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N L Reinsmoen

Publications and source records attributed to N L Reinsmoen.

At least 37 records · Page 2Linked to original sources
PubMed1994

The impact of the quality of initial graft function on cadaver kidney transplants.

Living unrelated donor (LURD) transplants have immunologic barriers similar to cadaver transplants, yet the outcome is better (1-year graft survival = 96%). One advantage of LURD transplants is that, with the extremely short preservation time, the kidney functions immediately. We studied whether the quality of initial renal function affects the outcome of primary cadaver transplants. We divided 301 non-6-antigen-matched recipients transplanted between 1/1/86 and 8/1/92--who had no graft loss due to hyperacute rejection, primary nonfunction, or technical reasons--into 5 groups based on the quality of initial renal function (serum creatinine level in the first week). We determined patient and graft survival rates for each group. We found that the quality of initial function had a significant effect on patient and graft survival rates. Recipients whose serum creatinine level was < 3 mg/dl on posttransplant day 5 (groups 1 and 2) had better patient and graft survival than either those whose serum creatinine level was > 3 mg/dl on day 7 (group 4) or those who required dialysis (group 5). Because some early dysfunction may be immunologic, we reanalyzed the data excluding patients with percent reactive antibody > or = 15; the quality of initial function in this group had a significant impact on outcome. Similarly, when patients with graft loss due to "death with function" were excluded, the quality of initial function had a significant impact on survival rates. We conclude that the quality of early posttransplant function is an important predictor of long-term outcome. Cadaver recipients with immediate good function have outcomes similar to living donor recipients. Our data suggest that increased effort should be made to improve immediate posttransplant function.

Adult↗
PubMed1994

Frequent HLA class I and DP sequence mismatches in serologically (HLA-A, HLA-B, HLA-DR) and molecularly (HLA-DRB1, HLA-DQA1, HLA-DQB1) HLA-identical unrelated bone marrow transplant pairs.

The rates of graft-versus-host disease (GVHD) and rejection are significantly higher among recipients of unrelated donor marrow (BM) than in recipients of marrow from HLA-identical siblings, even when donors and recipients are mixed lymphocyte culture (MLC) compatible and serologically and Dw identical. It has been hypothesized that phenotypically silent HLA class I and DP sequence mismatches might be associated with these differences, but little is known about their incidence. We have sequenced the HLA-A, HLA-B, HLA-C, HLA-DPA1, and HLA-DPB1 genes expressed by 12 unrelated marrow transplant pairs, 11 of whom were molecularly matched at DRB, DQA1, and DQB1 loci. Nine of these pairs were also HLA-A and HLA-B matched by serology. Six of these nine "HLA-identical" pairs were HLA-A (2 of 6), HLA-B (1 of 6), and HLA-C (6 of 6) mismatched at the sequence level. The mismatched class I alleles of all these pairs had strikingly different sequence motifs in the six specificity pockets of their antigen recognition site, and in five pairs they also had sequence differences at positions implicated in T-cell receptor (TCR) binding. Two of the three pairs who were serologically mismatched for one HLA-A or HLA-B antigen were also sequence mismatched at HLA-C. Finally, 10 of 11 pairs tested expressed different DP sequences. These data indicate that HLA class I, especially HLA-C, and DP sequence mismatches are frequent among unrelated subjects defined as HLA identical by current typing methods. We speculate that these sequence differences may explain, at least in part, the higher incidence of acute GVHD and rejection in unrelated BM transplantation as opposed to transplantation between HLA-identical siblings. Because of their high frequency, the role of HLA-A, HLA-B, HLA-C, and HLA-DP mismatches in transplantation outcome is now amenable to direct study.

Adolescent↗
PubMed1994

Cellular rejection in discordant xenografts when hyperacute rejection is prevented: analysis using adoptive and passive transfer.

