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Biomedical subjects

W Irish

Publications and source records attributed to W Irish.

At least 55 records · Page 3Linked to original sources
PubMed1995

Tacrolimus (FK 506), a treatment for primary sclerosing cholangitis: results of an open-label preliminary trial.

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease of the liver that is characterized by progressive cholestasis and the development of secondary biliary cirrhosis. There is no widely recognized therapy for this disease, although anti-inflammatory agents (steroids), immunosuppressive agents (methotrexate), anti-fibrotics (colchicine), and choleretic agents (ursodeoxycholic acid) have been used in various small series. In the present study, Tacrolimus (FK 506), a new and powerful immunosuppressive macrolide antibiotic, has been used to treat 10 patients with PSC. Each subject had a liver biopsy, ERCP with visualization of the intra- and extrahepatic biliary tree, and a panel of hematological, serological, and biochemical laboratory tests before the initiation of the FK 506 therapy. The FK 506 was administered orally at 12-h intervals and was monitored by serial plasma FK 506 trough levels. After 360 days of treatment, the median serum bilirubin level was reduced by 75%, and the serum alkaline phosphatase was reduced by 70%. Moreover, the serum ALT and AST levels were reduced by 80 and 86%, respectively. No change in the serum level of BUN and creatinine levels occurred as a consequence of the FK 506 treatment. These data demonstrate that: 1) FK 506 can be used to treat PSC; 2) the response to FK 506 by patients with PSC is rapid; and, 3) no adverse effect on the serum BUN and creatinine levels was observed. It is anticipated that FK 506 will become an important agent for the treatment of patients with PSC because of its powerful immunosuppressive activity.

Adult↗
PubMed1995

Tacrolimus: a potential new treatment for autoimmune chronic active hepatitis: results of an open-label preliminary trial.

Autoimmune chronic active hepatitis (CAH-A) is a chronic liver disease of unknown etiology that is believed to have an autoimmune pathogenesis. The disease is slowly progressive until hepatic failure and portal hypertension develop and either death or liver transplantation occur. Currently, the only widely recognized therapy is the administration of glucocorticoids, which have both anti-inflammatory and immunosuppressive actions. Many patients cannot tolerate such therapy because of the psychiatric, osteoporotic, and weight-enhancing actions of steroids. Tacrolimus (FK 506) is a new macrolide antibiotic that has an immunosuppressive activity that is estimated to be 10-200 times greater than that of cyclosporine. Because of its greater immunosuppressive activity, we have used it in the treatment of 21 patients with autoimmune chronic active hepatitis. Before each subject was treated, a liver biopsy and a panel of hematological, serological, and biochemical parameters were assessed. The Tacrolimus was administered orally at 12-h intervals, and the dose was controlled by monitoring plasma FK trough levels. After 3 months of therapy at an oral dose of 3 mg twice a day, having achieved a median blood level of 0.5 ng/ml, the serum ALT level was reduced by 80%, and the AST level was reduced by 70%. Modest change in the white blood cell count and platelet count were noted. The median BUN level increased from a level of 12 to 18 mg/dl, and the serum creatinine increased from 0.9 to 1.3 mg/dl. These preliminary data demonstrate that: 1) Tacrolimus can be used to successfully treat CAH-A; 2) the response of CAH-A to Tacrolimus treatment is rapid and sustained; and 3) a minor increase in the serum BUN and creatinine levels occurs as a consequence of Tacrolimus treatment. It is anticipated that with continued treatment for periods of 1-2 yr, the natural history of CAH-A will be changed such that hepatic failure and the requirement for liver transplantation may be averted.

Adult↗
PubMed1994

A prospective randomized trial comparing sequential ganciclovir-high dose acyclovir to high dose acyclovir for prevention of cytomegalovirus disease in adult liver transplant recipients.

