Pretransplant exposure to donor HLA-DR antigen in random transfusion units and the development of donor antigen-specific hyporeactivity

Our previous studies have shown that the in vitro assay of donor antigen-specific hyporeactivity is a useful marker for identifying solid organ transplant recipients (kidney, lung and heart) at low risk for immunologic complications (i.e., late acute rejection episodes and chronic rejection). Donor antigen-specific hyporeactivity is defined as a significantly decreased post- vs. pretransplant proliferative response to donor antigens while response to third-party controls remains unchanged. We analyzed whether exposure to the same HLA-DR antigen pretransplant via random blood transfusion and posttransplant via the transplanted organ influenced the development of hyporeactivity. Thirty previously nontransfused recipients, each receiving two 150 ml pretransplant random blood transfusions, were assessed for hyporeactivity at 1 year posttransplant. Of the 12 recipients with pretransplant exposure to kidney HLA-DR via transfusions, 6 (50%) developed hyporesponsiveness; in contrast, of the 18 recipients who were not preexposed, only 3 (15%) exhibited this form of immunomodulation. Of interest, 2 of the 3 hyporesponsive recipients who were not preexposed, received units containing HLA-DR antigens previously shown to share crossreactive epitopes with the kidney HLA-DR. In conclusion, these results suggest a increased incidence in the development of hyporeactivity in patients receiving pretransplant transfusions which share an HLA-DR antigen with the transplanted kidney.

Colon perforation after renal transplantation: a single-institution review

Colon perforation (CP) is an uncommon but dramatic complication after renal transplantation. Of 1530 consecutive kidney transplants performed at our center, 8 recipients had an CP (incidence of 0.5%), either early (n = 5, 2-14 days) or late (n = 3, 8-48 months) post transplant. Clinical symptoms were generally vague. Biological findings were inconstant. Risk factors for CP included a cadaver graft (versus a living donor), high body weight, history of diverticulitis, and Kayexalate use. Crucial to outcome were: 1) immediate diagnosis and 2) aggressive surgical care consisting of resectional therapy, broad-spectrum antibiotics, and reduced immunosuppression. Applying these principles, mortality in our patients (25%) was lower than in previously reported series (33-64%). All grafts were functioning at the time of diagnosis; graft function was preserved in recipients who recovered from CP. Patients with a documented history of diverticulitis should undergo prophylactic colonic resection. Constipation and colonic dilatation should be treated aggressively in the early post-operative period.

Combined liver and kidney transplantation

Patients with end-stage renal and hepatic failure may be treated with combined liver and kidney transplantation (CLKTx). We reviewed the indications and outcomes of 16 CLKTx performed at the University of Minnesota between 1980 and 1994. The majority of the recipients (87.5%) were young patients affected by congenital hepatic anomalies and concomitant end-stage renal failure. Fourteen were treated with cyclosporin-based immunosuppression and had an excellent outcome: with an average of 6 years of follow-up, patient survival was 85.7%, liver graft survival 85.7%, and kidney graft survival 72%. The incidence of rejection episodes was similar to the rate of rejection in our solitary kidney and liver transplants. In conclusion, our experience supports the value of CLKTx in treating patients with simultaneous failure of both organs or with congenital enzymatic hepatic deficits leading to renal failure.

Pregnancy after donor nephrectomy

Potential female donors frequently ask whether unilateral nephrectomy will impair future childbearing capabilities. To address this question, we surveyed 220 women who underwent donor nephrectomy between 1985 and 1992. Of the 144 women who responded, 33 became pregnant after donation for a total of 45 pregnancies. Seventy-five percent of the pregnancies were carried to term without difficulty. Complications incurred during gestation included miscarriage (13.3%), preeclampsia (4.4%), gestational hypertension (4.4%), proteinuria (4.4%), and tubal pregnancy (2.2%). Four of the 45 pregnancies (excluding miscarriages) required preterm hospitalization, resulting in an overall morbidity of 8.8%. There were no pregnancy-related deaths, and no fetal abnormalities were reported. Problems with persistent hypertension, proteinuria, or changes in renal function were not noted. None of the above complications exceeded what has been noted for the general population. Infertility was a problem in 8.3% (3/36) of our respondents, compared with a worldwide incidence of 16.7%. Based on these results, we conclude that donor nephrectomy is not detrimental to the prenatal course or outcome of future pregnancies.

