Renal transplantation (first of two parts)

Renal transplant immunology in the last 20 years: A revolution towards graft and patient survival improvement

To deride the hope of progress is the ultimate fatuity, the last word in poverty of spirit and meanness of mind. There is no need to be dismayed by the fact that we cannot yet envisage a definitive solution of our problems, a resting-place beyond which we need not try to go. -P.B. Medawar, 1969 * Thomas E. Starlz, also known as the Father of Clinical Transplantation, once said that organ transplantation was the supreme exception to the rule that most major advances in medicine spring from discoveries in basic science [Starzl T. The mystique of organ transplantation. J Am Coll Surg 2005 Aug;201(2):160-170]. In fact, the first successful identical-twin kidney transplantation performed by Murray's team in December 1954 (Murray J et al. Renal homotransplantations in identical twins. Surg Forum 1955;6:432-436) was the example of an upside down translation medicine: Human clinical transplantation began and researchers tried to understand the underlying immune response and how to control the powerful rejection pathways through experimental models. In the last 20 years, we have witnessed an amazing progress in the knowledge of immunological mechanisms regarding alloimmune response and an outstanding evolution on the identification and characterization of major and minor histocompatibility antigens. This review presents an historical and clinical perspective of those important advances in kidney transplantation immunology in the last 20 years, which contributed to the improvement in patients' quality of life and the survival of end-stage renal patients. In spite of these significant progresses, some areas still need substantial progress, such as the definition of non-invasive biomarkers for acute rejection; the continuous reduction of immunosuppression; the extension of graft survival, and finally the achievement of real graft tolerance extended to HLA mismatch donor: recipient pairs.

Assessment of Health-Related Quality of Life in Chronic Dialysis Patients with the COOP/WONCA Charts

BACKGROUND

The aim of the present work was to determine the health-related quality of life (HRQOL) of our patients on hemodialysis using the COOP/WONCA charts. A further aim was to explore its psychometric characteristics.

METHODS

The present study included all patients attending the hemodialysis unit of our hospital. The comparative study of the results was conducted with other population groups in which this questionnaire has been applied previously (primary-care patients, their accompanying persons, pregnant women, Alzheimer patient carers and drug addicts). The dimensional structure of the questionnaire was explored by factorial analysis of principal components, and internal consistency was evaluated with the Cronbach alpha factor. Concurrent validity was determined by comparative analysis of the results of the COOP/WONCA charts with those of another questionnaire, the 36-item short form of the Quality of Life Score (SF-36). To do so, 60 randomly chosen patients completed both questionnaires.

RESULTS

98.9% of patients completed the COOP/WONCA charts in their entirety. The mean scores of all the charts, with the exception of overall health, are in the range of what could be called 'favorable area of quality of life' (below 3). With respect to the rest of the groups, the dialysis patients had the best scores on the 'feelings' and 'social activities' charts and none of the worst ones. The joint factorial analysis revealed that the questionnaire has a 3-factor structure: factor 1 or daily functioning, factor 2 or quality of life and health, factor 3 or the psychosocial factor. The Cronbach alpha value for the 9 charts was 0.766. All the correlations between equivalent dimensions of questionnaires COOP/WONCA and SF-36 were statistically significant (p < 0.01). The convergent validity mean was 0.57 and the discriminant validity mean was 0.22, appreciably lower than convergent validity.

CONCLUSIONS

This study shows that the process of psychological adaptation to problems deriving from dialysis is satisfactory. Moreover, the COOP/WONCA charts are a useful instrument for the determination of the HRQOL in hemodialysis patients without losing psychometric quality.

Salmonella bacteremia in renal transplant recipients

Three cases of salmonella bacteremia in renal transplant recipients are reported. Two patients had prolonged salmonella infections with recurring bacteremia. The longest interval between bacteremic relapses was 15 years. 27 cases from the literature of salmonella bacteremia in renal transplant recipients are reviewed. The courses of salmonellosis in renal transplant recipients are more serious than in other non-compromised patients, being complicated by bacteremia in 70% of the cases. Renal transplant recipients have prolonged carrier states and frequent relapses or recurrences of salmonellosis. 45% of the salmonella bacteremias in renal transplant recipients are seen after a high dose methylprednisolone treatment for graft rejection episodes.

