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Biomedical subjects

S C Jordan

Publications and source records attributed to S C Jordan.

At least 19 recordsLinked to original sources
PubMed1999

Antithrombin III treatment improves parameters of acute inflammation in a highly histoincompatible model of rat lung allograft rejection.

BACKGROUND: Antithrombin III (AT-III) is an antithrombotic agent with known anti-inflammatory properties that is also known to attenuate acute inflammation, prevent ischemia-reperfusion injury, and disseminated intravascular coagulation (DIC) associated with sepsis and endotoxemia. Here, we examined the ability of AT-III to modify parameters of acute inflammation in a highly histoincompatible model of rat lung allograft rejection (AR). METHODS: After left single lung transplantations (BN-->Lew), recipient animals were treated i.v. with 50 U/kg of human AT-III (low dose group), 500 U/kg of human AT-III (high dose group), or normal saline (control group) on days 2 and 4 posttransplant. All animals were sacrificed on day 6, and several pathological categories of acute inflammation related to AR were scored (0-4). The effect of AT-III on concanavalin A (Con A)-stimulated rat spleen cell proliferation was also examined. RESULTS: The stage of AR, and the degrees of edema, hemorrhage, and necrosis were significantly reduced in the high dose group compared with the control group. AT-III significantly inhibited rat spleen cell proliferation in response to Con A, in a dose-dependent manner. Maximal inhibition was seen at 15 U/ml in culture. Identical inhibition of Con-A-stimulated cultures occurred in both serum free and serum-containing media, indicating that AT-III inhibition of Con-A-stimulated rat spleen cell proliferation is independent of its actions on thrombin. CONCLUSIONS: 1) AT-III treatment significantly improves parameters of acute inflammation seen in a highly histoincompatible model of rat lung AR. 2) AT-III inhibits in vitro T cell proliferation to the potent mitogen Con A, suggesting that protease inhibition may inhibit T cell activation in vitro. 3). The beneficial effects of AT-III on parameters of lung AR relate to the anti-coagulant, anti-inflammatory, and possibly immunoregulatory actions of AT-III.

Acute Disease↗
PubMed1999

The clinical significance of antibodies to human vascular endothelial cells after cardiac transplantation.

BACKGROUND: Vascular endothelial cells are primary targets for injury during both cellular and humoral allograft rejection (AR). In cardiac transplantation, the role of humoral immunity in mediating AR has not been extensively characterized. METHODS: Antibodies against human vascular endothelial cells (AECA) were measured using a cellular ELISA developed from human umbilical vein endothelial cells in 80 consecutive patients after cardiac transplantation. The aim was to determine the incidence of AECA formation after transplantation and their association with different types of AR, graft survival, and development of cardiac allograft vasculopathy (CAV). At least eight serum samples obtained from each patient were examined for AECA and an endomyocardial biopsy was performed at regular intervals during the first year after transplantation. RESULTS: Of the 80 patients examined, 31 were AECA (+) and 49 patients were AECA (-). There were no significant differences between the AECA (+) and (-) groups when examined for age, sex, and pretransplantation ischemia time. A significant correlation was found between the presence of AECA and humoral AR (P<0.015). AECA positivity did not correlate with the presence of cellular AR or the number of rejection episodes. In addition, allograft survival at 2 years after transplantation was significantly better in the AECA (-) group compared with that in the AECA (+) group (89.8% vs. 71.0%, P<0.0004). The persistence of AECA positivity during the first year after transplantation was also associated with a significantly greater incidence of CAV when compared with the patients who were AECA (-) (25.8% vs. 14.3%, P<0.004). CONCLUSIONS: AECA may be important in the mediation of humoral AR, may decrease allograft survival, and may identify a high-risk group for CAV.

Adolescent↗
PubMed1999

Expression of gamma-IFN mRNA in bronchoalveolar lavage fluid correlates with early acute allograft rejection in lung transplant recipients.

