A77 1726, the active metabolite of leflunomide, attenuates lupus nephritis by promoting the development of regulatory T cells and inhibiting IL-17-producing double negative T cells.

Lupus nephritis (LN) is a challenging problem that affects 50% of patients with systemic lupus erythematosus (SLE) without effective therapy. Here, we report that A77 1726, the active metabolite of leflunomide, effectively inhibits development of LN and attenuates the generalized autoimmune features. A77 1726 suppresses the expansion of double negative (DN) T cells, and inhibits T and B cell activation. Intriguingly, A77 1726 treatment significantly increases CD4(+)Foxp3(+) regulatory T cells but suppresses potential "pathogenic" IL-17-producing DN T cells in lymph nodes. In vitro experiment shows that A77 1726 potentiates the conversion of naive CD4(+)CD25(-) T cells into CD4(+)CD25(+)Foxp3(+) inducible regulatory T cells (iTregs) by inhibiting Akt. Taken together, our data indicate that the therapeutic effects of A77 1726 in murine LN are mediated, at least in part, by augmenting iTregs which suppress pathogenic IL-17-producing DN T cells through an Akt-dependent mechanism.

Inhibition of p70 S6 kinase (S6K1) activity by A77 1726 and its effect on cell proliferation and cell cycle progress.

Leflunomide is a novel immunomodulatory drug prescribed for treating rheumatoid arthritis. It inhibits the activity of protein tyrosine kinases and dihydroorotate dehydrogenase, a rate-limiting enzyme in the pyrimidine nucleotide synthesis pathway. Here, we report that A77 1726, the active metabolite of leflunomide, inhibited the phosphorylation of ribosomal protein S6 and two other substrates of S6K1, insulin receptor substrate-1 and carbamoyl phosphate synthetase 2, in an A375 melanoma cell line. A77 1726 increased the phosphorylation of AKT, p70 S6 (S6K1), ERK1/2, and MEK through the feedback activation of the IGF-1 receptor-mediated signaling pathway. In vitro kinase assay revealed that leflunomide and A77 1726 inhibited S6K1 activity with IC50 values of approximately 55 and 80 µM, respectively. Exogenous uridine partially blocked A77 1726-induced inhibition of A375 cell proliferation. S6K1 knockdown led to the inhibition of A375 cell proliferation but did not potentiate the antiproliferative effect of A77 1726. A77 1726 stimulated bromodeoxyuridine incorporation in A375 cells but arrested the cell cycle in the S phase, which was reversed by addition of exogenous uridine or by MAP kinase pathway inhibitors but not by rapamycin and LY294002 (a phosphoinositide 3-kinase inhibitor). These observations suggest that A77 1726 accelerates cell cycle entry into the S phase through MAP kinase activation and that pyrimidine nucleotide depletion halts the completion of the cell cycle. Our study identified a novel molecular target of A77 1726 and showed that the inhibition of S6K1 activity was in part responsible for its antiproliferative activity. Our study also provides a novel mechanistic insight into A77 1726-induced cell cycle arrest in the S phase.

Plasma cell densities and glomerular filtration rates predict renal allograft outcomes following acute rejection.

The contribution of T cells and graft-reactive antibodies to acute allograft rejection is widely accepted, but the role of graft-infiltrating B and plasma cells is controversial. We examined 56 consecutive human renal transplant biopsies classified by Banff schema into T-cell-mediated (N = 21), antibody-mediated (N = 18), and mixed (N = 17) acute rejection, using standard immunohistochemistry for CD3, CD20, CD138, and CD45. In a predominantly African-American population (75%), neither Banff classification nor C4d deposition predicted the return to dialysis. Immunohistochemical analysis revealed CD3(+) T cells as the dominant cell type, followed by CD20(+) B cells and CD138(+) plasma cells in all acute rejection types. Using univariate Cox Proportional Hazard analysis, plasma cell density significantly predicted graft failure while B-cell density trended toward significance. Surprisingly T-cell density did not predict graft failure. The estimated glomerular filtration rate (eGFR) at diagnosis of acute rejection also predicted graft failure, while baseline eGFR ≥6 months prior to biopsy did not. Using multivariate analysis, a model including eGFR at biopsy and plasma cell density was most predictive of graft loss. These observations suggest that plasma cells may be a critical mediator and/or an independently sensitive marker of steroid-resistant acute rejection.

