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S M Krams

Publications and source records attributed to S M Krams.

At least 37 records · Page 2Linked to original sources
PubMed1996

Elevations in IFN-gamma, IL-5, and IL-10 in patients with the autoimmune disease primary biliary cirrhosis: association with autoantibodies and soluble CD30.

Antimitochondrial antibodies (AMA) which recognize the E2 component of the pyruvate dehydrogenase complex are found in virtually all patients with the autoimmune liver disease primary biliary cirrhosis (PBC). The factors that contribute to elevated AMA and the relationship of the autoantibodies to disease pathogenesis have not been elucidated. Since cytokines are important regulators of antibody production and isotype switching, the association of specific cytokines to antibody production was examined in patients with PBC. Elevations in IL-2, IFN-gamma, IL-4, IL-5, and IL-10 were detected in serum from patients with PBC. However, only IFN-gamma (6012 +/- 1128 pg/ml vs 147 +/- 89 pg/ml, P < 0.0001) and IL-5 (382 +/- 103 pg/ml vs 29 +/- 12 pg/ml, P < 0.001) were significantly elevated compared to normal controls. Moreover, there was a positive correlation in the levels of IFN-gamma, and to a lesser extent IL-5, with the levels of soluble CD30 (sCD30) in the circulation. The elevated levels of sCD30 detected in patients with PBC (194 +/- 29 U/ml vs 39 +/- 9 U/ml in normal controls) suggest that CD30+ cells may produce cytokines, which contribute to the immune abnormalities in patients with PBC.

Autoantibodies↗
PubMed1995

Expression of cytokines and immune mediators during chronic liver allograft rejection.

To determine the immune processes involved in chronic liver allograft rejection (CR) we examined in situ cytokine production in tissue from 15 patients with both clinical and histopathological diagnoses of CR. Total RNA was isolated from liver samples, reverse-transcribed and analyzed by RT-PCR for the production of proinflammatory cytokines and immunoregulatory mediators. Transcripts for the Th1-like cytokines IL-2 and IFN-gamma were detected in 53.3% and 46.7% of CR grafts, while they were detected in only 16% and 0% of stable grafts, respectively. The cytotoxic T cell mediator granzyme B was expressed in the majority of liver grafts undergoing CR, but was expressed only in a minority of stable grafts (80% vs. 16%, P < 0.05). The T cell product IL-5 was also significantly upregulated in CR as compared with stable livers (80% vs. 16%, P < 0.01). Other Th2 cytokines--IL-4 and IL-10--and macrophage products--IL-1 beta, IL-6, IL-8, TGF-beta, and TNF-alpha--were not substantially upregulated in CR grafts as compared with stable grafts. PDGF-beta transcripts were detected in the majority of the CR grafts, but were not detected in stable liver grafts (73% vs. 0, P < 0.05). By immunohistochemical staining, we observed that CD3+CD4+, and CD3+CD4- T cells were detected in CR grafts along with CD20+ B cells and CD68+ macrophages. There was, however, a predominant infiltration of CD3+CD4+ lymphocytes. Taken together, these data suggest that infiltrating cells produce proinflammatory and immunoregulatory cytokines that have a role in mediating graft damage in CR.

Adolescent↗
PubMed1995

An increased incidence of Epstein-Barr virus infection and lymphoproliferative disorder in young children on FK506 after liver transplantation.

The incidence of Epstein-Barr virus (EBV) infection and lymphoproliferative disorder (LPD) was determined in a pediatric liver transplant population consisting of 51 children treated with FK506 and 91 treated with cyclosporine. The incidence of symptomatic EBV infection was 21.9% (23 of 105 cases) in children < 5 yr old and 10.8% (4 of 37 cases) in children 5 to 17 yr old as compared with 2.7% (9 of 323 cases) in adults (P < 0.0001). In the under 5 yr old group on cyclosporine, the incidences of EBV infection and LPD were 9 of 68 (13.2%) and 2 of 68 children, (2.9%), respectively. In contrast, in children under 5 yr old group on FK506, the incidences of EBV infection and LPD in the FK506 group were 14 of 37 (37.8%) and 7 of 37 children (18.9%), respectively. The difference between these two groups was statistically significant (P < 0.02). There were no cases of LPD in the 5-17 yr-old children on either cyclosporine (n = 23) or FK506 (n = 14). The incidence of EBV infections in the 5 to 17 yr age group, 17.4% on cyclosporine and 0% on FK506, was less than for the younger children on FK506 (37.8%). A total of 39% (9 of 23) of children under 5 yr old who had symptomatic EBV infections developed LPD, and 44% (4 of 9) with LPD died. The higher incidence of EBV infections and LPD in the younger children treated with FK506 was probably related to a greater intensity of immunosuppression for patients on FK506 than those on cyclosporine.

