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R A Krom

Publications and source records attributed to R A Krom.

At least 91 records · Page 5Linked to original sources
PubMed1993

Hepatic allograft rejection: new developments in terminology, diagnosis, prevention, and treatment.

Hepatic allograft rejection remains a major cause of morbidity related to the need for increased immunosuppression and continues to be a principal cause of late failure of the graft. Hepatic allograft rejection is defined on the basis of morphologic findings; cellular rejection is defined as portal or periportal hepatitis with nonsuppurative cholangitis or endotheliitis (or both), and ductopenic rejection is defined as loss of interlobular and septal bile ducts, typically in at least 50% of the portal tracts. The overall incidence of episodes of cellular rejection, which usually occur within the first 2 weeks after liver transplantation, varies from 50 to 100%. Ductopenic rejection occurs in approximately 8% of patients who undergo initial liver transplantation and is usually diagnosed between 6 weeks and 6 months after transplantation. Induction and maintenance immunosuppression with triple-drug (cyclosporine, prednisone, and azathioprine) therapy and other combinations that include antilymphocyte preparations, however, has decreased the incidence of both cellular and ductopenic rejection. In patients experiencing episodes of cellular rejection, high-dose intravenously administered corticosteroid therapy yields the best response and is associated with a lower incidence of ductopenic rejection than is low-dose and orally administered corticosteroid therapy. The correlation between degree of biochemical liver dysfunction and presence of histologic rejection is minimal early after transplantation. Histologic severity of rejection, however, suggests which patients will require more immunosuppression and which patients may need antilymphocyte therapy for controlling the rejection episode. With the availability of new immunosuppressive agents, distinguishing patients at high risk for rejection is important. The goals for use of new immunosuppressive agents and regimens are to improve graft and patient survival, to decrease the incidence of cellular and ductopenic rejection, and to minimize side effects and complications.

Adrenal Cortex Hormones↗
PubMed1993

Risk factors for cytomegalovirus and severe bacterial infections following liver transplantation: a prospective multivariate time-dependent analysis.

Risk factors for cytomegalovirus and severe bacterial infections were studied prospectively by univariate, multivariate and time-dependent Cox model analysis in 79 consecutive liver transplant patients treated with selective bowel decontamination. Cytomegalovirus infection occurred in 39 patients (49%) and was symptomatic in 22 patients. Twenty-six patients (33%) developed at least one of 43 documented severe bacterial infections. In a multivariate analysis of risk factors for all cytomegalovirus infections, the cytomegalovirus seronegative recipient-cytomegalovirus seropositive donor group was the highest risk group (P < 0.001). Using the same analysis for risk factors for symptomatic cytomegalovirus infections, a prolonged prothrombin time (P < 0.005), a diagnosis of acute fulminant hepatitis as the underlying liver disease (P < 0.01) and a cytomegalovirus seronegative patient receiving a liver from a seropositive donor (P < 0.001) were significant. The treatment with OKT3 therapy (P < 0.008) and hepatic artery thrombosis (P < 0.02) were found to be significant risk factors in a time-dependent univariate analysis but were not independent risk factors when multivariate analysis was utilized. Significant risk factors for major bacterial infections (P < 0.03) using univariate analysis included a prolonged anesthesia, anhepatic and surgical times, as well as the transfusion of large amounts of fresh frozen plasma or autologous blood. In a multivariate analysis, only the transfusion of large amounts of fresh frozen plasma (P < 0.04) was a significant independent risk factor. Cytomegalovirus infection was a risk factor for the development of severe bacterial infections (P < 0.03) in a multivariate time-dependent analysis.

Adult↗
PubMed1993

Increased bile duct complications in liver transplantation across the ABO barrier.