A third kidney transplant: cost-effective treatment for end-stage renal disease?

Given the organ donor shortage, some question whether a third kidney transplant can be justified. We studied the outcome of 51 third transplants (mean age 28 +/- 2 yr) done between 1 January 1985 and 31 December 1994. We compared hospital stay (mean +/- S.E.), cost, readmissions, readmission days, and outcome of third (vs. first and second) transplants. We found that patient survival for third transplants was equivalent to first and second transplants; graft survival was not as good. However, when third transplant recipients with recurrent disease (specifically, hemolytic uremic syndrome and focal sclerosis) were excluded from our analysis, we found no difference in 5-yr graft survival (vs. first or second transplant recipients). Of the 51 third transplant recipients, 41 had a cadaver donor transplant. Third cadaver transplant recipients tended to have a longer hospital stay (p = NS) than first cadaver transplant recipients but had no more readmissions or readmission days than first and second cadaver transplant recipients. Employment data are available for 28 third transplant recipients; 16 (57%) are currently working or going to school. Of the 21 recipients who responded to quality of life questionnaires, 17 (81%) reported being healthy and all 21 (100%) said transplantation was not a drawback to their health. We conclude that third transplants should be considered for selected patients with renal failure whose first and second transplants have failed. Such patients can often be successfully transplanted.

The importance of early cyclosporine levels in pediatric kidney transplantation

We studied the impact of early cyclosporine (CSA) levels on the incidence of rejection in pediatric transplant recipients. Between 1 January 1984 and 31 December 1994, a total of 234 pediatric patients underwent kidney transplants and received CSA immunosuppression. We analyzed the impact of CSA levels (at 1 wk, 2 wk, 1 month, 2 months, and 3 months) on the incidence of rejection in the first 3 and the first 6 months post-transplant. We found that CSA levels at all timepoints correlated, i.e. recipients with low levels in the early post-transplant period tended to have low levels throughout the first 12 months. Multivariate analysis for risk factors by biopsy-proven rejection in the first 3 months revealed that the CSA trough level was the critical factor (p < 0.05). Recipients with CSA trough levels < 100 ng/ml had 2.24 times the risk of rejections vs. those with blood levels > 100 ng/ml. Similarly, the CSA trough level at 1 month was the critical risk factor for biopsy-proven rejection within the first 6 months (p < 0.05). The major risk factor for graft loss within the first 12 months was a biopsy-proven rejection episode. We conclude that in pediatric kidney transplant recipients, early CSA trough levels < 100 ng/ml are associated with a significantly increased incidence of rejection in the first 6 months post-transplant.

Kidney transplant recipients who die with functioning grafts: serum creatinine level and cause of death

How to analyze death with function (DWF) in transplant survival statistics has become an important issue. DWF is a predominant cause of late graft loss. We recognize that some deaths may be related to the transplant. However, considering DWF as a graft loss may obscure some analyses. An additional consideration is whether patients who "die with function" actually had good kidney function or whether their death was related to or hastened by impaired function. To answer this question, we studied the serum creatinine level and cause of death for kidney recipients who died with function. Between January 1, 1985, and December 31, 1994, we did 1932 kidney transplants for 1806 recipients. Of these, 220 died with function. For the 220, we assessed the time posttransplant that death occurred, the serum creatinine level before the terminal event, and the cause of death. The most common causes of death were infection (22%), myocardial infarction (17%), and sudden death (15%). Mean serum creatinine levels were less than 2 mg/100 ml at 1 year before and at the time of death for the vast majority of these recipients. Our findings demonstrate that kidney recipients who die with function have good renal function--additional support for presenting graft survival data both with and without death censored.

