Sequential Immunotherapy Research Articles

Delayed graft function may not adversely affect short-term renal allograft outcome.

Delayed graft function (DGF) is commonly believed to adversely impact both short- and long-term renal allograft function. Because immunosuppressive therapy is commonly altered after DGF is identified, retrospective analyses are difficult to interpret. We therefore prospectively sought to examine the natural history of DGF in a controlled patient population under identical immunosuppressive protocols. Adult patients undergoing cadaveric renal transplantation were treated with sequential triple drug immunotherapy. High-dose steroids were administered in the operating room and rapidly tapered to 20 mg prednisone by post-operative day (POD) 6. Cyclosporine (CsA) microemulsion was begun on POD 1, and dosed asymmetrically at 12-h intervals to reach a daytime Cav of 650 ng/mL (utilizing 2-h and 6-h levels), while PM doses were adjusted to an AM trough of 300 ng/mL. Mycophenolate (1000 mg q12 h) was added on POD 3 in most patients and discontinued after 3 months. No induction agents were used. All patients were followed for at least 6 months. Sixty consecutive patients received 64 allografts (four double grafts). In all, 17 patients required dialysis and were considered to have DGF. Eight of these patients received marginal organs turned down by at least one other centre. Cold ischaemia time was significantly longer in patients with DGF (24 h vs. 19 h, P < 0.01) All patients were treated as planned and there were no major protocol violations. One patient had primary non-function and was excluded from analysis. CsA trough and Cav values were similar between groups. Mean serum creatinine levels (mg/mL) fell more slowly in patients with DGF but there was no significant difference by 3 months (1.7 vs. 1.5) and the creatinine clearance was not significantly different between the groups after 1 year (71 cm3/min in DGF vs. 61 cm3/min, P = 0.13). Our data demonstrate that alterations in routine immunosuppressive strategies may not be necessary to achieve equivalent outcomes in patients with DGF.

Quantification of donor and recipient hemopoietic cells by real-time PCR of single nucleotide polymorphisms.

Analysis of changes in recipient and donor hemopoietic cell origin is extremely useful to monitor the effect of stem cell transplantation (SCT) and sequential adoptive immunotherapy by donor lymphocyte infusions (DLI). We developed a sensitive and accurate method to quantify the percentage of recipient and donor cells by real-time PCR using single nucleotide polymorphisms (SNPs) as markers. Allele-specific PCR of seven SNPs resulted in specific markers for donor or recipient in 97% of HLA-identical sibling pairs. Both, recipient- and donor-derived hemopoietic cells can be simultaneously analyzed in 67% sibling pairs. We expect this can be increased to approximately 99% by developing three additional SNP-PCR. Serial dilution of SNP-positive DNA into either SNP-negative DNA or water revealed a detection limit of 0.1-0.01% depending on the amount of input DNA and start C(t) of the used SNP-PCR. Application of our real-time SNP-PCR method for a CML patient treated by allogeneic SCT and DLI demonstrated its feasibility to follow donor T-cell chimerism and early detection of residual and recurrent autologous hemopoiesis in response to treatment. This detailed monitoring of the genetic origin of hemopoietic cells, in particular immune effector cells and target cells after SCT and DLI, may substantially contribute to understanding of the mechanisms that play a role in the success of treatment.

Chemoimmunotherapy of advanced malignant melanoma: sequential administration of subcutaneous interleukin-2 and interferon-α after intravenous dacarbazine and carboplatin or intravenous dacarbazine, cisplatin, carmustine and tamoxifen

