A clone-specific monoclonal antibody that inhibits cytolysis of a cytolytic T cell clone.

Monoclonal antibody 384.5 specifically inhibited cytolysis of P-815 target cells by cloned L3 cytotoxic T lymphocyte (CTL) effector cells. The lytic activity of other cloned CTL that have other distinct specificities was not affected. Antibody 384.5 did not inhibit the cytolytic activity of bulk populations of C57BL/6 mixed lymphocyte culture (MLC) cells. Concanavalin A-facilitated cytolysis by T cell clone L3 but not T cell clone B18 was inhibited by antibody 384.5, whereas phytohemagglutinin-facilitated cytolysis by L3 cells was not strongly inhibited. Antibody 384.5 binds specifically to L3 cells but not to several other T lymphocytes clones, or to a detectable portion of populations of primary MLC cells, normal spleen, thymus, lymph node, or bone marrow cells. In contrast, C57BL/6 anti-B10.A(5R) secondary MLC cells (genetically enriched for reactivity against the H-2Dd region gene products) contained a small population which reacted with the antibody 384.5. The determinant detected by antibody 384.5 was susceptible to trypsin treatment, and was reexpressed after overnight incubation. These results suggest that the monoclonal antibody 384.5 detects an endogenously synthesized clone-specific determinant associated with the cytolytic activity of the L3 CTL clone. These properties make antibody 384.5 an attractive candidate for an antibody that reacts with the antigen-recognition site of a cytolytic T cell antigen receptor.

FTY720 and everolimus in de novo renal transplant patients at risk for delayed graft function: results of an exploratory one-yr multicenter study.

This exploratory, multicenter, open-label study evaluated the efficacy and safety of FTY720, as a part of an immunosuppressive regimen, in combination with everolimus and steroids in de novo renal transplant recipients at increased risk of delayed graft function (DGF). Patients received FTY720 (5 mg) and everolimus (4 mg) 2-12 h pre-transplantation, followed by 2.5 mg/d FTY720 and concentration-controlled everolimus (4-8 ng/mL) post-transplant for 12 months. Induction therapy was prohibited. After enrollment of 56 of the planned 200 patients between 2000 and 2002, the recruitment was terminated. The primary endpoint, rate of graft loss, or death at three months was 15.4% and the biopsy-confirmed acute rejection was 42.3%. Death or graft loss at 12 months in the DGF and non-DGF arms was 36.0% and 25.9%, respectively. The mean estimated creatinine clearance at three months was 63 and 55 mL/min in the non-DGF and DGF groups, respectively, while at 12 months it was 56 mL/min in both the groups. Although there was no comparator arm, the results from this exploratory study (compared with data from other phases II and III trials) indicated no apparent benefits of FTY720-based regimens for prevention of acute rejection and preservation of renal function in renal transplant recipients at high risk of DGF.

Blockade of CD2-LFA-3 interactions protects human skin allografts in immunodeficient mouse/human chimeras.

A human skin allograft injury model in immunodeficient mice, engrafted with human peripheral blood mononuclear cells from a different donor, has been used to test whether reagents that block human T cell CD2 interactions with its principal ligand, LFA-3 (CD58), can inhibit immune reactions in vivo. In this model, human skin grafts show a reproducible pattern of progressive human T-cell infiltration and human graft microvascular injury that resembles human first-set skin graft rejection. Murine Mab to human LFA-3 or human LFA-3-IgG1 fusion protein, but not isotype-matched control antibodies, each markedly protected skin grafts from leukocyte infiltration and injury. These data provide the first evidence that LFA-3 functions in vivo and establish the ability of this new model to test human-specific immune modulators.

Exposure-efficacy relationships of a fingolimod-everolimus regimen in kidney transplant patients at risk for delayed graft function.

OBJECTIVE: We explored relationships between blood levels of fingolimod (FTY720) and everolimus versus treated biopsy-proven acute rejection (BPAR) in an open-label trial in de novo kidney transplant recipients. METHODS: Patients (n = 52) who fulfilled predefined criteria placing them at increased risk of delayed graft function received fingolimod 2.5 mg/d, everolimus 2 mg twice daily with trough blood levels (C0) adjusted to 4 to 8 ng/mL, and corticosteroids. Everolimus and fingolimod C0 were collected over 1 year; efficacy readout was at 3 months. RESULTS: Fingolimod C0 accumulated over the first 3 months with a time-averaged level (C0avg) of 5.7 +/- 3.5 ng/mL. At steady state in months 3 to 12, C0 was 7.0 +/- 4.4 ng/mL. Overall, 30 patients (58%) were free from BPAR to month 3. Patients were divided into four groups based on whether their fingolimod C0avg and everolimus C0avg were above or below the population medians. Freedom from BPAR was 53% and 57% for low fingolimod combined with low and high everolimus, whereas the percentages were improved to 83% and 85% for high fingolimod combined with low and high everolimus. CONCLUSIONS: This pilot study with an everolimus-fingolimod regimen demonstrated trends in freedom from rejection that were drug concentration-related and that underscored, in particular, a strong contribution to efficacy from fingolimod.