An open-label, concentration-ranging trial of FK506 in primary kidney transplantation: a report of the United States Multicenter FK506 Kidney Transplant Group

This was a multicenter, open-label, concentration-ranging trial of FK506 and cyclosporine in 120 patients undergoing primary cadaveric kidney transplant. Patients were randomized to a cyclosporine-based regimen or to one of three FK506-based regimens designed to achieve low (5-14 ng/ml), medium (15-25 ng/ml), or high (26-40 ng/ml) trough whole blood levels. Corresponding initial doses of FK506 were 0.2, 0.3, and 0.4 mg/kg/day. Patients were evaluated at 42 days after transplant for the occurrence of the first episode of acute rejection or toxicity, necessitating a dosage reduction. There was no significant difference among the three FK506-based regimens and the cyclosporine-based regimen for rejection or toxicity at 42 days. However, the incidence of acute rejection was significantly lower (14% for FK506 and 32% for cyclosporine; P=0.048) for the aggregate of all FK506-treated patients versus cyclosporine. The incidence of neurotoxic and gastrointestinal events was higher among FK506-treated patients during the first month after transplant. A significant trend was observed for increasing toxicity with increasing maximum trough FK506 concentrations (P=0.01) and for decreasing rates of rejection with increasing minimum trough FK506 concentrations (P=0.021). FK506 was effective in preventing early rejection in kidney transplant recipients. The target range of whole blood levels that optimizes efficacy and minimizes toxicity seems to be 5-15 ng/ml. The corresponding recommended initial dose of FK506 for kidney transplant recipients seems to be 0.2 mg/kg/day.

Combined liver and kidney transplantation

Patients with end-stage renal and hepatic failure may be treated with combined liver and kidney transplantation (CLKTx). We reviewed the indications and outcomes of 16 CLKTx performed at the University of Minnesota between 1980 and 1994. The majority of the recipients (87.5%) were young patients affected by congenital hepatic anomalies and concomitant end-stage renal failure. Fourteen were treated with cyclosporin-based immunosuppression and had an excellent outcome: with an average of 6 years of follow-up, patient survival was 85.7%, liver graft survival 85.7%, and kidney graft survival 72%. The incidence of rejection episodes was similar to the rate of rejection in our solitary kidney and liver transplants. In conclusion, our experience supports the value of CLKTx in treating patients with simultaneous failure of both organs or with congenital enzymatic hepatic deficits leading to renal failure.

Babesiosis and hemophagocytic syndrome in an asplenic renal transplant recipient

Babesiosis is a malaria-like illness transmitted by the tick Ixodes dammini. The disease is endemic to the Northeast coastal region and parts of the Midwest. Symptoms-which include fever, anemia, elevated liver function tests, and hemoglobinuria-may be especially severe in asplenic or immunocompromised patients. In rare cases, infection with Babesia may be associated with marked pancytopenia. Bone marrow biopsy may reveal hemophagocytosis and marrow histiocytosis. We report a severe case of babesiosis and hemophagocytic syndrome in an asplenic renal transplant patient.

Impact of age on renal graft survival in children after the first rejection episode

Infants are thought to be more immunoreactive and at a greater risk for developing irreversible rejection compared with older children. We investigated this by analyzing patient and graft survival rates, incidence of acute rejection, reversibility of acute rejection, development of a subsequent acute rejection, and incidence of graft loss due to rejection in 154 children (< 18 years of age) after primary renal transplantation. Most patients (n = 139) were treated with quadruple immunosuppression (antibody, azathioprine, prednisone, cyclosporine). Treatment of the first acute rejection episode (ARE) consisted of antibody and increased prednisone (68%) or increased prednisone alone (30%), and was not significantly different between the age groups. Transplants were from living donors (LRD) in 80% of cases. Patients were followed for at least 1 year (mean 58 +/- 30 months); 68% (105/154) of recipients experienced 1 or more ARE. The incidence of ARE was significantly lower in patients < 2 years of age (45%) compared with patients 2-5 (76%, P = 0.01), 6-12 (78%, P = 0.005), and 13-17 (76%, P = 0.009) years of age. There was no significant difference in the 1-, 2- and 5-year patient or graft survival rates, the development of a subsequent acute rejection, or the incidence of graft loss due to acute rejection when analyzed by age group. These data suggest that the impact of an ARE is similar for younger and older children in our population receiving predominantly LRD transplants and quadruple immuno-suppression.