Cardiac consequences of renal transplantation: changes in left ventricular morphology and function

To characterize changes in left ventricular morphology and function associated with renal transplantation, noninvasive cardiac evaluations were performed in 41 adults at the time of surgery and at follow-up. At the time of transplantation, 36 patients had undergone hemodialysis through a fistula for 2.3 +/- 2.5 years (mean +/- SD); their hematocrit level was 26 +/- 6% and systolic blood pressure was 151 +/- 19 mm Hg. Perioperatively, left ventricular hypertrophy was present in 93% of patients by echocardiography, but in only 37% by electrocardiography. Abnormal left ventricular diastolic function was present in 67% of patients and indicated a high risk for perioperative pulmonary edema. At follow-up (1.5 +/- 1.4 years), mean hematocrit level increased to 39 +/- 7%, systolic blood pressure decreased to 132 +/- 14 mm Hg and spontaneous closure of the fistula occurred in 13 patients. Left ventricular mass by echocardiography decreased from 237 +/- 66 to 182 +/- 47 g (p less than 0.001), a decrease of 23%. Left ventricular volumes and cardiac index also decreased significantly, reflecting the rapid resolution of a pretransplant high output state. Despite proportionate regression of left ventricular hypertrophy within months of transplantation, diastolic function did not improve. The significant regression of left ventricular hypertrophy that occurs after renal transplantation may help explain the improved cardiovascular survival of patients with a renal transplant over that of patients on long-term dialysis.

Serial immunologic studies in recipients of hepatic allografts

Thirty recipients of hepatic allografts had serial immunologic evaluations. Prior to transplant, patients had marked depression of lymphocyte subsets and impaired in vitro immunoglobulin synthesis, while phytohemagglutinin responsiveness was similar to that of controls. Following transplantation and introduction of cyclosporine and low-dose steroid therapy, there was a significant decline in both T cell subsets, but only the T4 population remained significantly depressed throughout the entire study period. The T4:T8 ratio in 5 patients who experienced acute rejection episodes was 1.4 +/- 0.6 prior to transplant. It increased to a mean of 2.0 +/- 0.6 by the time the diagnosis of rejection was made. By contrast, 12 subjects transplanted during a similar time period who did not demonstrate rejection had a T4:T8 ratio of 4.0 +/- 3.9 prior to transplant which fell to 1.5 +/- 0.6 (P less than 0.01) by 1 week post-transplant. In all 12 of these, the T4:T8 ratio fell in the 7 days post-transplant. The results indicate that monitoring the T4:T8 ratio in hepatic allograft recipients may be a useful marker for determining patients at risk for a rejection episode.

Blood transfusion and disease-free survival in carcinoma of the breast

A retrospective study was undertaken to determine the effect of perioperative blood transfusion on disease-free survival rates in patients with carcinoma of the breast. The charts of 81 patients participating in a NSABP breast cancer protocol at The Mt. Sinai Medical Center, Cleveland, Ohio, were reviewed. There was no statistically significant difference in disease-free survival between those patients receiving blood transfusions and those that did not when considering the entire group of patients or subgroups based upon age, nodal status, estrogen receptor status, or progesterone receptor status. However, the subgroup of patients receiving tamoxifen chemotherapy, especially those with positive estrogen receptors, had significantly reduced disease-free survival (P less than .05) when given blood transfusions. These results suggest an adverse effect of blood transfusion on disease-free survival in breast cancer patients treated with tamoxifen chemotherapy.

Treatment bias in the management of end-stage renal disease

A study was conducted of 419 patients with end-stage renal disease (ESRD) being treated by center or home hemodialysis or by renal transplantation at four facilities located within 2.5 km of each other. The objectives were to examine the distribution of patients among the three modes of treatment and to analyze patient transfers to alternate modes of ESRD therapy. While white patients at each facility were comparable (P greater than 0.05) on age, sex, travel time to treatment, marital status, work or employment status, and the presence of diabetes mellitus, the distribution of patients among the treatment modes differed significantly (P less than 0.001) across the facilities. Similarly, the sociodemographic and diagnostic characteristics of the nonwhite patients were comparable at each of the facilities (P greater than 0.05); however, despite observable variation among the facilities in the distribution of these patients, the differences did not achieve statistical significance (P greater than 0.05). Patient transfers to alternate modes of ESRD therapy were infrequent, and among center hemodialysis patients, the distribution of transfers differed significantly across the facilities (P less than 0.001). It is concluded that the distribution of patients was dependent on the patient's initial mode of therapy and the staff attitudes at the individual facilities.