OBJECTIVE: This study evaluated the outcome of liver grafts from ABO incompatible donors, focusing on biliary complications, and compared the results to an ABO compatible control group. Also, the expression of donor ABH antigens in the liver graft was analyzed. SUMMARY BACKGROUND DATA: The outcome of liver transplantation using an ABO incompatible graft is still debated. These blood group related (ABH) antigens are known to be expressed not only on the surface of the erythrocytes, but also on the epithelial cells of large bile ducts. Because the biliary epithelium of hepatic allografts may continue to express donor ABH antigens, it may be more susceptible to immunologic bile duct injury after transplantation across the ABO barrier. METHODS: Eighteen ABO incompatible grafts were compared with 18 ABO compatible grafts in patients who were matched according to medical urgency, primary liver disease (PLD), and recipient age. After transplantation, the grafts were analyzed with cholangiography, Doppler ultrasound, or arteriography and liver histology according to protocol. Immunoperoxidase staining for ABH antigens was performed on hepatic tissue. RESULTS: Biliary complications developed in 82% of the ABO incompatible donors, compared to 6% of the ABO matched controls. Hepatic artery thrombosis occurred in 24%. Cellular rejection was diagnosed in 65% versus only 28% in the control group. The 1-year actuarial graft survival rate was 44% versus 78% in the control group. ABH antigens of the donor were expressed on vascular endothelium and bile duct epithelial cells as long as 150 days after transplant. CONCLUSIONS: Using ABO incompatible allografts, a high incidence of biliary and hepatic artery complications and decreased graft survival in liver transplantation were found. An immunologic injury to the bile duct epithelium and/or to vascular endothelium is suspected.

ABO Blood-Group System↗
PubMed1993

An increase in cytosolic protease activity during liver preservation. Inhibition by glutathione and glycine.

Degradative cytosolic proteolysis contributes to cell injury following ATP depletion. Although ATP depletion is a salient feature of ischemic liver storage for transplantation, information regarding cytosolic protease activity during liver storage is lacking. Thus our aim was to measure liver cytosolic protease activity following ischemic storage. A progressive increase in total cytosolic protease activity was observed over time at both 37 degrees C and 4 degrees C, but the increase was greater at 37 degrees C. Total cellular proteolysis was also temperature-dependent during anoxia (37 degrees C > 4 degrees C), demonstrating a physiologic correlation between cellular proteolysis and measurements of cytosolic protease activity. The stimulation of total cytosolic protease activity was due to an increase in metallo- and aspartate protease activity. Of particular interest, glutathione (GSH) inhibited both metalloprotease and aspartate protease activity from cytosol of stored livers. Glycine, the carboxyl-terminal amino acid of GSH, also inhibited both metalloprotease and aspartate protease activity. In addition to being an antioxidant, GSH may exert its protective effects during organ preservation by inhibiting cytosolic proteases--perhaps via its glycine moiety. These experiments support the hypothesis that degradative proteolysis contributes to liver injury during organ preservation.

Animals↗
PubMed1993

Systemic and renal hemodynamic differences between FK506 and cyclosporine in liver transplant recipients.

Immunosuppression after transplantation is complicated by hypertension and nephrotoxicity, reflecting widespread vasoconstriction associated with CsA. FK506 is a novel alternative immunosuppressive agent, structurally unrelated to CsA. These studies compared systemic and renal vascular changes developing in the initial 4 weeks after liver transplantation in patients treated with FK506 (plus PRED) and CsA (plus PRED and AZA). We studied arterial pressure, cardiac index (pulsed doppler ultrasound), and systemic resistance index (SVRI) before and weekly after liver transplant in 32 patients treated with CsA (2 mg/kg initial dose plus PRED; median dose at week 4, 30 mg/day) and 14 patients treated with FK506 (0.15 mg/kg/day initial dose and PRED; mean week 4 dose, 12.5). Renal plasma flow and glomerular filtration rate (GFR) were measured by clearance of para-amino hippurate and 125-iothalamate. Renin activity, aldosterone, and urinary prostanoids were measured by RIA. Pretransplant pressures and hemodynamics reflected low SVRI and increased cardiac index typical of end-stage liver disease. After transplantation, SVRI and pressures rose in both groups, but after week 2, SVRI was lower in patients treated with FK506. This was associated with less prevalent clinical hypertension during the subsequent 4 months (4/14 FK506 (28%) vs. 25/32 (78%) CsA, P < 0.01). By contrast, renal blood flow and GFR fell in both treatment groups similarly, whereas renal vascular resistance rose. Urinary 6-keto-PG-F1-alpha was suppressed in all transplant recipients, but to a greater degree in FK506-treated patients. This value correlated directly to post-transplant GFR (r = 0.48, P < 0.001). These data indicate that FK506-based immunosuppression differs from CsA by inducing less systemic vasoconstriction and hypertension. Renal vasoconstrictive effects were at least as great as those seen with CsA, however, and indicate that nephrotoxicity will remain a common feature to both regimens.