One-year follow-up of an open-label trial of FK506 for primary kidney transplantation. A report of the U.S. Multicenter FK506 Kidney Transplant Group

Patients undergoing primary cadaveric kidney transplantation were followed for 1 year as part of a phase II, multicenter, open-label concentration-ranging trial of FK506 and cyclosporine. One hundred twenty patients were randomly assigned to a cyclosporine-based regimen or one of three FK506-based regimens designed to achieve low (5-14 ng/ml), medium (15-25 ng/ml), or high (26-40 ng/ml) trough whole blood levels. Corresponding initial doses of FK506 were 0.2, 0.3, or 0.4 mg(kg/day, respectively. Patients with toxicity to FK506 had their target concentration reduced by lowering the dose of FK506. Ninety-two patients completed a 1-year follow-up to determine patient and graft survival and long-term safety. At 1-year, the patient survival rate was 98% for FK506 and 92% for cyclosporine, and the graft survival rate was 93% and 89% in the FK506 and cyclosporine groups, respectively. The incidence of acute rejection was significantly lower (14% FK506, 32% cyclosporine, P=0.048) at day 42 after transplantation. However, the incidence of rejection episodes requiring treatment at 1 year was similar in both groups (33% for FK506 and 32% for cyclosporine). Nephrotoxicity occurred with a similar frequency with FK506 and cyclosporine, but the incidence of neurotoxic events and the incidence of new insulin use were higher among FK506-treated patients. The target range of whole blood levels that optimizes efficacy and minimizes toxicity seems to be 5-15 ng/ml. The corresponding recommended initial dose of FK506 for kidney transplant recipients is 0.2 mg/kg/day. These results indicate that the efficacy and safety of FK506 were comparable to that for cyclosporine for primary immunosuppression in patients undergoing cadaveric kidney transplantation.

[Technical options of renal transplant in the absence of a viable ilio-caval venous circuit. Presentation of a case and review of the literature]

Congenital absence of useful ilio-caval venous segment is a very infrequent congenital anomaly and makes unfit grafting of a kidney transplant in iliac fossa. We report the case of a 18 years old male affected by this abnormality who was transplanted in intraabdominal situation. We review technical alternatives offered by the literature.

Delayed graft function in the absence of rejection has no long-term impact. A study of cadaver kidney recipients with good graft function at 1 year after transplantation

We previously reported that delayed graft function (DGF) in the absence of biopsy-proven acute rejection (Rej) had no effect on outcome of primary cadaver kidney transplantation (TX). By contrast, DGF in combination with Rej strongly predicted poor long-term graft survival. We asked whether this poor long-term outcome was due to early graft loss associated with DGF, or to an ongoing process leading to late graft loss. To answer this question, we studied a subset of 298 cadaver kidney transplant recipients who had not suffered early graft loss and had a serum creatinine level < or = 2.0 mg/dl at 1 year after TX. The incidence of DGF (defined by dialysis during the first week after TX) in this subset was 19%. DGF was associated with cold ischemia time >24 hr (P = 0.0003) and Rej (P = 0.06). For grafts with versus without DGF, the incidence of late acute Rej (>1 year after TX) was similar. Actuarial graft survival was similar for Rej-free recipients with versus without DGF (P = 0.9) and was worse for those with Rej and no DGF (P < 0.02). Importantly, however, in our recipients who all had a serum creatinine level < or = 2.0 mg/dl at 1 year after TX, the worst long-term outcome was noted in the subgroup with both DGF and Rej (P < 0.0001). By multivariate analysis, DGF was also only a risk factor in combination with Rej (P = 0.002, relative risk = 3.7), while a 0-antigen HLA mismatch had no impact. Patient survival decreased for recipients with both DGF and Rej by univariate (P = 0.009) and multivariate (P = 0.02, relative risk = 2.9) analyses. We conclude that DGF without Rej has no impact on long-term survival. However, our data for recipients with both DGF and Rej suggest that a chronic ongoing process leads to late graft failure. Further research is necessary to identify the exact pathophysiology of this process, which appears to be, at least in part, HLA antigen independent.