T-cell lineage of a Friend virus-induced lymphatic leukemia in athymic rats.

Athymic (rnu/rnu) and euthymic rats inoculated with the Friend virus-associated lymphatic leukemia virus developed lymphocytic leukemia. Neoplastic cells from these animals were evaluated by means of indirect immunofluorescence and flow cytofluorometry with monoclonal antibodies Ox-1, Ox-7, and W3/25, which react with surface antigens present on normal rat lymphoid cell populations. Lymphoid cells from leukemic animals revealed characteristic alterations in cell surface fluorescence profiles when compared to normal, healthy controls. Athymic and euthymic leukemic rats were similar in that many cells from both the spleen and bone marrow had markers on the cell surface normally found on thymocytes but not on mature peripheral lymphocytes. These studies provided evidence supporting the presence of T-lineage lymphocytes in the athymic rat. Further, this population of early or "pre"-T-lymphocytes included the predominant leukemia cell type induced by the Friend virus-associated lymphatic leukemia virus.

Pharmacokinetic and phase I trial of intraperitoneal carboplatin and cyclosporine in refractory ovarian cancer patients.

PURPOSE: The feasibility and pharmacokinetics of cyclosporine (CsA) delivered intraperitoneally (IP) have not been previously explored. We performed a pharmacokinetic study of IP CsA followed by a phase I dose-escalation trial of the combination of IP CsA and carboplatin in refractory ovarian cancer patients. PATIENTS AND METHODS: A pilot study was performed of three patients who received 1, 10, and 20 mg/kg IP CsA alone. Subsequently, a phase I trial of 35 patients was performed between April 1990 and April 1993. Whole-blood and IP fluid CsA concentrations were measured at serial time points. The highest dose delivered IP was 34.6 mg CsA/kg in combination with carboplatin (250 mg/m2 or 300 mg/m2, depending on creatinine clearance), which was not dose-escalated. The area under the concentration-time curve (AUC) for CsA and half-life (T1/2) were calculated. Objective and serologic responses were noted, and toxicity was graded using the National Cancer Institute common toxicity criteria. RESULTS: The feasibility of delivering IP CsA alone was established. We observed a 1,000:1 ratio between IP fluid and blood concentrations at 20 mg CsA/kg. Pharmacokinetic analysis confirmed that at 20 mg CsA/kg, there was an IP fluid-to-blood AUC ratio of 600:1 in favor of peritoneal exposure. At the highest dose delivered, 34.6 mg CsA/kg, the mean IP CsA levels of 1,110 micrograms/ mL were tolerated moderately well and the IP fluid-to-blood ratio of 1,000:1 was maintained. Blood and IP CsA concentrations were analyzed in the presence and absence of IP carboplatin. At 20 mg CsA/kg, there was no difference in either mean blood CsA levels (0.9 microgram/ mL) or mean IP CsA concentrations (1,000 micrograms/mL) obtained in the absence or presence of carboplatin. The most common toxicity in the phase I study was anemia, seen in 66% of patients. Common toxicities at the maximum CsA dose delivered (34.6 mg/kg) were anemia, leukopenia, thrombocytopenia, and hypertension. In this trial, three objective responses (two complete and one partial) were observed for a duration of 3 to 11 months. Control of platinum-resistant ascites was an important feature, noted in five of eight patients. CONCLUSION: We have established the feasibility of delivering IP CsA up to doses of 34.6 mg/kg in conjunction with carboplatin, and the sustaining of IP fluid to blood ratios of 1,000:1. The IP administration of CsA resulted in a favorable ratio of exposure for the peritoneal cavity compared with systemic exposure, indicating a therapeutic advantage of this approach with a significant decrease in systemic toxicity. We recommend that 34.6 mg/ kg of IP CsA be tested as a phase II dose in combination with carboplatin in refractory ovarian cancer patients. This report provides the groundwork for future studies using IP CsA, both as a chemomodulator of platinum and of multidrug resistance.