Adolescent↗
PubMed1995

Differential patterns of circulating intercellular adhesion molecule-1 (cICAM-1) and vascular cell adhesion molecule-1 (cVCAM-1) during liver allograft rejection.

During allograft rejection, adhesion molecules play an integral role in infiltration, activation, and binding of effector cells to target tissue. Some adhesion molecules, including ICAM-1 and VCAM-1, exist in soluble, circulating forms that retain ligand-binding activity. In the present study the levels of circulating ICAM-1 (cICAM-1) and VCAM-1 (cVCAM-1) were compared in the serum and bile of pediatric liver recipients. The cICAM-1 was significantly elevated in the serum during allograft rejection and infection relative to periods when no rejection was apparent. Biliary cICAM-1, however, was specifically elevated during rejection and not during infection or when no rejection was apparent. The cVCAM-1 levels were elevated in the serum during rejection compared with levels when no rejection was evident. In contrast, cVCAM-1 was not detected in the bile. Serum levels of both cICAM-1 and cVCAM-1 decreased rapidly following successful treatment for rejection, whereas elevated levels persisted, or increased, in ongoing rejection. The differential patterns of the circulating forms of ICAM-1 and cVCAM-1 were consistent with the membrane expression of these molecules during graft rejection. ICAM-1 expression was extensive on bile duct epithelium, endothelium, hepatocytes, and infiltrating leukocytes during rejection, while VCAM-1 was restricted to endothelium. These findings indicate that the release of circulating adhesion molecules is a prominent feature of liver allograft rejection. Measurement of these markers may be useful in distinguishing rejection from infection and in determining the efficacy of treatment for rejection.

Adolescent↗
PubMed1995

Viral and immunologic aspects of Epstein-Barr virus infection in pediatric liver transplant recipients.

Pediatric allograft recipients in particular are at increased risk for Epstein-Barr virus (EBV)-associated disorders. Early identification and diagnosis of EBV-associated disorders is critical, since disease progression can often be halted by reduction of immunosuppression. In this study we examined viral and immunologic parameters of EBV infection in the circulation of pediatric liver recipients to identify factors associated with disease. Peripheral blood DNA from pediatric liver recipients was analyzed by PCR for the EBV genes coding for the nuclear antigen 1 (EBNA-1) and the viral capsid antigen gp220. Sequences for these viral genes could be readily detected in the circulation of 36.5% of patients. Moreover, identification of the EBV genome was associated with symptomatic infection, suggesting that circulating EBV may be a useful marker of disease. Since EBV-infected B cells release the low-affinity IgE receptor (sCD23), we measured sCD23 in the circulation of pediatric liver recipients and found it to be elevated in patients with detectable virus or symptoms of infection. However, sCD23 was also elevated in cases where no EBV was detectable, suggesting that factors other than viral infection could stimulate release of sCD23. To further characterize the immune response to EBV infection, the peripheral levels of IL-4, IL-5, IL-10, and IFN-gamma were determined in pediatric liver recipients. Each of these cytokines was elevated in patients with symptoms or circulating virus compared with stable, age-matched liver recipients. IL-4, in particular, was significantly increased, indicating an important role for this cytokine in EBV infection. Together, these findings suggest that (1) monitoring circulating levels of EBV may be useful in patients at high risk and (2) cytokines that promote B cell growth and differentiation contribute to EBV-associated disorders.

Adolescent↗
PubMed1995

Apoptosis as a mechanism of cell death in liver allograft rejection.

