Graft Neutrophil Sequestration and Concomitant Tissue Plasminogen Activator Release During Reperfusion in Clinical Kidney Transplantation

BACKGROUND

Inflammation, coagulation, and fibrinolysis are tightly linked together. Reperfusion after transient ischemia activates both neutrophils, coagulation, and fibrinolysis. Experimental data suggest that tissue plasminogen activator (tPA) regulates renal neutrophil influx in kidney ischemia and reperfusion injury.

METHODS

In 30 patients undergoing kidney transplantation, we measured renal neutrophil sequestration and tPA release from blood samples drawn from the supplying artery and renal vein early after reperfusion. tPA antigen levels were measured using a commercial enzyme-linked immunosorbent assay kit. For each parameter, transrenal difference (Δ) was calculated by subtracting the value of the arterial sample (ingoing blood) from the value of the venous sample (outgoing blood).

RESULTS

Positive transrenal gradients of tPA antigen occurred at 1 minute [Δ = 14 (3-46) ng/mL, P < .01] and 5 minutes [Δ = 5 (-3 to 27) ng/mL, P < .01] after reperfusion. At 5 minutes after reperfusion, a negative transrenal gradient of neutrophils was observed [Δ = -0.17 (-1.45 to 0.24) x 10E9 cells/L, P < .001]. At 1 minute after reperfusion, neutrophil sequestration into the kidney (ie, negative transrenal neutrophil count) correlated significantly with tPA release from the kidney (ie, positive transrenal tPA concentration), (R = -0.513 and P = .006).

CONCLUSIONS

The findings suggest a proinflammatory role for tPA in ischemia and reperfusion injury in human kidney transplantation.

Matrix Metalloproteinase-9 and Graft Preservation Injury in Clinical Renal Transplantation

BACKGROUND

Deleterious effects of matrix metalloproteinase-9 (MMP-9) have been established in experimental renal ischemia-reperfusion models but not in clinical renal transplantation thus far.

METHODS

We studied MMP-9 and its physiological inhibitor tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) in 45 consecutive patients of a larger trial in renal transplantation: perioperative anti-thymocyte globulin (group A, n = 15), perioperative basiliximab (group B, n = 16), and conventional triple therapy (group C, n = 14). In addition to systemic blood samples, local blood samples were obtained simultaneously at 1 and 5 minutes after reperfusion from iliac artery and graft vein for calculation of transrenal changes. Because anti-thymocyte globulin activates inflammation, group A was analyzed separately. Groups B and C were pooled (group BC).

RESULTS

Anti-thymocyte globulin infusion caused a robust rise of MMP-9 in the systemic circulation in group A. No significant transrenal difference of MMP-9 or TIMP-1 occurred in either group during graft reperfusion. In group BC, strong transrenal release of MMP-9 at 1 minute after reperfusion correlated with cold ischemia time (R = 0.66, P = .0001) and was associated with delayed graft function (P = .052).

CONCLUSIONS

Renal production of MMP-9 on graft reperfusion is associated with cold ischemia time and emergence of delayed graft function. MMP inhibition may offer a means to reduce reperfusion injury in renal transplantation.

Type 1 Diabetes Mellitus Donor Mesenchymal Stromal Cells Exhibit Comparable Potency to Healthy Controls In Vitro

: Bone marrow mesenchymal stromal cells (BM-MSCs) have been characterized and used in many clinical studies based on their immunomodulatory and regenerative properties. We have recently reported the benefit of autologous MSC systemic therapy in the treatment of type 1 diabetes mellitus (T1D). Compared with allogeneic cells, use of autologous products reduces the risk of eliciting undesired complications in the recipient, including rejection, immunization, and transmission of viruses and prions; however, comparable potency of autologous cells is required for this treatment approach to remain feasible. To date, no analysis has been reported that phenotypically and functionally characterizes MSCs derived from newly diagnosed and late-stage T1D donors in vitro with respect to their suitability for systemic immunotherapy. In this study, we used gene array in combination with functional in vitro assays to address these questions. MSCs from T1D donors and healthy controls were expanded from BM aspirates. BM mononuclear cell counts and growth kinetics were comparable between the groups, with equivalent colony-forming unit-fibroblast capacity. Gene microarrays demonstrated differential gene expression between healthy and late-stage T1D donors in relation to cytokine secretion, immunomodulatory activity, and wound healing potential. Despite transcriptional differences, T1D MSCs did not demonstrate a significant difference from healthy controls in immunosuppressive activity, migratory capacity, or hemocompatibility. We conclude that despite differential gene expression, expanded MSCs from T1D donors are phenotypically and functionally similar to healthy control MSCs with regard to their immunomodulatory and migratory potential, indicating their suitability for use in autologous systemic therapy.

