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Background: Flow cytomeric crossmatch (FCXM) has grown in popularity and has become the "standard of practice" in many programs. Although FCXM is the most sensitive method for detecting alloantibody, the B cell FCXM has been problematic. Difficulties with the B cell FCXMs have been centered around high nonspecific fluorescence background owing to Fc-receptors present on the B cells and autoantibodies. To improve the specificity and sensitivity of the B cell FCXM, we utilized the proteolytic enzyme pronase to remove Fc receptors from lymphocytes before their use in FCXM., Methods: Lymphocytes isolated from peripheral blood, spleen, or lymph nodes were treated with pronase and then used in a three-color FCXM. A total of 167 T- and B cell FCXMs using pronase-treated and untreated cells were performed. Testing used serial dilutions of HLA allosera (22 class I and 6 class II), with the titer of each antibody at one dilution past the titer at which the complement-mediated cytotoxicity anti-human globulin crossmatch became negative., Results: After pronase treatment, the actual channel values of the negative control in both T cell and B cell FCXMs declined from 78+/-10 to 57+/-4 (P<0.05) and 107+/-11 to 49+/-3 (P<0.00001), respectively. Pronase treatment resulted in improved sensitivity of the T and B cell FCXM in detecting class I antibody by 20% and 80%, respectively. In no instance was a false-positive reaction observed. In this study, pronase treatment improved the specificity of B cell FCXM for detecting class II antibodies from 75% to 100% (P=0.03). In no instance was a false-negative reaction recorded. Lastly, on the basis of these observations we re-evaluated three primary transplant recipients who lost their allografts because of accelerated rejection. One of the patients was transplanted across negative T and B cell FCXM, whereas the other two patients were transplanted across a positive T cell, but negative B cell, FCXM. After pronase treatment, T and B cell FCXMs of each patient became strongly positive, and donor-specific anti-HLA class I antibody was identi. fied in each case., Conclusion: Utilization of pronase-treated lymphocytes improves both the sensitivity and specificity of the FCXM.

Background: Antiphospholipid antibody syndrome (APAS) is characterized by the presence of anticardiolipin antibodies (ACA) in association with thrombotic disorders of arterial and/or venus systems, spontaneous abortion(s) or thrombocytopenia., Methods: In this multicenter study, 502 end-stage renal disease (ESRD) patients awaiting renal transplants were screened to determine the frequency of APAS, the potential risk associated with APAS, and strategies for therapeutic intervention. Ninety-three patients (19%) had high titers of ACA. Twenty-three patients had documented evidence of one or more of the thrombotic disorders such as lupus, frequent abortions, frequent thrombosis of arteriovenous shunts, biopsy-proven microrenal angiopathy, or thrombocytopenia and thus were diagnosed with APAS. Of these 23 patients, 11 received kidney transplants either with (4 patients) or without (7 patients), concomitant anticoagulation therapy., Results: All seven of the patients with APAS not treated with anticoagulation therapy lost their allografts within 1 week as a result of renal thrombosis. In contrast, three out of four transplant patients with APAS treated with anticoagulation therapy maintained their allografts for over 2 years. The fourth patient lost his graft within a week because of thrombosis. Of the remaining 70 patients with high titers of ACA but no evidence of thrombotic disorders, 37 received kidney transplants. None lost their allografts as a result of thrombosis. Our data suggest that, although 19% of our ESRD patients exhibit high titer of ACA, only 5% of the patients have APAS., Conclusion: In conclusion, our data suggest that the patients with APAS are at high risk of posttransplant renal thrombosis. Anticoagulation therapy could prevent patients from posttransplant thrombosis in patients with APAS.

Background: Patients undergoing chronic steroid therapy for organ transplantation are at increased risk for development of human herpes virus 8(HHV-8)-associated Kaposi's sarcoma (KS). It has also been reported that following steroid withdrawal, KS lesions often undergo partial or complete regression., Methods: We have examined the effect of corticosteroid treatment on HHV-8 replication, gene expression, and lytic protein expression in BCBL-1 cells in vitro. BCBL-1 cells were collected after culture for 24-72 hr with hydrocortisone (HC) 1-5 microM, phorbol ester 20 ng/ml (positive control), and culture medium only (negative control). HHV-8 genomic conformation was examined by Gardella gel analysis. mRNA expression of viral cyclin (v-Cyc), viral Bcl-2 (v-Bcl-2), viral macrophage inflammatory protein-I (v-MIP-I), viral interferon regulatory factor-1(v-IRF-1), and viral tegument protein (TP) was examined by RT-PCR Southern blot. Viral protein expression within the cells was examined by indirect immunofluorescence using 5 different HHV-8 positive antisera from 4 renal transplant recipients and 1 patient with classic KS., Results: Gardella gel analysis revealed that HC induced an accumulation of the linear replicative genomic form of the virus in a time-dependent fashion. Southern blot analysis of the RT-PCR products revealed that HC induced increased expression of v-IRF-1, v-Bcl-2, and TP mRNA, with little discernible effect on v-Cyc, and v-MIP-I. Immunofluorescence revealed that HC induced increased numbers of cells expressing lytic antigens., Conclusions: These data indicate that hydrocortisone acts directly on BCBL-1 cells to activate the lytic cycle of HHV-8 and provide further support for the hypothesis that HHV-8 is activated in corticosteroid-treated immunocompromised patients.