Hyperacute rejection of discordant xenografts occurs rapidly, precluding cellular infiltration. Thus the role of cellular rejection in discordant xenografts is debated. Using adoptive transfer of sensitized splenocytes and passive transfer of sensitized serum, we evaluated the influence of cellular and humoral elements on cellular infiltration and rejection in the guinea-pig-to-rat discordant xenograft model. Guinea-pig hearts were transplanted into Lewis rats. Pretransplant, rats underwent splenectomy and plasma exchange and were started on daily cobra venom factor injections. Xenografts rejected faster after adoptive (1, 2, 2 and 2 days) or passive (1, 1, 2 and 2 days) transfer than controls (4, 4, 4 and 4 days; p < 0.05). Macrophages and neutrophils were predominant in early prerejection specimens. Over time, cellular infiltrates were dominated by mononuclear cells. Natural killer cells were present in all groups, as were interleukin 2 receptor positive cells. Our data suggest that either sensitized serum or sensitized cells are capable of initiating an accelerated rejection characterized by cellular infiltration. Despite subtle differences, the population of infiltrating cells was similar in each group. Thus, although rejection may be initiated by either cellular or humoral influences, the ultimate result is the same. We have, therefore, established a small animal model to study cellular rejection in discordant xenografts. This model will help evaluate the role of cell subsets and xenoantibodies in xenograft rejection and will help determine the precise relationship between the two when hyperacute rejection is prevented.

Acute Disease↗
PubMed1993

Evidence that improved late renal transplant outcome correlates with the development of in vitro donor antigen-specific hyporeactivity.

Previous studies suggest stable renal transplant recipients can have either prednisone (P) or cyclosporine withdrawn; however, 30% of these patients undergo rejection requiring reinstitution of P or CsA. Some patients return to baseline creatinine levels, while others either stabilize at a higher creatinine level or lose their graft. It would be ideal to establish immunologically based criteria for selecting patients who can be successfully withdrawn or tapered from immunosuppression. We have investigated the development of donor antigen-specific hyporeactivity by using donor cells and/or homozygous typing cells defining the HLA-Dw specificities of the donor cells as stimulator cells in the mixed lymphocyte culture (MLC) and comparing the pre- and posttransplant responses of peripheral blood mononuclear cells from 199 kidney transplant recipients. Of these, 27% of the haploidentical living-related donor and 25% of the cadaver recipients developed in vitro donor antigen-specific hyporeactivity. The LRD recipients who did so have lower mean creatinine levels at 6, 12, and 24 months posttransplant (1.3, 1.3, and 1.2, respectively) than those who remained responsive to the donor antigens (1.6, 1.7, and 1.8) (P < 0.05). However, no differences in the mean creatinine levels were observed between CAD recipients who developed donor antigen-specific hyporeactivity and those who remained responsive. Rejection episodes were common in all groups in the first 3 months posttransplant; however, recipients who developed donor antigen-specific hyporeactivity tended to experience fewer rejection episodes after 3 months posttransplant. The percentage of recipients who remained rejection-free after 3 months post-transplant was 95% for CAD recipients who developed donor antigen-specific hyporeactivity vs. 83% for those who remained responsive. Only 1 hyporesponsive recipient (0/15 LRD; 1/20 CAD) developed chronic rejection vs. 12 (5/41, LRD; 7/60, CAD) recipients who remained responsive. For those with graft function at 3 months (when hyporesponsiveness was first determined), the actuarial 36-month graft survival was higher in the hyporesponsive (92%, LRD; 94%, CAD) than in responsive groups (LRD, 76%; CAD, 91%). No differences in the degree of HLA-DR mismatching (MM) were observed for the LRD hyporesponsive (1.20 DR MM) vs. reactive (0.98 DR MM) groups or for the CAD hyporesponsive (1.35 DR MM) vs. reactive (1.30 DR MM) groups. Donor antigen-specific hyporeactivity could not be determined (UND) for 30 of the LRD recipients and 33 of the CAD recipients due to lack of mismatching for DR antigens (0.03 DR MM and 0.25 DR MM, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1993

Are multiple immunopathogenetic events occurring during the development of obliterative bronchiolitis and acute rejection?

