Transplantation of a New Biological Product in Rare Diseases, Such as Epidermolysis Bullosa: Response and Clinical Outcome.

BACKGROUND: Epidermolysis bullosa (EB) is a phenotypically diverse group of hereditary blistering disorders involving mutations in 20 different genes. Those debilitating disorders are currently incurable; however, there are a number of promising preclinical trials, where some treatments already approach the stage of early clinical trial. In this paper we introduce a novel surgical approach to the treatment of EB-induced ulcerations. The purpose of our study was to evaluate the safety and efficacy of a new biological dressing in the form of an allogenic human skin equivalent graft before using multipotent stem cells, classified as an advanced therapy medicinal product. METHODS: Implanted human acellular dermal matrices were prepared from the superficial layers of donated human skin. Scaffold sterilization was conducted via irradiation with the use of a linear electron accelerator. Following water-knife debridement, wounds were surgically covered with accordingly prepared grafts and dressed in burn-injury fashion. Subsequently, the wounds were monitored for infection and viability. RESULTS: Our data indicate that grafting as a potential new medicinal product was safe and effective in patients with rare diseases, such as EB, and may be used for stem cells to create new Advanced Therapy Medicinal Products. During a 200-day follow-up, we proved the safety of using human scaffolds (allogeneic graft) by observing no apparent infection or necrosis. Instead, we noted fewer required dressing changes, promoted wound healing, pain reduction, and an overall improvement in the quality of life in patients with EB. CONCLUSION: The protocol for grafting allogenic acellular epidermal sheets is the most promising treatment for severely affected skin areas in EB patients to date.

New Treatment of Wound Healing With Allogenic Acellular Human Skin Graft: Preclinical Assessment and In Vitro Study.

BACKGROUND: Nonhealing wounds can be a major clinical problem. Impaired wound healing is often related to massive tissue injury, concomitant wound healing deficiencies (chronic wounds), burn injury, or congenital conditions. We propose a novel biological dressing as an alternative surgical approach. The dressing is a form of an allogenic human skin graft equivalent with further use of allogeneic stem cells classified as an advanced therapy medicinal product. This new allogenic acellular human skin graft has been specifically developed to address the clinical indications for dressing wound lesions and promoting tissue repair in specific rare genetic diseases. METHODS: This case report illustrates the use of an acellular human skin allograft seeded with multipotent stem cells in the treatment of tissue injuries (burns), congenital conditions, and chronic wounds. Donor-tissue processing yields an acellular dermal matrix with integral collagen bundling and organization, as well as an intact basement membrane complex. RESULTS: Preclinical observations show prolonged viability of acellular human skin grafts with multipotent stem cells. This was confirmed with histological and electron-microscopic evaluation of biopsies, which demonstrated host-cell infiltration and neovascularization of the biological dressing. Moreover, the dressings were characterized by low immunogenicity, as confirmed by histology exam and T-cell proliferation assays in vitro. CONCLUSION: Our data confirmed the safety and efficacy of the evaluated acellular human skin grafts, which may be used in patients with rare diseases, such as epidermolysis bullosa, burn injuries, and chronic wounds.

Trichosporon asahii as a prospective pathogen in solid organ transplant recipients.

Trichosporon spp. is not an important factor of mycotic infections in immunocompetent patients. It may be a cause of invasive mycoses with a high mortality rate in patients undergoing solid organ transplantation. We have analysed the antifungal agents' susceptibility of Trichosporon asahii and its frequency of occurrence as a prospective etiological agent of infections in liver, kidney and simultaneous pancreas-kidney transplant recipients. Clinical specimens (urine, blood, peritoneal fluid and swabs) were obtained from patients hospitalised in the Institute of Transplantation Medicine, Department of General and Transplantation Surgery, Medical University of Warsaw in 2005 and 2006. Microbiological tests were performed in Mycological Laboratory, Department of Microbiology, Medical University of Warsaw. A total of 475 strains of yeast-like fungi were isolated from clinical specimens taken from 263 liver, kidney and simultaneous pancreas-kidney transplant recipients and from 26 organ donors. Trichosporon asahii was found in 26 clinical samples taken from 18 patients and one organ donor. Positive cultures were obtained from 22 urine samples, one stoma fluid, one wound swab, one tracheal aspirate and one ejaculate. Isolates of Trichosporon asahii were found in 6% of total positive mycological cultures in the solid organ transplant recipients. Among cultured strains, 11 isolates were resistant to fluconazole, four to itraconazole and three of them demonstrated resistance to amphotericin B.

