Anticardiolipin antibodies in hemodialysis patients and in renal transplant recipients: prevalence and significance

Increased anticardiolipin antibodies (aCL) serum levels have been recently described in haemodialysis patients and in renal transplant recipients, with a prevalence ranging from 4.8 to 46.4%. The causes and the clinical significance of aCL positivity in these patients are uncertain. We measured IgG- and IgM-aCL serum levels in 61 haemodialysis patients, in 14 renal transplant recipients and in 38 healthy controls. Increased levels of IgG-aCL were found in 4 haemodialysis patients (6.55%), in 2 transplant patients (14%) and in 2 of the healthy controls (5.26%). IgM-aCL serum levels were normal in all the patients. After one year of follow-up, no vascular events have been observed in aCL positive patients. It is probable that the presence of aCL in the serum of patients with end-stage renal disease is only an epiphenomenon and does not play a pathogenetic role.     

Excess prevalence of fasting and postmethionine-loading hyperhomocysteinemia in stable renal transplant recipients

Hyperhomocysteinemia, either fasting or after methionine loading, may contribute to the increased incidence of cardiovascular disease events experienced by renal transplant recipients. Limited data are available on fasting homocysteine (Hcy) levels, and none on postmethionine-loading Hcy levels, in these patients. We assessed the prevalence and potential determinants of fasting and postmethionine-loading hyperhomocysteinemia in 29 stable renal transplant recipients and 58 age- and sex-matched, population-based controls free of renal disease with serum creatinine levels of 1.5 mg/dL or less. Total (t) plasma Hcy was determined fasting and 2 hours after methionine loading, along with fasting determinations of the B-vitamin cofactors/substrates for Hcy metabolism, ie, pyridoxal 5'-phosphate, B-12, and folate and serum creatinine. Geometric mean fasting (18.1 versus 9.8 microM, P < .001) and postmethionine-loading increase (22.0 versus 15.2, P = .001) in tHcy levels were significantly greater in the renal transplant recipients, as were the prevalence odds (with 95% confidence intervals) for fasting [14.8 (3.4-64.7)], postmethionine loading [6.9 (1.5-32.8)], combined fasting and postmethionine-loading [18.0 (2.3-142.1)] hyperhomocysteinemia, and inadequate circulating folate [4.2 (1.1-16.5)] or pyridoxal 5'-phosphate [3.2 (0.9-11.0) status. Correlation analyses suggested important potential relationships between creatinine and both fasting (+0.64, P < .001) and postmethionine-load increase (+0.38, P = .045) in tHcy, folate and fasting (-0.41, P = .025) tHcy, and pyridoxal 5'-phosphate and postmethionine-loading increase (-0.33, P = .091) in tHcy. We conclude that there is an excess prevalence of fasting and postmethionine-loading hyperhomocysteinemia in stable renal transplant recipients. Renal function is related to both fasting and postmethionine loading-hyperhomocysteinemia, inadequate folate status is associated with fasting hyperhomocysteinemia, and inadequate vitamin B-6 status may be related to postmethionine-loading hyperhomocysteinemia in this patient population.     

Kaposi's sarcoma in renal transplant recipients

One hundred and seventeen of 270 (43%) recipients of organs obtained from donors with malignancies had evidence of transmitted cancers. In 9 instances these were removed from renal allografts immediately prior to transplantation. Including these cases there were 45 recipients of organs in which a neoplasm involved the allograft, 6 others in whom adjacent structures were invaded, and another 66 patients who had distant metastases. Precautions to prevent cancer transmission include meticulous preoperative screening of donors, careful examination of all organs at the time of harvesting, biopsy of any suspicious lesions, and routine donor autopsy, if possible.     

Carotid atherosclerosis in renal transplant recipients

BACKGROUND: Cardiovascular accidents are the major cause of morbidity and mortality in renal transplant recipients. However, there is little information concerning carotid atherosclerotic wall changes in renal transplant recipients, their relationship with cardiovascular accidents and their possible association with cardiovascular risk factors in such patients. METHODS: Between April 1991 and December 1997, we prospectively assessed cardiovascular accidents in 79 renal transplant recipients who had received a transplant at our institution before January 1, 1986. Carotid morphology by B-mode ultrasonography, relevant clinical and laboratory cardiovascular risk factors, including lipid abnormalities and total homocyst(e)ine, were determined at the start of the follow-up period. Seventeen healthy subjects matched for age and sex with renal transplant recipients served as controls who volunteered for ultrasonographic examination of carotid arteries. RESULTS: Nine patients experienced cardiovascular events during the period of follow-up. Compared with healthy, age- and sex-matched control subjects (n = 17), the frequency of carotid plaques was higher in renal transplant recipients with cardiovascular events (n = 9), but not in those without such events (n = 70). The frequency of cardiovascular accidents was related to the number of carotid plaques (4, 17 and 24% for no plaque, one plaque and > 1 plaque respectively, P < 0.04). However, by multivariate analysis, serum total cholesterol [odds ratio (OR) of 1.8 for each 1.0 mM, P < 0.07) and the presence of diabetes mellitus (OR of 28.4 for presence, P < 0.01) were the only predictors of cardiovascular events in such patients, whereas the presence of carotid plaques was not. Moreover, neither serum lipoprotein (a) nor total homocyst(e)ine concentrations could be identified as risk factors. CONCLUSIONS: This prospective study shows that although a close association exists between asymptomatic carotid atherosclerosis and cardiovascular accidents in renal transplant recipients with long-term follow-up and relatively good renal function, other potentially modifiable risk factors appear to be better predictors of cardiovascular events. Consequently, the assessment of carotid atherosclerosis may not be clinically useful for the systematic identification of renal transplant recipients with an increased risk of developing cardiovascular events.     