SIGNIFICANCE

The potential for mesenchymal stromal cells (MSCs) as a cell-based therapy in the treatment of immunologic disorders has been well established. Recent studies reported the clinical potential for autologous MSCs as a systemic therapy in the treatment of type I diabetes mellitus (T1D). The current study compared the genotypic and phenotypic profiles of bone marrow-derived MSCs from T1D and healthy donors as autologous (compared with allogeneic) therapy provides distinct advantages, such as reduced risk of immune reaction and transmission of infectious agents. The findings of the current study demonstrate that despite moderate differences in T1D MSCs at the gene level, these cells can be expanded in culture to an extent corresponding to that of MSCs derived from healthy donors. No functional difference in terms of immunosuppressive activity, blood compatibility, or migratory capacity was evident between the groups. The study findings also show that autologous MSC therapy holds promise as a T1D treatment and should be evaluated further in clinical trials.

Serum neutrophil gelatinase-associated lipocalin and recovery of kidney graft function after transplantation

Background

Neutrophil gelatinase-associated lipocalin (NGAL) is a marker for acute kidney injury. We studied whether serum NGAL predicts delayed graft function (DGF) and recovery of kidney function after transplantation.

Methods

Serum NGAL was analyzed using commercial ELISA and point-of-care (POC) (Triage®, Biosite) methods. Serum samples were collected from 176 consecutive, deceased-donor kidney recipients just before transplant surgery and on day 1 and 14 after transplantation. The first 132 samples were analyzed with both methods and the remaining samples with the POC method.

Results

The correlation between the ELISA and POC methods was 0.89, p < 0.0001 and hence the POC method was used for the remaining analyses. DGF was seen in 66/176 patients. Day 1 sNGAL was significantly higher in DGF (588 ng/ml, SD 189.6) compared to early graft function (355 ng/ml, SD 166.2, p < 0.0001) and this difference persisted on day 14. Day 1 sNGAL predicted DGF with an area under the curve (AUC) of 0.853 (CI 0.792-0.914, p < 0.0001). At the optimal cutoff level of 423 ng/ml the sensitivity was 87% and the specificity 77%. In a multivariate analysis, day 1 sNGAL emerged as an independent predictor of DGF. The sNGAL also predicted DGF lasting longer than 14 days with an AUC of 0.825 (CI 0.751-0.899, p < 0.0001). At the optimal cutoff level of 486 ng/ml, the sensitivity was 80% and specificity 75%.

Conclusion

Serum NGAL predicts clinically significant DGF and is useful in the care of kidney transplant recipients.

Heme oxygenase 1 gene polymorphisms and outcome of renal transplantation

Heme oxygenase isoenzyme HO-1 has been linked to several cytoprotective functions with a potentially beneficial role in transplantation. In the present study, the effect of genetic variation in HO-1 on renal allograft outcome was investigated. Six hundred and eighty patients subject to renal transplantation in a single transplant unit and their cadaveric kidney donors were included in this study. Four single-nucleotide polymorphisms and one microsatellite marker in the HO-1 gene region were analysed. Some statistically nominally significant associations were observed in preliminary analyses between polymorphisms studied and clinical outcomes, but after correction for multiple comparisons none remained significant. Our data suggest that the HO-1 gene polymorphisms studied have no significant role on outcome of kidney transplantation in the Finnish population.

Single bolus antithymocyte globulin versus basiliximab induction in kidney transplantation with cyclosporine triple immunosuppression: efficacy and safety

BACKGROUND

The aim of this prospective randomized study was to examine the effect of induction immunosuppression and low initial cyclosporine (CsA) on the onset of graft function and its long-term consequences.

