HLA-identity--long-term renal graft survival, acute vascular, chronic vascular, and acute interstitial rejection

Prevalence, consequences, and determinants of nonadherence in adult renal transplant patients: a literature review

This literature review summarizes the evidence on the prevalence, determinants, clinical and economic consequences of nonadherence with immunosuppressive drugs in renal transplant patients. A literature search yielded 38 articles measuring nonadherence by self-report, collateral report, assay, refill prescriptions or electronic monitoring. The weighted mean prevalence of self-reported nonadherence was 28%. Nonadherence is associated with poor clinical outcomes, contributing to 20% of late acute rejection episodes and 16% of the graft losses (weighted means). In addition, nonadherence results in lower lifetime costs because of shorter survival, yet also in a lower number of quality adjusted life years. Consistent determinants of nonadherence were younger age, social isolation, and cognitions (e.g. low self-efficacy, certain health beliefs). Determinants concerning the health care system/team seem to be under-investigated. Because the evidence summarized in this review is based on older immunosuppressive regimens, further research should focus on prevalence, determinants and consequences of nonadherence with newer immunosuppressive regimens.

Highly altered V beta repertoire of T cells infiltrating long-term rejected kidney allografts

Chronic rejection represents a major cause of long-term kidney graft loss. T cells that are predominant in long-term rejected kidney allografts (35 +/- 10% of area infiltrate) may thus be instrumental in this phenomenon, which is likely to be dependent on the indirect pathway of allorecognition only. We have analyzed the variations in T cell repertoire usage of the V beta chain at the complementary determining region 3 (CDR3) level in 18 human kidney grafts lost due to chronic rejection. We observed a strongly biased intragraft TCR V beta usage for the majority of V beta families and also a very high percentage (55%) of V beta families exhibiting common and oligoclonal V beta-C beta rearrangements in the grafts of patients with chronic rejection associated with superimposed histologically acute lesions. Furthermore, V beta 8 and V beta 23 families exhibited common and oligoclonal V beta-J beta rearrangements in 4 of 18 patients (22%). Several CDR3 amino acid sequences were found for the common and oligoclonal V beta 8-J beta 1.4 rearrangement. Quantitative PCR showed that biased V beta transcripts were also overexpressed in chronically rejected kidneys with superimposed acute lesions. In contrast, T lymphocytes infiltrating rejected allografts with chronic rejection only showed an unaltered Gaussian-type CDR3 length distribution. This pattern suggests that late graft failure associated with histological lesions restricted to Banff-defined chronic rejection does not involve T cell-mediated injury. Thus, our observation suggests that a limited number of determinants stimulates the recipient immune system in long-term allograft failure. The possibility of a local response against viral or parenchymatous cell-derived determinants is discussed.

The impact of recurrent glomerulonephritis on graft survival in recipients of human histocompatibility leucocyte antigen-identical living related donor grafts

BACKGROUND

Graft loss due to rejection is uncommon after human histocompatibility leukocyte antigen-identical living related donor (LRD) transplantation, resulting in an excellent long-term graft survival. Data on the impact of recurrence of the original disease on graft survival after LRD transplantation are scarce.

METHODS

We have studied the influence of recurrent glomerulonephritis in adult recipients of a human histocompatibility leukocyte antigen-identical LRD graft transplanted in our center in the period from 1968 to 1996. To that end, the data of 33 patients with proven or suspected primary glomerulonephritis and 27 patients with nonglomerular diseases were analyzed.