Various cytokines are upregulated in acute allograft rejection (AR). Local production of Th-1 cytokines is suggested to play a pathogenic role in AR, and Th-2 cytokines in the development of allograft tolerance. The purpose of this study was to correlate the expression of Th-1 [interleukin-2 (IL-2) and gamma-interferon (gamma-IFN)], and Th-2 [interleukin-10 (IL-10)] cytokines in bronchoalveolar lavage (BAL) fluid with AR in lung transplant (LT) recipients. The role of Th-1 dominance expressed as IgG2/IgG1 ratio in BAL in AR was also examined. The mRNA expression for IL-2, gamma-IFN and IL-10 was examined in 64 BAL specimens from 23 LT recipients using reverse transcriptase-polymerase chain reaction (RT-PCR). IgG1 and IgG2 levels were measured in 55 BAL specimens by enzyme-linked immunosorbent assay (ELISA). The expression on mRNA for these cytokines, and the ratio of IgG2/IgG1 was correlated with AR (early AR occurring within 3 months of transplant and late AR occurring after 3 months). Ten patients had 17 episodes of biopsy proven AR. Twelve episodes of AR (6 patients) occurred within the first 3 months of transplantation. In 5 patients, AR was diagnosed 4, 5, 6, 9 and 24 months post-transplantation. Detection of gamma-IFN mRNA correlated significantly with early AR (p < 0.001), whereas it lacked correlation with late AR. Expression of IL-2 and IL-10 mRNA did not correlate with AR. IL-10 was present in most samples irrespective of the presence or absence of AR. The ratio of IgG2/IgG1 was similar in patients with or without AR. Our findings suggest that the detection of gamma-IFN mRNA in BAL by RT-PCR is useful for immune monitoring of early AR in LT recipients. Absence of elevated IgG2/IgG1 ratio, and presence of IL-10 in BAL during AR suggests that Th-1 cytokines may not be the sole mediator of rejection in LT recipients.

Acute Disease↗
PubMed1999

Th1 and Th2 cytokine mRNA profiles in childhood nephrotic syndrome: evidence for increased IL-13 mRNA expression in relapse.

Idiopathic nephrotic syndrome of childhood is thought to be associated with T lymphocyte dysfunction often triggered by viral infections, with the production of circulating factor(s) resulting in proteinuria. In view of the conflicting evidence of T cell activation and Th1 or Th2 pattern of cytokine synthesis in this disease, this study examined the mRNA expression of interleukin-2 (IL-2), interferon-gamma, IL-4, and IL-13 from CD4+ and CD8+ T cells in steroid-responsive nephrotic patients in relapse and remission. Fifty-five children with steroid-responsive nephrotic syndrome were included in this study, together with 34 normal controls and 24 patient controls with viral infections. RNA was isolated from purified CD4+ or CD8+ cells from peripheral blood and subjected to reverse transcription-PCR. Cytokine mRNA expression was measured semiquantitatively, and a cytokine index was derived from densitometric readings, with cyclophilin as the housekeeping gene. Both cross-sectional and paired data showed an increased CD4+ and CD8+ IL-13 mRNA expression in patients with nephrotic relapse as compared to remission, normal, and patient controls (P < 0.008). This was also associated with increased cytoplasmic IL-13 expression in phorbol myristate acetate/ionomycin-activated CD3+ cells (6.66+/-3.39%) from patients with nephrotic relapse compared to remission (2.59+/-1.35%) (P < 0.0001). However, there was no significant difference in CD4+ or CD8+ IL-2, interferon-gamma and IL-4 mRNA expression. IL-13 is an important T cell cytokine with anti-inflammatory and immunomodulatory functions on B cells and monocytes. It is conceivable that IL-13 may act on monocytes to produce vascular permeability factor(s) involved in the pathogenesis of proteinuria in patients with relapse nephrotic syndrome.

Adolescent↗
PubMed1998

A stable prostacyclin analog, beraprost sodium, attenuates platelet accumulation and preservation-reperfusion injury of isografts in a rat model of lung transplantation.