Frequency of Human Papilloma Virus Occurrence Among Pathological Changes of the Oral Cavity in Kidney Allotransplant Recipients Undergoing Long-Term Pharmacological Immunosuppressive Therapy.

Recipients of allotransplants are more susceptible to viral infections, among which the human papilloma virus infection is an independent factor inducing precancerous lesions and cancers of both the anogenital and the cervicocephalic region. MATERIALS AND METHODS: The study included a group of 69 allogenic kidney transplantation recipients aged 20 to 70, who were treated with cyclosporine, azathioprine, and prednisone. The patients in whom the macroscopic examination of the oral mucosa revealed lesions were qualified for a biopsy. The infection with human papilloma virus (HPV) was confirmed by a histopathological examination and genotyping with the use of polymerase chain reaction (PCR) and Hybrid Capture II test. RESULTS: Papillomatous lesions in the oral cavity occurred in 36.1% of the research group participants. The HPV16 virus was the most common genotype in this group of patients (25%). The pathologic changes in the oral cavity were predominantly situated on the gingivae. In the group of transplant recipients, clinical changes resulting from HPV infection occurred within a period of 2 years following the transplantation. Cyclosporine used in the immunosuppression scheme has correlated in as many as 53.7% of cases of allogenic kidney transplant recipients with the appearance of clinical signs and symptoms of HPV infection. In 50% of cases there was a correlation with acute kidney transplant rejection. When induction therapy (anti-thymocyte globulin [ATG] and muromonab-CD3 [OKT3]) was applied, at least 1 oral cavity lesion in each case of allogenic transplant recipients was reported. CONCLUSIONS: Typing of HPV with the use of molecular methods should be a standard diagnostic technique.

Frequency of Pathologic Changes in the Oral Cavity in Patients Subjected to Long-term Pharmacologic Immunosuppressive Therapy After Kidney, Liver, and Hematopoietic Cell Transplantation.

INTRODUCTION: Patients subjected to long-term immunosuppressive therapy after organ and cells transplantation are more susceptible than healthy people to the development of the pathologic changes in the oral cavity, including precancerous lesions, oral cancers, lesions following viral infections (herpes simplex virus, Epstein-Barr virus, and cytomegalovirus), fungal infections mainly caused by Candida albicans, drug-induced gingival overgrowth, stomatitis, and tongue disorders. MATERIAL AND METHODS: Clinical case material included 38 patients after kidney, liver, or blood-forming cells transplantation subjected to various immunosuppressive therapy schemes. The study comprised standard case taking and physical examination of the patient, including detailed intraoral and extraoral stomatological examinations. RESULTS: Extraoral examination confirmed 1 case of multifocal basal cell carcinoma in the auricular region and one case of systemic lupus erythematosus. Intraoral examination revealed gingivitis (60.5%), gingival recession (58%), periodontitis (55.26%), macroglossia (15.8%), lingual papillary atrophy (13.16%), leukoplakia aphthae/ulcerations (10.5%), lichen planus, pallor of mucous membranes (7.9%), pathologic pigmentation of oral mucosa, geographic tongue (5.26%) and erythroplakia (2.6%). When their histories were taken, patients reported xerostomia (68.42%), halitosis (23.68%), gum bleeding while brushing teeth (18.42%), and dysgeusia (15.78%). DISCUSSION: Both the patients after organ and hematopoietic stem cells transplantations and those qualified for a transplant should undergo multispecialty treatment, particularly dental treatment, to enable the detection of pathologies at an early stage and commencement of effective therapy. Cooperation between the main doctor and the dentist is crucial in the process of treatment of this group of patients.

Evaluation of the Safety and Clinical Efficacy of Allogeneic Bone Grafts in the Reconstruction of the Maxilla and Mandible.