METHODS

During 1999-2001, 155 patients were randomized to single 9 mg/kg dose antithymocyte globulin (ATG)-Fresenius (group A) or two 20-mg doses of basiliximab (group B) with reduced dose CsA or conventional CsA triple therapy without induction (group C).

RESULTS

Delayed function (DGF) was lower in group A than in groups B or C (5.7% vs. 24.1% and 15.9%, P<0.025) and need of dialysis was less in groups A and B compared to C (10.3 and 10.4 vs. 20.0 days, P<0.05). Acute rejections occurred in 11.3%, 12.1% and 20.5%, and the mean (median) time to rejection was 16 (13), 97 (46) and 101 (35) days in groups A, B, and C, respectively (P<0.005). One-and 5-year graft survivals (GS) were 98.1% and 90.6% (group A), 96.6% and 96.6% (group B), and 93.2% and 84.1% (group C). Five-year GS was significantly better in group B than in group C (P<0.05). The death censored 5-year GS in groups A, B, and C were 94.3%, 96.6%, and 90.0% (P=NS). Single high-dose ATG induction was associated with hemodynamic and pulmonary disturbances without, however, serious or long-term consequences.

CONCLUSIONS

ATG induction significantly reduced DGF. Both induction regimens together with low initial CsA led to significantly less posttransplant dialysis and excellent survival. The high dose ATG was associated with significant hemodynamic and pulmonary side effects during drug infusion.

Lack of association between thrombosis-associated and cytokine candidate gene polymorphisms and acute rejection or vascular complications after kidney transplantation

BACKGROUND

Acute rejection episodes and vascular complications are common after renal transplantation and have negative impact on the long-term patient and graft survival. We investigated whether the risks of acute rejection, thrombosis, infarction and graft loss could be predicted based on the presence of functional polymorphisms in the genes of the coagulation and endothelial inflammation cascade.

METHODS

The study consisted of 772 consecutive cadaver kidney transplantations from a single centre. The effects of gene polymorphisms FVL, F5R2, FII G20210A, MTHFR C677T, F13A1 V34L, TFPI P151L, PROC W380G, TNF G(-308)A, IL10 A(-592)C, IL10 A(-1082)G and IL6 C(-174)G of recipients and donors were investigated.

RESULTS

We were unable to find statistically significant associations between any of the studied polymorphisms and clinical outcomes.

CONCLUSIONS

Our results indicate that high-risk renal transplant candidates cannot be identified through the routine analysis of the polymorphisms.

Diagnosis of Acute Renal Allograft Rejection by Analyzing Whole Blood mRNA Expression of Lymphocyte Marker Molecules

BACKGROUND

Currently, the diagnosis of acute rejection after kidney transplantation is based on a kidney biopsy taken after clinical rejection suspicion. A robust, noninvasive diagnostic method would allow easier and more frequent monitoring of the patient and the graft. Potentially, a straightforward method would be the analysis of lymphocyte marker molecule expression from whole blood samples.

METHODS

Whole blood samples were collected prospectively in a single kidney transplantation center from 50 adult kidney recipients transplanted between 2001 and 2005. The mRNA expression of granzyme B, perforin, FasL, granulysin, CD154, ICOS, CTLA4 and PD-1 were analyzed with real-time quantitative polymerase chain reaction.

RESULTS

The expression of ICOS and CD154 were significantly lower in rejection patients than in control patients (P<0.001). Both genes gave statistically significant area under receiver operating characteristic curve (AUC; 0.87, 0.88) with 84% sensitivity and 100% specificity for CD154 and 76% and 86% for ICOS, respectively. In paired rejection and postrejection therapy samples, the expression of both genes significantly increased during rejection therapy (P<0.001). When rejection patients were compared to patients biopsied because of other reasons of graft dysfunction, both CD154 and ICOS were lower in rejection patients but only CD154 was statistically significant (P=0.028, AUC=0.740, sensitivity 52%, specificity 90%). The other studied genes gave no consistent statistically significant results.

CONCLUSIONS

The whole blood gene expression quantities of costimulatory molecules CD154 and ICOS reasonably robustly differentiated rejection patients from control patients. The clinical use of the analysis is limited by poor capability to differentiate patients with rejection from patients with other causes of graft dysfunction.