6-Ketoprostaglandin F1 alpha↗
PubMed1993

Use of Prograf (FK 506) as rescue therapy for refractory rejection after liver transplantation. US Multicenter FK 506 Liver Study Group.

This report describes the clinical characteristics and demographics of patients enrolled into this rescue trial for patients experiencing refractory rejection after liver transplantation. Actuarial graft and patient survival at 12 months postconversion was 50% and 72%, respectively. Actual treatment success at 3 months postconversion was 70%. Karnofsky scores and liver function tests were significantly improved for patients continuing on therapy indicating clinical benefit in these patients. The safety profile of FK 506 is acceptable for such a high-risk group of patients. These preliminary clinical results support the conclusion that FK 506 can effectively control and reverse refractory rejection in a majority of liver transplantation patients.

Acute Disease↗
PubMed1993

Efficacy of hepatic transplantation in patients with primary sclerosing cholangitis.

Controlled trials to assess the therapeutic benefit of orthotopic hepatic transplantation (OHTx) for primary sclerosing cholangitis (PSC) cannot be justified in view of improvement of patient survival after this operation since 1981. However, the actual patient survival with OHTx can be compared with the Mayo model estimated survival probabilities without OHTx. This model, which encompasses physical, biochemical and histopathologic parameters of PSC, was constructed from a study of 392 conservatively treated PSC patients at five international centers in England and North America. We compared the actual survival of 216 adult patients with the diagnosis of advanced PSC who underwent hepatic replacement with the expected survival estimated by the Mayo PSC natural history model, "the simulated control technique." OHTx was performed at the University of Pittsburgh and Mayo Medical Center between 5 December 1981 and 26 December 1990. The mean (plus or minus standard deviation) post-OHTx follow-up period was 34 +/- 25 months (range of zero to 104 months). Before transplantation, biliary or portal hypertensive operation, or both, was performed upon 104 patients. At operation, the mean age of recipients was 42.1 +/- 11.3 years and the mean value of total serum bilirubin was 13.3 +/- 13.0 milligrams per deciliter. Extensive septal fibrosis and cirrhosis were histologically documented in 97 percent of the patients, with splenomegaly in 63 percent. Immunosuppressive therapy was based primarily on cyclosporin in 184 recipients and FK-506 in 32. Within six months, the Kaplan-Meier survival probability after OHTx (0.89) already was higher than predicted by the Mayo model (0.83). At five years, the Kaplan-Meier actual survival with OHTx was 0.73 compared with 0.28 expected Mayo model survival. The overall increased survival rate with transplantation was statistically significant (chi-square equals 126.6; p < 0.001). At all risk stratifications, OHTx significantly improved survival with a p value of 0.031 (low risk), 0.001 (moderate risk) and < 0.001 (high risk). Thus, OHTx is effective therapy for PSC. Disease gravity and unsuspected cholangiocarcinoma in the excised native liver adversely influenced short and long term survival rates after transplantation, respectively.

Actuarial Analysis↗
PubMed1993

Histological evidence for recurrence of primary biliary cirrhosis after liver transplantation.