Phase I trial of intravenous carboplatin and cyclosporin A in refractory gynecologic cancer patients.

Our objective was to determine the maximum tolerated dose of cyclosporin A (CsA) delivered as a loading dose (LD) and continuous i.v. infusion (CI) in combination with carboplatin in patients with refractory gynecologic cancers. Twenty-nine heavily pretreated patients (25 ovarian epithelial, 2 cervical, and 2 endometrial carcinomas) received 113 cycles of CsA and carboplatin from September 1989 to September 1991. Twenty-four of these 29 carcinomas were strictly defined to be platinum resistant. CsA was administered as a LD escalated from 6 to 10 mg/kg followed by a 24-h CI from 2.5 to 14.5 mg/kg/day. Carboplatin was targeted to an area under the time versus concentration curve (AUC) of 6 mg/ml x min and was not dose escalated. Whole-blood CsA concentrations (fluorescence polarization immunoassay) at the maximum tolerated dose (10 mg/kg LD, 14.5 mg/kg/day CI) ranged from 2.4 to 3.0 microgram/ml over 12 h. Estimated median carboplatin AUC, based on calculated carboplatin clearance, was 7.9 mg/ml x min. The dose-limiting toxicity of the combination of CsA and carboplatin was grade 4 thrombocytopenia. Grade 3 or 4 thrombocytopenia occurred in 35% of the patients, which could be explained by the effects of carboplatin (AUC of 6 mg/ml x min) alone. Overall, neutropenia occurred in 24% of the patients and anemia in 17% of the patients. Grade 3 or 4 nausea or vomiting was noted in 10 and 14% of the patients, respectively. Grade 3 hypertension during CsA administration occurred in 14% of the patients. No grade 3 or 4 nephrotoxicity was seen in this trial. Three objective responses were noted: one complete response (11 months) and one partial response (5 months), both in potentially platinum-sensitive patients with platinum-free intervals of only 9 months each. One platinum-resistant patient had a partial response for 21 months. Five additional patients experienced >75% reduction of CA-125 or a return to a normal CA-125 titer. We concluded that whole-blood CsA concentrations of >3.0 microgram/ml (as seen when CsA is used as a modulator of multidrug resistance) were not achievable in this combination with carboplatin in this population of heavily pretreated gynecologic cancer patients. However, because CsA is used in this trial as a chemosensitizer in platinum-sensitive tumors and as a chemomodulator of platinum resistance, we targeted a CsA concentration of >1.0 microgram/ml, which was achieved. The CsA dose recommended for a Phase II trial of this combination is 10 mg/kg LD and 11.6 mg/kg/day CI, which results in blood CsA concentrations ranging from 1.2 to 1.3 microgram/ml over 12 h. Responses in this population of refractory gynecologic cancer patients are unusual, and these encouraging results form the basis for a Phase II trial of this combination.

Effects of H2-receptor antagonists on renal function in cyclosporine-treated renal transplant patients.

H2-receptor antagonists have been frequently avoided in cyclosporine-treated transplant patients because of concern regarding possible exacerbation of nephrotoxicity. To determine whether the reported increase of serum creatinine levels in cyclosporine-treated transplant patients receiving H2-receptor antagonists was due to a true decrease in glomerular filtration rate or was secondary to altered renal tubular handling of creatinine, simultaneous inulin and creatinine clearances were analyzed in 11 cyclosporine-treated renal transplant recipients before and after H2-receptor antagonist administration. Seven patients received one week of cimetidine 300 mg p.o. four times daily and eight received one week of ranitidine 150 mg p.o. two times daily. Prior to study, all patients had stable renal function and were maintained on prednisone (mean dose 0.2 +/- 0.01 mg/kg/day) and cyclosporine (mean dose 5 +/- 0.6 mg/kg/day). Four patients were also receiving azathioprine (2 mg/kg/day). Cimetidine administration resulted in a significant increase (P less than 0.05) in mean serum creatinine concentration from 2.0 +/- 0.3 mg/dl to 2.4 +/- 0.3 mg/dl and a significant reduction (P less than 0.05) in mean creatinine clearance remained unchanged during this same period. Serum creatinine levels returned to baseline values for all patients following discontinuation of the drug. Ranitidine administration had no consistent effect on serum creatinine concentration, creatinine clearance or inulin clearance. Cyclosporine trough levels and BUN were unchanged by either drug. These results confirm previous observations demonstrating an increase in serum creatinine and a reduction in creatinine clearance following administration of H2 receptor antagonists, especially cimetidine. Failure to document a simultaneous reduction in inulin clearance is consistent with the hypothesis that H2-receptor antagonists do not exacerbate cyclosporine nephrotoxicity and lower GFR, but rather compete with creatinine for tubular secretion.