The impact of donor cytokine gene polymorphisms on the incidence of cytomegalovirus infection after kidney transplantation

Cytomegalovirus (CMV) seronegative recipients of kidneys from CMV seropositive donors are at a high risk of CMV infection after transplantation since viruses in the allograft may reactivate in patients without prior immunity. We hypothesized that the genetic background of the graft has an influence on the incidence of infection. Effects of IL10, IL6 and IFNG gene polymorphisms, known to affect CMV infectivity, were investigated in 71 CMV seronegative recipients of grafts from CMV seropositive cadaver donors. Donor IL10(-1082 AA) genotype reduced the incidence of CMV infection (p=0.031) and CMV episodes in these patients tended to occur later (AA: median 83 days,

AG/GG

median 45 days, p=0.072). In multivariate analysis, other explaining factors than the donor IL10(-1082 AA) genotype alone did not improve Cox hazard model (HR=0.3, 95% CI=0.09-0.96, p=0.043). Recipient polymorphisms did not reduce the incidence of CMV infection. We conclude that donor IL10 gene polymorphisms may influence the likelihood of CMV infection in the high risk patients investigated.

Early Cyclosporine C0 and C2 Monitoring in De Novo Kidney Transplant Patients: A Prospective Randomized Single-Center Pilot Study

BACKGROUND

C2 monitoring of cyclosporine (CsA) has been promoted as improving the results of organ transplantation. No randomized, controlled studies in de novo kidney transplant recipients are available.

METHODS

Between June 2003 and August 2004, 160 consecutive cadaveric kidney recipients allocated to CsA, mycophenolate and steroids were randomized to either C0 or C2 monitoring of CsA for the first 3 weeks posttransplant. Both levels were measured, keeping the other level blinded until 3 weeks. Altogether, 1451 double measurements were done. The target C0 was 200-300 microg/L and C2 1500-2000 microg/L. From the fourth week on, only C0 monitoring was used. Median follow up time was 505 days.

RESULTS

The overall 3-month rejection rate was 7.5% in Group C0 vs. 10.8% in Group C2 and the one-year graft survival rates were 92.5% vs. 94.6% (NS). Rate of delayed graft function was similar in the groups. Plasma creatinine tended to be higher in group C2 at 3 weeks, but not thereafter. During the first three weeks posttransplant, the mean CsA dose was 57%, mean C2 levels were 55%, and mean C0 levels were 98% higher in group C2 than in group C0 (P < 0.00001).

CONCLUSION

This pilot study showed no advantages of C2 monitoring but led to significantly higher CsA doses and blood levels than C0 monitoring.

Serum sCD30 in monitoring of alloresponse in well HLA-matched cadaveric kidney transplantations

In kidney transplantation, pretransplant serum sCD30 testing has been proposed in immunological risk estimation together with anti-HLA antibodies. We evaluated the risks associated with high pretransplant serum sCD30 in well HLA-matched cadaveric kidney recipients recruited in a clinical study comparing different immunosuppressive regimens. Rejection rate was similar in 37 recipients with high pretransplant serum sCD30 compared to 117 recipients with low serum sCD30 (16% vs. 15%, P=NS). Compared to pretransplant levels, the posttransplant sCD30 levels generally decreased, also in patients with rejection, although on day 21 posttransplant, rejecting patients had significantly higher relative sCD30 than nonrejecting patients (P<0.01). However, steroid-resistant rejection was associated with increasing posttransplant sCD30 levels. High pretransplant sCD30 values were associated with tubulointerstitial rejection. There was no correlation of sCD30 with delayed graft function. Good HLA matching seems to be effective in neutralizing the negative effect of a high pretransplant serum sCD30.