Whether primary biliary cirrhosis recurs after orthotopic liver transplantation remains a controversial issue. Sixty consecutive patients with primary biliary cirrhosis with at least 1 yr of follow-up after liver transplantation were studied. All patients were treated with triple-drug immunosuppression (cyclosporine, prednisone, azathioprine). Hepatic biochemical parameters and protocol liver biopsy specimens were evaluated 1 wk, 3 wk, 4 mo and yearly after orthotopic liver transplantation and at times of liver dysfunction. Antimitochondrial antibody titers and IgM levels were determined at 4 mo and yearly. At the time of last follow-up, all patients had marked symptomatic improvement compared with their pretransplant condition, and 91% of the patients had normal hepatic biochemical parameters, including serum levels of alkaline phosphatase, bilirubin, ALT and IgM. In addition, all patients had significant decreases in antimitochondrial antibody titer (p = 0.0001) and significant decreases in serum levels of IgM (p = 0.0001). Forty-one of the 60 patients had near-normal liver histological appearance. Of those with abnormal histological appearance, five patients, 2 to 6 yr after orthotopic liver transplantation, had histological features typical of a florid duct lesion, suggesting recurrent primary biliary cirrhosis. All five patients with portal granulomas had normal hepatic biochemical values and were clinically asymptomatic. Two of the five patients had persistent antimitochondrial antibody titers. We consider the documented histological changes highly suggestive of recurrence of primary biliary cirrhosis after liver transplantation but, so far, have no evidence that the condition in these patients is progressive.

Adult↗
PubMed1993

Advances in the diagnosis, treatment, and prevention of cytomegalovirus infections after liver transplantation.

CMV is one of the most frequent viral infections after orthotopic liver transplantation. Thus, there should be a high index of clinical suspicion, particularly in liver transplant recipients who have risk factors for the development of CMV disease, including donor CMV seropositivity, the use of antilymphocyte preparations, and retransplantation. The availability of effective antiviral therapy to treat CMV disease has emphasized the importance of an aggressive approach to the early diagnosis and treatment of this viral infection. Ganciclovir has been a major advancement in the treatment of severe CMV disease and has had a major impact on reducing the incidence and severity of CMV disease and its complications in the liver transplant recipient. Furthermore, these antiviral agents are now being evaluated for their prophylactic potential. Indeed, a number of these agents or combinations of these agents have been shown to be effective in reducing the incidence and severity of CMV disease, particularly in the CMV-seropositive transplant recipient; however, the cost-effectiveness of such therapy and its overall impact on long-term graft and patient outcome remain poorly defined at this time. Further investigations will be needed to define the role and importance of prophylactic therapy for the prevention of CMV infection and disease in the liver transplant recipient.

Cytomegalovirus Infections↗
PubMed1992

Prognostic features and role of liver transplantation in severe corticosteroid-treated autoimmune chronic active hepatitis.

To identify prognostic features and to define the role of liver transplantation in severe autoimmune chronic active hepatitis, findings before and after corticosteroid therapy in 111 patients were correlated with outcome and compared with the findings in 24 patients who had been selected independently for liver transplantation. Patients whose condition deteriorated during corticosteroid treatment were younger (32 +/- 3 yr vs. 43 +/- 2 yr; p less than 0.02) than those who experienced remission, but no individual features predicted outcome. Patients in whom therapy failed required longer durations of continuous treatment than did those who experienced remission (60 +/- 14 mo vs. 20 +/- 12 mo; p = 0.001). Of 13 patients who did not experience remission within 4 yr, 9 (69%) ultimately deteriorated. Ascites developed more often in those patients whose therapy failed and who died of liver failure than in counterparts who survived (86% vs. 33%). Patients undergoing transplantation were similar to those whose treatment failed, but they died less frequently (8% vs. 56%, p less than 0.01). Indeed, the 5-yr survival rate after transplantation was comparable to that of patients who had entered remission (92% vs. 100%). Successive biopsy samples failed to disclose recurrent autoimmune hepatitis after transplantation. Human leukocyte antigens A1, B8 occurred more commonly in patients in whom treatment failed or who underwent transplantation (70% vs. 41%, p less than 0.05). We conclude that failure to achieve remission within 4 yr and the human leukocyte antigen A1, B8 phenotype are associated with poor prognosis. Manifestations of liver decompensation, such as ascites, in patients who have been unable to experience remission justify consideration of transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