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1.
Urol Case Rep ; 3(3): 53-5, 2015 May.
Article in English | MEDLINE | ID: mdl-26793500

ABSTRACT

Though rare, renal transplantation into a bowel containing urinary diversion is necessary in select clinical situations. Compared to renal transplant patients with functional native bladders, patients with urinary diversion have comparable long-term graft and patient survival rates. However, compounding the increased risk of malignancy in those on chronic immunosuppression are the inherent risks of urinary diversion. We present a case report of a high grade adenocarcinoma with neuroendocrine differentiation arising in an ileal conduit and discussion on the pathophysiology, management, and screening of this highly select population.

2.
Neurol Neuroimmunol Neuroinflamm ; 1(1): e11, 2014 Jun.
Article in English | MEDLINE | ID: mdl-25340055

ABSTRACT

OBJECTIVE: To compare performance of contemporary aquaporin-4-immunoglobulin (Ig) G assays in clinical service. METHODS: Sera from neurologic patients (4 groups) and controls were tested initially by service ELISA (recombinant human aquaporin-4, M1 isoform) and then by cell-based fluorescence assays: fixed (CBA, M1-aquaporin-4, observer-scored) and live (fluorescence-activated cell sorting [FACS], M1 and M23 aquaporin-4 isoforms). Group 1: all Mayo Clinic patients tested from January to May 2012; group 2: consecutive aquaporin-4-IgG-positive patients from September 2011 (Mayo and non-Mayo); group 3: suspected ELISA false-negatives from 2011 to 2013 (physician-reported, high likelihood of neuromyelitis optica spectrum disorders [NMOSDs] clinically); group 4: suspected ELISA false-positives (physician-reported, not NMOSD clinically). RESULTS: Group 1 (n = 388): M1-FACS assay performed optimally (areas under the curves: M1 = 0.64; M23 = 0.57 [p = 0.02]). Group 2 (n = 30): NMOSD clinical diagnosis was confirmed by: M23-FACS, 24; M1-FACS, 23; M1-CBA, 20; and M1-ELISA, 18. Six results were suspected false-positive: M23-FACS, 2; M1-ELISA, 2; and M23-FACS, M1-FACS, and M1-CBA, 2. Group 3 (n = 31, suspected M1-ELISA false-negatives): results were positive for 5 sera: M1-FACS, 5; M23-FACS, 3; and M1-CBA, 2. Group 4 (n = 41, suspected M1-ELISA false-positives): all negative except 1 (positive only by M1-CBA). M1/M23-cotransfected cells expressing smaller membrane arrays of aquaporin-4 yielded fewer false- positive FACS results than M23-transfected cells. CONCLUSION: Aquaporin-4-transfected CBAs, particularly M1-FACS, perform optimally in aiding NMOSD serologic diagnosis. High-order arrays of M23-aquaporin-4 may yield false-positive results by binding IgG nonspecifically.

3.
Neurogastroenterol Motil ; 25(1): 84-8.e10, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23072523

ABSTRACT

BACKGROUND: Autoimmune gastrointestinal dysmotility (AGID) is a limited form of dysautonomia. The only proven effector to date is IgG specific for ganglionic nicotinic-acetylcholine receptors containing α3 subunits [α3*- nicotinic acetylcholine receptor (nAChR)]. Rabbits immunized with recombinant α3-polypeptide produce α3*-nAChR autoantibodies, and profound AGID ensues. Human and rabbit α3*-nAChR-specific-IgGs induce transient hypomotility when injected into mice. Here, we describe success and problems encountered inducing gastrointestinal hypomotility in mice by active immunization. METHODS: We repeatedly injected young adult mice of seven different strains susceptible to autoimmunity (spontaneous diabetes or neural antigen immunization-induced myasthenia gravis or encephalomyelitis) with: (i) α3-polypeptide, intradermally or (ii) live α3*-nAChR-expressing xenogeneic cells, intraperitoneally. We measured serum α3*-nAChR-IgG twice monthly, and terminally assessed blue dye gastrointestinal transit, total small intestinal α3*-nAChR content (radiochemically) and myenteric plexus neuron numbers (immunohistochemically, ileal-jejunal whole-mount preparations). KEY RESULTS: Standard cutaneous inoculation with α3-polypeptide was minimally immunogenic, regardless of dose. Intraperitoneally injected live cells were potently immunogenic. Self-reactive α3*-nAChR-IgG was induced only by rodent immunogen; small intestinal transit slowing and enteric α3*-nAChR loss required high serum levels. Ganglionic neurons were not lost. CONCLUSIONS & INFERENCES: Autoimmune gastrointestinal dysmotility is inducible in mice by active immunization. Accompanying enteric α3*-nAChR reduction without neuronal death is consistent with an IgG-mediated rather than T cell-mediated pathogenesis, as is improvement of symptoms in patients receiving antibody-depleting therapies.