Activated protein C reduces graft neutrophil activation in clinical renal transplantation

We studied the role of endogenous activated protein C (APC), the major physiological anti-coagulant with concomitant anti-inflammatory properties, on ischemia/reperfusion (I/R) in 45 patients participating in a larger trial comparing three immunosuppressive protocols in cadaveric renal transplantation: perioperative anti-thymocyte globulin (ATG, Fresenius AG, Bad Homburg, Germany), perioperative basiliximab and conventional triple therapy. Blood samples for assessing plasma APC, protein C, and lactoferrin concentrations, neutrophil CD11b and L-selectin expressions and blood leukocyte differential counts were obtained preoperatively and before reperfusion from central venous cannula, complemented with simultaneous samples from iliac artery and graft vein for calculation of transrenal differences (Delta) of study parameters at 1 and 5 min after reperfusion. Unlike basiliximab or conventional therapy groups, ATG infusion induced a substantial increase in plasma APC concentration (119 [88-144]% before infusion vs. 232 [85-1246]% after infusion, p<0.001), resulting in renal graft sequestration of APC at 1 min after reperfusion (Delta=-72 [-567 to 12]%, p<0.001). Graft APC consumption was associated with transrenal reduction of neutrophil activation markers (L-selectin r=0.7, p=0.01; lactoferrin r=-0.6, p=0.02; CD11b r=-0.8, p=0.001), and with both warm (r=0.6, p=0.01) and cold ischemia time (r=0.6, p=0.02) and donor age (r=0.6, p=0.01). These findings suggest that APC has an anti-inflammatory role in I/R injury in clinical renal transplantation.

Cytokine Gene Polymorphisms and Risks of Acute Rejection and Delayed Graft Function after Kidney Transplantation

BACKGROUND

Pretransplantation identification of patients at an increased risk for adverse events would allow more individualized treatment strategies possibly improving long-term outcome. We studied cytokine gene polymorphisms of kidney allograft recipients and their donors to identify factors predisposing for acute rejection (AR) and delayed graft function (DGF).

METHODS

A total of 291 adult cadaver kidney recipients transplanted at a single transplantation centre between 1999 and 2002 were investigated. Recipients and donors were typed for TNF-alpha(-308G/A), TGF-beta1(codon 10T/C, codon 25C/G), IL-10(-1082G/A, -819C/T, -592C/A), IL-6(-174C/G), and IFN-gamma(+874T/A) polymorphisms using a SSP-PCR kit. An AR episode was defined based on clinical and histological findings (Banff criteria). RESULTS.: The incidence of AR was 17%. In univariate statistical analyses recipients with TNF-alpha -308AA-genotype were found to be at a significantly increased risk for rejection (odds ratio [OR] 5.0, 95% CI 3.0-8.3, P = 0.003). The association was independent from the patient-donor HLA-mismatch status. In addition, patients with IL-10 ACCACC, ATAATA, GCCATA (-1082A/G, -819C/T, -592C/A, respectively) haplotypes were predisposed to rejection (OR 1.9, 95% CI 1.1-3.1, P = 0.016). Further, the combination of recipient TGF-beta1 25GG-genotype and donor IL-10 -819T-allele was associated with rejection (OR 1.8, 95% CI 1.1-3.0, P = 0.027). These variables remained significant risk factors also in a multivariate logistic regression analysis. The incidence of DGF was 22%. The risk was increased by a donor TNF-alpha -308GA-genotype (OR 1.6, 95% CI 1.1-2.6, P = 0.040).

CONCLUSIONS

Our results confirm that cytokine gene polymorphisms influence the outcome of kidney transplantation. Our data especially identify the TNF-alpha -308AA-genotype as a factor predisposing for AR episodes.

Weak humoral posttransplant alloresponse after a well-HLA-matched cadaveric kidney transplantation

BACKGROUND

Screening of donor-specific antibodies or alloantibodies after kidney transplantation has not been performed routinely. The aim of this study was to evaluate the humoral antidonor and alloresponse of immunologically low-risk recipients of cadaveric renal allografts during the first posttransplant year.

METHODS

Alloresponse against the donor was analyzed by means of T-cell immunoglobulin (Ig)G and IgM and B cell IgG flow cytometric crossmatch (FCXM) tests with sera from days 0, 21, 90, and 365 posttransplant. In addition, panel reactive anti-human leukocyte antigen (HLA) class I and class II antibodies (PRA I and PRA II) were analyzed using flow cytometric methods. The recipients were treated either with a low initial cyclosporine regimen with single-bolus antithymocyte globulin (ATG) or basiliximab induction or conventional cyclosporine triple therapy.