The primed lymphocyte test (PLT) has been used to detect donor antigen-specific reactivity of bronchoalveolar lavage (BAL) lymphocytes associated with acute lung rejection and obliterative bronchiolitis (OB). To identify more precisely the immunopathogenetic events related to these processes, we have determined the PLT alloreactivity of 162 BAL specimens from 40 recipients as being directed against individual class I or class II antigens. We used selected homozygous typing cells representing the specific HLA class I and II antigens expressed by the recipient and donor cells. Our previous studies demonstrated a predominant CD8+ cell population mediating class I donor antigen-specific reactivity, correlating with OB in 3 out of 3 recipients tested, and a predominant CD4+ cell population mediating class II donor antigen-specific reactivity, correlating with acute rejection episodes in 13 out of 15 recipients tested. The obstructive airway disease OB, which is frequently fatal, is identified histologically by the presence of small airway inflammation and fibrosis of the lamina propria and lumen, and is characterized clinically by rapidly progressive airflow obstruction. However, a subgroup of patients with histologically proven OB demonstrates stabilization or only minimal progression of airflow limitation after augmentation of their immunosuppressive regimen, usually with high-dose methylprednisolone. To further characterize this subgroup, we tested the BAL-derived lymphocytes from 4 of these patients and observed PLT reactivity that correlated with the class II antigens of the donor, in contrast to the predominant donor class I antigen-specific PLT reactivity of patients with progressive OB. The distinct patterns of PLT reactivity observed for the BAL-derived lymphocytes from patients with the progressive versus the less progressive form of OB suggest that more than one immune process or perhaps different cell targets are involved. Alternatively, these clinical and in vitro findings may represent different stages of the same disease process. Taken together, these results suggest that distinct immunopathogenetic events may be occurring during acute lung rejection and OB.

Acute Disease↗
PubMed1992

Differentiation of class I- and class II-directed donor-specific alloreactivity in bronchoalveolar lavage lymphocytes from lung transplant recipients.

Previous studies have demonstrated that donor antigen-specific primed-lymphocyte-test (PLT) reactivity of bronchoalveolar lavage lymphocytes is strongly associated with acute pulmonary rejection and with obliterative bronchiolitis (OB); however, a systematic analysis of PLT reactivity as being class I-or II-directed has not been performed. To assess reactivity directed against individual class I or II antigens, we tested a total of 67 BAL-derived lymphocyte samples from 26 recipients for alloreactivity in the PLT, using a pool of allogeneic cells and selected homozygous typing cells (HTCs) representing the HLA class I and II antigens expressed by the recipient and donor cells. The results obtained by PLT were correlated with the clinical status of the recipient with regard to rejection, infection, and OB. In 9 of 10 cases where transbronchial biopsy results were consistent with rejection, donor antigen-specific allogeneic PLT reactivity was observed and, more specifically, could be determined to be directed toward donor class II antigen in 8 of these cases. For 3 of 4 recipients tested chronologically, positive donor antigen-specific PLT reactivity was observed at the time of and 2-3 1/2 months prior to the diagnosis of rejection by transbronchial biopsy. During periods of acute infection, donor antigen-specific PLT reactivity was not observed; instead, non-specific PLT reactivity of BAL-derived cells (i.e., reactivity that did not correlate with any defined HLA antigens) was observed as well as reactivity associated with the self-antigens expressed by the recipients' cells. The PLT reactivity of BAL-derived cells from a recipient diagnosed with OB correlated specifically with one of the disparate donor class I antigens (HLA-B44). In 23 cases, BAL cells were propagated in the presence of autologous cells and rIL-2, thereby allowing for sufficient numbers of cells to test with a panel of 29 HTCs and to analyze for cell surface phenotype. The cultured BAL cells from 4 recipients undergoing a rejection episode demonstrated a predominant CD4+ phenotype consistent with the class II-directed reactivity observed in PLT. However, these results did not demonstrate a phenotype distinctive from the 7 BAL results obtained from 4 quiescent recipients. In marked contrast, the cultured BAL cells obtained from 4 recipients diagnosed with OB demonstrated a predominant CD8+ phenotype, with 60-92% of the cultured cells being CD8+. These results are consistent with the class I-directed reactivity observed in PLT.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1991

Heterogeneity of the T-cell receptor beta gene rearrangements generated in myelin basic protein-specific T-cell clones isolated from a patient with multiple sclerosis.