Subject(s)
Autoimmune Diseases/immunology , Disease Models, Animal , Primary Dysautonomias/immunology , Receptors, Nicotinic/immunology , Animals , Autoantibodies/blood , Autoantibodies/immunology , Autoantigens/immunology , Autoimmune Diseases/metabolism , Gastrointestinal Transit/immunology , Humans , Immunoglobulin G , Mice , Myenteric Plexus/immunology , Myenteric Plexus/metabolism , Primary Dysautonomias/metabolism , Receptors, Nicotinic/metabolism , Vaccination
4.
Am J Transplant ; 11(2): 261-71, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21219568

ABSTRACT

This manuscript reports the demographics, education and training, professional activities and lifestyle characteristics of 171 members of the American Society of Transplant Surgeons (ASTS). ASTS members were sent a comprehensive survey by electronic mail. There were 171 respondents who were 49 ± 8 years of age and predominantly Caucasian males. Female transplant surgeons comprised 10% of respondents. ASTS respondents underwent 15.6 ± 1.0 years of education and training (including college, medical school, residency and transplantation fellowship) and had practiced for 14.7 ± 9.2 years. Clinical practice included kidney, pancreas and liver organ transplantation, living donor surgery, organ procurement, vascular access procedures and general surgery. Transplant surgeons also devote a significant amount of time to nonsurgical patient care, research, education and administration. Transplant surgeons, both male and female, reported working approximately 70 h/week and a median of 195 operative cases per year. The anticipated retirement age for men was 64.6 ± 8.6 and for women was 62.2 ± 4.2 years. This is the largest study to date assessing professional and lifestyle characteristics of abdominal transplant surgeons.


Subject(s)
Specialties, Surgical , Transplants , Academic Medical Centers , Adult , Aged , Data Collection , Education , Female , Humans , Life Style , Male , Middle Aged , Societies, Medical , Specialties, Surgical/education , United States , Workload
5.
Neurology ; 71(2): 93-100, 2008 Jul 08.
Article in English | MEDLINE | ID: mdl-18509092

ABSTRACT

BACKGROUND: In adult patients, autoantibodies targeting the water channel aquaporin-4 (AQP4) are a biomarker for a spectrum of CNS inflammatory demyelinating disorders with predilection for optic nerves and spinal cord (neuromyelitis optica [NMO]). Here we describe the neurologic, serologic, and radiographic findings associated with CNS AQP4 autoimmunity in childhood. METHODS: A total of 88 consecutive seropositive children were identified through service evaluation for NMO-IgG. Sera of 75 were tested for coexisting autoantibodies. Clinical information was available for 58. RESULTS: Forty-two patients (73%) were non-Caucasian, and 20 (34%) had African ethnicity. Median age at symptom onset was 12 years (range 4-18). Fifty-seven (98%) had attacks of either optic neuritis (n = 48; 83%) or transverse myelitis (n = 45; 78%), or both. Twenty-six (45%) had episodic cerebral symptoms (encephalopathy, ophthalmoparesis, ataxia, seizures, intractable vomiting, or hiccups). Thirty-eight (68%) had brain MRI abnormalities, predominantly involving periventricular areas (in descending order of frequency): the medulla, supratentorial and infratentorial white matter, midbrain, cerebellum, thalamus, and hypothalamus. Additional autoantibodies were detected in 57 of 75 patients (76%), and 16 of 38 (42%) had a coexisting autoimmune disorder recorded (systemic lupus erythematosus, Sjögren syndrome, juvenile rheumatoid arthritis, Graves disease). Attacks were recurrent in 54 patients (93%; median follow-up, 12 months). Forty-three of 48 patients (90%) had residual disability: 26 (54%) visual impairment and 21 (44%) motor deficits (median Expanded Disability Status Scale 4.0 at 12 months). CONCLUSIONS: Aquaporin-4 autoimmunity is a distinctive recurrent and widespread inflammatory CNS disease in children.


