesions are triggered by lymphocytes. Studies have shown efficacy in autoimmune bullous dermatoses, atopic dermatitis and psoriasis. However, there are no placebo-controlled trials that support the use of MMF as first line therapy in these skin diseases.

Classic Kaposi Sarcoma: to treat or not to treat?

Background

Classic Kaposi Sarcoma (KS) is vascular sarcoma, known to be more common in Mediterranean elderly men and characterized by an indolent clinical behavior. To our knowledge, this is the first evidence in literature, describing a spontaneous partial regression in a non-HIV, non-iatrogenic KS.

Case presentation

A 68-years old woman, presenting with weight loss and respiratory symptoms, was diagnosed with a classic KS involving lungs and mediastinal lymph nodes. No skin or mucosal lesions were identified, HIV positivity was ruled out. Due to patient’s choice, she was kept under surveillance with 3-monthly thorax-abdomen-pelvis computed tomography scan (TAP CT). A first reassessment proved progressive disease (PD) associated with symptoms worsening. A new TAP CT, performed at 5 months from the diagnosis, showed stable disease (SD), with a minor reduction in size of mediastinal lymphadenopathies. A further reassessment, performed 5 months later, resulted in a partial response (PR) despite the absence of any medical treatment. Up to date, the disease is in remission, patient is asymptomatic and still on surveillance.

Conclusion

Given the possible indolent behaviour of KS, we believe that close surveillance can represent a valuable approach in selected cases.

Epidemiology of de novo malignancies after solid-organ transplantation: immunosuppression, infection and other risk factors

Organ transplantation is an increasingly used medical procedure for treating otherwise fatal end-stage organ diseases, and a large number of anti-rejection drugs have been developed to prolong long-term survival of both the individual and the transplanted organ. However, the prolonged use of immunosuppressive drugs is well known to increase the risk of opportunistic diseases, particularly infections and virus-related malignancies. Although transplant recipients experience a nearly twofold elevated risk for all types of de novo cancers, persistent infections with oncogenic viruses are associated with up to hundredfold increased risks. Women of the reproductive age are growing in number among the recipients of solid-organ transplants, but specific data on cancer outcomes are lacking. This article updates evidences linking iatrogenic immunosuppression, persistent infections with oncogenic viruses, other risk factors and post-transplant malignancies. Epidemiological aspects, tumourigenesis related to oncogenic viruses, clinical implications, as well as primary and secondary prevention issues are discussed to offer clinicians and researchers alike an update of an increasingly important topic.

Effect of mycophenolate mofetil plus adriamycin on HepG-2 cells

AIM

To investigate the influence of mycophenolate mofetil (MMF) plus adriamycin (ADM) on hepatocellular carcinoma (HCC) cells.

METHODS

HCC cells were treated with 100 μg/ml of MMF alone (MMF group), 1 μg/mL of adriamycin (ADM group) alone, or a combination of the drugs (MMF + ADM group). We performed an 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay to measure the growth inhibition rate of HCC cells. Flow cytometry was used to determine the percentage of cells in different phases of the cell cycle and the number of apoptotic cells. Hoechst 33258 staining revealed the morphological changes associated with apoptosis in HCC cells.

RESULTS

The results of MTT assays revealed that monotherapy with ADM or MMF showed inhibition of cell growth, while MMF + ADM therapy afforded an inhibition rate of more than 90% with cell distribution in G1 and G2/M phase greater than that in S phase. MMF + ADM treatment also downregulated Bcl-2 expression markedly. The growth of HCC cells was markedly inhibited and apoptosis was enhanced in all the 3 groups. Compared with other 2 groups, the MMF + ADM group showed more obvious apoptosis of cells.

CONCLUSION

The MMF plus ADM combination exerts remarkable inhibitory effects on the growth of HCC cells.

Kaposi sarcoma related to an ectopic hypothalamic adrenocorticotropic hormone-secreting adenoma: case report

OBJECTIVE

We aim to report a case of Kaposi sarcoma (KS) with Cushing's syndrome caused by endogenic glucocorticoid-induced immunosuppression.

CLINICAL PRESENTATION

A 43-year-old woman presented with delirium, hirsutism, fatigue, and hypertension. At the time of presentation, physical findings showed a Cushingoid appearance, with moon-like facies, hirsutism, and hyperpigmentation. Laboratory findings showed the following: adrenocorticotropic hormone, 86.7 pg/mL (normal range, 0-46 pg/mL); baseline cortisol level, 50 microg/dL (normal range, 6.2-19 microg/dL); potassium, 2.2 mEq/L (normal range, 3.5-5 mEq/L); and midnight cortisol level, 33 microg/dL. Serum cortisol levels failed to suppress after low and high doses of dexamethasone; these findings confirmed the diagnosis of ectopic adrenocorticotropic hormone production. Magnetic resonance imaging revealed a 12 x 15-mm, round, hypothalamic mass lesion in the center of the median eminence.