RESULTS

The patient survival was similar in both groups at 5, 10, and 20 years. The functional graft survival, i.e., graft survival after censoring for death, was, however, significantly worse for patients with glomerulonephritis as underlying disease (P<0.01). At 5 years graft survival was 100% vs. 88%, at 10 years 100% vs. 70%, and at 20 years 100% vs. 63%, respectively. Thus none of the patients with nonglomerular diseases lost a graft, whereas eight grafts were lost in the group of patients with glomerulonephritis. The main cause of graft loss in this patient group was recurrent glomerulonephritis (n=5), whereas chronic vascular rejection caused graft loss in two patients and occlusion of a transplant artery was the cause in one. A clinically significant proteinuria was detected in six more patients in the glomerulonephritis group: a recurrent glomerulonephritis was diagnosed in four patients and in two patients there was no biopsy. The cumulative incidence of recurrence was as high as 45% at 12 years after transplantation.

CONCLUSION

Recipients of a human histocompatibility leukocyte antigen-identical LRD kidney have a good prognosis with respect to graft survival. After censoring for death, recurrent glomerulonephritis is the main cause of graft failure in these patients and the impact of recurrent disease on graft survival will become even more prominent with longer follow-up.

HLA-identical sibling renal transplantation--a 21-yr single-center experience

Human lymphocyte antigen (HLA)-identical sibling organs offer the best long-term outcomes for recipients of a renal transplant apart from an identical twin. Unlike cadaveric transplants, however, factors that affect long-term survival of these immunologically privileged grafts are not well described. We reviewed 108 HLA-identical transplants performed at our institution between January 1977 and February 1993. Variables chosen for graft survival analysis were: gender, age and ABO blood type of donors and recipients, panel reactivity antibodies (PRA), blood transfusions prior to transplant, pregnancies, and the underlying renal disease. Additionally, incidence of acute rejection (AR), timing of AR, serum creatinine levels at 1 wk and at 1 yr, and presence of hypertension were included in the analysis. Mean follow-up was 130.9 +/- 58.2 months (range 38-250 months). Actual 5-yr patient and graft survivals were 92 and 88%, respectively. Thirty-eight grafts were lost, and 22 recipients died during the observation period. Death was the main cause of graft failure. Cardiac events accounted for the majority of deaths. AR occurred in 46% and repeated rejections in 11% of recipients. Actuarial graft survival at 10 yr was poorer for patients with any AR (69%), and significantly worse with repeated AR (33%), compared to patients without AR (86%), p = 0.001). Sixty percent of all rejections and 88% of the first rejections occurred in the first 60 d post-transplantation. The first AR that occurred after 60 d was associated with poor graft survival (49 vs. 70%, p = 0.04). Recipients with renal diseases with potential to recur (membranous glomerulonephritis (MGN), membrano-proliferative glomerulonephritis (MPGN), focal and segmental glomerulonephritis (FSGN), polyarteritis nodosa (PAN), rapid progressive glomerulonephritis (RPGN), Henoch-Schoenlein purpura (HSP), diabetes mellitus (DM), interstitial nephritis, systemic lupus erythematosus (SLE) and chronic glomerulonephritis (CGN)) faired worse as a group than recipients with hypertensive nephrosclerosis (HTN), autosomal dominant polycystic kidney disease (ADPKD), Alport's, reflux or congenital dysplasia (68 vs. 96% at 10 yr, p = 0.0009). Poor patient survival was seen in diabetics (71 vs. 88% at 10 yr, p = 0.01). There was a trend to poorer graft survival in diabetic recipients when compared to non-diabetics (65 vs. 81% at 10 yr, p = 0.054). Elevated creatinine at 1 yr was associated with worse graft survival. Likewise, the magnitude of creatinine increase during the first year directly correlated with the risk of graft loss. Hypertensive patients were more likely to lose their grafts than normotensive recipients (72 vs. 86%, p = 0.04). Pre-transplant blood transfusion, pregnancy, and PRA level were not associated with increased graft failure or AR. Graft survival was not affected by gender, age, or ABO blood type of donors or recipients. In conclusion, better prevention and treatment of AR, hypertension, and cardiac disease should improve graft and patient survival. Close attention to recurrence of disease and subtle changes in the creatinine level during the first year might dictate early diagnostic and, hopefully, therapeutic interventions.