Delayed endocrine pancreas graft function after simultaneous pancreas-kidney transplantation. Incidence, risk factors, and impact on long-term outcome

BACKGROUND

The incidence of delayed endocrine pancreas graft function and its impact on long-term outcome after simultaneous pancreas-kidney transplantation are unknown.

METHODS

We studied 54 technically successful adult type I insulin-dependent diabetic recipients of cadaver, whole organ, bladder-drained simultaneous pancreas-kidney transplants (mean age, 37.6 years; 65% male, 35% female; 9% pancreas retransplants; 63% on chronic pretransplant dialysis; mean duration of diabetes, 25.1 years). Insulin was administered during the first 2 weeks after transplantation, as needed, to keep blood glucose < 150 mg/dl. Delayed endocrine pancreas graft function was defined as total, cumulative insulin requirement of > 30 U between day 5 and day 10, and/or > 15 U between day 11 and 15. Quadruple immunosuppression was used for all recipients.

RESULTS

The incidence of delayed endocrine pancreas graft function was 69%. By univariate analysis, delayed endocrine graft function was associated with pretransplant recipient weight > 80 kg (P = 0.04), donor age > 45 years (P = 0.02), and cardiocerebrovascular (P = 0.06) and nontraumatic causes of donor death (P = 0.02). The incidence of acute pancreas rejection episodes was similar for recipients without and with delayed endocrine pancreas graft function. Pancreas graft survival at 1 and 3 years was 94% and 82% without versus 76% and 59% with delayed endocrine graft function (P = 0.03).

CONCLUSIONS

Increased pancreas graft failure after delayed endocrine function was a consequence of insufficient functional reserve (e.g., older donors) rather than increased immunogenicity. Pretransplant reduction of recipient weight and careful donor selection are therefore crucial in order to decrease the incidence of delayed endocrine pancreas graft function and its negative impact on long-term outcome.

Does re-exposure to mismatched HLA antigens decrease renal re-transplant allograft survival?

We analyzed 420 kidney retransplants at the University of Minnesota, 87 of which did and 333 which did not share HLA mismatches with the previous transplant. There was no difference in outcome. We conclude that exceptions to routine HLA matching policies do not have to be made for kidney retransplants.

OBJECTIVE

To determine if the kidney graft functional survival rate for retransplants is influenced by presence of HLA mismatches in common with the previous (failed) transplant.

SUMMARY BACKGROUND DATA

Kidney retransplants have a lower function rate than primary grafts. An anamnestic response to HLA antigens shared with the previous donor could be one factor responsible, but reports in the literature are conflicting.

METHODS

Of 420 kidney retransplants with HLA information done at the University of Minnesota, 87 shared > or = 1 HLA antigens specifically mismatched with the previous donor (63 cadaver and 24 living donor retransplants), while 333 did not (247 cadaver, 86 living donor). Patient and graft survival rates were calculated by life-table analysis for recipients with vs. without repeat mismatches, with the significance of differences determined by the Lee-Desu statistic.

RESULTS

Patient and kidney graft retransplant survival rate curves were not significantly different (p > or = 0.41) for those exposed or not exposed to the same HLA mismatches as before. At 2 years, 70% vs. 61%, respectively, of cadaver grafts and 71% vs. 78%, respectively, of living donor grafts were functioning.

CONCLUSIONS

The probability of a successful outcome with a kidney retransplant is no different for patients who do than for those who do not receive an organ sharing HLA mismatches with the previous donor. Exceptions to routine HLA matching policies do not need to be made for kidney retransplants.