HIV-infected liver and kidney transplant recipients: 1- and 3-year outcomes.

Improvements in human immunodeficiency virus (HIV)-associated mortality make it difficult to deny transplantation based upon futility. Outcomes in the current management era are unknown. This is a prospective series of liver or kidney transplant recipients with stable HIV disease. Eleven liver and 18 kidney transplant recipients were followed for a median of 3.4 years (IQR [interquartile range] 2.9-4.9). One- and 3-year liver recipients' survival was 91% and 64%, respectively; kidney recipients' survival was 94%. One- and 3-year liver graft survival was 82% and 64%, respectively; kidney graft survival was 83%. Kidney patient and graft survival were similar to the general transplant population, while liver survival was similar to the older population, based on 1999-2004 transplants in the national database. CD4+ T-cell counts and HIV RNA levels were stable; and there were two opportunistic infections (OI). The 1- and 3-year cumulative incidence (95% confidence intervals [CI]) of rejection episodes for kidney recipients was 52% (28-75%) and 70% (48-92%), respectively. Two-thirds of hepatitis C virus (HCV)-infected patients, but no patient with hepatitis B virus (HBV) infection, recurred. Good transplant and HIV-related outcomes among kidney transplant recipients, and reasonable outcomes among liver recipients suggest that transplantation is an option for selected HIV-infected patients cared for at centers with adequate expertise.

Major histocompatibility complex class I deficiency prolongs islet allograft survival.

Because of islet allograft rejection, nonimmunosuppressed pancreatic islet allotransplantation has been unsuccessful for the treatment of type I diabetes. The role of major histocompatibility complex class I antigen expression on islet allograft survival was evaluated with the use of mice homozygous for a beta 2-microglobulin gene disruption. These mice express little if any functional major histocompatibility complex class I antigen. When these major histocompatibility complex class I-deficient islets were used as donors in an allogenic murine transplantation model, islet allograft survival was markedly prolonged. These results demonstrate a major importance for the alloresponse directed against major histocompatibility complex class I antigen.

Generation of allospecific cytolytic T-lymphocytes stimulated by pure pancreatic beta-cells in absence of Ia+ dendritic cells.

A murine mixed islet-lymphocyte coculture system (MILC) was used to quantitate the immunogenicity of a pure population of pancreatic beta-cells to more clearly define whether stimulator major histocompatibility complex (MHC) class II-positive dendritic cells are a major component leading to islet immunogenicity. Pancreatic beta-cells express MHC class I antigen but not class II antigen. These experiments compared the in vitro immunogenicity of fluorescence-activated cell sorted (FACS-IV) pure beta-cells (MHC class I-positive cells only) relative to unpurified dispersed islet cells (MHC class I-positive cells and class II-positive cells). The results demonstrated the surprising finding that pure DBA/2J (H-2d) pancreatic beta-cells stimulated a strong cytotoxic T-lymphocyte (CTL) response when exposed to C57BL/6 (H-2b) allosplenocytes in the MILC, similar to DBA/2J nonpurified dispersed islet cells. Furthermore, the stimulation of CTL by both purified beta-cells and nonpurified dispersed islet cells was blocked by addition of MHC-specific anti-class I monoclonal antibody directed against stimulator MHC antigen. The data imply that the highly immunogenic MHC class II-positive passenger leukocytes present in the islets were not necessary for the generation of the immune response in the presence of MHC class I-positive beta-cells. Although most of the pretreatment regimens attempting to decrease islet immunogenicity have been directed at eliminating the MHC class II-positive passenger leukocytes from the islets, this work suggests that modulation of MHC class I antigen may be an important approach.

Effect of immunodepletion of MHC class II-positive cells from pancreatic islets on generation of cytotoxic T-lymphocytes in mixed islet-lymphocyte coculture.