We have prevented graft-versus-host disease (GVHD) by tolerizing graft donors to host antigens by intrathymic injection of recipient-type splenocytes into donors. A unidirectional GVHD model was used in which intravenous injection of 3-4 x 10(8) Lewis rat (donor) lymphocytes into (Lewis x Brown Norway)F1 rats (recipients) causes lethal GVHD. The donor animals were divided into five treatment groups. The group 1 donor animals received no treatment. The group 2 donors received a single intraperitoneal injection of 1 ml of antilymphocyte antiserum (ALS). The group 3 donors received an intrathymic injection of 50x10(6) host splenocytes. The group 4 donors received both ALS (intraperitoneally) and intrathymic allograft. The group 5 donors received both ALS (intraperitoneally) and intravenous allograft. Two weeks after these treatments, 3-4x10(8) lymphocytes from each of these donors were injected (intravenously) into the recipients. The clinical signs of GVHD, as measured by profound weight loss, hair loss, inflammation of foot pads and ears, and profound splenomegaly, were evident in recipients of groups 1, 2, and 3 between days 9 and 10 and in the recipients (two of four) of group 5 on day 17. No GVHD was observed by histopathology in all 14 hosts that received lymphocyte injection from the group 4 donor animals (up to 300 days). These results demonstrate that GVHD can be eliminated by tolerizing donors toward host by intrathymic injection of the recipient-type lymphocytes into the donor. A single injection of ALS is necessary to possibly eliminate antihost response from the donor for the tolerance induction. The thymic route appears to be superior to the intravenous route for tolerance induction.

Pancreatic islet transplantation may be the most ideal treatment for patients with insulin-dependent diabetes mellitus. However, immunosuppressive agents such as cyclosporine A(CsA) and FK506, used for these transplanted patients have been reported to cause glucose intolerance. In the present study, we have compared the effects of CsA and FK506 on glucose-stimulated insulin release from the isolated dog pancreatic islets, which have been maintained in culture for 3 days after isolation. The isolated dog pancreatic islets, pretreated for 24 hr with either CsA or FK506 (1, 10, and 100 nM), were perifused with 16.7 mM glucose. Pretreatment with both drugs suppressed glucose-stimulated insulin secretion in a dose-dependent fashion. CsA (100 nM), which is a therapeutically relevant concentration, significantly suppressed both the first and second phases of glucose-stimulated insulin release compared with 100 nM FK506. These findings suggest that, with a therapeutically relevant concentration, FK506 may be less toxic than CsA against pancreatic islets in patients with organ or cell transplantation.

Serum and lymph albumin and Ig levels were measured during 6 weeks of lymphocyte depletion by thoracic duct drainage (TDD) in 21 patients prior to renal allotransplantation. In ten of these patients, the amount of protein lost from all sources (blood sampling, dialysis, and lymph centrifugation) was measured. The total amount of albumin lost was significantly greater than the amount of IgG lost. However, serum IgG declined at a faster rate and to a greater extent than albumin. Hyperacute or acute humoral rejection occurred in 14 grafts in 10 patients prepared by TDD despite negative crossmatch tests. These data suggest that removal of lymphocytes by TDD, rather than protein loss alone, affects IgG levels. On the other hand, TDD and IgG depletion do not prevent hyperacute or acute humoral rejection. This is most likely due to the inability of currently employed crossmatch tests to predict accurately which patients will manifest antibody-mediated graft rejection.

Renal damage caused by cyclosporine (CsA) has been documented. Clinical experiences have shown preservation injury further potentiates CsA nephrotoxicity. This study examined the mechanism of nephrotoxicity defined by changes in protein synthesis, DNA synthesis, and ornithine decarboxylase activity in an in vitro model. Initial results showed that CsA inhibited dog kidney epithelium cell (MDCK) replication at a dose of 200 ng after 24 hr (P less than .01) and 100 ng after 48 hr (P less than .01). Protein synthesis was inhibited with 100 ng after 24 and 48 hr (P less than .01). There was a reduction in ODC activity with 200 ng CsA (P less than .05). Methods for simulating transplant-related injuries were then developed. Under ischemic conditions, 18 hr were required before a synergistic effect with CsA produced a reduction in replication (P less than .05). Incubation of MDCK cells in preservative solution at 4 degrees C under hypoxic conditions resulted in a time-dependent reduction in synthetic and replicative capacity that plateaued at 24 hr (P less than .01). The next step was to simulate the clinical situation by combining treatments. MDCK cells were incubated for 24 hr in preservative solution under hypoxic conditions at 4 degrees C, and then CsA was added at defined intervals. The addition of CsA before 24 hr resulted in a significant decrease in cell replication (P less than .05) compared with CsA addition after 48 hr. Similar results were obtained with cells incubated for 48 hr in preservative solution with hypoxia. These data suggest that renal injury from ischemia and cold storage requires a period of cellular repair and replication. Administration of CsA before this period results in further renal injury. Our analysis offers an explanation of CsA nephrotoxicity seen in the human situation and, therefore, may provide a model for studying human nephrotoxicity.