Subject(s)
Aquaporin 4/immunology , Autoantibodies/analysis , Myelitis, Transverse/immunology , Neuromyelitis Optica/immunology , Adolescent , Autoimmunity , Biomarkers/analysis , Brain/pathology , Child , Child, Preschool , Female , Humans , Magnetic Resonance Imaging , Male , Methylprednisolone/therapeutic use , Myelitis, Transverse/diagnosis , Myelitis, Transverse/drug therapy , Neuromyelitis Optica/diagnosis , Neuromyelitis Optica/drug therapy , Recurrence , Serologic Tests
6.
Neurology ; 69(24): 2221-31, 2007 Dec 11.
Article in English | MEDLINE | ID: mdl-17928579

ABSTRACT

BACKGROUND: Autoantibody specific for the aquaporin-4 astrocytic water channel is restricted to serum and CSF of patients with neuromyelitis optica (NMO) and related CNS inflammatory demyelinating disorders (relapsing optic neuritis and longitudinally extensive transverse myelitis). NMO-typical lesions are distinct from MS-typical lesions. Aquaporin-4 is lost selectively at vasculocentric sites of edema/inflammation coinciding with focal deposits of immunoglobulins (Ig) G, M, and terminal complement products, with and without myelin loss. Evidence for antigen-specific autoantibody pathogenicity is lacking. METHODS: We used confocal microscopy and flow cytometry to evaluate the selectivity and immunopathological consequences of Ig binding to surface epitopes of living target cells expressing aquaporin-4 fused at its cytoplasmic N-terminus with GFP. We tested serum, IgG-enriched and IgG-depleted serum fractions, and CSF from patients with NMO, neurologic control patients, and healthy subjects. We also analyzed aquaporin-4 immunoreactivity in myelinated adult mouse optic nerves and spinal cord, and plasma cell Ig isotypes in archived brain tissue from an NMO patient. RESULTS: Serum IgG from patients with NMO binds to the extracellular domain of aquaporin-4; it is predominantly IgG(1), and it initiates two potentially competing outcomes, aquaporin-4 endocytosis/degradation and complement activation. Serum and CSF lack aquaporin-4-specific IgM, and plasma cells in CNS lesions of NMO contain only IgG. Paranodal astrocytic endfeet highly express aquaporin-4. CONCLUSIONS: NMO patients' serum IgG has a selective pathologic effect on cell membranes expressing aquaporin-4. IgG targeting astrocytic processes around nodes of Ranvier could initiate demyelination.


Subject(s)
Aquaporin 4/metabolism , Binding Sites, Antibody , Extracellular Fluid/metabolism , Immunoglobulin G/metabolism , Neuromyelitis Optica/immunology , Neuromyelitis Optica/metabolism , Animals , Aquaporin 4/immunology , Cell Line , Endocytosis/immunology , Extracellular Fluid/immunology , Humans , Mice , Neuromyelitis Optica/pathology , Protein Binding/immunology
7.
Am J Transplant ; 7(5 Pt 2): 1376-89, 2007.
Article in English | MEDLINE | ID: mdl-17428286

ABSTRACT

The number of liver transplants performed yearly has slowly and steadily increased over the last 10 years, reaching 6441 procedures in 2005. The number of living donor liver transplants performed rose steadily from 1996 to 2001, when it peaked at 519; since 2003 there have been approximately 320 such procedures performed each year. The continual increase in the size of the waiting list for a liver transplant, which peaked in 2001 at 14 897 patients, was interrupted in 2002 by the implementation of the allocation system based on the model for end-stage liver disease and pediatric end-stage liver disease (MELD/PELD). Activity in all areas of intestinal transplantation continues to increase. One-year patient and graft survival following intestine-alone transplantation now seem to be superior to outcomes following liver-intestine transplantation. Other topics covered here include the recent 'Share 15' component of the MELD allocation system; liver transplantation following donation after cardiac death; simultaneous liver-kidney transplantation and waiting list and post-transplant outcomes for both liver and intestine transplantation, broken out by a variety of clinical and demographic factors.