Natural history of post-liver transplantation hepatitis C: A review of factors that may influence its course.

Our aim was to assess long-term survival in patients transplanted for HCV-related end-stage liver disease (ESLD) and evaluate potentially modifiable predictors of survival. We performed a retrospective analysis of adult liver transplants (LT) at our institution for HCV-related ESLD since the program's inception. Pertinent demographic, clinical, and biochemical information was retrieved from electronic medical records and histological data from 990 per-protocol liver biopsies were collected. Three hundred eighty LT were performed at our institution during the study period, 206 patients were transplanted for HCV-related ESLD; 6 died within 30 days of transplantation and were not included. The remaining 200 recipients (DDLT 168 LDLT 32) constituted the evaluable population. The demographics were as follows: 150 males, median age 53 years; median donor age 39 years; hepatocellular carcinoma (HCC) in 26%. Overall 1-, 5-, and 7-year survival: 95%, 81%, and 79%; median survival 43 months, mortality 15%. Significant HCV recurrence (HAI >or=6 and/or fibrosis >or=2) was present in 49%, "early recurrence" (within 1 year of LT) in 30.5% and biopsy-proven acute rejection was present in 27%. Factors with a significant negative impact on patient survival included: fibrosis stage >or=2 at 12-month biopsy, advanced donor age, history of HCC and early acute rejection. Survival was similar regardless of the donor type (DDLT vs. LDLT). Early and aggressive HCV recurrence has a very heavy toll on patient survival. Prompt recognition and treatment of "rapid fibrosers" may impart benefit. As has been described before, avoidance of rejection and selection of young donors for HCV-positive recipients will also improve survival in this population. On the basis of our findings, LDLT is a good option for HCV-positive recipients.

Clinical factors associated with graft fibrosis in kidney-transplant recipients on steroid-avoidance immunosuppression.

BACKGROUND: Recent studies have documented good patient and graft outcomes and a low risk of acute rejection with steroid-avoidance immunosuppression in kidney-transplant recipients, but the risk of progressive graft fibrosis is not well studied. METHODS: All adult primary kidney transplant or combined kidney and pancreas transplant recipients on steroid avoidance immunosuppression were eligible for study. All recipients received induction with antithymocyte globulin or basiliximab. Corticosteroids were stopped after day 4 post-transplantation. Patients were maintained with tacrolimus and mycophenolate mofetil. Protocol biopsies were done at reperfusion and at one, four, and 12 months after transplantation. RESULTS: Eighty one-yr protocol biopsies with adequate specimens were obtained from 132 kidney or kidney-pancreas transplant recipients. Fifteen (19%) of the biopsies showed moderate to severe graft interstitial fibrosis (GIF) (Banff ci score > or = 2). Recipients with GIF were older, had lower body mass index, greater human lymphocyte antigen (HLA) mismatch, older donors, serum creatinine > or = 1.6 mg/dL at one month, a Banff ci score > 0 on one-month biopsy, BK nephropathy, and interstitial cellular infiltrates on the one-yr biopsy. In the unadjusted logistic regression analysis, BK nephropathy, serum creatinine > or =1.6 mg/dL at one month, recipient age, Banff ci score > 0 on one-month biopsy, and donor age were the only variables associated with a higher risk of GIF on the one-year biopsy. In the multivariate logistic regression model adjusted for these variables, BK nephropathy, serum creatinine > or = 1.6 mg/dL at one month after transplantation, and recipient age were independently associated with the risk of GIF on the one-year biopsy. CONCLUSION: In this small study of primary kidney or combined kidney-pancreas transplant recipients on steroid-avoidance immunosuppression, we found that 19% had GIF on a one-year protocol biopsy. BK nephropathy, serum creatinine > or = 1.6 mg/dL one month after transplantation, and recipient age correlated with an increased risk for GIF on the one-yr biopsy.