A three-year experience with serum anodal trypsinogen as a biochemical marker for rejection in pancreatic allografts. False positives, tissue biopsy, comparison with other markers, and diagnostic strategies.

Serum values of immunoreactive anodal trypsinogen (sAT) have been claimed to correlate well with rejection occurring in pancreatic allografts. We have studied the behavior of sAT in serial serum samples obtained from 39 type I diabetics undergoing whole-organ pancreas transplantation during the past 3 years. Patients had either received a pancreatic allograft simultaneously with a transplanted kidney (SPK, n = 33) or after a previous kidney transplant (pancreas after kidney [PAK] n = 6). The behavior of sAT was studied in relation to the clinical diagnosis of rejection. Graft amylase output for all 39 patients and serum creatinine for the 33 SPK recipients were also studied. Tissue biopsies were obtained from 11 patients with elevated sAT values and a presumptive diagnosis of rejection. Nine of these patients had SPK grafts and simultaneously elevated creatinine values. Tissue was obtained from the simultaneously transplanted kidney; all specimens revealed rejection. Two of the 11 patients had PAK allografts. Biopsies performed on the graft duodenum were consistent with acute rejection. Three additional patients with unchanged sAT values had biopsies for other reasons; these biopsies failed to demonstrate signs of acute rejection. Thus graft biopsy correlated exactly with sAT behavior in every case in which rejection was suspected. Five patients had elevations of sAT not associated with rejection: one resulted from direct trauma, two had outlet obstruction, and two had clinical diagnoses of graft pancreatitis. The sAT was more sensitive and specific than GAO and as sensitive as creatinine for SPK recipients. These studies confirm that sAT is a reliable, graft-specific biochemical marker for the early diagnosis of pancreatic rejection. The use of sAT should allow for the proper timing of graft biopsies and the judicious use of immunosuppressive agents, which will result in increased allograft survival for PAK and pancreas-alone allografts.

The immunochemical distribution of cyclophilin in normal mammalian tissues.

Cyclophilin, a 17 Kd proline cis-trans isomerase, high-affinity (Kd 10(-8) M) target for the immunosuppressive drug cyclosporine has ubiquitous phylogenic distribution, but its tissue localization in mammals has not been detailed. To explore a potential relationship between the multiple systemic effects of CsA and the cellular and tissue distribution of CYP, thirty-three different normal porcine tissues were examined using an immunohistochemical technique. Tissue was obtained from farmbred pigs, immediately fixed in buffered formalin, and prepared as embedded 5-mu sections. Immune-specific staining was accomplished using an ABC immunoperoxidase method and an affinity-purified, monospecific, rabbit anti-CYP IgG. Cut sections served as their own blanks and controls, and all tissues were stained in batch to minimize the effects of variation in technique. Consistent with earlier reports, CYP was present in all tissues studied, however, there was remarkable heterogeneity in CYP distribution. Renal parenchymal cells, cardiac and striated muscle, pulmonary and skin demonstrated cytoplasmic immunospecific CYP--however, the cellular localization varied. Cytoplasmic staining of endothelial, neural, and glandular elements was consistently observed. Contrasting with previous reports, CYP localized to the nucleus as well as the cytoplasm of some lymphoid cells, hepatocytes, and cells of the large intestine. Generally, greater CYP-specific staining was noted in organs amenable to CsA immunosuppression (heart, liver, kidney), compared with organs deemed more immunologically vulnerable when allografted under CsA (pancreas, lung, small bowel). Similarly, CYP-immunospecific staining was abundant in tissues susceptible to CsA toxicities (neural tissue, smooth muscle, kidney, liver). This detailed immunohistological examination affords a correlation between CYP content and sensitivity to CsA. It also raises some new questions about tissues with little extractable CYP but significant histological staining.

Hepatobiliary and pancreatic complications of cyclosporine therapy in 466 renal transplant recipients.

