Fibroinflammatory biliary stricture: a rare bile duct lesion masquerading as cholangiocarcinoma.

INTRODUCTION: Fibroinflammatory biliary stricture (FIBS) is a rare benign tumor-like process of the extrahepatic bile duct that masquerades as cholangiocarcinoma. METHODS: In order to distinguish this unusual entity from cancer, we performed a systematic analysis of 11 patients with FIBS. All patients presented with jaundice; six patients had coexisting autoimmune disease. Preoperative evaluation included computed tomography scan and endoscopic retrograde cholangiopancreatography with benign brush cytology. Surgical treatment included nine bile duct resections with five concurrent liver resections and two incisional biopsies. Light microscopy demonstrated fibrous lesions admixed with chronic inflammation. RESULTS AND DISCUSSION: Immunohistochemistry demonstrated smooth muscle actin expression in all lesions except one; five tumors exhibited IgG4 positive plasma cells. The lesions were negative for cytokeratin, ALK1, CD21, S100, Ki67, and p53. Six patients received postoperative immunosuppression. At 41 month median follow-up (range 15-58 months), there was no evidence of recurrent FIBS in ten patients, while one was lost to follow-up. CONCLUSION: FIBS is a rare myofibroblastic lesion with an immunohistochemical profile distinct from other epithelial and stromal neoplasms of the extrahepatic bile duct. A subset of these cases appear to represent IgG4-related sclerosing cholangitis. Because preoperative cytology is not diagnostic of FIBS, surgical resection remains the mainstay of diagnosis and treatment, while immunosuppression may reduce the risk of recurrence.

Surgically-induced weight loss significantly improves nonalcoholic fatty liver disease and the metabolic syndrome.

OBJECTIVE: To evaluate the effects of surgical weight loss on fatty liver disease in severely obese patients. SUMMARY BACKGROUND DATA: Nonalcoholic fatty liver disease (NAFLD), a spectrum that extends to liver fibrosis and cirrhosis, is rising at an alarming rate. This increase is occurring in conjunction with the rise of severe obesity and is probably mediated in part by metabolic syndrome (MS). Surgical weight loss operations, probably by reversing MS, have been shown to result in improvement in liver histology. METHODS: Patients who underwent laparoscopic surgical weight loss operations from March 1999 through August 2004, and who agreed to have an intraoperative liver biopsy followed by at least one postoperative liver biopsy, were included. RESULTS: There were 70 patients who were eligible. All patients underwent laparoscopic operations, the majority being laparoscopic Roux-en-Y gastric bypass. The mean excess body weight loss at time of second biopsy was 59% +/- 22% and the time interval between biopsies was 15 +/- 9 months. There was a reduction in prevalence of metabolic syndrome, from 70% to 14% (P < 0.001), and a marked improvement in liver steatosis (from 88% to 8%), inflammation (from 23% to 2%), and fibrosis (from 31% to 13%; all P < 0.001). Inflammation and fibrosis resolved in 37% and 20% of patients, respectively, corresponding to improvement of 82% (P < 0.001) in grade and 39% (P < 0.001) in stage of liver disease. CONCLUSION: Surgical weight loss results in significant improvement of liver morphology in severely obese patients. These beneficial changes may be associated with a significant reduction in the prevalence of the metabolic syndrome.

Emergent lung retransplantation after discovery of two primary malignancies in the donor.

A 50-year-old woman underwent single lung transplantation for advanced chronic obstructive pulmonary disease. Shortly after the procedure, it was discovered that the donor suffered from both a renal cell carcinoma and a spindle-cell sarcoma of the ascending aorta, which had metastasized to the spleen. The patient was emergently listed for a retransplantation and underwent bilateral lung transplantation after a new donor became available 4 days after the initial transplantation procedure. After 24 months, the patient is without evidence of malignancy. This case illustrates the role of immediate retransplantation for patients who have inadvertently received thoracic organs from donors harboring occult malignancies.

A simple method for culturing mouse vascular endothelium.

Vascular endothelium is an important site for a wide array of immunological processes such as inflammation, atherosclerosis and allograft rejection. Culture methods of mouse vascular endothelium would provide an important in vitro correlate to immunological murine in vivo models. We describe a simple method to culture mouse vascular endothelium from thoracic aorta. Our cultured cells express typical phenotypic (CD105, CD31, CD106), morphological and ultrastructural (intercellular junctions, Weibel-Palade bodies) markers of vascular endothelium. They also possess functional receptors for uptake and processing of acetylated low-density lipoproteins. The mouse vascular endothelium within our system expresses high levels of MHC class I and MHC class II after activation with IFN-gamma. In addition, these cells express the accessory molecules CD80 and CD54, while they lack constitutive expression of CD86 and CD40, providing them the means to function as antigen presenting cells. Alloreactive CD4(+) and CD8(+) T lymphocytes demonstrate evidence of DNA synthesis after co-culture with activated vascular endothelium indicating their commitment to proliferation. In conclusion, we describe a simple culture system to isolate and grow mouse vascular endothelium, which provides a powerful tool to study biological interactions in vitro.