Seventeen T-cell clones derived from the peripheral blood of a patient with multiple sclerosis and reactive with a synthetic peptide corresponding to residues 152-170 of the human myelin basic protein molecule were previously shown to be cytotoxic for myelin basic protein-coated target cells. Genetic restriction studies have now demonstrated that these clones recognize myelin basic protein in association with human leukocyte antigen DRw13. Studies of the T-cell receptor beta gene rearrangements generated by these clones demonstrated 12 different patterns, as evaluated by Southern blot analysis. Thus, the human T-cell response to myelin basic protein is exceedingly heterogeneous, even among T cells that recognize the same small fragment of the molecule in association with the same class II restriction element.

Clone Cells↗
PubMed1990

Functional analysis of MHC class II-restricted T cells derived from a Caucasian with a DR4, Dw15, DQw8 haplotype.

Rabies virus-specific CD4+ T lymphocyte clones were isolated from a Caucasian male vaccine recipient (DR4/7, DQw2/w8; DPw4) and studied for their major histocompatibility complex restricting elements. None of the rabies-specific T-cell clones could be induced to proliferate to antigen by either lymphoblastoid cells or DR-transfected L cells expressing DR4 molecules of the Dw subtypes commonly found on Caucasian individuals (Dw4, Dw10, Dw13, Dw14). The HLA-Dw subtype of the rabies vaccine recipient was determined by conventional mixed lymphocyte culture, and the results revealed that this individual had a DR4 (Dw15), DR7 (Dw7) phenotype. The presence of the DR4, Dw15 antigen was confirmed by nucleotide sequencing of the DR4B1 gene corresponding to the DRB1*0405 allele. Significant antigen-induced T-cell proliferative responses were obtained with two DR4, Dw15, DQw4 homozygous lymphoblastoid cell lines of Japanese origin (HAS-15 and KT-3) and with a L-cell transfectant expressing the DR4, Dw15 molecule. The existence of the DR4, Dw15 antigen in the Japanese has been reported to be associated with the DQw4 specificity. However, the presence of DQw8 (previously designated DQw3.2) and the absence of DQw4 in the lymphoblastoid cells of the Caucasian rabies vaccine was confirmed with monoclonal antibodies IVD12 (anti-DQw7 + DQw8 + DQw9) and HU46 (anti-DQw4) and by the reactivity of a DQw8-restricted antigen-specific T-cell clone. These studies indicate, contrary to previous findings, that the DR4, Dw15 molecule may be present in Caucasian (non-Japanese) individuals in association with DQw8.

Alleles↗
PubMed1990

Structural model for T-cell recognition of HLA class II-associated alloepitopes.

In an effort to investigate the structure-function relationship of HLA class II molecules vis-à-vis alloepitope expression, cloned T-cell reagents were used to define polymorphic epitopes associated with DR and DQ molecules. DNA sequences of genes encoding allelic or isotypic DR or DQ molecules that appear to express the same T-cell-defined epitopes were compared in an attempt to identify association of shared sequences with shared epitopes. When sequence sharing is associated with shared epitope expression, we suggest that it is the shared sequence that encodes the epitope in question. Based on the hypothetical three-dimensional structure of the class II molecule, an approximation is made as to which parts of the HLA class II molecule are involved in alloepitope expression. T-cell clones were generated from cells primed against HLA-DR2 haplotypes representing the cellularly defined subgroups Dw2 or Dw21 (previously designated MN2, FJ0, or Tb24). Those clones determined to be DR- or DQ-directed based on monoclonal antibody inhibition assays were tested by panel cell analysis utilizing DR2-positive and DR2-negative target cells. The data support the concept that amino acids 67, 70, 71, and 74 for DR molecules and amino acids 57, 70, and 71 for DQ molecules, which appear to comprise one face of the alpha helix, are of primary importance in T-cell recognition. In other cases, sharing of both the second hypervariable region (amino acids 25-33) and the third hypervariable region (amino acids 67-74) appears necessary to explain epitope sharing for DR molecules. We emphasize that the involvement of these two hypervariable regions may indicate that alloepitope expression involves the complex of class II molecule plus peptide, with the second HVR primarily involved in determining which peptides are bound and the third in T-cell receptor (TcR) recognition and/or peptide binding; we do not rule out that conformational changes of the second HVR can induce conformational changes in the third HVR. Finally, shared alloepitopes detected by some clones could not be explained based on shared primary sequences.