Vitamin A toxicity: when one a day doesn't keep the doctor away.

Vitamin A toxicity has been reported to cause severe liver disease and, occasionally, liver failure. Herein we present the case of a 60-year-old male with symptoms of muscle soreness, alopecia, nail dystrophy, and ascites. He continued to deteriorate with the development of refractory ascites, renal insufficiency, encephalopathy, and failure to thrive. A liver biopsy demonstrated presence of Ito cells and vacuolated Kupffer cells without the presence of cirrhosis. His clinical history revealed ingestion of large doses of vitamin A. His worsening clinical situation ruled out the possibility of a transjugular intrahepatic portosystemic shunt. The patient underwent orthotopic liver transplantation with resolution of symptoms. Vitamin A toxicity should be considered in the differential diagnosis of noncirrhotic portal hypertension. In conclusion, liver transplantation is a valid option if no improvement occurs in spite of cessation of the medication.

Interobserver agreement in hepatitis C grading and staging and in the Banff grading schema for acute cellular rejection: the "hepatitis C 3" multi-institutional trial experience.

CONTEXT: Establishing adequate interobserver agreement is crucial not only for standardization of patient care but also to ensure validity of findings in multi-institutional trials. OBJECTIVE: To evaluate interobserver agreement in assessing chronic hepatitis C (HCV) and acute cellular rejection (ACR) among 17 hepatopathologists involved in the "Hepatitis C 3" trial. DESIGN: The trial is a randomized multicenter (17 institutions) study involving 312 patients undergoing transplantation for HCV. Patients are randomized to 3 treatment arms. For final data analysis, all biopsy specimens are reviewed by a central pathologist (G.J.N.). Recurrence of HCV is evaluated according to the Batts and Ludwig schema. The 1997 Banff schema is used to evaluate ACR. To assess interobserver agreement, hematoxylin-eosin-stained sections from 11 liver biopsy specimens (6 HCV and 5 ACR) were sent by the central pathologist to 16 local pathologists from 13 institutions. Statistical analysis was performed on raw ACR/HCV data as well as data grouped according to clinically significant primary endpoint cutoffs. RESULTS: Statistically significant agreement was found among all participating pathologists (P < .001). On kappa analysis, the degree of agreement was rated "moderate" for HCV grade and stage and ACR global grading (kappa = 0.30, 0.33, and 0.37, respectively). Interobserver agreement was weaker for rejection activity index scoring of ACR (kappa = 0.15). A stronger degree of agreement was found when scores were grouped based on endpoint cutoffs (kappa = 0.76 "almost perfect" for HCV and 0.62 "substantial" for ACR). CONCLUSIONS: An overall statistically significant interobserver agreement was found among 17 pathologists using the 1997 Banff schema and the Batts and Ludwig schema.

Telepathy: maximizing resident exposure to surgical pathology decision making.

BACKGROUND: General surgery residents are often not present for the critical intraoperative discussion between surgeon and pathologist regarding surgical pathology findings. METHODS: A prospective pilot study analyzed general surgery resident exposure to surgical pathology. Thereafter, an operating room was equipped to view frozen section images in real time and verbally communicate with the pathologist (TelePATHy). Total operative cases, cases using frozen sections, and use of TelePATHy were recorded. RESULTS: Most residents (78%) reported they were exposed to frozen-section surgical pathology < or =10% of the time. Overall, 202 operations were performed over the 123-day period. Forty-four cases had frozen-section specimens. General surgery residents were present for 40 cases. TelePATHy was successfully used in 32 cases (80%). CONCLUSIONS: General surgery resident exposure to intraoperative pathology findings increased from a reported < or =10% to an observed 80%. TelePATHy is a novel intraoperative tool capable of maximizing the intraoperative experience of the surgical resident.