Central venulitis in pediatric liver allografts.

Central venulitis (CV), a distinct histologic lesion described in adult liver transplants, can occur with acute portal tract rejection or in isolation (ICV). Possible etiologies include immunosuppressive drug toxicity, acute cellular rejection, viral hepatitis, ischemic injury, and recurrent disease. This study was designed to characterize ICV and to assess its potential etiology in pediatric liver recipients because this population generally does not develop recurrent disease or viral hepatitis. All posttransplantation liver biopsy specimens that were obtained from children who received liver allografts over a 4-year period were reviewed. ICV was identified in 12 of 127 posttransplantation biopsies and in 7 of 45 allograft recipients. Only 4 liver transplantations were performed for potentially recurrent diseases (primary sclerosing cholangitis). ICV first appeared in posttransplantation biopsy specimens significantly later than did portal rejection alone. The finding of CV was not significantly correlated with elevation of Tacrolimus levels, reason for transplantation, donor/recipient cytomegalovirus (CMV) status or blood type, cold ischemic times, or the incidence of outflow obstruction. The responses of CV to therapy were variable and, although the majority of cases resolved, several episodes persisted or recurred. In conclusion, ICV occurs in 16% of pediatric liver allograft recipients and does not appear to be related to recurrent disease, viral hepatitis, drug toxicity, or graft ischemia. CV may be a variant of acute rejection, but longer follow-up is required to determine the most adequate therapy for this entity.

Donor antigen-presenting cells are important in the development of obliterative airway disease.

OBJECTIVE: Obliterative airway disease, which resembles obliterative bronchiolitis histologically, develops in murine heterotopic tracheal allografts. Chimeric tracheas were used to examine whether donor-type antigen-presenting cells are important in the development of obliterative airway disease. To separate the contributions of CD4(+) and CD8(+) direct pathways, we transplanted tracheas from knockout mice lacking major histocompatibility complex (MHC) class I or II antigens. METHODS: Chimeric tracheas were created via bone marrow transplantation in fully MHC-mismatched combinations. Tracheas from naive B6, autologously reconstituted B6, chimeric B6 bearing recipient-type C3H antigen-presenting cells, MHC class I knockout B6 (B6(I-)), MHC class II knockout B6 (B6(II-)), or C3H mice were transplanted into C3H recipients. The tracheas were harvested at days 14 and 28. RESULTS: At day 28, isografts showed no occlusion, normal respiratory epithelium, and minimal infiltrates. Naive or autologously reconstituted B6, B6(I-), and B6(II-) tracheas showed minimal occlusion at day 14 but contained intraepithelial infiltrates. By day 28, the naive or autologously reconstituted B6 tracheas had occlusion of 69.5% +/- 11.6% (mean +/- standard error of the mean), and in comparison, B6(I-) and B6(II-) tracheas had occlusions of 53.0% +/- 16.3% and 52.2% +/- 15.9%, respectively (P =. 20,.19). In chimeric B6 tracheas, minimal occlusion was seen at day 14 and remained 33.6% +/- 16.2% (P =.039) at day 28. Subtle epithelial changes and minimal infiltrates were seen. CONCLUSIONS: Obliterative airway disease appears to involve donor-type antigen-presenting cells and develops in the absence of either MHC class I or II antigens. These findings suggest that either CD8(+) or CD4(+) direct allorecognition is important in the development of obliterative airway disease.

Immune monitoring in xenotransplantation: the multiparameter flow cytometric mixed lymphocyte culture assay.

Xenotransplantation requires monitoring of complex cellular interactions in vitro. A tool to monitor cell proliferation in detail would be instrumental in understanding these cellular interactions in heterogeneous xenogeneic lymphocyte cultures and in patients after xenotransplantation. To accomplish this, we used a fluorescent cell proliferation marker, 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE), in combination with flow cytometry. CFSE, a green fluorescent molecule, binds covalently to intracellular macromolecules. Each cell division reduces the fluorescent intensity per cell by half and shows a characteristic multipeak pattern in flow cytometric analysis. For this study, human lymphocytes were labeled with CFSE and cultured in the presence of irradiated porcine lymphocytes. Cell proliferation was detected in CFSE-labeled lymphocytes in both a single and a multiparameter flow cytometry setting. Concurrently, tritiated ((3)H) thymidine incorporation, a common method to measure gross cell proliferation, was assessed. The kinetics of CFSE-labeled cell proliferation correlated with (3)H-thymidine incorporation in that both methods showed a lag phase for days 1-3 and a log phase for days 4-7. Multiparameter flow cytometric monitoring of mixed lymphocyte cultures allowed phenotyping and assessment of viability of proliferating populations in heterogeneous xenogeneic stimulated human lymphocyte cultures and complemented the classical (3)H-thymidine incorporation assay. The use of this technique will allow a wide array of immunologic parameters to be measured in a heterogeneous xenogeneic mixed lymphocyte culture. The information gained from these assays is essential to understanding the biological significance of xenogeneic cellular interaction and for monitoring the immune status of the xenotransplanted patient.