INTRODUCTION: Loss of teeth caused by inflammatory processes or trauma is one of the causes of bone atrophy of the maxilla alveolar process and the alveolar part of the mandible. Often, restoring these deficiencies with dental implants requires additional reconstructive procedures. Methods using autogenous, allogeneic, xenogeneic, or synthetic bone grafts are commonly used. MATERIALS AND METHODS: Patients who had bone atrophy of the maxilla or mandible were qualified for deep-frozen transplantation, radiation-sterilized allogeneic bone from the Bank of Tissues in the form of cortico-spongy bone blocks and spongy bone granules. Bone blocks were stabilized with titanium screws, and the free spaces were additionally supplemented with chips from autogenous bone and covered with allogeneic pericardial transplants and platelet-rich fibrin (PRF). Four months after the bone reconstruction, titanium implants were placed, and then after the osseointegration period prosthetic restoration was performed. Clinical safety and efficacy were determined by analyzing the quantity and quality of the reconstructed bone tissue and the degree of resorption was assessed. RESULTS: The surgical procedures performed confirmed the safety and efficacy of biological material in the reconstruction of the jaw. In two cases, the treatment was not effective and the transplant was removed. In the remaining cases, titanium implants were successfully placed and loaded with prosthetic works. DISCUSSION: Implanting deeply frozen, radiation-sterilized bone is a safe and effective surgical procedure. As an appropriate technique for fixing the allogeneic bone block, additional use of autogenous bone chips and PRF allows one to obtain a good, long-lasting clinical result.

Road accident rates: strategies and programmes for improving road traffic safety.

INTRODUCTION: Nowadays, the problem of road accident rates is one of the most important health and social policy issues concerning the countries in all continents. Each year, nearly 1.3 million people worldwide lose their life on roads, and 20-50 million sustain severe injuries, the majority of which require long-term treatment. DISCUSSION: The objective of the study was to identify the most frequent, constantly occurring causes of road accidents, as well as outline actions constituting a basis for the strategies and programmes aiming at improving traffic safety on local and global levels. Comparative analysis of literature concerning road safety was performed, confirming that although road accidents had a varied and frequently complex background, their causes have changed only to a small degree over the years. The causes include: lack of control and enforcement concerning implementation of traffic regulation (primarily driving at excessive speed, driving under the influence of alcohol, and not respecting the rights of other road users (mainly pedestrians and cyclists), lack of appropriate infrastructure and unroadworthy vehicles. CONCLUSIONS: The number of fatal accidents and severe injuries, resulting from road accidents, may be reduced through applying an integrated approach to safety on roads. The strategies and programmes for improving road traffic should include the following measures: reducing the risk of exposure to an accident, prevention of accidents, reduction in bodily injuries sustained in accidents, and reduction of the effects of injuries by improvement of post-accident medical care.

Multiple neoplastic lesions of the lower genital tract in a human papilloma virus-infected kidney-pancreas allograft recipient: a case report.

States of immunodeficiency are associated with an increased rate of certain cancers. Immunosuppressed allograft recipients are at high risk of Human Papilloma Virus (HPV)-related de novo malignancies. A female pancreas plus kidney transplant patient developed multiple genital malignancies within 6 years. The genome of human papilloma virus type 16 was detected in malignant lesions obtained from surgical procedures. All detected lesions were removed at an early state of development.

Dependence of acquired systemic tolerance to rat islet allografts induced by intrathymic soluble alloantigens on host responsiveness, MHC differences, and transient immunosuppression in the high responder recipient.

Recent studies suggest that the adult immune system can be manipulated by intrathymic (IT) inoculation of donor Ag to accept cardiac and islet allografts in the low responder rat combination of Lewis-to-WF. We have now extended this study to examine the effect of IT inoculation of soluble protein Ag obtained from 3M KCl extracts of resting T cells combined with transient ALS immunosuppression on islet allograft survival in the high responder combination of WF-to-Lewis. We first confirmed the earlier observation that IT injection of 2 mg soluble Ag on day -7 led to permanent islet graft survival (>200 days) in the Lewis-to-WF rat combination without the use of recipient immunosuppression and found this to be true in the Lewis-to-ACI rat combination. In the high responder combination of WF-to-Lewis, unmodified Lewis rats pretreated with IT inoculation of 2 mg soluble Ag acutely rejected WF and BN islet allografts. IT inoculation of donor Ag combined with 1 ml ALS transient immunosuppression on day -7 led to a modest graft prolongation [24.8+/-10.1 days as compared with 15.2+/-3.6 days in ALS only treated controls]. Intrathymic injection of soluble Ag on day -7 combined with 1 ml ALS on days -7 and 0 relative to allografting resulted in 100% permanent islet graft survival (>200 days) compared with an MST of 20.6+/-2.3 days in ALS only-treated controls. Similar treatment led to acute rejection of 3rd party (BN) grafts, thus demonstrating donor-specificity. In addition, extrathymic inoculation of donor Ag in similarly immunosuppressed animals did not result in islet graft prolongation, once again confirming the importance of the thymus in tolerance induction. To examine them for donor-specific tolerance, long-term unresponsive (>120 days) Lewis recipients of renal subcapsular islets underwent nephrectomy of the islet bearing kidneys and were challenged with intraportal donor- or third party-type islets after becoming diabetic. All the nonimmunosuppressed recipients of donor-type (WF) islets became permanently normoglycemic (>100 days) while the third-party (BN) grafts were promptly rejected, with an MST of 10.6 days. These findings confirm that acquired thymic tolerance induced by IT inoculation of soluble protein Ag in the low to moderate responder rat combinations is reproducible in the high responder combination provided that adequate peritransplant immunosuppression is used. This study suggests that acquired thymic tolerance in the rat model is dependent on host responsiveness to alloantigens, MHC differences between the donor-recipient pair, and the use of transient immunosuppression in the high responder recipient. This model may have potential clinical application in the development of strategies for specific transplantation tolerance.