BACKGROUND: Recent studies have shown that the extent of platelet accumulation in the vasculature of transplanted organs correlates with the degree of preservation-reperfusion injury. In this study, we examined the effect of a stable prostacyclin analog, beraprost sodium, which possesses potent antiplatelet activity, on parameters of platelet accumulation and preservation-reperfusion injury of isografts in a rat model of lung transplantation. METHODS: The heart-lung blocks of donor rats were flushed with and preserved in modified Euro-Collins solution at 4 degrees C for 6 hr or 24 hr. The left lung was transplanted into recipient rats and reperfused for 1 hr. Lung injury was evaluated by the pulmonary blood flow ratios to the lung isografts, the weight gain of the isografts, and histological examination. Small portions of the lung isografts were excised and stained with an antibody specific for rat platelets. A scoring system was developed to semiquantitate the intensity of antibody staining (score 0-4). The recipient rats received oral administration of beraprost sodium (0.3 mg/kg) before lung transplantation. Control animals received no beraprost sodium. RESULTS: In the 6-hr preservation study, administration of beraprost sodium significantly reduced the score for platelet accumulation (1.8+/-0.4 vs. 3.3+/-0.5, P<0.01). This observation was accompanied by a significantly decreased degree of preservation-reperfusion injury as evidenced by an increased blood flow ratio (13.7+/-2.6% vs. 4.5+/-3.6%, P<0.01) and a reduced weight gain (0.7+/-0.2 g vs. 1.1+/-0.2 g, P<0.01). Histological examination revealed severe capillary congestion in three of six cases in the control group, while no capillary congestion was observed in the beraprost group. In the 24-hr preservation study, no differences were seen in platelet accumulation scores or parameters of lung injury. CONCLUSION: Beraprost sodium, an antiplatelet agent, reduces platelet accumulation and preservation-reperfusion injury of lung transplants at 6 hr in this rat isograft model.

Animals↗
PubMed1998

Posttransplant therapy using high-dose human immunoglobulin (intravenous gammaglobulin) to control acute humoral rejection in renal and cardiac allograft recipients and potential mechanism of action.

BACKGROUND: Intravenous gammaglobulin (i.v.IG) contains anti-idiotypic antibodies that are potent inhibitors of HLA-specific alloantibodies in vitro and in vivo. In addition, highly HLA-allosensitized patients awaiting transplantation can have HLA alloantibody levels reduced dramatically by i.v.IG infusions, and subsequent transplantation can be accomplished successfully with a crossmatch-negative, histoincompatible organ. METHODS: In this study, we investigated the possible use of i.v.IG to reduce donor-specific anti-HLA alloantibodies arising after transplantation and its efficacy in treating antibody-mediated allograft rejection (AR) episodes. We present data on 10 patients with severe allograft rejection, four of whom developed AR episodes associated with high levels of donor-specific anti-HLA alloantibodies. RESULTS: Most patients showed rapid improvements in AR episodes, with resolution noted within 2-5 days after i.v.IG infusions in all patients. i.v.IG treatment also rapidly reduced donor-specific anti-HLA alloantibody levels after i.v.IG infusion. All AR episodes were reversed. Freedom from recurrent rejection episodes was seen in 9 of 10 patients, some with up to 5 years of follow-up. Results of protein G column fractionation studies from two patients suggest that the potential mechanism by which i.v.IG induces in vivo suppression is a sequence of events leading from initial inhibition due to passive transfer of IgG to eventual active induction of an IgM or IgG blocking antibody in the recipient. CONCLUSION: I.v.IG appears to be an effective therapy to control posttransplant AR episodes in heart and kidney transplant recipients, including patients who have had no success with conventional therapies. Vascular rejection episodes associated with development of donor-specific cytotoxic antibodies appears to be particularly responsive to i.v.IG therapy.

Adult↗
PubMed1998

Nephronophthisis associated with Ellis-van Creveld syndrome.

Ellis-van Creveld (EvC) and Jeune's asphyxiating thoracic dystrophy (ATD) are related disorders characterized by narrow thoracic cage and short-limbed dwarfism. Some patients have overlapping features of both ATD and EvC, indicating that these syndromes may be a part of a disease spectrum. Nephronophthisis has been occasionally reported in patients with ATD, but not with EvC syndrome. We report a patient who was diagnosed with EvC syndrome at birth. He developed hypertension at 5 months of age and gradually progressive renal failure, requiring renal transplantation at 8 years. Histopathological findings in the nephrectomy specimen were indicative of nephronophthisis. The association of nephronophthisis in a patient with EvC syndrome has not been reported previously. This association further supports the hypothesis that ATD and EvC syndromes are related and represent a spectrum of disorders.