Amino Acid Sequence↗
PubMed1990

The impact of HLA matching on graft survival and on sensitization after a failed transplant--evidence that failure of poorly matched renal transplants does not result in increased sensitization.

There are costs (both financial and ethical) to distributing kidneys by HLA-match (time, transportation, repeat crossmatch; possibly bypassing a more deserving recipient). Arguments favoring matching include better short- and long-term survival, and decreased panel-reactive antibody (PRA) if a well-matched vs. poorly matched transplant fails. We studied these phenomena in a single institution. Since 1970, 1329 patients received cadaver (CAD) transplants; for those with defined antigens (n = 1316) there was no difference in 10-year graft survival in those with a less than or equal to 1 AB match vs. those with greater than 1 AB match or those with less than or equal to 1 AB mismatch (mm) vs. greater than 1 AB mm. Similarly there was no difference in those with less than or equal to 2 BDR mm vs. greater than 2 BDR mm. In fact, those with less than ABDR mm had worse 10-year graft survival (55%) than those with greater than or equal to 3 ABDR mm (61%) (P = .001). For patients with function greater than 6 months there was no difference in long-term outcome based on HLA match or mm. These findings were similar for patients both with and without CsA immunosuppression, and for primary and retransplants. A total of 382 patients transplanted since 1980 have lost their grafts (146 died with function). All had received pretransplant transfusions. Of 236 alive after graft loss, 64 had no postgraft failure PRAs (22 out of state, 23 chose to remain on dialysis, 19 died less than 3 months after graft loss); 172 had PRAs after failure; 106 (62%) have been retransplanted. Mean peak PRA in those retransplanted was 23 +/- 31 (range 0-100) vs. 46 +/- 39 (range 0-100) in those not retransplanted (P less than .05). Patients were stratified by PRA prior to first transplant (0%, 1-20%, greater than 20%). For recipients with 0% PRA, failure of a CAD transplant (n = 58) was no more likely to result in an increase of PRA than failure of a living-related donor (LRD) transplant (n = 49) (NS). For those with an increase, mean increase was 45% +/- 34 after LRD transplant and 41% +/- 28 after CAD transplant (NS). The proportion developing PRA greater than or equal to 60% was not different after a failed LRD (7/49) or CAD (11/58) transplant (NS). Other subgroups had similar results. AZA or CsA immunosuppression did not affect development of increased PRA after a failed graft.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibody Formation↗
PubMed1990

A new in vitro approach to determine acquired tolerance in long-term kidney allograft recipients.

Previous studies indicate some kidney allograft recipients treated with total lymphoid irradiation, cyclosporine, or conventional immunosuppressive therapy demonstrate specific proliferative unresponsiveness in mixed lymphocyte culture (MLC) to donor cells at various times posttransplant. To investigate possible donor-specific hyporeactivity, we have studied 3 patients treated with TLI whose grafts have survived longer than 10 years; 2 patients given the same immunosuppressive protocol but without TLI whose grafts have survived longer than 10 years; and 27 CsA-treated living-related donor and cadaver-allograft recipients 1 year posttransplant. We confirmed previous observations of hyporeactivity of some patients' cells to stimulation by donor cells. In addition, we identified hyporeactivity to stimulation by homozygous typing cells (HTCs) defining the HLA-Dw specificities of the donor cells for all 3 of the 3 TLI patients, 1 of the 2 non-TLI patients, and 9 of the 27 patients 1 year posttransplant. The LRD recipients with donor-specific hyporeactivity as defined by the HTC analysis demonstrated fewer rejection episodes (25% vs. 57%) and lower mean creatinine levels (1.18 vs 1.78 mg/dL) than patients without donor-specific hyporeactivity. These studies demonstrate the feasibility of monitoring the immune status of allograft recipients posttransplant by means of HTC analysis, eliminating the need for pretransplant specimens. This approach provides a possible means to assess which patients may have acquired donor-specific hyporeactivity to their kidney allograft and thus may require less immunosuppression.