Cytomegalovirus disease is an important cause of morbidity following liver transplantation. To date there has not been an effective prophylaxis for CMV disease after liver transplantation. One hundred forty-three patients were randomized to receive either high dose oral acyclovir (800 mg 4 times a day) alone for 3 months after transplantation (acyclovir group) or intravenous ganciclovir (5 mg/kg twice a day) for 14 days followed by high dose oral acyclovir to complete a 3-month regimen (ganciclovir group). Of 139 patients available for evaluation, 43 of 71 (61%) patients from the acyclovir group developed CMV infection compared with 16 of 68 (24%) from the ganciclovir group (relative risk, 3.69; 95% confidence interval, 2.07-6.56; P < 0.00001). Of those randomized, CMV disease was seen in 20 (28%) of the acyclovir group compared with 6 (9%) of the ganciclovir group (relative risk, 5.11; 95% confidence interval, 2.05-12.75; P = 0.0001). The median time to onset of CMV infection was 45 days in the acyclovir group compared with 78 days in the ganciclovir group (P = 0.004). The median time to onset of CMV disease was 40 days in the acyclovir group compared with 78 days in the ganciclovir patients (P = 0.02). With respect to primary CMV infection, there was no difference in the rates in the 2 groups, but tissue invasive disease and recurrent CMV disease were less frequent in the ganciclovir group. It is concluded that a course of 2 weeks of ganciclovir immediately after transplantation followed by high dose oral acyclovir for 10 weeks is superior to a 12-week course of high dose oral acyclovir alone for prevention of both CMV infection and CMV disease after liver transplantation. However, the lack of significant effect in seronegative recipients who received grafts from seropositive donors suggests that other strategies are needed to prevent CMV infection in this high risk population.

Acyclovir↗
PubMed1994

Combined immunosuppressive therapy with low dose FK506 and antimetabolites in rat allogeneic heart transplantation.

Following rat heterotopic heart allotransplantation, low to lethal doses of the antimetabolites mizoribine (MIZ), RS-61443 (RS), and AZA were given alone or in combination with subtherapeutic doses of FK506 (0.04 mg/kg/day) for 14 days after transplantation. With the median effect analysis of Chou and Kahan for quantitative drug interactions, substantial therapeutic synergism was demonstrated between FK506 and non-toxic doses of MIZ (2.5, 5, and 10 mg/kg/day) or AZA (5, 30, and 45 mg/kg/day), which was particularly evident with the lowest dose MIZ (2.5 mg/kg/day). When FK506 was used in combination with MIZ or AZA but not with RS, the maximum effect (peak median graft survival) was enhanced significantly from 15 days (MIZ alone) to 26 days (P < 0.05), and from 19 days (AZA alone) to 32 days (P < 0.01). In contrast, RS interacted with FK506 no more than additively. Although RS was the most powerful single antimetabolite, the best overall survival was obtained by combining AZA and FK506. The addition of FK506 did not significantly increase the percent mortality and LD50 of the antimetabolites.

Animals↗
PubMed1994

Can adenine nucleotides predict primary nonfunction of the human liver homograft?

Sixty-eight primary liver grafts were analyzed to see whether adenine nucleotides (AN: ATP, ADP, and AMP) or purine catabolites (PC: adenosine, inosine, hypoxanthine, and xanthine) of tissue or effluent can predict primary graft nonfunction. AN, PC, and nicotinamide adenine dinucleotide, oxidized form (NAD+) of the tissue before (pretransplant) and after graft reperfusion (post-transplant) and of the effluent were analyzed. The graft outcome was classified into two groups (group A: successful, n = 64; group B: primary nonfunctioning, n = 4). No significant differences were observed in pretransplant measurements between groups A and B, whereas ATP, ADP, total AN, total AN + total PC (T) and NAD+, in post-transplant tissues, were significantly higher in group A. Xanthine in the effluent was significantly higher in group B than in group A. ATP, ADP, total AN, T, and NAD+ in post-transplant tissue were significantly associated with primary graft nonfunction by logistic regression analysis.

Adenine Nucleotides↗
PubMed1994

Disease gravity and urgency of need as guidelines for liver allocation.