It is generally recognized that there are two mechanisms of cell death, apoptosis and necrosis. Apoptosis--programmed cell death--is involved in numerous states of physiological cell deletion. Recent studies have demonstrated that hepatocytes, under certain conditions, undergo apoptosis. The purpose of this work was to determine if apoptotic cell death is involved in liver allograft rejection. Groups of Lewis (RT1l) rats underwent orthotopic liver transplantation (OLT) from disparate DA (RT1a) or syngeneic Lewis rats. Liver samples were harvested at 1, 2, 3, 4, and 7 days posttransplant and analyzed for apoptotic cell death. Since the characteristics of apoptosis are difficult to discern using routine hematoxylin and eosin staining, we utilized a novel method that detects the classic indicator of apoptosis, nonrandom DNA degradation. Paraffin-embedded tissue sections were end-labeled with nonradioactive dUTP and detection of apoptotic bodies accomplished by immunoassay. The incidence of apoptotic cells increased steadily over time in allografts, in contrast to syngeneic grafts. In this study apoptotic cell death paralleled standard indicators of liver allograft rejection including pathology, mononuclear cell infiltration, and increases in liver enzymes. Moreover, increased expression of TGF-beta 1 correlated with apoptosis in liver allografts, supporting the previously described role for this cytokine in hepatocyte apoptosis. Our results demonstrate, for the first time, that apoptosis may be a mechanism of cell death in liver allograft rejection.

Animals↗
PubMed1995

Heterogeneity of autoreactive T cell clones specific for the E2 component of the pyruvate dehydrogenase complex in primary biliary cirrhosis.

The extraordinary specificity of bile duct destruction in primary biliary cirrhosis (PBC) and the presence of T cell infiltrates in the portal tracts have suggested that biliary epithelial cells are the targets of an autoimmune response. The immunodominant antimitochondrial response in patients with PBC is directed against the E2 component of pyruvate dehydrogenase (PDC-E2). Hitherto, there have only been limited reports on the characterization and V beta usage of PDC-E2-specific cloned T cell lines. In this study, we examined peripheral blood mononuclear cells (PBMC) for their reactivity to the entire PDC complex as well as to the E1- and E2-specific components. We also examined the phenotype, lymphokine profile, and V beta usage of PDC-specific T cell clones isolated from cellular infiltrates from the livers of PBC patients. We report that PBMC from 16/19 patients with PBC, but not 12 control patients, respond to the PDC-E2 subunit. Interestingly, this response was directed to the inner and/or the outer lipoyl domains, despite the serologic observation that the autoantibody response is directed predominantly to the inner lipoyl domain. Additionally, lymphokine analysis of interleukin (IL) 2/IL-4/interferon gamma production from individual liver-derived autoantigen-specific T cell clones suggests that both T helper cell Th1- and Th2-like clones are present in the liver. Moreover, there was considerable heterogeneity in the T cell receptor for antigen (TCR) V beta usage of these antigen-specific autoreactive T cell clones. This is in contrast to murine studies in which animals are induced to develop autoimmunity by specific immunization and have an extremely limited T cell V beta repertoire. Thus, our data suggest that in human organ-specific autoimmune diseases, such as PBC, the TCR V beta repertoire is heterogenous.

Adult↗
PubMed1995

Acute liver allograft rejection in the rat. An analysis of the immune response.

Liver allografts are vigorously rejected in 9-12 days in Lewis recipients of fully histoincompatible DA livers. The purpose of this study was to examine the initial events in this cascade, specifically the role of CD4+ T helper cells. Lewis recipients of DA or Lewis livers were killed at days 1, 2, 3, 4, and 7 days after transplant. Indicators of acute liver rejection, including a marked inflammatory infiltrate and decreased liver function, progressed in untreated recipients of allografts. Splenocytes taken from allogeneic recipients on days 1-4 and 7 proliferated in response to donor and third-party stimulators, whereas graft-infiltrating cells did not respond to donor and third-party antigens until day 3 after transplant, but thereafter maintained a good response. To further characterize the host T helper cell response to liver allografts, cytokine expression was analyzed in graft tissue and in the periphery. IL-4 mRNA was present in both syngeneic and allogeneic liver grafts, while message for IL-10 was present early in all liver grafts but persisted only in allografts. In contrast, IL-2 and IFN-gamma transcripts were specific to rejecting allografts. Similar patterns of cytokine expression were observed in the spleen, indicating the immune response to the graft involves the peripheral lymphoid organs. Thus, the cytokine profile detected during liver allograft rejection is extremely similar to that observed in other experimental models of transplantation.