Ellis-Van Creveld Syndrome↗
PubMed1998

Pre-transplant donor-specific transfusions induce allograft rejection and IL-2 gene expression in the WKY-->F344 functional tolerance model of rat lung transplantation.

Our previous studies have shown that a spontaneous functional tolerance develops in a rat model of lung transplantation (WKY-->F344). The tolerance observed in this model may be due to the minor histocompatible differences in this combination, however, the possibility of a tolerogenic effect related specifically to the lung allograft must be considered. To further examine this model, the effect of pre-transplant donor-specific spleen cell transfusions (DSTs) was examined on the functional tolerance state seen in this model. F344 rats received WKY spleen cells on days -45 and -30 before lung transplantations. Control F344 rats received lung transplants without DSTs. Recipients in both groups were killed on day 7, 14, 21 and 49 post-transplant, and allograft rejection (AR) was graded histologically (stage 0-IV). Intragraft cytokine gene transcripts were examined on day 7 and 14 post-transplant using reverse transcriptase-polymerase chain reaction (RT-PCR) techniques to investigate the underlying immunological events occurring in each group. In addition, allogeneic (WKY) and third party (BN) skin grafts were placed on lung recipients at day 35 post-transplant to evaluate the development of systemic tolerance. It was seen that control animals showed moderate to severe lymphocytic infiltrations (stage II-III AR) in the first 3 weeks followed by spontaneous recovery with stage I-II AR on day 49. In marked contrast, DST-treated animals showed more aggressive AR with severe lymphocytic infiltration and haemorrhagic infarction (stage III-IV AR) by day 14-21, without any evidence of recovery on day 49. WKY skin grafts showed prolonged survival in control animals, but were promptly rejected in DST-treated animals. Intragraft cytokine gene expression in control animals was characterized by no or weak expression of IL-2 and high IL-10, while DST-treated animals showed high levels of IL-2 transcripts. IL-2:IL-10 and IL-2:IL-4 ratios were significantly increased in DST-treated animals compared with controls on day 7 post-transplant. It was concluded that pre-transplant DSTs did not enhance allograft survival, but actually induced AR and ablated any immunological benefit of the lung allograft on induction of tolerance in the WKY-->F344 lung transplant model. It was found that the DST-induced AR was associated with a deviation of cytokine immune responses from a predominant Th2 to Th1 profile characterized by increased IL-2 gene expression in the allografts. We also conclude that factors other than the degree of histocompatibility matching, such as the route and timing of alloantigen exposure, and the amount or nature of alloantigens associated specifically with lung allografts, are involved in deviating native immune responses toward acceptance or rejection of lung allografts in this model of lung transplantation.

Animals↗
PubMed1998

Immunomodulatory actions of intravenous immunoglobulin (IVIG): potential applications in solid organ transplant recipients.

Intravenous gammaglobulin (IVIG) products are known to have powerful immunomodulatory and anti-inflammatory functions in vitro and in vivo. In addition, IVIG has shown benefit in the treatment of many human autoimmune and inflammatory disorders. One potential mechanism of action responsible for these beneficial effects is the down-regulation of deleterious autoantibody titers through idiotypic-anti-idiotypic networks. Until recently, few data were available on the use of IVIG in the management of alloimmune disorders. In this review, we will discuss current data on the use of pooled human gammaglobulin as an agent with potential to regulate undesirable alloimmune responses and allosensitization through similar idiotypic-anti-idiotypic circuits and how this therapy could be of benefit in the management of highly sensitized patients both pre- and post-transplant. We will also discuss other potential anti-inflammatory and immunoregulatory mechanisms induced by IVIG treatment and how these may be applied to improve transplantability and outcomes in human transplantation.

Adjuvants, Immunologic↗
PubMed1997

Parvovirus B19 infection-related complications in renal transplant recipients: treatment with intravenous immunoglobulin.