One thousand one hundred and twenty-eight candidates for liver transplantation were stratified into five urgency-of-need categories by the United Network for Organ Sharing (UNOS) criteria. Most patients of low-risk UNOS 1 status remained alive after 1 yr without transplantation; the mortality while waiting was 3% after a median of 229.5 days. In contrast, only 3% of those entered at the highest risk UNOS 5 category survived without transplantation; 28% died while waiting, the deaths occurring at a median of 5.5 days. The UNOS categories in between showed the expected gradations, in which at each higher level fewer patients remained as candidates throughout the 1-yr duration of study while progressively more died at earlier and earlier times while waiting for an organ. In a separate study of posttransplantation survival during the same time period, the best postoperative results were in the lowest-risk UNOS 1 and 2 patients (88% combined), and the worst results were those in UNOS 5 (71%). However, a relative risk cross-analysis showed that a negative benefit of transplantation may have been the result in terms of 1-yr survival for the low-risk elective patients, but that a gain in life extension was achieved in the potentially lethal UNOS categories 3, 4 and 5 (greatest for UNOS 3). These findings and conclusions are discussed in terms of total care of patients with liver disease, and in the context of organ allocation policies of the United States and Europe.

Adult↗
PubMed1994

Response to interferon alpha therapy is influenced by the iron content of the liver.

Seventy-nine subjects (19 women and 60 men) with chronic viral hepatitis were studied to determine the role of hepatic iron and its biochemical correlates in determining response to interferon alpha therapy. Each subject was treated for 6 months with interferon alpha. A total of 45 (57%) subjects achieved either a full or partial response. No differences between responders and non-responders were evident for the type of hepatitis, age, initial alanine aminotransferase, serum iron, total iron binding capacity, %sat, or ferritin. In contrast, the hepatic iron content of non-responders was almost twice that of responders (1156 +/- 283 micrograms/g dry weight vs. 638 +/- 118; p < 0.05). Hepatic iron correlated with total iron binding capacity (r = 0.435) and ferritin (r = 0.585). This study showed that: 1) the hepatic iron content of responders is less than that of non-responders, 2) the relationships of hepatic iron with %sat and ferritin in patients with viral hepatitis are weak, and 3) hepatic iron content predicts a response to interferon therapy.

Adult↗
PubMed1994

Influence of FK 506 (tacrolimus) on circulating CD4+ T cells expressing CD25 and CD45RA antigens in 19 patients with chronic progressive multiple sclerosis participating in an open label drug safety trial.

We have taken the opportunity of a clinical trial of the potential efficacy and safety of FK 506 (tacrolimus) in chronic progressive multiple sclerosis (MS) to examine the influence of this potent new immunosuppressant on circulating T-lymphocytes in an otherwise healthy non-transplant population. Peripheral blood levels of subsets of CD4+ T lymphocytes expressing the activation molecule interleukin-2 receptor (p55 alpha chain; CD25) or the CD45RA isoform were determined sequentially in 19 patients that were treated continuously with oral FK 506 (starting dose 0.15 mg/kg/day) for 12 months. No significant change in the proportion of circulating CD25+ CD4+ cells was observed over the study period in which the mean trough plasma FK 506 level rose from 0.3 +/- 0.2 to 0.5 +/- 0.4 ng/ml. There was also no significant effect of FK 506 on the percentage of CD45R+ CD4+ cells in the peripheral blood at 12 months compared with pretreatment values. Analysis of a subgroup of 7 patients, who showed a sustained reduction in CD25+ CD4+ cells and a reciprocal increase in CD45RA+ CD4+ cells for at least 6 months after start of treatment, did not reveal any difference in disability at one year compared with the treatment group as a whole. The side effects of FK 506 were mild and the overall degree of disability estimated by the mean Kurtzke expanded disability status scale (EDSS) score or the ambulation index did not deteriorate significantly in the 19 patients studied over the 12 months of FK 506 administration.

Administration, Oral↗
PubMed1994

Improving results of pediatric renal transplantation.