Acute Disease↗
PubMed1995

Elevated biliary interleukin 5 as an indicator of liver allograft rejection.

Interleukin 5 (IL-5) is a T cell-derived cytokine that acts as a potent and specific eosinophil differentiation factor in humans. During liver allograft rejection, intragraft IL-5 mRNA and eosinophilia have been observed. The objective of this study was to correlate the levels of IL-5 in bile and serum with eosinophilia and allograft rejection in paediatric liver recipients. IL-5 levels were determined by ELISA (enzyme-linked immunosorbent assay) in bile (n = 85) and serum (n = 106) and obtained prospectively from 15 patients during the first 3 weeks post-transplantation. Biliary and serum IL-5 levels were significantly elevated during allograft rejection compared to IL-5 levels when no rejection was apparent or during infectious complications. The highest IL-5 levels were measured in the bile during the early rejection period (3 days prior to biopsy-proven rejection). Fifteen of 16 rejection episodes were marked by increases in IL-5 as revealed by analysis of sequential samples from individual patients. In all patients with rejection, elevations in serum IL-5 were associated with elevations in peripheral eosinophil counts. These results indicate that IL-5 is produced in the liver and may be a useful and specific marker of allograft rejection. Furthermore, these findings provide further evidence for a pathway of liver allograft rejection mediated by IL-5 activated eosinophils.

Adolescent↗
PubMed1995

Expression of the cytotoxic T cell mediator granzyme B during liver allograft rejection.

Cytotoxic T lymphocytes (CTL) constitute a major component of the alloreactive response following organ transplantation. The molecular mechanisms of CTL killing remain to be determined but multiple candidate molecules involved in CTL-mediated cytotoxicity have been identified. Granzyme B, a serine protease, participates in perforin-dependent pathways of cytotoxicity and is necessary for induction of DNA fragmentation in target cells. In this study the expression of granzyme B in liver biopsies obtained from liver allograft recipients was determined by semiquantitative reverse transcriptase polymerase chain reaction. Biopsies were classified into four groups--no evidence of rejection, preservation injury, acute rejection, or resolving rejection--according to histopathological criteria. There was a significantly higher frequency of transcripts for granzyme B in the acute rejection group (82.8%) compared to the no rejection (20.0%), resolving rejection (12.5%) and preservation injury (0%) groups. Analysis of granzyme B gene expression in sequential samples from individual patients prior to, and after, treatment for rejection revealed an inverse correlation between granzyme B mRNA and response to treatment. These findings indicate that the cytopathic mediator granzyme B may participate in CTL-mediated cytotoxicity during liver allograft rejection.

Base Sequence↗
PubMed1995

Cytokine patterns and cytotoxic mediators in primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is an autoimmune disease of the liver with unknown etiology. Autoreactive T lymphocytes that infiltrate the liver may play a major role in the bile duct damage that accompanies the disease. We hypothesized that cytokines produced by T lymphocytes and other cells are central to the disease process. Therefore, we used reverse transcription-polymerase chain reaction (PCR) and Southern hybridization to identify cytokine message directly from liver tissue of 11 patients with PBC and 5 patients with autoimmune hepatitis (AI-CAH). Messenger RNA (mRNA) for interleukin (IL)-2, IL-5, IL-6, interferon gamma (IFN-gamma), and transforming growth factor beta (TGF-beta) were detected in the majority of the specimens from patients with PBC. The presence of IL-5 was associated with PBC (P < .001, PBC vs. AI-CAH). Because IL-5 is a potent eosinophil differentiation factor, we looked for evidence of activated eosinophils within the infiltrate. We observed the deposition of the primary cytotoxic granule protein of eosinophils, major basic protein (MBP), within the portal region of livers from patients with PBC. Moreover, we detected message for a cytotoxic T-lymphocyte (CTL) granzyme in 87.5% of these livers indicating that mature CTL are present. Thus, we present evidence for two effector pathways that may contribute to the tissue damage observed in PBC and have identified message for cytokines that may regulate these pathways.

Base Sequence↗