Two hundred twenty-eight patients from a total of 466 (49%) receiving renal allografts under cyclosporine/prednisone (CsA/Pred) immunosuppression experienced at least one episode of posttransplant hepatotoxicity. All patients were documented to have normal serum bilirubin, serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvate transaminase (SGPT), lactic acid dehydrogenase (LDH), and alkaline phosphatase (AP), as well as negative results of biliary ultrasound and upper gastrointestinal contrast examinations prior to transplantation. Hepatotoxic episodes usually were self-limited (82%), and generally occurred during the very early posttransplant period (76%). Liver function abnormalities included hyperbilirubinemia (48% of patients), elevated SGOT (47%), SGPT (73%), LDH (84%), and AP (59%). The CsA serum trough radioimmunoassay (RIA) was relatively high among hepatotoxic patients with a mean value of 225 +/- 17 ng/ml. Pharmacokinetic parameters, including bioavailability and drug clearance, were significantly altered among this group of patients. The management strategy of CsA dose reduction was effective; however, 11 patients (2.4%) developed biliary calculous disease posttransplant while under CsA/Pred immunosuppression. Seven patients had cholelithiasis, and two patients underwent choledochoduodenostomy because of primary choledocholithiasis. The results contrast with 279 renal transplant recipients from an overlapping nonrandomized group treated with azathioprine (Aza)/Pred in whom cholelithiasis was not identified. Pancreatic abnormalities were relatively common, but clinical pancreatic disease occurred in only six patients. There were two episodes of acute pancreatitis, three patients developed pancreatic abscess, and one patient developed a pancreatic pseudocyst. The apparent proclivity of CsA-treated patients to develop biliary calculous disease, and the occurrence of serious pancreatic complications in a small percentage of patients did not affect the majority of CsA-treated patients. They may, however, represent important problems associated with the use of this immunosuppressive agent.

Immunoregulatory mechanisms in cyclosporine-treated renal allograft recipients.

Cyclosporine (CsA)-treated recipients of a primary cadaveric (CAD) renal allograft were postoperatively evaluated for their donor and nonspecific immune responsiveness. Recipients with posttransplant (Tx) T helper (TH):T suppressor (TS) cell ratios less than 1.0 (averaged for the first 0-30 post-Tx days) had significantly better one-year serum creatinines (SCr) of 1.8 +/- 0.7 vs. 2.3 +/- 0.6 for recipients with TH:TS ratios greater than 1.0, P less than 0.05. Significantly fewer rejection episodes (30 vs. 57) and immune graft losses (10 vs. 19) were experienced by recipients with TH:TS ratios less than 1.0 vs. greater than 1.0, P less than 0.001 and 0.05, respectively. Recipients with TH:TS ratios less than 1.0 vs. greater than 1.0 displayed significantly lower post-Tx panel mixed lymphocyte culture (PMLC) stimulation indices (SI) of 24 +/- 11 vs. 38 +/- 6, P less than 0.05 and donor MLC SI of 15 +/- 6 vs. 31 +/- 8, P less than 0.05, respectively. Moreover, the post-Tx:pre-Tx donor MLC ratio of 0.58 +/- 0.2 vs. 1.1 +/- 0.32 was significantly lower in recipients with TH:TS ratios less than 1.0 vs. greater than 1.0, P less than 0.05. The suggested donor hyporesponsiveness in recipients with post-Tx TH:TS ratios less than 1.0 was further investigated by studying 46 CsA-treated allograft recipients for their ability to display regulatory T cell or adherent monocyte MLC suppressor activity. With a mean follow-up time of 5 +/- 4 months (range 0.5-14 months) we observed that 46% (21/46) of the patients displayed T cell suppressor activity, including 35% (16/46) with T-donor-specific and 46% (21/46) with T non-specific MLC suppressor activity. Additionally, 59% (27/46) of the patients also displayed nonspecific adherent monocyte MLC suppression. Recipients displaying either T cell or adherent monocyte suppression experienced significantly fewer rejection episodes than patients with no suppressor cell activity (P less than 0.05). Moreover, patients with T cell suppressor activity displayed a significantly lower panel and donor MLC vs. patients not displaying T suppressor activity (P less than 0.05. and 0.05, respectively). Finally, there was a significant correlation between the display of T cell suppressor activity in patients who were matched with their donors at the HLA-DR locus vs. no display of T suppressor activity in those patients unmatched with their donors at the HLA-DR locus.

The effect of cyclosporine administration on the cellular distribution and content of cyclophilin.