BACKGROUND: Chronic red cell aplasia can develop in immunocompromised patients including transplant recipients infected with parvovirus B19 (PV B19). Renal involvement with PV B19 infection is not well-recognized. METHODS: We diagnosed erythroid hypoplasia associated with PV B19 infection in three renal transplant recipients; one of them developed de novo collapsing glomerulopathy. These patients were treated with intravenous immunoglobulin (IVIG). RESULTS: In two patients, anemia responded promptly to IVIG therapy. One of them had recurrence of anemia that responded to a second course of IVIG. Despite IVIG treatment, persistent infection with PV B19, recurrent anemia, and de novo collapsing glomerulopathy leading to allograft failure developed in the third patient, who had received the most intense immunosuppression. CONCLUSIONS: These findings indicate that PV B19 infection in transplant recipients can cause chronic red cell aplasia that generally responds to IVIG therapy. In some patients, particularly those who are heavily immunosuppressed, infection may persist despite treatment. As the cellular receptor for PV B19 is expressed in the kidney, persistent infection may result in development of glomerulopathies in these patients.

Adult↗
PubMed1997

Long-term allograft acceptance in a patient with posttransplant lymphoproliferative disorder: correlation with intragraft viral interleukin-10.

BACKGROUND: Viral (v) interleukin (IL)-10 is expressed by Epstein-Barr virus (EBV) and has pro- and anti-inflammatory actions similar to human IL-10. EBV is also a known factor in the development of posttransplant lymphoproliferative disorder (PTLPD) in allograft recipients. We observed a patient with widespread PTLPD 9 months after renal transplantation, who subsequently maintained renal function despite minimal immunosuppression, and we investigated a possible link between these factors. METHODS: The patient's chart was reviewed for relevant history. EBV DNA in blood and tissues was assessed by polymerase chain reaction. Human and vIL-10 and gamma-interferon mRNA were evaluated with reverse transcription-polymerase chain reaction using nested primers. RESULTS: After the diagnosis of PTLPD, the patient was maintained on prednisone (8 mg/day) as the only immunosuppression with preserved renal function for 17 months until death as a result of pulmonary failure. She had continuously high blood levels of EBV DNA, although only mild persistent intrarenal atypical lymphocytic infiltrates. Human IL-10 mRNA was never present; in contrast, intragraft vIL-10 mRNA was identified and associated with resolution of an intervening episode of severe acute transplant rejection. CONCLUSIONS: We suggest that the preserved renal function resulted from the anti-inflammatory actions of vIL-10 inhibiting acute rejection in the renal allograft.

Adult↗
PubMed1997

Ureteritis and cholecystitis: two unusual manifestations of cytomegalovirus disease in renal transplant recipients.

BACKGROUND: Common clinical manifestations of cytomegalovirus (CMV) infection include flu-like symptoms with fever, diarrhea, leukopenia, and elevated liver enzymes. Diagnosis is made by detection of the virus by buffy-coat blood culture or by polymerase chain reaction (PCR) analysis. METHODS: Here we describe two renal transplant recipients who presented with unusual manifestations of CMV disease (cholecystitis and ureteritis). In both patients, no symptoms or signs of systemic CMV infection were present, and they were thought to have other common causes for cholecystitis and ureteral obstruction. RESULTS: Retrospective analysis of peripheral blood by PCR analysis was positive for CMV DNA. Histologic examination of the resected gall bladder and stenotic ureteric segment showed CMV inclusions, confirmed subsequently by in situ hybridization. Thus, we report that CMV infection may present with acute cholecystitis or ureteral obstruction without its classical clinical symptoms. CONCLUSIONS: Because CMV infection is common in transplant patients, the atypical manifestations of CMV should be considered in the differential diagnosis of posttransplant complications. Detection of CMV DNA in the peripheral blood by PCR analysis may help identify these patients.

Adult↗
PubMed1997

Accumulation of platelets in rat syngeneic lung transplants: a potential factor responsible for preservation-reperfusion injury.