Transplantation tolerance to rat cardiac and islet allografts by posttransplant intrathymic inoculation of soluble alloantigens.

The search for strategies for induction of specific tolerance in adult animals that will avoid long-term host immunosuppression with its complications has led to the deliberate introduction of alloantigens (Ag) into the adult thymus. However, pretransplant intrathymic (IT) inoculation of alloantigens (Ag), which has consistently induced tolerance to vascularized and neovascularized allografts in adult rodents, has limited future clinical application. To overcome the practical limitations of pretreatment, we have examined in the Lewis-to-WF combination the effect on graft survival of either simultaneous or posttransplant IT inoculation of soluble Ag obtained from 3M KCl extracts of donor T cells in transiently rabbit antirat lymphocyte serum (ALS) immunosuppressed recipients. While IT injection of 2.0 mg soluble Ag alone on day of cardiac transplantation caused acute graft rejection, IT inoculation of 2.0 mg Ag combined with 1 ml ALS transient immunosuppression of the recipient on day 0 led to long-term graft survival (> 250 days) in 5/6 recipients. Similarly, IT injection of soluble Ag on posttransplant day 3 or day 7 combined with 1 ml ALS on day 0 relative to allografting resulted in permanent graft survival in all recipients. In contrast, intravenous injection of soluble Ag combined with ALS immunosuppression on day 0 led to acute graft rejection that paralleled the rejection seen in ALS treated controls. Third-party Brown Norway (BN) hearts were acutely rejected in similarly prepared recipients of IT-Ag, thus confirming donor specificity. The long-term unresponsive Wistar-Furth (WF) recipients challenged 100 days after cardiac transplantation with a second-set graft specifically and permanently (> 100 days) accepted the second-set donor cardiac allografts, thus demonstrating donor-specific tolerance. In similar experiments, IT inoculation of 2 mg soluble Ag combined with transient ALS immunosuppression resulted in donor-specific unresponsiveness to islets in the same rat combination of Lewis-to-WF. Our findings suggest that this new strategy of immunologic manipulation of the adult thymus offers a safe, effective, and reproducible method of inducing tolerance that may have therapeutic application in cadaveric organ transplantation.

Fludarabine phosphate: A DNA synthesis inhibitor with potent immunosuppressive activity and minimal clinical toxicity.

Fludarabine phosphate selectively eliminates normal and malignant mononuclear cells in large animals and man through the inhibition of DNA synthesis. The drug depletes mononuclear cells from culture within 24 hours of initial exposure, CD4 and CD8 T cells being more sensitive than either CD20 B cells or CD34 bone marrow precursors. Mitogenic activation of lymphocytes enhances cellular elimination from culture. Fludarabine inhibits PHA-induced T-cell proliferation by >90 per cent and mixed lymphocyte reactions (allogeneic and xenogeneic) by >95 per cent. Fludarabine exerts its cytolytic effects through the induction of endonuclease-independent apoptosis. A 5-day course of fludarabine (50 mg/m2 intravenously once daily) induces both T- and B-cell lymphopenia in Cynomolgus monkeys and Papio baboons. Transient neutropenia was the only side-effect seen in experimental animals. Pretreatment of Cynomolgus monkeys with this regimen of fludarabine causes a prolongation of ABO-compatible skin allograft survival from 8 days (control) to 16 days (drug treated group). Secondary allotransplantation into presensitized recipients showed a similar prolongation of graft survival with fludarabine pretreatment (8 days vs 5 days control). Fludarabine promises to be a potent immunosuppressive agent with low clinical toxicity.

Pancreatic islets isolation using different protocols with in situ flushing and intraductal collagenase injection.