In vitro manipulation of pancreatic islets to decrease islet immunogenicity before transplantation has largely been directed at eliminating the major histocompatibility complex (MHC) class II-positive passenger leukocytes from the islets. The mixed islet-lymphocyte coculture (MILC) system was used to quantitate the efficacy of immunodepletion of MHC class II-positive cells from pancreatic islets in terms of reducing immunogenicity. With these experiments we compared the in vitro immunogenicity of MHC class II-depleted islets with untreated islets. B10.BR (H-2k) islets were treated with anti-Iak alloserum followed by complement. This treatment successfully eliminated MHC class II-positive cells from the islets, as demonstrated by indirect immunofluorescence techniques. Depleted islets generated slightly lower amounts of allospecific cytotoxic T-lymphocyte (CTL) activity when exposed to C57BL/6 (H-2b) splenocytes in the MILC than untreated control islets. Although the amount of CTL generated by the depleted islets was slightly less than that generated by untreated islets, there was significant stimulation of CTL by the MHC class II-depleted islets. Therefore, the presence or absence of MHC class II cells within the islet is unlikely to be the decisive factor contributing to islet immunogenicity.

Liver allograft rejection. An analysis of the use of biopsy in determining outcome of rejection.

Two-hundred-seventy biopsy specimens from 47 patients undergoing liver transplants at the University of Minnesota were analyzed to determine if histological features could predict the eventual outcome of rejection episodes. Thirty-six patients (76.6%) rejected the transplant. Of these, five either suffered acute liver failure due to rejection (two cases) or developed chronic rejection (three cases). Features of significance in predicting such a bad outcome were arteritis, bile duct paucity, or simultaneous hepatocellular ballooning and hepatocellular dropout and necrosis. Other features, such as type and intensity of infiltrate, degree of bile duct damage, or simple presence of hepatocellular necrosis, were not predictive of outcome. Our conclusion is that biopsy is useful in predicting outcome. Since many of the histologic findings of predictive value were not present in initial pretreatment biopsy specimens, follow-up biopsies of patients being treated for rejection are recommended to assess efficacy of therapy.

Quo vadis, my transplant fellow: a discussion of transplant surgery fellowship training activity in the United States and Canada: 1991-1997. Education Committee of the American Society of Transplant Surgeons.

This is a discussion of transplant surgery fellowship training issues that pertain to educational quality guidelines of fellowship programs, the number of fellows being trained, and the individual's fate in securing transplant surgery positions after training. In 1995, the Council of the American Society of Transplant Surgeons (ASTS) revised the academic guidelines to enhance the educational standards of programs seeking ASTS approval as a transplant surgery fellowship training program. The criteria for accrediting training programs in kidney and liver transplant surgery were redefined, and new criteria for pancreas transplant surgery training were developed. Regarding the number of transplant surgery fellows being trained per year, during the period from 1991 to 1997, a total of 327 transplant surgery fellows completed training at ASTS-accredited transplant surgery fellowship training programs. The annual number of transplant surgery fellowship graduates has remained nearly constant at approximately 45 per year. However, the proportion of transplant surgery trainees who are foreign medical graduates has increased annually since 1995. Currently, 49% of the trainees are foreign medical graduates. Regarding the individual's fates in securing transplant surgery positions after training, the proportion of U.S./Canadian medical graduates who received transplant surgery training during the last year but are practicing in surgical disciplines other than transplant surgery appears to be increasing. Before 1996, it was rare for transplant surgery trainees to pursue surgical practice activities that did not include transplantation. Among the current group of 28 U.S./Canadian medical graduates who completed transplant surgery training between January 1997 and July 1997, six did not secure an acceptable position in transplantation. Instead, they are practicing in either general surgery or vascular surgery, or obtaining additional transplant training. These changes in the demographics and dynamics of transplant surgery fellowship training activity provoke important concerns.

Fifty-percent partial liver transplantation in the rat.