Subject(s)
Intestines/transplantation , Liver Transplantation/statistics & numerical data , Transplantation, Homologous/statistics & numerical data , Adolescent , Adult , Age Distribution , Child , Demography , Female , Hepatectomy , Humans , Liver Transplantation/trends , Living Donors , Male , Middle Aged , Reoperation/statistics & numerical data , Tissue and Organ Harvesting/methods , Tissue and Organ Procurement/statistics & numerical data , Tissue and Organ Procurement/trends , Transplantation, Homologous/trends , United States , Waiting Lists
8.
J Invest Dermatol ; 117(5): 1261-5, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11710942

ABSTRACT

We have identified and isolated ectopically expressed tyrosinase transcripts in normal human melanocytes and lymphocytes and in a human melanoma (MNT-1) cell line to establish a baseline for the expression pattern of this gene in normal tissue. Tyrosinase mRNA from human lymphoblastoid cell lines was reverse transcribed and amplified using specific "nested" primers. This amplification yielded eight identifiable transcripts; five that resulted from alternative splicing patterns arising from the utilization of normal and alternative splice sequences. Identical splicing patterns were found in transcripts from human primary melanocytes in culture and a melanoma cell line, indicating that lymphoblastoid cell lines provide an accurate reflection of transcript processing in melanocytes. Similar splicing patterns have also been found with murine melanocyte tyrosinase transcripts. Our results demonstrate that alternative splicing of human tyrosinase gene transcript produces a number of predictable and identifiable transcripts, and that human lymphoblastoid cell lines provide a source of ectopically expressed transcripts that can be used to study the biology of tyrosinase gene expression in humans.


Subject(s)
Alternative Splicing , Lymphocytes/physiology , Melanocytes/physiology , RNA, Messenger/genetics , Tyrosine/genetics , Cells, Cultured , Humans , Reference Values
9.
Curr Gastroenterol Rep ; 3(4): 334-42, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11470003

ABSTRACT

Significantly reduced morbidity and mortality is needed before intestinal transplantation will be applicable in most patients with intestinal failure who are on long-term total parenteral nutrition (TPN). However, transplantation does play a role if TPN fails, with failure defined by Medicare as liver failure, frequent line sepsis, major central vein thrombosis, or recurrent dehydration. Of these complications, the relationship between liver failure and subsequent death in high-risk subgroups of long-term TPN patients has been shown clearly. Patients with less than 100 cm of postduodenal small bowel, an end-jejunostomy, no ileocecal valve or cecum, or persistently elevated liver function levels are at high risk for end-stage liver disease (ESLD). Early referral to experienced centers is suggested in these circumstances. High-risk patients may also take part in clinical trials of promising therapies to increase intestinal adaptation and prevent liver failure. Living donors should be considered for transplant candidates to minimize waiting time and optimize HLA matching. ESLD patients need a liver-intestine transplant. Because their waiting-list mortality is very high, their status on the liver waiting list should be elevated if possible. High incidence of early death from sepsis is reported after intestinal transplant, even at experienced centers. Aggressive measures should be taken if uncontrolled sepsis occurs, including discontinuing immunosuppression and removing the graft. Further research is needed in intestinal immunology and in development of strategies to decrease the need for aggressive immunosuppression in these transplant recipients. The ultimate role of intestinal transplantation will be determined by its capacity to show superiority, both in effectiveness and safety, to long-term TPN.


Subject(s)
Intestinal Diseases/surgery , Intestines/transplantation , Humans , Liver Failure/prevention & control , Parenteral Nutrition, Total , Treatment Failure
12.
J Biosci Bioeng ; 91(3): 305-10, 2001.
Article in English | MEDLINE | ID: mdl-16232994

ABSTRACT

For many applications avian antibody from egg yolk (IgY) offers advantages over the well-known mammalian antibodies. Different experimental techniques for the purification of IgY from chickens immunized with an alphagalactose-containing antigen (alphaGal-trisaccharide) were compared. These included ammonium sulfate precipitation, filtration with diatomaceous earth, treatment with deoxycholate, and thiophilic and affinity chromatography. Samples were tested for overall purity, protein and lipid content, and specific activity. Evaluated on the basis of these results and the simplicity of the process, the favored purification method is ammonium sulfate precipitation of diluted egg yolk directly followed by affinity chromatography. The high lipid content of IgY preparations is greatly reduced by either thiophilic or affinity chromatography. Affinity purification of ammonium sulfate precipitated material resulted in anti-alphaGal-trisaccharide IgY preparations with approximately 1% of the original protein content but approximately 100-fold higher specific activity for the alphaGal-trisaccharide epitope.