BACKGROUND: Platelets are known to play an important role in the pathogenesis of adult respiratory distress syndrome as well as preservation-reperfusion injury of liver allografts. However, the role of platelets in pulmonary preservation-reperfusion injury is unknown. In this study, we examined whether the extent of platelet accumulation in the preserved and subsequently reperfused lungs correlated with the degree of preservation-reperfusion injury in a rat lung isotransplant model. METHODS: Heart-lung blocks from donor rats were flushed with and preserved in modified Euro-Collins solution at 4 degrees C for 0 hr (n=5), 6 hr (n=6), and 24 hr (n=6). The left lung was divided from the heart-lung block, transplanted into the recipient rat, and reperfused for 1 hr. Lung injury was evaluated by the left-to-right pulmonary blood flow ratio, the weight gain of the isograft, and the scores for histological categories of lung injury (intra-alveolar edema, intra-alveolar hemorrhage, and capillary congestion). Small portions of the lung isograft were excised and stained with an antibody specific for rat platelets. A scoring system was developed to semiquantitate the intensity of antibody staining in isografts. RESULTS: Lung isografts were injured and platelets accumulated in the capillaries in proportion to the length of preservation endured before transplantation. The extent of platelet accumulation evaluated by our morphological scoring system correlated significantly with the degree of lung injury assessed by the blood flow ratio (P<0.001), the weight gain (P<0.001), and the histological scores for intra-alveolar hemorrhage (P<0.05) and for capillary congestion (P<0.001). CONCLUSIONS: The results of this study suggest that platelet accumulation is a potential factor responsible for preservation-reperfusion injury of lung isografts in the rat.

Animals↗
PubMed1997

Correlation of cytomegalovirus DNA levels with response to antiviral therapy in cardiac and renal allograft recipients.

BACKGROUND: Cytomegalovirus (CMV) infection represents a significant morbidity factor for transplant recipients. A rapid, sensitive, specific, and reliable test is desirable for early detection of CMV infection and for monitoring the efficacy of antiviral therapy. METHODS: We examined the incidence of CMV infection in 95 cardiac and 25 renal allograft recipients followed for up to 3 years using qualitative and quantitative polymerase chain reaction (PCR) techniques. Results were subsequently correlated with clinical findings. Of the 236 samples analyzed by the CMV PCR, 84 and 20 were also analyzed by blood buffy coat culture and anti-CMV antibody IgM assays, respectively. RESULTS: The sensitivity of the CMV PCR was found to be superior to that of the other assays, although the specificity of the blood buffy coat culture is as good as that of the CMV PCR, which is higher than that of the anti-CMV antibody IgM assay. CMV infection was detected by the CMV PCR in 17 of 95 cardiac and 9 of 25 renal transplant recipients. Clinical symptoms were observed when > or =500 copies of CMV DNA/1 microg of total DNA were detected by a quantitative CMV PCR assay using an external control CMV plasmid; however, some patients had symptoms when 50-100 copies were present. The levels of CMV DNA detected varied (50-1000 copies) in patients who developed asymptomatic CMV infection. The CMV DNA levels decreased to 50-100 copies 1-2 weeks after antiviral therapy was initiated and correlated well with disappearance of clinical symptoms. CMV DNA levels decreased to < or =5 copies at 4-7 weeks after treatment. This contrasts with patients who were unresponsive to anti-CMV therapy, in whom high levels of CMV DNA (> or =500 copies) persisted for at least 5 weeks and significant levels of CMV DNA (50-100 copies) were detected for several months afterward, despite multiple courses of anti-CMV therapy. Clinical symptoms also did not disappear during this period of observation. CONCLUSIONS: (1) The CMV PCR represents a rapid, sensitive, specific, reliable test for detection of CMV infection, especially for detection of virus replication in an incipient phase. (2) The quantitative CMV PCR is useful for monitoring the efficacy of antiviral therapy to distinguish patients who respond to therapy from those who do not. (3) CMV DNA levels > or =500 copies/1 microg of total DNA analyzed by the quantitative CMV PCR can be used to differentiate CMV infection from other infections and rejection.

Cytomegalovirus↗
PubMed1997

Selective expression of the interleukin-2 gene discriminates between the auto- and allo-mixed lymphocyte reaction.

