PubMed Health⌕ Search

Biomedical subjects

M Suthanthiran

Publications and source records attributed to M Suthanthiran.

At least 127 records · Page 7Linked to original sources
PubMed1982

Enhanced kidney graft survival with retroplacental source gamma-globulin. Results of a 5-year prospective study at a single center.

We examined the possibility that retroplacental source gamma-globulin (RPGG), with its content of anti-HLA antibodies, would improve cadaver kidney graft survival rates. In a 5-year controlled prospective study of 208 transplants, we found that the addition of RPGG to a standard immunosuppressive drug regimen (azathioprine and prednisone) resulted in significant improvement of the cumulative survival rate (CSR) of first and second grafts. At 2 years, the overall CSR of first grafts increased from a control value of 37% +/- 6 to 52% +/- 6 (P = 0.037). Among second graft recipients, the CSR increased from a value of 19% +/- 8 to 50% +/- 10 (P = 0.014). This improvement in graft survival was seen as early as 3 months after surgery and was sustained through 3 years without added recipient morbidity or mortality. When recipient populations were stratified for various factors, those groupings remonstrative of an intact or active humoral immune response capacity were found to have the highest survival rates in the study; 2-year graft CSRs of 70% +/- 6 and 65% +/- 10 were found in recipients with preformed antibody resulting from blood transfusions (P - 0.003) and cytomegalovirus infectivity (P = 0.0006), respectively. These findings indicate that the improved graft survival seen in this study may have resulted from a recipient's immunological response to challenge with RPGG.

ABO Blood-Group System↗
PubMed1982

Abrogation of proliferation and generation of cytotoxic T cells in human mixed lymphocyte culture reactions by modification of the cell surface with mitogenic oxidizing agents.

Multiple lectins with specificity for cell surface glyco-proteins inhibit cellular and humoral immune responses and induce transplantation tolerance. Because cell surface glycoproteins play a significant role in various immune events involving cell to cell interactions and because the mixed lymphocyte culture (MLC) reaction is a prototype of immune phenomenon involving cell to cell interactions as well as an in vitro analogue of graft-destructive immune events, the effect of modification of the cell surface with oxidizing mitogens was investigated. Treatment of responder or stimulator cells with neuraminidase and galactose oxidase (NAGO) or with sodium periodate (IO-4) resulted in marked suppression of alloantigen-induced proliferation and in vitro generation of primary cytotoxic T cells (CTLs) in human MLCs. A prominent coupling of mitogen-induced proliferation to abrogation of MLC was consistently observed with modification of stimulator or responder cell surface with either NAGO or IO-4. The possibility that destruction of receptor sites and/or stimulatory units was responsible for the suppression of MLCs was excluded by restoring both proliferation and generation of primary CTLs by reduction of mitogen-oxidized cell surfaces with sodium borohydride. The ability of polyclonal activators to inhibit antigen-specific responses might be useful in abrogating unfavorable alloimmune responses.

Adult↗
PubMed1981

Declining transplantability of prospective kidney transplant recipients.

The total number of cadaveric kidney transplants has been declining, despite an increasing dialysis population, greater understanding of transplant immunology, and improved transplant management. To explore the causes of this decline, various factors were studied in 140 dialysis patients who were awaiting transplantation and 100 consecutive recipients of cadaveric kidney transplants. The study indicates that there is a growing, now predominant, prospective kidney recipient population that is highly sensitized because of previous blood transfusions and kidney transplantations. As a result, 92% of the prospective recipients exhibit varying degrees of lymphocytotoxic antibodies. Thus, a major problem in clinical transplantation is the growing number of dialysis patients who are virtually untransplantable. The declining number of cadaveric kidney transplantations may be caused by, in part, changing immunologic characteristics in the recipient population.

Antilymphocyte Serum↗
PubMed1980

Immunological properties of subcellular rat lymphocyte preparations. Primary allogeneic stimulation in vitro by fractions containing Ia (RT1-B), but not RT1-A antigens.

Rat thymocyte membrane fractions have been prepared which exhibit strain-specific primary mixed-lymphocyte reaction (MLR)-stimulating and Ia (RT1-B) antigenic properties. These preparations lack the antigenicity of classical, serologically-defined RT1-A (Ag-B) antigens, as defined by in vitro serologic assays. Furthermore, after immunization of allogeneic hosts, specific anti-Ia and MLR-blocking antibodies, but not anti-AgB, alloantibodies are elaborated. Thymidine suicide experiments show that the same clones respond to whole cells and the fragments made from those cells, and the response segregates appropriately in F2 progeny as a major histocompatibility complex (RT1)-linked phenomenon. Hence, it is possible to generate Ia-related allogeneic helper signals in primary, as well as secondary, in vitro responses, using subcellular membrane fragments that have restricted expression of RT1-B-, but not RT1-A-, encoded antigens.