RESULTS

No significant posttransplant anti-HLA class I or class II sensitization was found in the recipients as a whole. Recipients receiving a single-bolus ATG showed significantly higher proportion of PRA I positivity in the day 21 sample compared with the other groups. Flow cytometric donor-specific T- and B-cell IgG alloresponses remained low, but the proportion of T-cell IgM crossmatch-positive recipients increased during the study. Positive T-cell IgM FCXM was found to be associated with acute rejection episodes and cytomegalovirus (CMV) infections.

CONCLUSIONS

In immunologically low-risk kidney-graft recipients, positive T-cell IgM FCXM at transplantation was found to be a risk factor for rejection episodes. Conversion of T-cell IgM FCXM to positive was found to be associated with CMV infections.

Association of graft neutrophil sequestration with delayed graft function in clinical renal transplantation

BACKGROUND

The authors studied the impact of neutrophil activation, detected in experimental models, on reperfusion injury in clinical renal transplantation.

METHODS

Forty-five patients from a larger trial comparing three immunosuppressive protocols were recruited: perioperative antithymocyte globulin (ATG) with low initial cyclosporine A (CsA) triple therapy (group A, n=15); two-dose basiliximab with low initial CsA triple therapy (group B, n=16); and conventional triple therapy (group C, n=14). Blood samples were obtained preoperatively, before reperfusion, and at 1 and 5 min after reperfusion. During reperfusion, samples were collected from the iliac artery and the graft vein for calculation of transrenal differences (Delta) of study parameters. Leukocyte differential counts, plasma lactoferrin concentration, and neutrophil CD11b and L-selectin expressions were assessed. Graft blood flow was measured at 2 and 30 min after reperfusion.

RESULTS

ATG induced neutrophil activation already before reperfusion. Thus, group A was excluded, but groups B and C were pooled for analysis of reperfusion-induced neutrophil activation. At 1 min after reperfusion, lactoferrin concentration was higher in graft vein than iliac artery, yielding Delta=15 microg/L (P<0.05). Concomitantly, Delta neutrophil count correlated with both Delta L-selectin expression (R=0.49, P=0.012) and graft blood flow at 2 min (R=0.51, P=0.007). At 5 min after reperfusion, 0.17 (-1.0-0.24)x10 cells/L neutrophils were sequestered in the graft (P<0.001). This sequestration correlated with graft blood flow at 30 min (R=0.53, P=0.005) and was stronger in patients with delayed graft function (DGF) (Delta = -0.38 [-1.45 to -0.2]) than those without (Delta = -0.12 [-0.41-0.24], P<0.001). In multiple regression analysis, sequestration was the most important parameter associated with DGF.

CONCLUSIONS

Neutrophils are activated and sequestered in the reperfused graft during clinical renal transplantation. Neutrophil sequestration is a powerful independent factor explaining the incidence of DGF.

Two decades of experience with cyclosporine in renal transplantation in helsinki

We present our experience on cyclosporine (CsA) triple immunosuppression in 2445 cadaveric kidney transplantations performed from 1984 to 2002 in Helsinki. Overall, delayed onset of graft function occurred in 30.2% and acute rejection in 25.6% of the transplantations. The 1-, 5-, and 10-year patient survival was 95.1%, 84.5%, and 69.1%; the graft survival rates were 90.0%, 74.9%, and 56.7%; and the death-censored graft survival, 93.3%, 83.5%, and 72.4%. During the study period, the 5-year patient survival improved from 70.8% to 90.6% and the graft survival from 58.2% to 88.0% with the graft half-life estimate of 1-year survivors improving from 7.6 to 21.8 years. Acute rejection episodes decreased from 33.0% to 19.9% and the calculated creatinine clearance at 1 year improved from 50.3 mL/min to 74.3 mL/min. Mean CsA dose diminished significantly, both at 3 weeks (from 8.2 mg/kg to 4.9 mg/kg) and at 1 year posttransplant (from 3.7 mg/kg to 2.8 mg/kg). In 16.7% of transplantations where azathioprine had to be discontinued early, significantly more rejections occurred (38.0% vs 23.2%) with inferior 1-year graft survival (80.2% vs 94.8%) compared to the transplantations continuing on triple therapy. Among 1-year survivors, the 6-month serum creatinine level was strongly associated with death-censored long-term graft survival. In this material, the CsA dosage at 1 year did not predict long-term graft survival.