Compliance with cyclosporine in adolescent renal transplant recipients

The percentage of non-tasters for phenylthiocarbamide in 915 Japanese students was 9.4%. The thresholds of the edge and back of the tongue to quinine hydrochloride were significantly smaller in the non-tasters than in the tasters. The thresholds of any tongue portions to NaCl, acetic acid or sucrose did not differ between the tasters and the non-tasters.     

High prevalence and usual persistence of serum monoclonal immunoglobulins evidenced by sensitive methods in renal transplant recipients

BACKGROUND: The occurrence of serum monoclonal immunoglobulins in kidney transplant recipients is well known but their significance and predictive value for the occurrence of lymphoma are a matter of debate. We therefore conducted a study of monoclonal immunoglobulins by a sensitive method during the long-term follow up of grafted patients. METHODS: Monoclonal immunoglobulins were characterized by high-resolution electrophoresis, conventional immunoelectrophoretic analysis, and a sensitive Western blotting procedure in the serum from 84 renal transplant recipients prior to grafting and subsequently, with a 1-8-year follow-up and excluding the patients who developed posttransplant lymphoma. RESULTS: Low abundance monoclonal immunoglobulins were detectable prior to transplantation in 56 cases (66.6%) and after graft in 72 cases (85.5%) (and in 1 case (1.2%) and 18 cases (21.4%) of cases respectively, by immunoelectrophoresis). These abnormalities were often multiple in individual sera. Monoclonal components detected by immunoblotting were transient in 23.8% of patients only (whereas those evidenced by immunoelectrophoresis usually became undetectable by this method) and their pattern was remarkably stable in the majority of cases. The frequency of post-transplant monoclonal immunoglobulins was higher in patients of more than 50 years of age than in younger patients. The appearance of monoclonal components after grafting and their transient character correlated with CMV infections. No correlation was found with various other parameters. The isotypic distribution of monoclonal immunoglobulins with an IgM, IgG3, and IgG1 predominance and an abnormally low kappa/lambda ratio was the same as that observed in various immunodeficiency states. The monoclonal immunoglobulin pattern in three further patients who developed post-transplant lymphoma was unremarkable. CONCLUSION: Monoclonal immunoglobulins hence are not discriminant for lymphoma and their characterization does not appear to be necessary in the evaluation of followed up grafted patients, at least for a prediction of post-transplant lymphoma.     

Epstein-Barr virus in malignancies in renal transplant recipients in Japan

A role for Epstein-Barr virus (EBV) in the development of malignancies including lymphomas, and carcinoma of the stomach, nasopharynx, thymus and salivary gland is suggested. It is indicated that EBV evokes polyclonal-B-cell-proliferative diseases in immunocompromised hosts, such as transplant patients, which results in monoclonal malignant lymphomas. The suppression of immune functions in these patients is thought to lead to incomplete elimination of the cells expressing EBV latent infection genes. To examine the etiological role of EBV in the development of malignancies following renal transplant in Japan, 42 malignancies in 1744 cases of renal transplant were studied for the presence and type of EBV. The polymerase chain reaction revealed that 5 malignancies were positive for EBV, all type A: 2 of 2 cases of non-Hodgkin's lymphoma (NHL), 2 of 8 cases of gastric adenocarcinoma of the common type, and 1 of 2 cases of gastric plasmacytoma. In situ hybridization revealed positive signals in the nucleus of tumor cells in 2 cases of NHL and 1 of plasmacytoma. Positive signals were found in the small lymphoid cells but not in the tumor cells in 2 cases of gastric carcinoma. On the basis of these findings, a role for EBV in the development of malignancies in renal transplant patients is unlikely except for lymphoid neoplasias.     

Gender discrepancies in living related renal transplant donors and recipients

Renal transplantation is the most successful treatment strategy for patients with ESRD to improve survival and quality of life. The study presented here examines the relationship of gender and living related (LR) transplantation donor and recipient rates in the United States. National data from the United States Renal Data System (USRDS) were used for this study. All LR transplants occurring between 1991 and 1993 among blacks and whites were included (N = 6193). Transplantation and donation rates for men and women were calculated. Poisson regression was used to calculate female/male transplantation and donation rate ratios. Overall, women were 10% less likely to receive a LR transplant than men (rate ratio [RR] = 0.90, P < 0.001). This gender difference increased over time from 1991 (Female/Male RR = 0.95, P = not significant [NS]) to 1993 (RR = 0.85, P < 0.001). In contrast, women were significantly more likely to donate a kidney than men (RR = 1.28, P < 0.001 and RR = 1.29, P < 0.001 among whites and blacks, respectively). Analyses by age subgroups revealed that only among ESRD patients aged 20 to 44 yr was the likelihood of receiving a LR kidney transplant equal for men and women. Higher donation rates among women compared with men were observed in all donor age and race subgroups except young blacks (aged 0 to 19 yr). Recipient gender appeared to influence donation rates. The female-to-male relative donation rates were higher when donations were to female, compared with male, recipients. This study of national data suggests an imbalance in LR donation and transplantation between men and women. Women are more likely to donate a kidney but are less likely to receive a LR transplant than men. Several potential explanatory factors are explored. These findings suggest a need for the development of gender-appropriate interventions to encourage donation among men and LR transplantation among women, to ultimately facilitate greater use of this ESRD treatment modality.