Capsula-protected homotransplantation - a hypothesis on bypassing immunological rejection in allogeneic organ transplantation

By influencing fetal brain development pregnancy may be prolonged beyond term for an unknown time period. In late gestation the mother animal (host) is nephrectomized. The urine of the fetus (transplant) is guided to the outside so that the fetal kidneys excrete the host's urinary secretory substances and eventually hypertrophy. The literature on hypertrophy of the (fetal) kidney, placental passage of urinary secretory substances, endocrine function of the (fetal) kidney and extrarenal tissue, prolongation of gestation, and some aspects of the immunological protection of the fetus is critically reviewed. Conclusions as to the eventual realisation of this hypothetic model of organ allotransplantation without rejection are set forth.

Cardiac function in end-stage renal disease

To assess cardiac status in end-stage renal disease, we compared clinical, ECG, and echocardiographic data from 37 patients on maintenance hemodialysis with data from 42 patients with functioning renal transplants. Cardiovascular symptoms and abnormal cardiovascular findings were more common in dialysis-maintained patients than in those with transplants. Follow-up studies indicated that despite a high prevalence of cardiac symptoms, abnormal physical signs, and dilated left ventricles among patients with end-stage renal disease, systolic left ventricular function was generally well preserved irrespective of renal failure therapy. Compared with maintenance hemodialysis, however, successful renal transplantation is associated with an overall enhancement of cardiac status, the majority of which is probably secondary to transplant-associated improvement in hemoglobin level and control of intravascular volume.

The quality of life of hemodialysis and transplant patients

This study demonstrates the application of a more comprehensive methodology for evaluating quality of life of hemodialysis and transplant patients and provides some heuristic data. Physiologic and psychologic measures were combined to assess the quality of life of 59 patients treated for endstage renal disease (ESRD). Patients with successful cadaveric transplants gave evidence of greater physical and occupational rehabilitation than patients on chronic hemodialysis. On measures of subjective quality of life, however, successful transplant and hemodialysis patients were similar in reporting normal affect whereas failed transplant patients showed a diminished quality of life. These results suggest that cadaveric transplantation may have limited value as an intervention to improve quality of life for patients with ESRD. Moreover, the results demonstrate the usefulness of questionnaire techniques adapted from psychological research for evaluating the quality of life of patients following medical intervention.

Prolongation of canine allograft survival with donor pretreatment

Donor pretreatment of 100 mg/kg each of cyclophosphamide (CY) and methylprednisolone (P) infused 5 hours before nephrectomy invariably prolongs the survival of DLA mismatched, MLC incompatible nonlittermate Beagle renal allografts as well as the survival of mongrel renal allografts. The effect of donor pretreatment appears to be mediated by cyclophosphamide and its metabolites because methylprednisolone pretreatment does not significantly prolong survival. Methylprednisolone is needed, however, because it abolishes cyclophosphamide pretreatment mediated early but transient postoperative renal (allograft) insufficiency. The effect of donor pretreatment appears to be mediated by drugs residing in the graft; mannitol infusions given 1 hour prior to donor nephrectomy or peroperatively into the recipient decrease the renal cortical content of carbon 14 cyclophosphamide and its metabolites and abolishes the prolonged survival. Because donor pretreated kidneys contain less than 0.5% of the infused dose of carbon 14 cyclophosphamide, the drugs appear to exert their effect locally in the transplanted kidney. Donor pretreatment mediating prolonged canine renal allograft survival appears to be an example of influencing a biological process by a localized drug delivery by virtue of unique properties of the drug and because early postoperatively host sensitization occurs mainly at the site of the graft.

Use of monoclonal antibodies to T-cell subsets for immunologic monitoring and treatment in recipients of renal allografts

Using monoclonal antibodies and flow cytometry, wer serially monitored lymphocyte subpopulations in renal-allograft recipients treated with either conventional immunosuppression or a monoclonal antibody. In 29 patients given conventional suppression, highly significant correlations between changes in T-cell subsets and rejection were noted. Normal or elevated ratios of OKT4 (helper/inducer) to OKT8 (suppressor/cytotoxic) cells were associated with rejection unless the donor was HLA identical or the total number of T cells was extremely low. In patients with low ratios, rejection seldom occurred. Two patients treated with OKT3 monoclonal antibody for acute rejection had rapid disappearance of OKT3-reactive cells from the peripheral blood and prompt reversal of rejection. The use of monoclonal antibodies allows the precise determination of changes in T-cell subsets and promises the development of therapeutic protocols that can be designed to manipulate selected lymphocyte populations.