Human islet transplantation seems to be a very promising clinical procedure for patients with type I diabetes mellitus. The aim of our study was to investigate the influence of in situ intravascular flushing with University of Wisconsin (UW) solution and intraductal collagenase injection at the time of pancreas procurement on the isolated islets and exocrine tissue injury. Our experiments indicated that in situ perfusion with the UW solution has a beneficial effect on pancreatic islets and intraductal distention results in an increase in the concentration of pancreatic enzymes released into the cold preservation solution during ischemic conditions. Cold ischemia reduced islet yield, but pancreas perfusion with the UW solution showed better ischemic tolerance of isolated islets during glucose static incubation. We conclude that intravascular pancreas flushing has a crucial effect on recovery and yield of pancreatic islets and protects against exocrine tissue injury.

Amylase levels in preservation solutions as a marker of exocrine tissue injury and as a prognostic factor for pancreatic islet isolation.

Occurrence of primary graft nonfunction of pancreatic islets demands research for new methods of organ preservation during cold ischemia conditions. Digestive enzymes released during preservation injure the islets for subsequent rewarming and islet isolation processes. The aim of our study was to assess the amylase level in preservation solution as a marker of exocrine tissue injury, allowing the prognosis of islet yield and viability. The experiments undertaken on rats used three commercially available preservation solutions: ViaSpan (UW); Custodiol (HTK); and Euro-Collins (EC). After 180 minutes of cold ischemia, the highest islet recovery was observed among pancreata stored in UW solution (508 +/- 139 vs HTK 344 +/- 103; P <.05 vs EC 322 +/- 113; P <.05). These islets also revealed the highest insulin stimulation index in glucose static tests (1.19 +/- 0.30 vs HTK, 0.87 +/- 0.43; P <.01, vs EC.25 +/-.06; P <.001). The highest amylase level in the preservation solution was associated with a decreased yield of islets during the isolation process and lowest insulin stimulation index (increasing 139 +/- 18% for EC, 108 +/- 12% for HTK; P <.05 vs 87 +/- 10% for UW; P <.05). Our data strongly suggest, that the dynamic of amylase release during pancreas preservation at 4 degrees C correlates with a reduced number and viability of isolated islets. These results suggest that measurement of amylase levels after pancreas preservation may have potential clinical application as a marker to evaluate pancreatic tissue injury.

Proliferation of transplanted allogeneic pancreatic islets.

Recent studies showed enhanced regeneration of pancreatic islets in some circumstances. The purpose of our study was to investigate the proliferate potential of rat pancreatic islet cells in allogeneic grafts. Adult Lewis female rats and WAG male rats served as recipients and donors, respectively. Diabetes was induced by single intravenous (IV) injection of streptozotocin producing diabetes as confirmed by nonfasting plasma glucose >300 mg% on 3 consecutive days. Islet rejection was considered complete when glycemia exceeded 250 mg% and was confirmed by histopathological examination. To obtain long survival of allogeneic islets a tolerance-inducing method used allogeneic UV-B irradiated bone marrow transplantation into nonlethally selectively cytoreducted recipients with a donor-type splenocyte infusion followed by cyclophosphamide 200 mg/kg bw. Endocrine cell proliferation was assessed morphometrically using double immunostaining for pKi-67 and insulin or glucagon. Double immunolabelling, propidium iodide staining, and TUNEL assay were used to identify both proliferating and apoptotic cells. The rise of glycemia >350 mg/dL after graftectomy in euglycemic recipients was correlated with immunohistological examination, showing that the euglycemia was due to properly functioning pancreatic islet allotransplants. The immunohistochemical examination confirmed the presence of endocrine beta and alpha cells. In comparison with normal pancreas which showed 0.4 +/- 0.12%, pKi-67-positive cells, long-surviving grafts had a significantly higher proliferation capacity (5.61 +/- 0.94%; P <.001). In contrast, rejected grafts/control groups did not show significantly enhanced proliferation (0.73 +/- 0.19%), and had endocrine cells undergoing apoptosis. The incidence of apoptosis in endocrine cells within long-surviving graft appeared to be extremely low. In conclusion, the growth and death of endocrine cells in allogeneic grafts differ between accepted and rejected cases. The level of proliferation in the graft at day 150 was significantly higher compared with normal pancreatic beta cells.

Human cystic and alveolar echinococcoses as indication to liver transplantation.