13.
Transplantation ; 72(12): 1940-5, 2001 Dec 27.
Article in English | MEDLINE | ID: mdl-11773893

ABSTRACT

BACKGROUND: The relevance of cytomegalovirus (CMV) in simultaneous pancreas kidney (SPK) transplant recipients in the modern era of immunosuppression and antiviral therapeutics is largely unquantified. We sought to determine the risk factors of CMV disease and its impact on SPK transplant outcomes in recipients all receiving a consistent regime of maintenance immunosuppression and CMV prophylaxis. METHODS: This is a retrospective, single center study of 100 consecutive SPK transplant recipients. All received maintenance immunosuppression with mycophenolate mofetil, tacrolimus, and prednisone. CMV prophylaxis consisted of a short course of parenteral gancyclovir followed by oral gancyclovir. Recipients at high-risk (D+/R-) for CMV also received CMV hyperimmune globulin. Multivariate analysis of risk factors for CMV disease and risk factors for adverse outcomes in SPK transplantation were determined. The effect of duration of prophylaxis on timing and severity of CMV disease in high-risk (D+/R-) SPK transplant recipients was also evaluated. RESULTS: The actual 1-year rate of CMV disease was 17.0% (12.0% noninvasive, 5.0% tissue invasive); and according to donor and recipient CMV serological status was: D-/R+: 0%; D-/R-: 2.8%; D+/R+: 25.6%; and D+/R-: 40.6%. Multivariate analysis showed transplantation of organs from a donor with positive CMV serology to be predictive of CMV disease with a relative risk of 63.37 (P=0.0052). In the high-risk (D+/R-) subgroup, the duration of prophylactic therapy delayed onset of CMV disease, but had minimal effect on severity. Invasive CMV disease was an independent predictor of mortality but did not decrease kidney or pancreas allograft survival. CONCLUSIONS: Outcomes of SPK transplantation have improved in the current era of modern immunosuppression, yet CMV remains an important pathogen. The serological status of the organ donor and the duration of CMV prophylaxis are predictive of who and when CMV disease may occur. Nevertheless, new strategies that reduce risk and severity of CMV disease are still needed.


Subject(s)
Cytomegalovirus Infections/etiology , Kidney Transplantation/adverse effects , Pancreas Transplantation/adverse effects , Adolescent , Adult , Antiviral Agents/administration & dosage , Antiviral Agents/therapeutic use , Cytomegalovirus Infections/epidemiology , Cytomegalovirus Infections/prevention & control , Drug Administration Schedule , Female , Forecasting , Ganciclovir/administration & dosage , Ganciclovir/therapeutic use , Humans , Incidence , Male , Middle Aged , Multivariate Analysis , Risk Factors , Tissue Donors
15.
Immunology ; 101(4): 467-73, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11122450

ABSTRACT

Chicken antibodies (immunoglobulin Y; IgY) to the alpha Gal epitope (galactose alpha-1,3-galactose) bind to alpha Gal antigens of mouse and porcine tissues and endothelial cells in vitro and block human anti-alpha Gal antibody binding, complement activation and antibody-dependent cell-mediated lysis mechanisms. The activities and toxicity of anti-alpha Gal IgY have not been tested in vivo. In this study, we tested the effects of multiple injections of affinity-purified anti-alpha Gal IgY (AP-IgY) in both wild-type (WT) and alpha-1,3-galactosyltransferase knockout (Gal KO) mice. WT and Gal KO mice were injected once, twice, three, or four times intravenously (i.v.) with AP-IgY and killed at 1 hr or 24 hr. Mice displayed no toxicity to four injections of AP-IgY. Heart, lung, liver, kidney, spleen and pancreatic tissue were evaluated using immunohistochemical techniques for the presence of the alpha Gal epitope using the GSI-B4 lectin, and for bound IgY, as well as mouse IgM and IgG. The binding of AP-IgY antibodies to the endothelium of WT mouse tissues was essentially identical to the pattern of binding of the GSI-B4 lectin after injection of WT mice and death at 1 hr. WT mice killed 24 hr after i.v. injection of AP-IgY showed little remaining bound IgY in their endothelia, indicating that IgY is cleared over that time period. We also evaluated the blood drawn at the time of death for the presence of anti-alpha Gal IgY, anti-IgY IgM and anti-IgY IgG by enzyme-linked immunosorbent assay. Anti-alpha Gal IgY was almost undetectable in WT mouse sera at all injection and killing times. In contrast, Gal KO mouse sera showed increasing anti-alpha Gal IgY levels until 24 hr after the fourth injection, when anti-alpha Gal IgY levels were almost undetectable. Anti-IgY IgM and IgG levels in WT and Gal KO mouse sera showed a typical increase in anti-IgY IgM 24 hr after the second injection (3 days after the first injection) and an increase in anti-IgY IgG 24 hr after the third injection (5 days after the first injection). These results show that IgY binds to alpha Gal epitopes in the WT mice and is cleared sometime over a 24-hr time period and that IgY is an expected immunogen in mice eliciting a rather typical anti-IgY IgM and IgG response.