Contribution of early acute rejection episodes to chronic rejection in a rat kidney retransplantation model

Chronic graft rejection represents the single most important risk factor for unsatisfactory long-term results after organ transplantation. In addition to various alloantigen dependent and independent factors, acute rejection episodes have been cited as a major immunological risk factor. However, the effects of acute rejection episodes on long-term graft outcome remains unknown. To examine the influence of a single early rejection event on ultimate graft outcome, acutely rejecting rat kidney grafts were retransplanted sequentially into syngeneic rats and their functional and structural behavior assessed over time. LEWxBNF1 kidney allografts and LEW isografts were removed from their LEW recipients after three, four, five and seven days (N = 12/group/time period) and retransplanted into donor strain hosts. The grafts were followed functionally and harvested four, eight, and 32 weeks later. Urinary protein excretion was measured weekly. Kidneys were examined morphologically and immunohistologically using monoclonal antibodies (mAbs) against macrophages (ED-1), T cells and their subsets (CD5, CD4, CD8), MHC class II expression (OX3) and adhesion molecules (ICAM-1 and LFA-1alpha). The mean standard time +/- SD of non-retransplanted allografts was 14.5 +/- two days; isografts functioned indefinitely. At five and seven days, acutely rejecting allografts showed massive cellular infiltrates associated with extensive necrosis. These changes could not be reversed by retransplantation and the syngeneic recipients later died of renal failure. In contrast, most allografts retransplanted earlier in the process recovered completely when retransplanted after three (12 of 12 allografts) and four (7 of 12 allografts) days. During the subsequent follow-up period, urinary protein excretion was comparable in retransplanted allografts and isografts. The increased mononuclear cell infiltration in non-retransplanted allografts seen at three and four days was only occasionally observed during the follow-up period after retransplantation. Only a few sclerosed glomeruli (approximately 15%), mild arterial changes and minimal cellular infiltrates were observed by 32 weeks, which were similar to that seen in retransplanted isografts. A single acute rejection episode was completely reversible and did not progress to chronic rejection if retransplanted into syngeneic donors when the inflammatory changes are still early. Those results demonstrate the critical effect of alloantigen-dependent events on chronic graft deterioration, and indicate that prompt and aggressive treatment of initial acute rejection episodes are beneficial to protect against late deleterious changes in the graft.

Factors contributing to the development of chronic rejection in heterotopic rat heart transplantation

BACKGROUND

The present study was devised to elucidate the influence of immunogenicity, immunosuppression, and ischemia on the development of transplant vasculopathy (TVP) as well as to investigate myointimal proliferation in syngeneic transplantation.

METHODS

Fischer 344 and Brown Norway rat heart allografts and Lewis isografts were treated with rapamycin or cyclosporine, exposed to 4 hr of cold ischemia, and observed for 100 to 300 days before the incidence and degree of TVP and perivascular infiltration were assessed.

RESULTS

The incidence of TVP in Fischer 344-->Lewis allografts (rapamycin, 0.5 mg/kg for 14 days) rose steadily, with dense mononuclear infiltration present in coronary lesions at all times (from 10+/-2% at 50 days to 85+/-15% at 150 days). Increased immunogenicity (Brown Norway-->Lewis) intensified TVP (62+/-13%) as compared with its control (25+/-15%, P<0.005). Enhanced immunosuppression (rapamycin, 0.5 mg/kg daily) decreased the incidence of TVP (22+/-11%, P<0.005), and additional low-dose cyclosporine was ineffective (1.5 mg/kg daily, 40+/-14%, NS). Four hours of cold ischemia before transplantation failed to have any effect on allografts, but promoted TVP in isografts (0 vs. 11+/-8%).

CONCLUSIONS

The antigenic stimulus has probably the most important impact on the development of TVP, but is not necessarily essential. In most allografts, TVP probably reflects ongoing sublethal acute rejection, whereas myointimal proliferation in isografts presumably results from a perioperative antigen-independent response-to-injury mechanism.