Replacement of graft-resident donor-type antigen presenting cells alters the tempo and pathogenesis of murine cardiac allograft rejection.

BACKGROUND: Graft-resident antigen presenting cells (APCs) are potent stimulators of the alloresponse. To test whether replacement of graft-resident donor-type APCs with those of recipient-type alters allorecognition and the pathogenesis of both acute and chronic rejection, we created chimeric hearts for transplantation into naive recipients. METHODS: To replace donor-type APCs with those of recipient-type, chimeric animals were created by bone marrow transplantation (BMT) in fully allogeneic mouse and rat strain combinations. The degree of APC replacement in chimeric organs was assessed phenotypically and functionally. Chimeric hearts were transplanted heterotopically into untreated recipients. RESULTS: Flow cytometric and immunohistochemical analysis did not detect residual bone marrow recipient-type APCs in mouse BMT chimeras. Although semi-quantitative reverse transcription polymerase chain reaction detected 0.001-0.01% residual cells, APCs isolated from chimeric organs were functionally unable to stimulate donor-type cells. When transplanted into naive recipients, chimeric mouse hearts had significantly prolonged survival but were nevertheless rejected acutely. Similar results were obtained in the ACI --> LEW rat strain combination. However, in the PVG --> DA rat model, the majority of chimeric hearts survived >100 days and all long-surviving hearts developed cardiac allograft vasculopathy. CONCLUSIONS: BMT leads to near complete replacement of organ-resident APCs. The virtual absence of donor-type APCs in chimeric hearts delays or prevents acute rejection in a strain-dependent manner. In contrast, this type of graft modification does not prevent cardiac allograft vasculopathy. This suggests that, although the CD4+ direct pathway may play a role in acute rejection, it is not essential for the development of chronic rejection in rodent cardiac allografts.

The usefulness of CD64, other monocyte-associated antigens, and CD45 gating in the subclassification of acute myeloid leukemias with monocytic differentiation.

Immunophenotyping by flow cytometry is widely used in the diagnosis and subclassification of acute myeloid leukemia (AML). CD14 is the monocyte-associated antigen most widely used to identify AML with monocytic differentiation (French-American-British classes M4 and M5); however, we observed that CD14 expression is frequently diminished or absent in such cases. To identify monocyte-associated antigens that might improve recognition of AML M4 and M5, we used 3-color flow cytometry and a panel of antibodies reported to distinguish cells of monocytic lineage in 44 cases of AML. In addition, CD45 vs logarithmic side scatter plots were analyzed in all cases. As expected, CD14 was highly specific but was only moderately sensitive for monocytic differentiation. CD64 had the best-combined sensitivity and specificity for AML M4 and M5. CD45 vs logarithmic side scatter analysis showed a higher percentage of monocytes in AML M4 and M5 compared with nonmonocytic AML. CD64 was expressed in 5 of 5 cases of acute promyelocytic leukemia (AML M3), but the intensity of staining was significantly less in AML M3 than in AML M4 and M5. Our findings show that addition of CD64 and CD45 vs logarithmic side scatter analysis to CD14 greatly improves flow cytometric detection of AML with monocytic differentiation and that CD64, also expressed in AML M3, may help distinguish AML M3 from other subtypes.

Kikuchi-Fujimoto disease: a benign cause of fever and lymphadenopathy.

PURPOSE: To describe 6 cases of Kikuchi-Fujimoto disease and to review the literature. PATIENTS AND METHODS: Review of 6 patients with biopsy-proven Kikuchi-Fujimoto disease detected at a university hospital over a 5-year period. RESULTS: Six patients presented with localized, mild lymph node enlargement. In 3 cases, dramatic fever, chills, weight loss and systemic complaints were present. These features prompted prolonged antibiotic therapy and extensive evaluations of fever of unknown origin before the diagnosis was made by biopsy of the minimally enlarged lymph nodes. The 3 remaining patients were otherwise asymptomatic and well. All 6 subjects recovered without specific therapy. CONCLUSIONS: Kikuchi-Fujimoto disease is a recently described cause of benign, self-limited lymphadenopathy that is easily confused histologically and clinically with lymphoma and systemic lupus erythematosis. Clinicians and pathologists must be aware of this condition. Although it is an uncommon cause of fever of unknown origin, early recognition of KFD will minimize potentially harmful and unnecessary evaluations and treatments.