Time course of serum prolactin and sex hormones following successful renal transplantation

BACKGROUND

Chronic renal failure is commonly associated with disturbances in hypothalamic-pituitary-gonadal function.

METHODS

The gonadotrophins, prolactin and estradiol or testosterone levels were measured immediately before renal transplantation, at discharge from the transplantation unit (19 +/- 8 days after Tx) and 6 months after transplantation in 21 patients, 7 females and 14 males, age range 21-60 years.

RESULTS

The mean prolactin level was high during uremia and decreased rapidly after transplantation, from 441 to 167 mU/l in males and from 1,057 to 521 mU/l in females. Hypergonadotrophism was seen in most uremic patients, with the mean LH and FSH levels of 14.2 and 6.0 U/l in males and 14.7 and 4.0 U/l in females, respectively. A temporary change to hypogonadotrophic hypogonadism took place 2-3 weeks after transplantation and was followed by normalization of the hypothalamic-gonadal function. The levels of circulating sex steroids were suppressed when the patients were discharged from the transplantation unit but returned to the normal range at 6 months.

CONCLUSIONS

We conclude that renal transplantation corrects the hyperprolactinemia induced by uremia and is followed by rapid onset of restoration of the hypothalamic-pituitary-gonadal axis.

Long-term results of 1047 cadaveric kidney transplantations with special emphasis on initial graft function and rejection

We studied the effect of initial graft function and acute rejection on graft survival in 1047 cadaveric renal transplantations during 1991-1997 with a constant policy of donor selection, graft allocation, and immunosuppression. The overall 1- and 5-year patient survival rates were 96 % and 88 %, and the 1- and 5-year graft survival (GS) rates were 92 % and 78 %. Delayed graft function (DGF) occurred in 31 % and there were 1.2 % never-functioning grafts. One-year GS in transplantations with early graft function (EGF) was 95 % compared to 87 % in DGF (P < 0.001). Donor age and cause of death, type of graft perfusion and cold ischemia time, and type and length of dialysis treatment were significant factors in determining the onset of graft function. These factors did not have a significant direct effect on GS. Early ( < 100 days) acute rejection occurred in 25 %. In transplantations without rejection, the 1 and 5-year GS was 93.3 % and 80.8 %. In acute rejection responding to steroids, the GS was equal to that up to 3 years, but after that a significantly worse survival rate was observed (1- and 5-year GS: 93.6 % and 73.4 %). DGF was detrimental to GS both in transplantations without rejection and in all rejection types.

The clinical significance of conversion of complement-dependent cytotoxic T cell crossmatch test after renal transplantation

The purpose of this study was to investigate the clinical relevance of conversion of post-transplant T cell crossmatch between kidney donor and recipient. This study comprises 892 cadaveric renal transplantations performed on 874 adult patients between August 1991 and December 1997. Recipient selection was based on a negative complement-dependent cytotoxic T cell crossmatch test with current (< or = 2 months old) serum. For this study, on day 0 and day 14 after transplantation, serum samples were collected for later crossmatching. On day 14 after transplantation, the crossmatch had converted to positive in 76 transplantations (8.5%). Acute rejection occurred in 50% of the converters and 22% of the non-converters (P < 0.005), and graft survival was significantly poorer (P < 0.025), being 85 vs 94% at 1 and 68 vs 83% at 5 years, respectively. In patients with delayed graft function, 1-year graft survival was 77% in the converters and 91% in the non-converters (P < 0.05). Conversion of T cell crossmatch, especially in connection with delayed graft function, identifies a subgroup of patients at high risk of severe rejection and poor graft survival.

Long-term graft outcome is not necessarily affected by delayed onset of graft function and early acute rejection

BACKGROUND

Both acute rejection episodes and delayed graft function (DGF) have been shown to be associated with decreased 1-year renal allograft survival. In our center, the incidence and the intensity of acute rejection episodes have been reduced by cyclosporine-based triple-drug therapy. We have also shown that DGF alone is not a risk factor for long-term graft survival.