BACKGROUND: Outcome after renal transplantation in children has been variable. We undertook a retrospective study of our experience over the past five years. STUDY DESIGN: From January 1, 1988, to October 15, 1992, 60 renal transplantations were performed upon 59 children at the Children's Hospital of Pittsburgh. Twenty-eight (47 percent) of the kidneys were from cadaveric donors, and 32 (53 percent) were from living donors. The recipients ranged in age from 0.8 to 17.4 years, with a mean of 9.8 +/- 4.8 years. Forty-six (77 percent) recipients were undergoing a first transplant, while 14 (23 percent) received a second or third transplant. Eight (13 percent) of the patients were sensitized, with a panel reactive antibody of more than 40 percent. Eleven of the 14 patients undergoing retransplantation and seven of the eight patients who were sensitized received kidneys from cadaveric donors. Thirty-three (55 percent) patients received cyclosporine-based immunosuppression, and 27 (45 percent) received FK506 as the primary immunosuppressive agent. RESULTS: The median follow-up period was 36 months, with a range of six to 63 months. The one- and four-year actuarial patient survival rate was 100 and 98 percent. The one- and four-year actuarial graft survival rate was 98 and 83 percent. For living donor recipients, the one- and four-year actuarial patient survival rate was 100 and 100 percent; for cadaveric recipients, it was 100 and 96 percent. Corresponding one- and four-year actuarial graft survival rates were 100 and 95 percent for the living donor recipients and 96 and 69 percent for the cadaveric recipients. Patients on cyclosporine had a one- and four-year patient survival rate of 100 and 97 percent, and patients on FK506 had a one- and three-year patient survival rate of 100 and 100 percent. Corresponding one- and four-year actuarial graft survival rates were 100 and 85 percent in the cyclosporine group, while one- and three-year actuarial graft survival rates were 96 and 84 percent in the FK506 group. The mean serum creatinine level was 1.24 +/- 0.64 mg per dL; the blood urea nitrogen level was 26 +/- 13 mg per dL. The incidence of rejection was 47 percent; 75 percent of the rejections were steroid-responsive. The incidence of cytomegalovirus was 10 percent. The incidence of post-transplant lymphoproliferative disorder was 8 percent. None of the patients on cyclosporine were able to be taken off prednisone; 56 percent of the patients receiving FK506 were taken off prednisone successfully. Early growth and development data suggest that the patients receiving FK506 off prednisone had significant gains in growth. CONCLUSIONS: These results support the idea that renal transplantation is a successful therapy for end-stage renal disease in children. They also illustrate the potential benefits of a new immunosuppressive agent, FK506.

Adolescent↗
PubMed1994

A prospective, randomized trial of FK-506 in renal transplantation--a comparison between double- and triple-drug therapy.

Previous clinical evaluation of FK506 in renal transplantation has demonstrated equivalent patient and graft survival when compared with cyclosporine-based regimens. However, lower steroid and anti-hypertensive mediation requirements and lower serum cholesterol levels have been seen in patients receiving FK506. In August, 1991, a prospective, randomized trial was begun, comparing FK506/prednisone with FK506/azathioprine/prednisone. Two-hundred-and-four adults were entered into this trial between August 1, 1991, and October 11, 1992. The mean recipient age was 43.8 +/- 13.7 years, with a range of 17.6-78.0 years. Sixty-one (30%) recipients received a 2nd, 3rd or 4th transplant, while 35 (17%) had a PRA greater than 40% at the time of transplant. Thirty-three (16%) of the transplants were in recipients over 60 years of age, Thirteen percent of the kidneys were from living donors; 13% of the cadaveric kidneys were from pediatric donors less than 3 years of age and were transplanted en bloc. The mean cold ischemia time was 31.4 +/- 8.4 hours, and the mean donor age was 34 +/- 2.10 years, with a range from 4 months to 75 years. With a mean follow-up of 9 +/- 4 months, the 1-year actuarial patient survival is 93%; for the two-drug group it is 95%, and for the three-drug group it is 91% (p = NS). One-year actuarial graft survival is 86%; in the two-drug group it is 90%, while in the three-drug group it is 82% (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