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Biomedical subjects

Y Iwaki

Publications and source records attributed to Y Iwaki.

At least 19 recordsLinked to original sources
PubMed1992

The adverse impact on liver transplantation of using positive cytotoxic crossmatch donors.

Because of the liver graft's ability to resist cytotoxic antibody-mediated rejection, it has become dogma that the conventional transplant crossmatch used to avoid hyperacute rejection of other organs is irrelevant to the liver. We examined this hypothesis in a consecutive series of adult primary liver recipients treated with FK506 and low-dose steroids. Twenty-five of 231 (10.8%) patients received a liver from a cytotoxic-positive crossmatch donor (more than 50% of donor T lymphocytes were killed by dithiothreitol-pretreated recipient serum). The outcome was compared with that of 50 negative crossmatch patients who had their transplantations just before and after the crossmatch positive cases. The one-year graft and patient survivals were 56% and 68%, for positive and 82% and 86% for negative crossmatch patients (P = 0.004, P = 0.03, respectively). The difference between patient and first graft survival was accounted for by retransplantation, which was 4 times more frequent in the positive-crossmatch cases. Histologically, failed allografts obtained at the time of retransplantation revealed a spectrum of pathologic findings related to vascular injury. This study showed a higher difficulty of intraoperative blood product management, a degraded prognosis, and a poorer average quality of ultimate graft function when liver transplantation was performed against positive cytotoxic crossmatches. In such patients for whom crossmatch-negative donors may never be found because of the broad extent and intensity of sensitization, special therapeutic strategies perioperatively must be evolved if results are to improve.

Adult↗
PubMed1992

[A case of hepatocellular carcinoma responding to intraarterial infusion of epirubicin and mitomycin C].

A 64-year-old male was admitted for treatment of hepatocellular carcinoma. He was diagnosed as having many tumors in the area of S6 and the AFP level was elevated to 878 ng/ml. Initially, intraarterial infusion of Epirubicin only was not effective. After the first course of treatment, tumors increased in size and the AFP level was elevated. Next, intraarterial infusion of Epirubicin and Mitomycin C was performed. After the second course of treatment, the AFP level decreased from 5,006 ng/ml to 754 ng/ml and the tumors had almost completely disappeared on angiography. The tumors continued to decrease in size and thereafter the AFP level decreased to 10 ng/ml and was not elevated. The tumors almost completely disappeared in this case, and the coadministration of Epirubicin and Mitomycin C provided effective.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1979

Thoracic duct fistula and renal transplantation.

Thoracic duct drainage (TDD) was established for 21-115 days in 40 kidney recipients with an average removal per patient day of 4.7 1 lymph and 1.88 billion cells. Cellular and humoral immunity were depressed. TDD and immunosuppressive drugs were started at transplantation in 35 recipients of cross-match negative grafts. Although the results were better than in precedent non-TDD controls, eight patients rejected their grafts before a full TDD effect, and three of the eight developed predominantly anti-B lymphocyte cytotoxic antibodies which were probably responsible for positive cross-matches with their next donors. With continuing TDD, all eight patients had good initial function after early retransplantation. In five more "nontransplantable" patients with performed cytotoxic antibodies, TDD was started 30-56 days before transplantation. In these five pretreated patients, antibodies persisted with positive antidonor cross-matches. Hyperacute rejection occurred repeatedly in two patients with high anti-T (and anti-B) titers, but was surmounted in three patients with lower titers. From the clinical and immunologic data, we have concluded that TDD should be used for pretreatment of all cases with or without prior antibodies, and have suggested an adjustable management plan that takes into account new developments in antibody monitoring.

Adolescent↗
PubMed1979

Retrospective tests of B-cold lymphocytotoxins and transplant survival at a single center.

Sera from 203 recipients prior to transplantation were examined against a panel of 30 T and B lymphocytes at 5 degrees C and 37 degrees C. Those patients classified as having B-cold cytotoxins only had higher 1-year transplant survival rates from cadaver donors (82%) than patients with no antibodies (58%) or patients with antibodies reactive to T and B lymphocytes in the warm (37%). These results based on transplants from a single center confirm earlier studies derived from patients in 27 centers.

Antilymphocyte Serum↗
PubMed1979

Dilutions and specificity analysis of pretransplant sera.

Six serial dilutions of 51 sera from pretransplant patients were reacted against T and B lymphocytes at 5 degrees C and 37 degrees C. By the use of defined panels of T and B lymphocytes it could be shown that 10% of the 51 positive sera contained T-warm antibodies against HLA-A, -B, and -C specificities. There were 28% of the sera that had antibodies against non-HLA antigens reactive to B lymphocytes in the cold. Other sera contained mixtures of HLA and non-HLA antibodies. By dilution analysis of the sera, the mixtures could be detected and the HLA specificities identified. This ability to distinguish between HLA and non-HLA antibodies should be important in classifying pretransplant patients into high- and low-risk patients. Prior evidence that we have presented suggests that the non-HLA antibodies may be enhancing antibodies.

Antibody Specificity↗
PubMed1979

Thoracic duct drainage before and after cadaveric kidney transplantation.

Twenty-seven consecutive recipients of cadaveric kidneys, including five with pre-existing warm cytotoxic antibodies, were treated with thoracic duct drainage before and after transplantation. Fourteen patients who had lymph drainage for 26 to 58 days before transplantation had minor cytotoxic antibody responses after grafting, even if the antibodies had been present before therapy. Only one of the 14 recipients had any rejection during the follow-up periods of one to six months. There were two deaths. The 13 patients pretreated for 17 to 23 days exhibited stronger cytotoxic antibody responsiveness, and five of these recipients had significant rejections of which four were reversible. One of the latter 13 patients died. These clinical and immunologic studies have established the value and have defined the appropriate timing of preoperative thoracic duct drainage in kidney transplantation. They have also directed attention to the rationale andthe probable value of using other immunosuppressive methods for preparatory host conditioning instead of beginning such therapy at the time of transplantation.

Adolescent↗
PubMed1979

A simple, rapid micro-latex fixation test.

A micro-latex fixation test (LFT) for the determination of rheumatoid factor (RF) is presented. Its advantages compared to similar tests are greater precision, simplicity, increased sensitivity, lower cost, reproducibility and adaptibility to large-scale testing. Micro-LFT titres are presented from a wide range of sample populations. The majority of normal samples show measureable titres whereas rheumatoid patients show high titres. A large sampling of pre- and post-transplant sera from kidney patients was studied and the micro-LFT titres were in the range of normal persons. The transplant sera were tested for lymphocytotoxic antibodies and no correlation was observed with the micro-LFT titres.

Adult↗
PubMed1978

Enhancement of human kidney allografts by cold B-lymphocyte cytotoxins.

The sera of 233 kidney transplant patients before transplantation were tested by cytotoxicity against a panel of B and T lymphocytes at 5 degrees C and 37 degrees C. The results divided the patients into four groups: those whose sera reacted with B lymphocytes at 5 degrees C; those reacting with B lymphocytes at 5 degrees C and 37 degrees C; those reacting with T lymphocytes at 37 degrees C; and those with no antibodies. The patients with pre-transplant antibodies reactive with B lymphocytes at 5 degrees C had a significantly higher kidney-transplant survival rate at 6 months (70%) and 1 year (65%) than patients who had no antibodies (47% and 46%, respectively). Patients with antibodies reactive at 37 degrees C had a 6-month survival-rate of 38% when reactive against B cells and 43% when reactive against T lymphocytes. The cold cytotoxins were IgM.

B-Lymphocytes↗