METHODS

We have now investigated whether an acute rejection episode together with DGF significantly effects long-term graft outcome. This study involved 862 first cadaveric renal allografts and 182 regrafts.

RESULTS

The incidence of DGF was 33% after first transplants and 44% after retransplants. The overall incidence of acute rejection episodes was 23% in first grafts and 28% in regrafts. After first grafts, there were no statistically significant differences in graft survival rates and half-lives between the early graft function (EGF) and DGF groups with or without acute rejection. In regrafts, graft survival was significantly higher in the EGF group without acute rejection than in the DGF group with acute rejection. However, if all other causes except chronic rejection were censored, the half-life in the EGF group without acute rejection was 17.3 years in first grafts, and in the DGF group with acute rejection, that number was 11.5 years in first grafts; for regrafts, the half-life was 12.3 years and 6.1 years, respectively.

CONCLUSIONS

Acute rejection together with DGF could contribute to initial damage to the graft, and this might lead to later chronic allograft failure. In our study, this effect was evident only in the case of retransplants.

Sequential changes in vitamin D and calcium metabolism after successful renal transplantation

A prospective study was made of sequential changes in the metabolism of vitamin D and calcium in 19 allograft recipient during the first year after successful renal transplantation. All but one of the patients received cyclosporine A combined with corticosteroids and azathioprine as immunosuppressive therapy. Shortly after transplantation most patients showed transient hypocalcemia and hypophosphatemia. At the time of transplantation 17 of 19 patients had an elevated plasma intact parathyroid hormone (PTH) level, and at the close of follow-up one in four patients. In six other patients intact PTH was within the reference range, but high in relation to simultaneously measured serum ionized calcium. According, one year after transplantation less than half of the patients showed complete resolution of hyperparathyroidism. The change towards normal in the metabolism of vitamin D began within the first post-transplantation week irrespective of the onset of diuresis. One to two weeks after transplantation 1,25(OH)2D3 and 24,25(OH)2D3 reached the lower limit of normal range. In these renal allograft recipients who received cyclosporine A the long-term values of serum 1,25(OH)2D3 did not differ from those of normal subjects.

Impaired renal function after pregnancy in renal transplant recipients

Twenty-two renal transplant recipients had 29 posttransplant pregnancies and 39 male transplant recipients became fathers to 65 children between 1971 and 1991. Of the deliveries of the female patients, 62% took place between the third and sixth year after transplantation. Seven patients had 2 pregnancies. Mean follow-up time after the first posttransplant pregnancy was 7.5 years. The patients survived the pregnancy well, but the increase in serum creatinine concentration from the prepregnancy level, registered 3 months and 1 year after delivery, was higher than in matched control patients without pregnancy at corresponding times after transplantation (the increase in serum creatinine was 47.7 and 61.2 mumol/L in the pregnant patients versus -2.7 and 5.4 mumol/L in the control patients, P < 0.0001 and P < 0.02, respectively). All pregnant and control patients were alive at the end of follow-up, but the long-term graft survival of those with a pregnancy was significantly (P < 0.005) worse than in the control patients. Ten-year graft survival was 69% in the pregnant versus 100% in the control patients. Although 80% of the neonates born to a mother with a transplanted kidney were below the mean for gestational age, the weight and length at birth were within normal limits and no severe intrauterine growth retardation was documented.

Acute vascular rejection in renal transplantation--diagnosis and outcome

Thirty episodes of histologically verified acute vascular rejection in kidney transplant recipients were studied. In 11 grafts the rejection was mainly vascular, whereas in 19 grafts a concomitant cellular rejection was seen. Histological features prognostic for bad outcome were glomerular necrosis and thrombi in the arteries and arterioles. Characteristic findings in transplant cytology, i.e., high number of monocytes and low number of lymphocytes and blast cells were noted prior to the onset of clinical signs of rejection, and this finding was also persisting throughout the rejection episode. The numbers of lymphocytes and blast cells were significantly lower in grafts with a pure vascular rejection than in grafts with a concomitant cellular rejection. Vascular rejection was reversible in 15 cases. As rescue therapy plasmapheresis and added immunosuppression were often successful.