Cyclophilin (CYP), an intracellular protein sharing amino acid sequence identity with the enzyme peptidyl-prolyl cis-trans isomerase has become the leading candidate for the receptor responsible for cyclosporine biological effects. Avid binding of CYP to cyclosporine and immunosuppressive cyclosporine metabolites has been demonstrated, while nonimmunosuppressive cyclosporine metabolites have tended not to bind to cyclophilin. A previous immunohistochemical analysis documented that CYP localized principally to the cytoplasmic cellular compartment, but nuclear staining was observed among some cells. This study was undertaken to more precisely define the ultrastructural distribution of CYP, and to determine whether CYP cellular content was affected by CsA therapy. Untreated Wistar rats or those receiving 7 days of CsA (15 mg/kg/day, i.p.) were anesthetized, perfusion-fixed in situ, and sacrificed. Analyses of lymph node, spleen, thymus, kidney, liver, heart, brain, and ileum used an affinity purified, rabbit anticyclophilin IgG. Transmission electron microscopy was performed after staining with anti-CYP using a horseradish peroxidase/biotin/avidin technique. Quantitative immunofluorescence was measured by confocal microscopy using anti-CYP, with a biotin/avidin/phycoerythrin technique. Cyclophilin localized to the cytoplasmic compartment--however, association with mitochondria endoplasmic reticulum, Golgi, and with the nuclear membrane among lymphocytes, as well as cells from kidney, liver and ileum--was documented. Cyclophilin was not identified within the nucleus proper. Tissues obtained from animals receiving CsA exhibited a generalized increase in CYP content compared with tissues from untreated controls, suggesting the possibility that CsA may exert a regulatory influence upon CYP gene activation. Collectively, the data were consistent with the hypothesis that CYP exerts a central role in cellular metabolism, and that CsA-mediated biologic effects result from the CsA/CYP interaction.

Control of cloned alloreactive T lymphocyte proliferative responses. A possible role for cell-surface-bound alloantigen.

Previous studies using flow cytofluorometry demonstrated that passively acquired alloantigens encoded by the I-A and H-2K/D regions of the MHC could be identified on the surface of murine cloned T lymphocytes. The present studies were designed to further characterize the nature of that bound alloantigenic material on cloned lines of alloreactive amplifier T cells (Th). Immune precipitation and polyacrylamide gel electrophoresis were used to substantiate that allogeneic I-A and H-2K/D antigens were present on he surface of these cloned Th. Using proteolytic digestion with papain, bound allogeneic I-A and H-2K/D was removed from the surface of a cloned Th designated L2. Allogeneic I-A or surface of a cloned Th designated L2. Allogeneic I-A or H-2K/D antigens were not reexpressed if papain digested cells were incubated overnight in culture medium without addition of fresh alloantigen. Further, cloned cells did not release detectable amounts of interleukin 2 (IL-2) in response to Con A stimulation immediately following enzymatic digestion. After overnight culture, papain-digested cells released amounts of IL-2 similar to untreated controls. The proliferative response of these cells measured by 3H-thymidine incorporation, however, was significantly less than that observed using undigested controls, unless alloantigen was provided in the form of fresh irradiated stimulating cells. The addition of partially purified preparations of monoclonal anti Ia antibodies to cultures of cloned Th resulted in marked reduction in incorporation of 3HTdR. These findings are consistent with the hypothesis that modulation of the Th proliferative response may occur at least partially through binding of allogeneic material to the cell surface.

Successful transplantation of cyclosporine-treated allograft recipients with serologically positive historical, but negative preoperative, donor crossmatches.

Eighteen renal allograft recipients (15 cadaveric and 3 haploidentical living-related donor transplants) with historically (Hx)3 positive, but pretransplant (pre-Tx) negative, donor crossmatches (XM) were treated postoperatively with cyclosporine (CsA) and prednisone (Pred). The one-year allograft survival for the 14 primary allograft recipients was 86% (12/14). This was comparable to, and not significantly different from, the 81% (51/63) graft survival for recipients of primary cadaveric donor allografts transplanted during the same period who displayed a negative donor crossmatch with both Hx and pre-Tx sera. All four retransplant recipients with (+) Hx, but (-) pre-Tx, donor Xms lost their grafts. This result was significantly different (P less than 0.05) from the 75% (27/36) graft survival for retransplant recipients displaying a negative donor crossmatch with both Hx and pre-Tx sera. A significant decrease in PRA of 52 +/- 19% to 19 +/- 16%, P less than 0.05, was displayed by 12/18 CsA patients when comparing (+) Hx to (-) pre-Tx sera, which could have influenced the allograft survival in those patients. However, a graft survival of 44% (4/9) was observed for azathioprine (Aza) and Pred-treated recipients of cadaveric donor renal allografts who also displayed a significant decrease in PRA of 50 +/- 22% to 5 +/- 4%, P less than 0.05 when comparing Hx to pre-Tx sera. The decreasing PRA did not beneficially affect these Aza-Pred patients' graft survival. Therefore, CsA-Pred afforded a beneficial effect when recipients of a primary cadaveric renal allograft displaying a (+) Hx, but (-) pre-Tx, XM were transplanted. Retransplant recipients, however, should receive a cadaveric donor allograft only when they are XM-unreactive, whether testing with pre-Tx or Hx sera.