Subject(s)
Chickens/immunology , Disaccharides/immunology , Immunoglobulins/immunology , Animals , Antibodies, Anti-Idiotypic/blood , Disaccharides/genetics , Enzyme-Linked Immunosorbent Assay , Epitopes/metabolism , Immunoglobulin G/blood , Immunoglobulin M/blood , Immunoglobulins/blood , Immunoglobulins/metabolism , Mice , Mice, Knockout
16.
Surgery ; 128(4): 726-37, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11015108

ABSTRACT

BACKGROUND: In the past, enteric drainage or the omission of induction immunotherapy has been shown to be predictive of suboptimal outcomes of simultaneous pancreas-kidney (SPK) transplantation. We have reassessed the need for bladder drainage and induction immunotherapy to optimize the outcome of SPK transplantation. METHODS: One hundred consecutive recipients of SPK transplants who received mycophenolate mofetil and tacrolimus immunosuppression were studied. The first 50 recipients had bladder-drained pancreas allografts and received induction immunotherapy. The results were compared with the next 50 recipients who had enteric-drained pancreas allografts, which included a subgroup (n = 17 patients) who were randomized to receive no induction immunotherapy. RESULTS: The 1-year actuarial patient, kidney, and pancreas survival rates in the bladder-drainage group were 98.0%, 94.0%, and 94.0%, respectively. The 1-year actuarial patient, kidney, and pancreas survival rates in the enteric-drainage group were 96.8%, 96.8%, and 89.4%, respectively. In the enteric-drainage group, the incidence of rejection at 1 year was 6.1% in recipients who received induction therapy versus 23.5% in recipients who did not receive induction therapy. The average number of readmissions per recipient was 1.8 in the bladder-drainage group versus 0.9 in the enteric-drainage group. CONCLUSIONS: Primary enteric drainage of the pancreas allograft in recipients of SPK transplantation is the preferred surgical technique in the tacrolimus/mycophenolate mofetil era.


Subject(s)
Drainage/methods , Immunosuppressive Agents/administration & dosage , Kidney Transplantation/methods , Mycophenolic Acid/analogs & derivatives , Mycophenolic Acid/administration & dosage , Pancreas Transplantation/methods , Tacrolimus/administration & dosage , Adult , Bacterial Infections/drug therapy , Bacterial Infections/mortality , Female , Graft Rejection/drug therapy , Graft Rejection/mortality , Graft Survival , Humans , Hypertension, Renal/therapy , Incidence , Intestines , Kidney Transplantation/mortality , Male , Middle Aged , Pancreas Transplantation/mortality , Patient Readmission , Postoperative Complications/mortality , Survival Analysis , Treatment Outcome , Urinary Bladder
17.
Transplantation ; 70(5): 828-36, 2000 Sep 15.
Article in English | MEDLINE | ID: mdl-11003366