INTERVENTION

Endoscopic biopsy from the floor of the third ventricle was performed, and pathological examination of the lesion showed a diffuse adrenocorticotropic hormone-secreting adenoma. The patient developed diffuse skin lesions that were proven to be a KS by skin biopsy while she was prepared for transcranial surgery. After surgical removal of the adenoma, she became hypocortisolemic and required cortisol replacement. Within 1 month after surgery, all KS lesions disappeared spontaneously.

CONCLUSION

Excessive cortisol may induce immunosuppression. KS is one of the most common malignant tumors of patients with immunosuppression. To the best of our knowledge, this is the first case of Cushing's syndrome with KS caused by endogenous glucocorticoid-induced immunosuppression.

Kaposi's sarcoma and mTOR: a crossroad between viral infection neoangiogenesis and immunosuppression

The incidence of Kaposi's sarcoma (KS) among the recipients of solid organ transplants is about 500 times the rate in the general population, suggesting a role for immunosuppression in the development of the disease. The drugs used for the induction and maintenance of immunosuppression and the length of treatment with these agents influence both the incidence and the type of cancer development. The clinical presentation of KS in transplant recipients is often limited to the skin. The risk of death from KS is related to the form and extent of the lesions. The main approach to managing transplant-associated KS is to reduce or even discontinue immunosuppressive therapy; this strategy carries a risk of acute rejection of the graft. KS is a multicentric tumor composed of endothelium-lined vascular spaces and spindle-shaped cells. Its pathogenesis is unclear. Recent evidence suggests that vascular endothelial growth factor (VEGF) is likely to be a growth factor for KS cells: blocking the interaction between VEGF and Flk-1/KDR can abolish VEGF-induced growth of the tumor. Recently, Sirolimus, a drug used in kidney-transplant recipients, has been suggested to reduce KS progression in transplant recipients. This unexpected effect of the drug confirms previous experimental information on KS pathogenesis and may shed light on an array of molecular mechanisms, modulated by Sirolimus, of potential clinical interest in the transplantation scenario.

Development of De Novo Cancer in p53 Knock-Out Mice is Dependent on the Type of Long-Term Immunosuppression Used

BACKGROUND

Development of cancer in transplant recipients may be influenced by different immunosuppressive agents. Recent publications suggest that rapamycin (RAPA), or possibly mycophenolate mofetil (MMF), may reduce established tumor growth; however, experimental data is lacking for de novo cancer prevention.

METHODS

We tested the effects of long-term immunosuppression on spontaneous tumor formation in p53 knock-out mice. Mice received no treatment, or were given RAPA, MMF, or cyclosporine (CsA) starting on week nine after birth, with the experimental endpoint being week 29.

RESULTS

All (9/9) untreated mice developed clinically evident tumors before week 26, as confirmed by histology (6 lymphomas, 2 sarcomas, 1 lymphoma+sarcoma). All CsA-treated mice (9/9) also developed clinical tumors before the endpoint (7 lymphomas, 1 sarcoma, 1 lymphoma+sarcoma). With MMF, 7/10 mice showed clinical evidence of tumor before the experimental endpoint (4 lymphomas, 2 sarcomas, 1 lymphoma+sarcoma), however, histologic tissue analysis revealed that the remaining three mice had subclinical cancer (3 lymphomas). In contrast, RAPA treatment resulted in only three mice with clinical tumors (all lymphomas), with histology revealing subclinical lymphomas in three additional mice, but no evidence of cancer in four animals. Statistically, cancer development was decreased with RAPA treatment (P=0.002), but was not affected with either MMF or CsA (P>0.10).

CONCLUSION

These experiments are the first to show immunosuppression under RAPA can reduce spontaneous de novo cancer associated with p53 mutations. Although neither CsA nor MMF treatment affects p53-associated tumor incidence, MMF may have some tendency to reduce clinical tumor appearance.

Incidence of cancer after immunosuppressive treatment for heart transplantation

Prolonged or intensive immunosuppressive therapy used after organ transplantation is complicated by an increased incidence of cancer. Striking differences in incidence are observed in heart and heart-lung transplant recipients when compared with renal transplant patients. The most significant increase was in the incidence of lymphomas in cardiac versus renal patients. Moreover, a two-fold greater increase of all neoplasms was found in cardiac recipients, with nearly a six-fold increase in visceral tumors. Several factors may account for these differences. In cardiac allograft recipients, intensive immunosuppression is frequently used to reverse acute rejection and the highest number of cardiac transplants was performed in the era of polypharmacy, usually consisting of triple therapy.