Reduced-size liver transplantation in the rat has been useful in the study of hepatic regeneration. We describe a modified technique for partial liver transplantation in the rat using a 50% reduced-size graft. Male Lewis rats (RT1(1)), weighing 250 to 280 g, were used as donors and recipients. The harvested donor liver was placed in 4 degrees C cold saline and graft reduction was performed ex situ by resecting the left lateral lobe, the left portion of the median lobe, and the caudate lobes. The reduced graft was composed of the right portion of the median lobe and the right lobe, weighing 5.33 +/- O.58 g (53.6 +/- 2.2% of the donor liver before reduction, n=7). The recipient 1-week survival rate was 85.7%. The use of reduced livers permits the study of host responses to a deficient graft. This technique provides another choice of liver volume to be implanted and allows the study of regeneration of small-for-size livers more precisely in combination with more extensive graft reduction.

Partial characterization of cytotoxic cells infiltrating sponge matrix allografts.

Adapting the Roberts and Hayry sponge allograft model, we have demonstrated the presence of an enriched, specifically cytotoxic population of cells which infiltrate rejecting sponge allografts. The number of cells infiltrating a rejecting sponge allograft peaks on day 14 after transplantation. Utilizing a short-term 51chromium cytotoxicity assay, peak antiallogeneic killing was demonstrable on day 14 also. Only T cell killing was apparent for the first 15 days after transplantation. After day 20, specific cytolysis was present which was not sensitive to anti-theta serum and complement. The infiltrating cytotoxic cells are large, specifically cytotoxic, do not proliferate in culture, do not respond to mitogen, and do not respond in mixed lymphocyte culture even to the same alloantigen to which the animal had been sensitized. In contrast, spleens from sponge-bearing animals kill poorly, respond to mitogen, and respond vigorously in mixed lymphocyte culture to specific and nonspecific alloantigens. The following hypotheses are set forth with regard to the cytotoxic lymphocytes (1) Such cells may be end stage and cannot proliferate. (2) The cytotoxic cells may kill the stimulator cells more rapidly than they can be stimulated to proliferate. (3) The sponge cell population may be enriched for nonspecific supressor cells. (4) The sponge cells may be devoid of helper T cells.

Prolongation of in vivo mouse islet allograft survival by modulation of MHC class I antigen.

Major histocompatibility complex class I-deficient islets from beta-2 microglobulin-deficient mice have been shown to have prolonged in vivo islet allograft survival. Additionally in vitro studies using the mixed lymphocyte islet coculture system have demonstrated a reduction in cytotoxic T lymphocyte activity against alloislets that have been pretreated with an antibody directed against MHC class I antigen. The clinical applicability of these findings are examined in this study, which evaluates the ability of MHC class I blocking antibody to prevent the in vivo destruction of alloislets. Recipients of allogenic islet transplants treated with phosphate-buffered saline or control F(ab')2 fragments rejected the transplanted alloislets in median times of 11.5 days and 11 days, respectively. Recipient mice treated with a monoclonal antibody or F(ab')2 fragments specific to the donor MHC class I antigen had significant prolongation in allograft survival (median allograft survival for both groups was 21 days) when compared with mice treated with PBS or control F(ab')2 fragment. These results demonstrate that treating recipients of alloislets with donor-specific MHC class I monoclonal antibody or the respective F(ab')2 fragments prolongs islet allograft survival. This confirms the importance of MHC class I antigen in the rejection of pancreatic islet allografts and suggests that blocking different domains on the MHC class I molecule could be used therapeutically in the protection of allografts from the immune system.

The migration of activated T lymphocytes in vitro. III. Paralysis and recovery of locomotor function during mitosis.