ABSTRACT

BACKGROUND: Acute vascular xenograft rejection (AVXR), also termed delayed xenograft rejection (DXR), occurs when hyperacute rejection (HAR) is prevented by strategies directed at xenoreactive natural antibodies and/or complement activation. We have hypothesized that AVXR/DXR is initiated in part by early components of the complement cascade, notably C1q. We have developed synthetic peptides (termed CBP2 and WY) that interfere with the interaction between C1q and antibody. METHODS: CBP2 and the WY-conjugates were used as inhibitors of immunoglobulin aggregate binding to solid phase C1q. Inhibition of complement activation by the peptides of the classical system was determined using lysis assays with sensitized sheep red blood cells or porcine aortic endothelial cells as targets and of the alternate complement pathway using guinea pig red blood cells as targets. Two transplant models were used to study the effects of administering peptides to recipients: rat heart transplant to presensitized mouse, and guinea heart transplant to PVG C6-deficient rats. RESULTS: CBP2 and WY-conjugates inhibited immunoglobulin aggregate binding to C1q. The peptides also inhibited human complement-mediated lysis of sensitized sheep red blood cells and porcine aortic endothelial cells in a dose-dependent manner and the WY-conjugates prevented activation of the alternate complement pathway as shown by inhibition of guinea pig red blood cells lysis with human serum. In addition, the use of the peptides and conjugates resulted in significant prolongation of xenograft survival. CONCLUSIONS: The CBP2 and WY peptides exhibit the functional activity of inhibition of complement activation. These peptides also prolong xenograft survival and thus provide reagents for the study of the importance of C1q and other complement components in transplant rejection mechanisms.


Subject(s)
Complement C1q/pharmacology , Immunoglobulins/pharmacology , Peptides/pharmacology , Transplantation, Heterologous , Animals , Complement C1q/antagonists & inhibitors , Cytotoxicity, Immunologic/drug effects , Drug Interactions , Graft Survival/drug effects , Heart Transplantation/immunology , Male , Mice , Mice, Inbred BALB C , Rats , Rats, Inbred Lew , Swine , Transplantation, Heterologous/immunology
18.
Transplantation ; 70(4): 602-6, 2000 Aug 27.
Article in English | MEDLINE | ID: mdl-10972217

ABSTRACT

BACKGROUND: Laparoscopic live donor nephrectomy (LDN) is a less invasive alternative to open nephrectomy (ODN) for living kidney donation. Concerns have been raised regarding the safety of LDN, the short and long term function of kidneys removed by LDN, and a potential higher incidence of urologic complications in LDN transplant recipients. METHODS: Between October 1997 and May 1999, 80 LDNs were performed at our center. All patients were followed longitudinally with office visits and telephone interviews. These LDNs were compared with 50 ODN performed from January 1996 to October 1997. RESULTS: LDN procedures took significantly longer than ODN (4.6 vs. 3.1 hr). However, LDN was associated with significant reduction in i.v. narcotic use, a rapid return to diet, and shorter hospital stay. Of the 80 LDN procedures, a total of 75 (94%) were completed laparoscopically. Five patients were converted to laparotomy: three for hemorrhage and two for complex vascular anatomy. ODN conversion was associated with large donor body habitus and/or obesity. Seven LDN patients had minor complications and 4 had major complications. All major complications consisted of vascular injuries (2 lumbar vein injuries, 1 renal artery, and 1 aortic injury). All patients made complete recoveries. All LDN kidneys functioned immediately posttransplant. We have observed 100% patient and 97% 1-year actuarial graft survival in LDN transplant recipients. There have been no short-or long-term urologic complications in this series. CONCLUSION: With increasing experience and standardization of technique, LDN is a safe and effective procedure. Patients undergoing LDN demonstrate clinically significant, more rapid postoperative recoveries and shorter hospital stays than ODN patients. Excellent initial graft function and long-term graft survival have been observed with LDN kidneys. Urologic complications can be avoided. LDN has become the preferred surgical approach for living kidney donation at our center.