Auto-Rejection of Renal Donor-Origin Metastatic Melanoma.

We report a case of metastatic malignant melanoma discovered in a living related donor shortly after renal transplant and subsequently diagnosed in the recipient. The recipient hepatic metastases were followed with serial computed tomography (CT) during regression/rejection of tumor after cessation of immunosuppression and allograft removal. Correlation made with serial liver mass biopsies.

Polyoma virus infection of renal allografts: relationships of the distribution of viral infection, tubulointerstitial inflammation, and fibrosis suggesting viral interstitial nephritis in untreated disease.

Whether polyoma virus (PV) infection of renal allografts induces an antiviral or antigraft immune reaction is unclear. By examination of the relationships of tubular PV to graft inflammation and scarring, this study sought histological evidence of viral interstitial nephritis in allograft biopsies with untreated PV infection and compared the inflammatory indices to controls with acute rejection (AR). Morphological features including viral cytopathic changes (VCCs) and modified Banff 97 histological indices were evaluated in sections of 28 diagnostic biopsies from a group of patients receiving prednisone, tacrolimus, and mycophenolate mofetil at constant dosage before biopsy. Two-micrometer paraffin sections were stained for PV large T antigen (TAg) and for C4d, by immunohistochemistry. Tubular profiles with 1 or more nuclei expressing TAg per x200 field were scored using an interval scale (0-10; none to 91-100%) by 2 observers. Controls with AR (n = 38, TAg negative) were matched for time after transplantation and severity of Banff 97 interstitial inflammation (i) and tubulitis (t) scores. Median t scores for tubules with VCC or TAg or both exceeded scores for tubules without VCC or TAg (3 versus 0, P = .001). Tubular TAg score correlated with i score (r = 0.58, P < .01) and sum ct + ci score (r = 0.61, P < .001). Atrophic tubules in scars had persistent VCC and/or TAg. Interstitial plasma cells (75% versus 21%) and neutrophils (32% versus 0%) were more frequent, and interstitial fibrosis was more severe (ci >1 in 54% versus 21%) in polyoma virus nephropathy (PVN) than in the group with AR (P < .01). Intimal arteritis (0% versus 35.7%), peritubular capillary C4d (0% versus 47.4%), and interstitial hemorrhage (4% versus 37%) were almost exclusively found in AR (P < .01). Tubular inflammation in untreated PVN involves infected tubular profiles with greater severity than those without evidence of infection. The extent of tubular PV infection is proportional to interstitial inflammation and scarring. Tubulointerstitial inflammation in PV infection has significant qualitative differences from AR. Observations in these examples of untreated PVN suggest that the allograft inflammatory reaction may exhibit features of viral tubulointerstitial nephritis distinct from AR.

Trasplante hepatico: nuevas esperanzas para muchos pacientes / Liver transplantation: new hopes for many patients

Debido al amplio rango de problemas fisiologicos y a las diversas fuentes potenciales de complicaciones, el paciente con trasplante de higado virtualmente requiere contribuciones de la totalidad del espectro de la ciencia medica. El trasplante de higado es una especialidad en evolucion que ha asimilado avidamente los avances en las tecnicas quirurgicas, los agentes anestesicos, el cuidado critico, la nutricion, la manipulacion inmunologica y la conservacion de los tejidos. El publico, estimulado por los resultados cada vez mas exitosos, parece haber aceptado lentamente el costo de esta labor y la terapia intensamente tecnologica. El papel de quienes trabajan en esta area es esforzarse no solo para mejorar los resultados sino tambien para controlar los costos