Clone Cells↗
PubMed1987

Determination of DR beta 1 alleles of DR4/Dw subtypes by oligonucleotide probing.

The extensive Dw polymorphism of HLA-D has, to date, been defined using cumbersome and lengthy techniques involving T-cell proliferative reactions. These techniques have not necessarily provided information about the genotype at any single locus of HLA-D because the products of more than a single locus of HLA-D (e.g., DR beta 1 and DR beta 2 of the DR2 haplotypes and in some cases DQ) can contribute to T-cell proliferation and thus to assignment of Dw phenotype. We have recently reported that DR beta 1 alleles relating to the Dw polymorphism can vary by only a single, or a very few, nucleotide differences; the products of this locus are recognized in allo- and restricted responses. Given the importance of defining this polymorphism, we have used specific oligonucleotides as hybridization probes to differentiate between these very closely related alleles. This approach provides the basis for a rapid method for HLA-D typing which, as additional sequence information becomes available, will likely be generally applicable. In addition, oligonucleotide probing allows definition of a gene transcript from an individual locus of HLA-D rather than the phenotype results provided by Dw typing.

Alleles↗
PubMed1987

T-cell clonal analysis of HLA-DR2 haplotypes.

Individuals carrying the serologically-defined DR2 haplotypes can be further subdivided by utilizing T cell response to define several HLA-Dw/LD clusters: Dw2, Dw12, LD-5a, and a related group composed of FJO, AZH, and MN2. We have used cytotoxic T cell clones generated against these DR2 haplotypes to define the DR and DQ associated Dw/LD polymorphisms. Clones were categorized as DR, DQ, DP, or class I-directed based on monoclonal antibody (MoAb) inhibition studies. We analyzed the distribution of the determinants detected by these clones based on analysis with panels of cells. Some DR-directed clones only lysed cells positive for the Dw subtype of the sensitizing cell. A few DR-directed clones lysed most DR2 positive cells. Other DR-directed clones detected determinants shared by cells of different subtypes: determinants shared by Dw2 and Dw12 positive cells and determinants shared by MN2, FJO, AZH, and LD-5a positive cells. The majority of the DQ-directed clones only lysed cells positive for the sensitizing HLA-Dw subtype. A group of clones primed against an LD-5a HTC, whose cytolytic activity was not blocked by any monoclonal antibodies tested, lysed some, but not all, DR2 positive cells as well as Dw1 and Dw10 positive cells. The results suggest the detection of determinants on these molecules which may be shared by cells of specific Dw subgroups and determinants shared by most cells of the sensitizing serological specificity. The basis of this observed polymorphism and influence on the allogeneic response are discussed.

Antibodies, Monoclonal↗
PubMed1987

Protein analysis of HLA-DR2.3 haplotype.

The human major histocompatibility antigens (HLA-DR, HLA-DQ, and HLA-DP), consisting of alpha and beta chains, show extensive polymorphism. Based on differences of T-cell responses, the serologically defined DR2 specificity has been divided into Dw2, Dw12, and several putative additional "Dw subtype" specificities (AZH, FJO, and MN2, which we shall designate as "DR2.3", and LD-5a). To investigate the relationships of these specificities, DR and DQ molecules were analyzed by two-dimensional gel electrophoresis (2D-PAGE). The 2D-PAGE patterns of the DR molecules are identical among DR2.3 cells. Three DR beta chain polypeptides are expressed on DR2.3 cells. The electrophoretic mobilities of two of these beta chains are different from those of beta chains from the Dw2 and Dw12 cells. The DR molecules of the LD-5a cells show similar 2D-PAGE patterns with those of DR2.3 cells. The 2D-PAGE patterns of DQ molecules are identical among DR2.3 cells. The electrophoretic mobilities of DQ beta chains are different for Dw2, Dw12, LD-5a, and DR2.3 cells. These results indicate that the AZH, FJO, and MN2 cells have identical or very similar DR and DQ molecules and constitute a third, and relatively homogeneous, subgroup ("DR2.3") of the DR2 specificity. In addition, DR2.3 cells have a unique characteristic in that they express three DR beta chains.

Antibodies, Monoclonal↗