Previous reports have stated that activated lymphocytes are more motile than unsensitized lymphocytes and that certain subpopulations of lymphocytes are more motile than others. In order to determine at what stage of activation lymphocytes become motile, we have examined lymphocyte motility as well as other functions at various times after mitogenic or allogeneic stimulation in culture. Lymphocytes cultured with concanavalin A (Con A) or with alloantigen become most motile after peak thymidine incorporation has occurred. Allosensitized lymphocytes need not possess cytolytic capacity in order to become motile. Allosensitized lymphocytes retain the ability to locomote at near maximal rates for at least 2 weeks after stimulation. When these motile, allosensitized lymphocytes are recultured in the presence of fresh irradiated stimulator cells, they lose their ability to locomote during active thymidine incorporation and become motile again when thymidine incorporation has abated. Lymphocyte clones demonstrated motility cycles similar to cycles observed with bulk cultures (i.e., peak motility is observed only after peak thymidine incorporation has occurred in the subculture). All T lymphocyte clones tested are motile, regardless of Lyt phenotype or function, if tested for motility on the appropriate day of subculture. Studies of clone motility at intervals less than 24 hr after restimulation revealed that motility ceased before tritiated thymidine uptake occurred. The migratory potential of lymphocytes in vitro does not seem to depend on phenotype or the nature of the mitogenic stimulus. It seems instead to be part of the cyclic response of the cell to activation, with early inhibition of motility and subsequent recovery of locomotor function. Whether ability to locomote is intrinsic to the activated cell or depends on environmental factors requires further investigation.

The management of T tube leaks in orthotopic liver transplant recipients with endoscopically placed nasobiliary catheters.

Biliary tract problems remain an important cause of complication following orthotopic hepatic transplantation. We describe 12 liver transplantation patients who developed bile peritonitis secondary to a biliary leak after T tube removal. Each of these patients underwent an urgent ERCP that exhibited leakage outside the T tube tract and nondilated intrahepatic ducts. At the time of the ERCP, a nasobiliary catheter was inserted to divert the bile flow. All of these patients resolved their symptoms and closed their leak. We advocate endoscopic placement of a nasobiliary catheter as first-line therapy for significant T tube tract leaks after liver transplantation.

Increased expression of class I major histocompatibility complex antigens on hepatocytes in rejecting human liver allografts.

We studied hepatocellular expression of major histocompatibility (MHC) antigens in 43 serial liver transplant biopsies from 22 patients (42 percutaneous, 1 autopsy specimen), 4 normal liver biopsies, and 8 percutaneous biopsies of diseased livers from non-liver-transplant patients. Frozen tissue sections were stained by an indirect immunofluorescence technique using monoclonal antibodies (MCAb) that recognize nonpolymorphic human class I or class II MHC determinants. Ethidium bromide was used to stain nuclei and rhodamine-conjugated anti-basement-membrane antibodies to delineate epithelial and vascular structures. HLA-DR antigens recognized by MCAb OKIa1 and I2 were not detected on hepatocytes but were detected on the bile duct epithelium in 7 of 27 transplant biopsies, including 5 with acute rejection and 1 with chronic liver disease that later progressed to chronic rejection. HLA-A, B, C antigens recognized by MCAb 34/28 intensely stained cells lining the liver sinusoids but were negative on hepatocytes in 4 normal liver biopsies and 7 of 8 non-transplant biopsies. Expression of class I MHC antigens on hepatocyte membranes was increased in 17 of 21 (81%) biopsies from patients with acute rejection, in 4 of 4 with chronic transplant liver disease, but in only 3 of 18 (17%) biopsies from patients with no rejection (chi square = 8.62, P less than 0.01). Our observations demonstrate increased expression of MHC class I antigens in association with acute rejection in human orthotopic liver transplantation. Histologic resolution of the rejection episode is generally followed by a decrease in hepatocyte class I antigen expression. Further analysis of this response may have value in assessing the severity of the rejection and effectiveness of treatment.

Evidence for direct and indirect pathways in the generation of the alloimmune response against pancreatic islets.