Human herpes virus-8 serology and DNA analysis in recipients of renal allografts showing Kaposi's sarcoma and their respective donors

Kaposi's sarcoma (KS) developed among 11 of 416 renal allograft recipients transplanted between 1985 and 2000. Only 3 among 364 Caucasian recipients developed KS, while it affected 8 of 52 Black patients, all of whom had been born in African countries (P <.001). All patients had their immunosuppression reduced; two also received daunorubicin and one received electrotherapy. Three patients developed accelerated renal allograft dysfunction, probably due to the reduced immunosuppression. Remission of KS was observed in seven patients, while lesions stabilized or improved partially in the other four. After resuming dialysis 2 of 11 patients died; both were in KS remission. Human herpes virus-8 (HHV-8) serology and DNA analysis was evaluated in sera obtained from seven donors: all were negative. Conversely, among eight sera collected pretransplant from the nine living recipients, HHV-8 IgG was detected in six and DNA was present in one. HHV-8 IgG was expressed in all patients (9/9) at some point posttransplant; DNA was detected in three patients. Therefore, the robust ethnic predisposition to KS was associated with a high pretransplant prevalence of HHV-8 among African recipients. Although some seroconversions were detected posttransplant, there was no evidence for donor-to-recipient transmission.

Pro- and anti-cancer effects of immunosuppressive agents used in organ transplantation

Development of cancer is a feared, and increasingly apparent, complication of long-term immunosuppressive therapy in transplant recipients. In addition to the need to reduce cancer occurrence in these patients, therapeutic protocols are lacking to simultaneously attack the malignancy and protect the allograft when neoplasms do occur. In this overview, we present the current literature regarding the pro- and anti-neoplastic effects of immunosuppressive agents on cancer growth and development. Recent experimental findings are paving the way for new therapeutic strategies aimed at both protecting an allograft from immunologic rejection and addressing the problem of cancer in this high-risk population.

Comparative Epidemiology and Pathogenic Factors for Nonmelanoma Skin Cancer in Organ Transplant Patients

BACKGROUND

Organ transplantation has been performed for almost 40 years with steadily increasing success regarding long-time survival of the graft as well as quality of life for the patient. An increase of skin cancers as a consequence of the lowered cellular immune response seems to parallel the overall increased survival rate of organ transplant recipients. Against the background of chronic immunosuppression, known risk factors like the amount of sun exposure before and after transplantation and oncogenic viruses as well as the genetic background and place of residence (latitude) are strongly related with the increased skin cancer incidence. The goal of this review is to compare the epidemiologic prevalence of nonmelanoma skin cancer between various geographic locations and to highlight pathogenesis factors.

METHODS

This study was based on a review of the current literature.

RESULTS

The increasing incidence of nonmelanoma skin cancer paralleling a prolonged survival of patients after organ transplantation represents a significant reason for morbidity and long-term mortality in organ transplant recipients worldwide. The incidence of nonmelanoma skin cancer in liver, kidney, and heart transplant recipients varies from 1.5% to 22%, 2% to 24%, and 6% to 34%, respectively, within 5 years of transplantation depending on geographic location and other pathogenesis factors. Ultraviolet radiation (UVR) as well as immunosuppressant therapy are crucial risk factors regarding the induction and progression of skin cancer. UVR is related to the induction of DNA damage as well as interference with Langerhans cell antigen presentation and a TH1-TH2 shift induced via release of IL-10. Whereas the overall duration of immunosuppression and the accumulative dosage applied are relevant measures in the pathogenesis of an increased tumor risk, individual differences between specific immunosuppressive agents are more difficult to assess.

CONCLUSIONS

Multiple international studies assess risk factors and pathophysiology of skin cancer in organ transplant patients, with variable results in the literature. Large multicenter studies with thorough multivariant analysis may provide useful information for center-independent analysis of pathogenesis factors for transplant-related skin cancer.

Mycophenolate mofetil: suggested guidelines for use in kidney transplantation

Mycophenolate mofetil (MMF) is an immunosuppressive drug designed to inhibit inosine monophosphate dehydrogenase (IMPDH). IMPDH is a key enzyme in the de novo purine synthesis of lymphocytes. It is crucially important for proliferative responses of human T and B lymphocytes. The inhibition of IMPDH thus leads to selective lymphocyte suppression. After successful use in various in vitro and animal models, MMF was brought to clinical trial in patients undergoing transplantation. The drug is rapidly and completely absorbed following oral administration. Pilot studies of administration with cyclosporin and corticosteroids suggested a significant reduction in the incidence of organ rejection at dosages of 1 to 3 g/day. As a result of these studies, 3 pivotal randomised double-blind multicentre trials, involving nearly 1500 patients, were designed to investigate the effects of addition of MMF to different standard immunosuppressive protocols on the prevention of acute renal allograft rejection. After 6 months, the rates of biopsy-proven rejection were significantly reduced in patients receiving MMF. In combination with cyclosporin and corticosteroids, the adverse effect profile resembled that of azathioprine. Most adverse effects were associated with the gastrointestinal tract, the blood system and opportunistic infections. MMF offers improved immunosuppressive therapy following renal and probably other solid organ transplantation. MMF has been licensed since 1995 for the prevention of acute renal allograft rejection in most countries. It has been used in different combinations of immunosuppressive drugs and in various dosages and regimens.