RAD in de novo renal transplantation: comparison of three doses on the incidence and severity of acute rejection.

BACKGROUND: The effects of three doses of RAD (40-O-[2-hydroxyethyl]-rapamycin), a novel macrolide with potent immunosuppressive and antiproliferative properties, on the incidence and severity of acute rejection episodes as well as its tolerability were evaluated in a dose-ranging study in de novo renal transplant recipients. METHODS: In this double-blind, parallel group, multicenter study, recipients were randomized to receive 1 mg, 2 mg, or 4 mg/day of RAD in combination with Neoral (cyclosporine, USP MODIFIED) and corticosteroids. The incidence and severity of biopsy-proven acute rejection episodes, graft survival, patient survival, infection rates, laboratory measurements, and adverse events were compared across groups after 6 months of therapy. RESULTS: Among the 103 recipients, patients receiving 1, 2, or 4 mg/day experienced a 32.4%, 14.7%, or 25.7% incidence of biopsy-proven acute rejection episodes within the first 6 months posttransplantation, respectively. Even though the study was not powered to demonstrate efficacy, the incidence of moderate and severe acute rejection episodes was found to be significantly lower among patients in the 2 mg and 4 mg/day groups than in the 1 mg/day group (P=0.002 and P=0.006, respectively). Overall graft and patient survival rates were excellent. RAD was generally well tolerated. Although blood lipid levels increased in all groups, changes were manageable with lipid-lowering agents and did not warrant discontinuation of study medication. The incidence of viral and fungal infections was low; however, it was higher among recipients treated with 4 mg/day. CONCLUSIONS: In combination with Neoral and corticosteroids, RAD doses of 2 mg and 4 mg/day resulted in lower rates of acute rejection episodes and efficacy failure than the 1 mg/day dose and were significantly more effective in reducing the severity of rejection. Large-scale, controlled, follow-up studies are currently in progress to confirm these initial findings.

Multivariate analysis of risk factors impacting on immediate and eventual cadaver allograft survival in cyclosporine-treated recipients.

A multivariate analysis dissected the impact of donor procurement variables, immunologic risk factors, and alternate cyclosporine and prednisone induction immunosuppressive regimens on the early and eventual function of 303 consecutive cadaveric renal allografts. Primarily warm, but to a slight extent cold, ischemia time had an adverse impact on allograft function, as did the requirement for vasopressor or diuretic therapy. The occurrence of initial graft non-function adversely affected the probability of three-month graft survival, but did not alter either the longevity of organs, which subsequently recovered function, or patient mortality rate. The major immunologic risk factor was a second or multiple transplant, which was associated with an increased incidence of early graft failure, and impaired renal function in successful transplants. Correlations with HLA-B and DR matching were reflected in the quality of renal function, but not in graft survival rates. Cyclosporine (CsA) administration by continuous intravenous infusion, in order to avert initial elevated mean three-day, serum radioimmunoassay drug levels reduced the incidence of initial graft non-function. High levels were also associated with impaired early and eventual renal function. Rapid posttransplant taper of corticosteroids to 30 mg prednisone by day six was associated with a greater incidence of rejection episodes and early graft failure than a taper that achieved 30 mg prednisone at 60 days. Both the serum creatinine value and the degree of hypertension observed at one month afforded good prognostic indices of eventual graft survival. Therefore, renal allografts in CsA-treated patients were sensitive not only to adverse donor and immunologic risk factors, but also to excessive CsA drug levels in the early postoperative period. These findings suggest an induction immunosuppressive strategy utilizing slightly higher initial doses of steroids for CsA-sparing during the first three days, followed by increased, but judicious, administration of CsA to achieve steroid-sparing by virtue of effective rejection prophylaxis.

Demographic factors affecting the pharmacokinetics of cyclosporine estimated by radioimmunoassay.