Both chemotherapy and interleukin-2 and/or interferon-α produce objective responses in a proportion of advanced malignant melanoma patients. While duration of response to chemotherapy is short, i.e. usually below 4 months, immunotherapy has resulted in a small number of long-lasting remissions in patients with metastatic melanoma. In two consecutive phase II trials in a total of 67 patients, we assessed the potential synergism between both modalities, i.e. chemo- and immunotherapy. Treatment consisted of intravenous (i.v.) carboplatin (CBDCA, 400 mg/m 2) and dacarbazine (DTIC, 750 mg/m 2) given twice (i.v. bolus over 30 min) at 3-week intervals, or 4 cycles of DTIC (220 mg/m 2 i.v. 3 days), cisplatin (DDP, 35 mg/m 2 i.v. 3 days), carmustine (BCNU, 150 mg/m 2 i.v. cycles 1 and 3) and tamoxifen (TAM, 20 mg oral/daily) at 3-week intervals. Chemotherapy was followed by immunotherapy with combined subcutaneous (s.c.) interleukin-2 (rIL-2) and SC interferon-α2 (rIFN-α). Among 40 patients who received a full cycle of chemotherapy with CBDCA/DTIC and sequential immunotherapy, there were 3 (7.5%) complete remissions (CRs) with a median duration of 19 months (range 13–26+). Partial remissions (PRs) were noted in 11 (27.5%) patients with a median response duration of 8 (range 5–14) months. Among 27 patients who received DTIC/DDP/BCNU/TAM and rIL-2/rIFN-α, there were 3 (11%) complete remissions and 12 (44.5%) partial remissions. Duration of complete and partial remissions ranged from 9+ to 13+ (median, 11+), and 5 to 15+ (median, 7+) months, respectively. Chemotherapy produced mostly moderate toxicity. Thrombocytopenia was common with the nadir after a median time of 18 days following start of CBDCA/DTIC and DTIC/DDP/BCNU, respectively. 10 patients required transfusion of thrombocytes. Nausea and vomiting due to chemotherapy were well tolerated using concomitant ondansetrone (8 mg i.v.). Immunotherapy was self-administered at home with mild to moderate side effects; malaise, fever, chills, nausea/vomiting, diarrhoea, anorexia and arthralgias were most frequent, but were spontaneously reversible after ending rIL-2/IFN-α. A mean 87 and 88% of the projected doses of rIL-2 and rIFN-α were administered on either protocol. There were no life-threatening complications and no treatment-related deaths. The sequential combination of chemotherapy and rIL-2 plus rIFN-α had at least additive therapeutic activity against metastatic malignant melanoma. The schedules produced long-lasting remissions and were tolerated well overall. These trials substantiate a potential role for low to intermediate dose immunotherapy in maintaining and consolidating therapeutic effects of chemotherapy in metastatic melanoma.

Sequential immunotherapy using interleukin-1 followed by interleukin-2 of ascitic MOPC104E-bearing mice.

This study shows that intraperitoneal injection of interleukin-1 (IL-1), followed by interleukin-2 (IL-2), can effectively eradicate murine ascitic tumor cells. This antitumor effect of IL-1 and IL-2 was abolished when administration of IL-2 preceded that of IL-1. Solid tumors inoculated subcutaneously (s.c.) into the back of mice were also sensitive to this combined i.p. therapy, indicating a systemically-operating antitumor mechanism. Splenocytes from tumor-bearing mice treated with IL-1 followed by IL-2 showed a strong tumor-neutralizing activity. The population responsible proved to be Lyt2.2 (CD8)-positive cells.

Serum Cyclosporine Kinetic Profile. Failure to Correlate with Nephrotoxicity or Rejection Episodes Following Sequential Immunotherapy for Renal Transplantation

Cyclosporine (CsA) level monitoring in renal transplant recipients has been thought to aid in separating clinical episodes of nephrotoxicity from rejection. Twenty-four-hour CsA pharmacodynamic profiles were obtained from 85 consecutive primary renal transplant recipients in the immediate peritransplant period in order to determine the value of this test in predicting subsequent episodes of nephrotoxicity or rejection. All patients were treated with sequential antilymphoblast globulin/CsA following transplantation. Serum samples from each recipient were analyzed for CsA levels estimated by radioimmunoassay (RIA) four days after initiation of a daily single oral CsA dose (10 mg/kg/day). A total of 52 episodes of rejection and 303 episodes of nephrotoxicity occurring within the first six months posttransplant were correlated with selected parameters from the immediate posttransplant CsA kinetic profile. For each profile these parameters were maximum CsA level, time to maximum CsA level, minimum CsA level, 95% clearance time of CsA, and total CsA accumulation and clearance during the 24 hr following ingestion of CsA. No significant correlation was found between any of these parameters and either the incidence or frequency of rejection or nephrotoxic episodes, as determined by least-squares linear regression analysis. Furthermore, following a single oral dose of CsA (10 mg/kg/day), no correlation could be found between the dose and the absorption, accumulation, metabolism, and clearance of the drug. In conclusion, maximum CsA level, time to maximum CsA level, minimum CsA level, 95% clearance time of CsA, and total CsA accumulation and clearance measured from CsA kinetic profiles cannot be correlated with or predict the incidence of rejection or nephrotoxic episodes that subsequently occur during the first six months following renal transplantation.