The role of the direct and indirect pathways of alloantigen presentation in the generation of the alloimmune response was dissected using the murine mixed lymphocyte-islet coculture system (MLIC). Stimulator DBA/2J (H-2d) pancreatic islet populations consisted of whole islets (MHC class I+, II+) or FACS-purified beta cells (MHC class I+, II-). Responding C57Bl/6 (H-2b) splenocyte populations were either: (1) untreated; (2) depleted of helper T cells with anti-L3T4 monoclonal antibody plus complement; (3) depleted of cytotoxic T lymphocytes with anti-Lyt2 mAb plus complement; or (4) depleted of antigen-presenting cells by passage through a Sephadex G-10 column. Whole islets were capable of stimulating a significant C57Bl/6 anti-DBA cytotoxic T cell response if the responding population was untreated or treated with complement alone. Depletion of responding splenocytes with either anti-Lyt2 or anti-L3T4 mAb plus complement abrogated the generation of allospecific CTL. If the responding splenocyte population was depleted of APCs, the allo-CTL response against whole islets was decreased, but still significant. If, however, the stimulator population consisted of FACS-purified DBA 2J beta cells, APC-depleted C57Bl 6 splenocytes were incapable of generating any CTL response. Adding responder type (C57Bl/6) APCs back to the microwells restored the capacity for both whole islets and purified beta cells to stimulate a strong allo-CTL response. These data demonstrate that both indirect and direct pathways of alloantigen presentation function in the MLIC.

Effect of systemic cyclosporine on tumor recurrence after liver transplantation in a model of hepatocellular carcinoma.

BACKGROUND: Long-term results after liver transplantation for hepatocellular carcinoma have been disappointing, largely because of the high recurrence rate. It is controversial whether the immunosuppressed state of the recipient contributes to this recurrence rate. We have developed a model in the rat system to examine the effect of immunosuppression on tumor recurrence after transplantation, as well as to evaluate other treatment strategies to decrease the recurrence rate. METHODS: A 2-mm3 nodule of Morris hepatoma 3924a was implanted intrahepatically at day 0. At postimplant day 16, the animals underwent syngeneic orthotopic liver transplantation. Two treatment groups were established. Group I received saline injections subcutaneously for 2 weeks, while group II received subcutaneous cyclosporine injections at 3 mg/kg/day for 14 days. Animal survival, tumor recurrence rate, and sites of recurrence and number of pulmonary nodules were recorded. RESULTS: Overall survival rate was reduced in animals receiving cyclosporine. The mean survival time was 74.4 days (SEM 6.39 days) in saline-treated animals and 50.4 days (SEM 7.63 days) in the cyclosporine-treated animals. The proportion surviving in group 1 was 47% and in group 2 was 18%. This difference in survival was statistically significant (P=0.025). The incidence of pulmonary nodules was increased in the cyclosporine-treated animals, and tumor recurrence in extrapulmonary sites was seen only in the cyclosporine-treated animals. CONCLUSION: Results from this study suggest that cyclosporine has an adverse effect on tumor recurrence after transplantation. This model will be useful to further examine treatment strategies to improve the outcome of transplantation for hepatocellular carcinoma.

Effects of HLA-A and B matching on success of cadaver grafts at a single center.

The effect of HLA matching on the success of cadaver renal allografts was examined utilizing computerized multifactoral analysis in a large single renal transplant center. One hundred ninety-one consecutive cadaver transplant recipients (from January 1968 to August 1975) were followed from 2 1/2 to 9 years. During the period surveyed we had not utilized the tissue typing results in a prospective manner to select recipients. The data presented attest to the beneficial effect of utilizing well matched cadaver grafts. HLA matching of two or more antigens results in significantly superior 2- and 4-year patient survival and graft function compared to results for cadaver kidneys matched for zero and one HLA antigen. The results are not greatly influenced when age, sex, or time of transplant are controlled. The importance of tissue typing is particularly clear if higher doses of antilymphoblast globulin (ALG) are administered. The risk inherent in advancing recipient age is markedly reduced by better transplant matches. Graft function is also superior in the diabetic patients receiving good HLA matches, but there are too few patients to make these results statistically significant.

Migration of mouse lymphocytes in vitro. I. Normal lymph node lymphocytes.