The in vitro mixed lymphocyte reaction (MLR) is a useful model to study alloresponsiveness to histocompatibility antigens. Secretion of different cytokine proteins in the supernatant of allo-MLR cultures has been reported in a few studies with no reference to results in auto-MLR. Since most cytokines are autocrine factors, their levels in the supernatant may not reflect the actual intracellular production. Therefore, we studied cytokine gene expression in auto- and allo-MLR by Northern dot blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. mRNA for IL-beta and IL-8 was detected in both auto- and allo-MLR by Northern dot blotting. mRNA for IL-2, gamma-IFN, TNF-alpha, IL-4, IL-10 and IL-2 receptor (IL-2R) was not found by Northern dot blotting and could only be detected by RT-PCR. Expression of mRNA for IL-4, IL-10, TNF-alpha, gamma-IFN and IL-2R by RT-PCR analysis was seen in both auto- and allo-MLR. There was slightly increased expression of gamma-IFN, IL-2R and TNF-alpha in allo-MLR in comparison to auto-MLR. However, IL-2 was exclusively expressed in allo-MLR and was detected as early as 5 h of initiation of culture. These results indicate that mRNA expression for a number of cytokines can be seen in both auto- and allo-MLR using RT-PCR analysis. However, the consistent expression of IL-2 in the allo-MLR indicates that it is an important cytokine which discriminates an allo- from an autoresponse. These findings suggest that detection of IL-2 gene expression by RT-PCR may be useful for immune monitoring of allograft rejection.

Blotting, Northern↗
PubMed1997

Cytomegalovirus infection induces anti-endothelial cell antibodies in cardiac and renal allograft recipients.

Cytomegalovirus (CMV) infection represents a significant morbidity factor for transplant recipients. CMV infection has an association with the development of allograft rejection (AR) through graft endothelial cell (EC) damage, but the mechanisms are not yet clear. There are few reports addressing the role of humoral immunity in vascular EC injury mediated by CMV infection whereas many reports are available regarding the mechanism(s) of CMV-associated allograft EC injury mediated by cellular immunity. Here we examine the incidence of CMV infection in 40 cardiac and 25 renal allograft recipients using polymerase chain reaction (PCR) techniques. We also monitored sera for the development of anti-EC antibodies (AECA) using an ELISA with human umbilical vein ECs as targets, and IL-2 levels using an ELISA. AECA levels (immunoglobulin-G and immunoglobulin-M) were significantly elevated in allograft recipients who demonstrated CMV-PCR positivity when compared with the CMV-PCR negative group (IgG: 23.1 +/- 16.4 vs 4.7 +/- 4.5, p < 0.0001; IgM: 47.0 +/- 53.6 vs 7.0 +/- 11.2, p < 0.0001). Serum AECA (IgG and IgM) levels increased one to four weeks after CMV DNA was detected and elevated AECA levels persisted for at least one to two months, and sometimes for several months. Elevated AECA levels correlated well with serum IL-2 levels. These results suggest that CMV infection is associated with an increased humoral immune response to EC antigens, which may be a risk factor for vascular rejection, chronic rejection and decreased allograft survival.

Autoantibodies↗
PubMed1996

Induction of specific tolerance through mixed hematopoietic chimerism prevents chronic renal allograft rejection in a rat model.

BACKGROUND: Chronic rejection is the leading cause of late graft loss in kidney transplantation. We tested the ability of mixed hematopoietic chimerism to prevent chronic renal allograft rejection in an established rat model and described possible mechanisms responsible for this tolerance. METHODS: Mixed hematopoietic chimerism was established in lethally irradiated F-344 rats by reconstitution with Lewis bone marrow. Four groups (n = 5 each) received orthotopic kidney transplants: (1) allograft controls, (2) isograft controls, (3) experimental chimeras, and (4) specificity control. After 120 days kidney grafts were examined histologically, immunohistochemically, and for cytokine interferon-gamma, interleukin-2 (IL-2), IL-4, and IL-10 gene transcripts by means of reverse transcriptase polymerase chain reaction techniques. RESULTS: Allograft control group exhibited severe parenchymal fibrosis; isograft control and chimera groups failed to develop this lesion. Immunohistochemical analysis revealed increased CD8+ lymphocytes and ED-1+ monocyte-macrophages infiltrating the tubulointerstitium of control allografts. Interferon-gamma and IL-2 were absent in isografts. IL-4 was absent and IL-10 was positive in all grafts. Chimeras promptly rejected third-party allografts. CONCLUSIONS: Induction of specific tolerance through mixed hematopoietic chimerism prevents chronic renal allograft rejection. These results support the hypothesis of an immunologic basis of chronic rejection and advance previous observations that the induction of specific tolerance enables long-term solid organ transplantation without the use of immunosuppression.

Animals↗