In order to assess the impact of demographic factors on serum levels of cyclosporine (CsA) estimated by radioimmunoassay (RIA) in renal allograft recipients, 493 pharmacokinetic studies were performed in 212 patients. Neither the presence of diabetes mellitus nor the CsA dosing frequency affected the measured pharmacokinetic parameters. Age over 45 years led to slower CsA clearance with resultant increase in maximum serum concentration (Cmax) per administered milligram, and increased volume of distribution. Female patients showed more rapid drug clearance, but greater volume of distribution. Concomitant hepatic impairment reduced drug clearance, increasing the area under the curve (AUC) per administered milligram of drug, and the Cmax. Patients treated with a rapid steroid taper showed a shorter half-life and lower Cmax than those receiving a slow steroid taper. Nephrotoxicity was associated with increased AUC per administered mg, while patients with acute tubular necrosis requiring dialysis showed poorer drug absorption, lower Cmax, and longer time to peak. The only effect of cimetidine administration was a slightly shortened time to peak. Serial analyses posttransplant in 17 patients suggested a tendency toward improved drug absorption with no effect on other parameters. These studies demonstrating the significant impact of demographic factors thus afford a basis on which to predict the trend of anticipated CsA levels as measured by RIA in renal allograft recipients.

Complications of cyclosporine-prednisone immunosuppression in 402 renal allograft recipients exclusively followed at a single center for from one to five years.

The therapeutic efficacy of cyclosporine (CsA) as an immunosuppressive agent was complemented by a modest, long-term incidence of toxic complications in 402 renal allograft recipients engrafted one to five years prior to analysis. The overall patient and graft survivals at one year were 97% and 84% (actual), and at five years 92% and 67% (actuarial). The immunosuppressive therapeutic index was excellent: only 12% of allografts were lost from rejection, with 5% of patients succumbing to infection. While infections were common, tending to emanate in the urinary tract or to be viral in etiology, they were generally mild and readily controlled. Only four patients displayed malignancies; none succumbed to this cause. The most common toxic complication was hypertrichosis, which was accentuated in pediatric patients. While tremors occurred in 20% of patients, primarily during the first three months, other neuroectodermal complications of parethesias, depression, somnolence, and seizures were rare. Hepatotoxicity, which was noted in 50% of patients, particularly recipients of cadaveric grafts, generally was first seen as a transaminase elevation, at least partially reversible by dose-reduction and abating by the third year. Associated disturbances of cholelithiasis and pancreatitis were occasionally observed. Nephrotoxicity was the only persistent, long-term complication. Hypertension occurred in 72% of patients during the first month, 36% in the second year, and about 15% thereafter. Hyperuricemia, which occurred in about 30% of recipients during the first two years, was occasionally associated with symptomatic gout. The mean serum creatinine level remained elevated throughout the follow-up period at 1.8-1.9 mg/dl, suggesting persistent, but nonprogressive, drug-induced renal injury. The present analysis documents the relative safety of CsA for long-term therapy, and highlights the need for new approaches to ameliorate drug-induced nephrotoxicity.

Investigation of HTLV-3 serology in a renal transplant population.

From June 1977 to March 1985, 572 renal transplants were performed at The University of Texas Medical School at Houston. This represented 220 patients (151 cadaveric [CAD] and 69 living-related donor [LRD] recipients) treated with azathioprine and prednisone (Aza-Pred) and 352 patients (250 CAD and 102 LRD) treated with cyclosporine (CsA) and Pred. Sera from each recipient before and after transplant (Tx) as well as from each of their 436 donors (265 CAD and 171 LRD) were retrospectively tested for the presence of antibody to the human T cell lymphotrophic virus type III (HTLV-3) by enzyme immunoassay (EIA) and Western Blot analysis. Of the 436 donors tested, only 1/265 (0.38%) CAD donors were both EIA repeatedly reactive and Western Blot positive, whereas none of the 171 LRD were reactive. Pre-Tx, 4/401 (1.0%) CAD and 1/171 (0.6%) LRD recipient sera were EIA repeatedly reactive, however, all 5 were to be Western Blot negative. Post-Tx, 4.2% of the sera (24/572, 4 LRD and 20 CAD recipients) were EIA-reactive. All 20 CAD recipient sera were subsequently found to be negative with Western Blot testing. However, 2 LRD sera (2/572, 0.35%) displayed EIA reactivity as well as Western Blot positivity. One LRD, Western-Blot-positive recipient is alive and well with a functioning allograft 39 months post-Tx, whereas the second LRD, Western Blot positive recipient died of septic complications 16 months post-Tx. Finally, the recipient of the Western-Blot-positive CAD allograft is alive with a well-functioning graft and remains EIA and Western-Blot-negative 36 months post-Tx.