Subject(s)
Laparoscopy , Living Donors , Nephrectomy/methods , Adult , Cohort Studies , Female , Follow-Up Studies , Humans , Length of Stay , Male , Morbidity , Pain, Postoperative/prevention & control , Postoperative Complications/classification , Postoperative Complications/epidemiology , Time Factors
19.
Clin Transpl ; : 239-46, 2000.
Article in English | MEDLINE | ID: mdl-11512317

ABSTRACT

The collective advances made by many groups have significantly improved the results of pancreas transplantation. We have focused on the development of safe and effective immunotherapy, including a new protocol of rapid withdrawal of corticosteroids, the analysis of surgical technique of pancreas exocrine drainage on outcome and the role of SPK transplantation in patients with significant cardiovascular disease. We have found that multimodal immunotherapy including induction with tacrolimus-based maintenance combined with either MMF or sirolimus, with or without corticosteroids, resulted in excellent patient and graft survival rates with low rates of rejection. In this setting, enteric drainage was preferable to bladder drainage because of a lower rate of complications leading to hospital readmissions. Careful pretransplant screening for cardiovascular disease should be routinely performed for all SPK candidates. If successful coronary revascularization can be achieved, these patients can safely undergo SPK transplantation, with 5-year outcomes similar to those for recipients without coronary disease. Finally, we have observed that pancreas transplantation has an important ameliorating effect on hypertension that is independent of the method of pancreas exocrine drainage.


Subject(s)
Pancreas Transplantation , Adrenal Cortex Hormones/administration & dosage , Cardiovascular Diseases/complications , Chicago/epidemiology , Clinical Protocols , Drainage , Graft Survival , Hospitals, University , Humans , Hypertension/complications , Immunosuppression Therapy , Kidney Transplantation/methods , Pancreas Transplantation/methods , Pancreas Transplantation/mortality , Pancreas Transplantation/statistics & numerical data , Safety , Survival Rate
20.
Transplantation ; 67(4): 586-93, 1999 Feb 27.
Article in English | MEDLINE | ID: mdl-10071032

ABSTRACT

BACKGROUND: The current study examines the use of mycophenolate mofetil (MMF) and tacrolimus as primary immunosuppression in simultaneous pancreas-kidney (SPK) transplantation. In addition, analyses of the rates of conversion from one immunosuppressive agent to another, and its subsequent consequences with respect to outcomes were determined. Quality of graft function, infections, and effect on preexisting essential hypertension are also described. METHODS: Immunosuppression consisted of quadruple therapy with antithymocyte globulin induction, tacrolimus, MMF, and prednisone. Patient and graft survival and rejection rates in 50 consecutive SPK recipients, followed for a minimum of 3 months and a mean of 14 months (range: 3-34 months), are described. RESULTS: Thirty-nine of 50 (78%) patients tolerated the MMF/tacrolimus combination long-term (mean duration of follow-up: 14+/-7 months). Nine of 50 patients (18%) were converted to Neoral, and 4 patients were converted to azathioprine as a substitute for MMF. The 2-year actuarial patient, kidney, and pancreas survival rates were 97.7%, 93.3%, and 90.0%, respectively. At 6 months after transplant, the overall incidence of acute rejection was 16%. There was a statistically significant (P< or =0.04, Cox-Mantel test) difference in the rate of rejection associated with conversion to Neoral. The incidence of rejection 6 months after transplant in the group maintained on MMF/tacrolimus was 10.2% vs. 44.4% in the group converted to Neoral (P< or =0.04, Cox-Mantel test). Overall, the 1-year actuarial cumulative incidence of tissue-invasive cytomegalovirus disease was 6.6%. There were no cases of fungal infections or post-transplant lymphoproliferative disorders. One patient developed Kaposi's sarcoma 10 months after transplant. With respect to hypertensive disease, 60% (12/20) of the patients who required pharmacologic control of blood pressure before transplant were off all antihypertensive medications at 1 year after transplant. An additional 20% (4/20) of patients had a reduction in the number of medications required to control blood pressure at 1 year after transplant. CONCLUSIONS: We conclude that the combination of MMF and tacrolimus as primary immunosuppression for SPK transplantation results in excellent patient and graft survival rates, a very low rate of acute rejection, and low rates of infection and malignancy.


Subject(s)
Immunosuppressive Agents/therapeutic use , Kidney Transplantation , Mycophenolic Acid/analogs & derivatives , Pancreas Transplantation , Tacrolimus/therapeutic use , Adolescent , Adult , Cytomegalovirus Infections/etiology , Female , Glycated Hemoglobin/analysis , Graft Rejection , Graft Survival , Humans , Hypertension/etiology , Kidney Transplantation/adverse effects , Kidney Transplantation/mortality , Male , Middle Aged , Mycophenolic Acid/therapeutic use , Pancreas Transplantation/adverse effects , Pancreas Transplantation/mortality , Transplantation, Homologous
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