Animals↗
PubMed1980

Generation of a lymphocyte growth factor by treatment of human cells with neuraminidase and galactose oxidase.

Supernates of neuraminidase and galactose oxidase (NAGO)-treated lymphocytes induce blastogenesis in nonproliferating cells harvested 7--14 d after treatment with mitogen or alloantigen and in cells incubated with mitogen for 7--14 d but not in freshly isolated peripheral blood lymphocytes9 Virtually all the growth factor is produced by NAGO-treated cells during the first 24 h of incubation, and no increase in factor activity is detected upon further cell culture. Serum is not required for growth factor production. NAGO-primed medium induces generation of specific cytotoxic T cells from mixed lymphocyte culture (MLC) memory cells to approximately the same extent as that induced by allogeneic cells (stimulating cells in the primary MLC). NAGO-primed medium provides a useful reagent for isolation and characterization of lymphocyte growth factors and other lymphokines.

Adult↗
PubMed1980

Role of humoral presenitization in human renal transplant rejection.

A prospective study of 31 cadaveric renal allograft recipients was performed to determine the significance of pretransplant presensitization undetected by the conventional microlymphocytotoxicity crossmatch. Donor-specific humoral presensitization revealed by the antibody-dependent cell-mediated cytotoxicity assay (ADCC) was associated with a high incidence of early graft rejection. Six-month graft survival was 20% in recipients with positive pretransplant ADCC and 75% in ADCC-negative recipients (P < 0.01). Among recipients highly presensitized to a random panel of HLA antigens, donor-specific humoral presensitization detected by chromium-51-release complement-dependent cytotoxicity (51Cr-CDC) was also highly correlated with accelerated rejection (P < 0.05). Pathologic study of the rejected allografts revealed antibody-mediated rejection vasculitis in all recipients. We conclude that humoral presensitization undetected by current conventional methods plays a cardinal role in early renal graft rejection and is a major factor responsible for low cadaveric renal transplant survival. This study suggests that use of the ADCC and 51Cr-CDC as routine adjunctive crossmatch procedures may contribute to improvement in renal transplant survival rates.

Antibody Formation↗
PubMed1980

Detection of alloimmune memory cells by chemical modification of the cell surface with mitogenic oxidizing agents.

The mitogenic oxidizing agents, neuraminidase and galactose oxidase (NAGO), and sodium periodate (IO-4) were used to induce the differentiation of human alloimmune memory cells. NAGO or IO-4 treatment of peripheral blood mononuclear (PBM) cells obtained from 10 sensitized potential allograft recipients resulted in the induction and augmentation of cytolytic activity to a D locus-defined lymphoblastoid cell panel (B cell panel) and to a HLA-disparate peripheral blood lymphocyte cell panel (PBL cell panel). The acquisition of cytolytic activity was determined in a 4-hr 51Cr release assay. Treatment of in vitro-primed PBM cells (alloimmune memory cells generated in primary long-term mixed lymphocyte cultures) obtained from normal subjects with NAGO or IO-4 also resulted in the induction of specific secondary cytolytic activity. In contrast, NAGO or IO-4 treatment of unprimed PBM cells from normal subjects did not result in the induction of cytolytic activity despite the extensive proliferation induced by such treatment. The strikingly similar results observed with PBM cells from sensitized patients and with in vitro-primed PBM cells suggest that in vivo- and in vitro-generated alloimmune memory cells can be detected by chemical modification of the cell surface induced by NAGO or IO-4. Furthermore, our findings indicate that alloantigen-independent activation of memory cells can be accomplished by treating the memory cells with the mitogenic oxidizing agents.

B-Lymphocytes↗
PubMed1979

Delayed hyperacute rejection in recipients of kidney transplants from HLA identical sibling donors.

Delayed hyperacute rejection, with its characteristic clinical course and histopathologic findings, occurred within one month after transplantation in five recipients of kidney transplants from HLA-A, B and D identical sibling donors. In all cases, unidirectional mixed lymphocyte cultures and immunologic studies to detect cytotoxic antibodies in the recipients against their respective donors, before kidney transplantation and after transplant nephrectomy, were unresponsive or negative. Onset of delayed hyperacute rejection was preceded by bacteremia in two of these patients. Two of these received second kidney transplants, three to six months later, from HLA-A, B and D identical sibling donors again. Although both have had an episode of acute rejection in the early postoperative period, the grafts have maintained excellent function for 21 and 25 months, respectively. Irreversible forms of transplant rejection, such as delayed hyperacute rejection, do occur even in recipients of kidney transplants from HLA-A, B and D identical sibling pairs, indicating that genetic determinants other than HLA-A, B and D loci, and perhaps other nongenetic immune mechanisms, play an important role in the ultimate results of kidney transplantation.

Adult↗