Normal unstimulated mouse lymph node lymphocytes (LNLs) migrated into filters in a gradient of normal mouse serum (NMS), heat-inactivated mouse serum (HI-MS), or zymosan-activated mouse serum (ZAS). Blind well chemotaxis chambers with 5-micrometer pore size cellulose nitrate membranes were used. Migration was assessed both by the leading front technique and the mean aggregate number. A concentration of 2.5 x 10(6) LNLs/ml or greater was needed to detect migration. Migration of LNLs to 1% NMS was time dependent and was inhibited by cytochalasin B. Comparison of the migration patterns of LNLs, neutrophils, and macrophages revealed that all cell types were responsive to NMS. LNLs responded as well to HI-MS as they did to NMS, neutrophils responded less well to HI-MS than to MMS, and macrophages did not respond to HI-MS. The LNL response to ZAS was significantly greater than the response to NMS to HI-MS and neutrophils and macrophages also responded strongly to ZAS. The migration of LNLs from various mouse strains to NMS revealed that the LNLs from different mouse strains possess varying degree of motility. The factor in mouse serum which induced migration was not strain specific. The LNLs from peripheral (inguinal, axillary, and brachial) nodes demonstrated greater motility in response to NMS than mesenteric LNLs. Using the checkerboard assay to discriminate chemotaxis from chemokinesis, mouse serum appeared to be solely chemokinetic when the leading front technique was used. However, using the mean aggregate number technique, mouse serum was determined to be both chemokinetic acid chemotactic for LNLs. The results indicate that the method can be reliably used to study those factors which influence the motility of normal or altered populations of lymphocytes.

100 second renal allografts from a single transplantation institution.

Between January 1, 1968 and March 1977, 100 of 131 patients who lost their first transplant at the University of Minnesota received a second renal allograft. Overall patient survival in the retransplanted group was 10% less than that in the dialysis group. The best results (graft function and patient survival were seen in young patients, nondiabetics, patients who received two sequential living related groups, and in those whose first graft was lost secondary to chronic rejection. The poorest results were seen in older patients (greater than 40 years), diabetics, and patients with acute rejection during the initial graft. Shared donor antigens do not affect graft outcome. These findings, although not the product of a randomized prospective study, may be useful in advising patients of the relative risks of retransplantation or hemodialysis.

Single-center long-term results of renal transplantation for IgA nephropathy.

BACKGROUND: Previous reports with short-term follow-up after renal transplantation for IgA nephropathy (IgAN) have suggested an incidence of recurrence up to 50%, an increased recurrence with living-related donors, and the rarity of graft loss due to recurrence. In this study, the long-term results of renal transplantation for IgAN were examined. METHODS: Between June 1980 and December 1994, 54 patients (61 renal transplants) with end-stage renal disease due to IgA nephropathy were performed at the University of California San Francisco. Actuarial patient and graft survival were compared with a matched reference group. Correlates of recurrent disease (biopsy confirmed) and graft loss were determined. RESULTS: Patient and graft survival for IgA patients were good (100% and 75%, respectively, at 5 years after transplant). Graft survival was lower in IgA recipients with living-related compared with cadaveric renal allografts (P<0.09) and also with renal allografts well matched at HLA-AB (< or =2 AB mismatches) (P<0.09) or HLA-DR (< or =1 mismatch) (P<0.01). Recurrence was not correlated with donor status, recipient age, race, gender, or immunosuppression. Recurrence (18 of 61) resulted in substantial graft loss (6 of 18) or deteriorating renal function (4 of 18) at a mean follow-up of 61 months. Mean time to diagnosis of recurrence and subsequent graft loss was 31 and 63 months, respectively. Despite re-recurrence of IgAN in three of five patients who were retransplanted, all have good long-term renal function. CONCLUSIONS: Substantial graft loss due to recurrent disease after renal transplantation for IgAN occurs with long-term follow-up. Living-related transplantation and HLA matching do not appear to confer an advantage for graft survival in patients with IgAN. Despite the potential for recurrence, IgAN patients enjoy good long-term graft survival.