The human cystic and alveolar echinococcoses are zoonotic diseases caused by larval stages of the tapeworms Echinococcus granulosus and E multilocularis. In man the liver form of the diseases develops most frequently. Recent epidemiological data indicate that the distribution of E multilocularis in the central Europe is wider than was previously anticipated; more cases of human alveococcosis during the last years have also been noted in Poland. In the present paper we analyzed several cases of human echinococcoses from Poland with respect to diagnosis and treatment as well as the indications for liver transplantation.

Oral cavity as a potential source of infections in recipients with diabetes mellitus.

Our previous observations showed alterations of oral cavity status among hemodialyzed patients and kidney allograft recipients as well as differences in the prevalence and composition of microorganisms occurring in the mouths of patients. In the present work, we analysed the results of oral cavity examinations, the identification of microorganisms, and the assessment of their importance to kidney allograft recipients or hemodialyzed patients with diabetes mellitus, in comparison with nondiabetic recipients, dialyzed patients, and control patients.

Effects of DL-penicillamine on cytotoxic reaction between baboon performed xenoantibodies and pig endothelial cells.

The purpose of this study was to evaluate effects of DL-Penicillamine (DLP), a compound interrupting S-S bonds (IgM pentamers) on binding and cytotoxicity of adult baboon performed xenoantibodies to pig endothelial cells. Pooled baboon serum was treated with different concentrations of DLP during various periods of time. Complement-mediated cytotoxicity assay was used to determine the reactivity of baboon xenoantibodies to pig aortic endothelial cells (PAEC). To assess IgM and IgG binding to PAEC, ELISA method was applied. Serum treated with DLP revealed significant reduction of cytotoxicity in a dose dependent manner. Cytotoxicity was also reduced during time prolongation of DLP exposure to PAEC. Results indicate that baboon performed IgM and IgG xenoantibodies bind to pig endothelial cells, but only IgM is able to cause degradation of the complement. DLP significantly reduces cytotoxicity and eliminates binding of IgMs to PAEC in spite of continued binding of IgG xenoantibodies to the surface of endothelium.

Leukocytes and endothelium interaction as rate limiting step in the inflammatory response and a key factor in the ischemia-reperfusion injury.

Leukocyte-endothelium interactions play a key role in regulation of the inflammatory response, leukocytes migration and ischaemia-reperfusion injury. These adhesive reactions controlling the circulation of leukocytes, are key parts of immune surveillance arising from extravasation of neutrophils, and migration into tissue to eliminate invading microorganism. They also play important role in the generation of ischaemic-reperfusion injury of different organs including brain. Plasma levels of soluble adhesion molecules may be a diagnostic marker of the systemic endothelial injury. It is likely that the next few years bring new therapies to control leukocyte-endothelial interaction by directly inhibiting the adhesion molecules or by modulating their expression.

The role of adhesion molecules in allotransplanted islet cells rejection. Prolongation of islet cells allograft survival by antiadhesion treatment.

Insulin-dependent diabetes mellitus is an autoimmune disease caused by the selective destruction of islet beta cells. Allo or xeno transplantation of islet cells may establish a novel promising method of IDDM therapy. Understanding how lymphocytes recognize beta cell antigens is essential for the elucidation of the pathogenesis of islet dysfunction. Leukocyte adhesion to the target cells (endothelium, islets) via adhesion molecule pathways plays an important role in auto and allo/xeno antigen recognition and effector cytodestruction of target cells. However, the expression of these molecules on the endothelium and islet cells during the rejection process still remains unclear. There are some publications describing possible roles of these antigens in the response to the graft. The expression of some of adhesion molecules may contribute to a new method for the diagnosis of graft rejection and its therapy when adhesion blocking substances are used for the treatment.

Hyperhomocysteinemia as a risk factor for cardiovascular diseases. The association of hyperhomocysteinemia with diabetes mellitus and renal transplant recipients.

Hyperhomocysteinemia has been recognised as an independent risk factor for cardiovascular, cerebrovascular and peripheral artery disease. There is strong evidence suggesting that hyperhomocysteinemia accelerates the process of atherogenesis. Possible explanations for this will be shortly reviewed. Recently a growing interest has been focused on the association of hyperhomocysteinemia with diabetes mellitus and with chronic renal disease, including renal transplant recipients. Some clinical aspects of this occurrence, such as interactions with insulin, metformin, and cyclosporine and also with some vitamins, will be described. The issue of hyperhomocysteinemia in heart transplant patients will also be mentioned. Last of all, the interaction of homocysteine concentration with some beverages will be considered.