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Biomedical subjects

J A Hansen

Publications and source records attributed to J A Hansen.

At least 109 records · Page 6Linked to original sources
PubMed1995

A retrospective analysis of the long-term effect of splenectomy on late infections, graft-versus-host disease, relapse, and survival after allogeneic marrow transplantation for chronic myelogenous leukemia.

The present study was performed as a retrospective analysis of the role of pretransplant splenectomy to determine the incidence of late bacterial infections, acute and chronic graft-versus-host disease (GVHD), relapse, and survival among 358 patients receiving HLA-identical marrow grafts for chronic myelogenous leukemia. Sixty-eight (19%) of the 358 patients had undergone splenectomy before transplantation. There was a trend towards more grade II-IV acute GVHD among splenectomized patients, but this was not significant in the multivariate analysis. The incidence of chronic GVHD was similar for splenectomized and nonsplenectomized patients. Late infectious complications did not significantly differ between splenectomized and control patients (rates per patient year were 0.16 and 0.14, respectively). The overall risk of leukemic relapse was significantly increased for splenectomized patients (56% v 32% for controls, P = .001) and control patients with splenomegaly (P < .0001). Splenectomy and splenomegaly remained significant and independent hazards for relapse in the multivariate analysis (hazard ratio [HR], 1.82, P = .029; and HR, 1.49, P = .002; respectively). Relapse was also increased in patients with advanced disease (HR, 2.95; P = .0001), in patients with T-cell-depleted marrow (HR, 4.51; P = .0001), and in the female donor and male recipient combination (HR, 1.74; P = .044). Patients with splenectomy had an increased overall mortality (HR, 1.18), but this was not statistically significant in the multivariate analysis. In summary, our study showed no significant influence of splenectomy on late posttransplant infections, acute or chronic GVHD, or overall survival. There was no evidence that splenectomy decreased recurrence of chronic myelogenous leukemia.

Abscess↗
PubMed1995

The significance of HLA-DRB1 matching on clinical outcome after HLA-A, B, DR identical unrelated donor marrow transplantation.

Despite matching for serologically defined HLA-A, B, DR antigens, acute graft-versus-host disease (GVHD) is a major complication contributing to increased morbidity and mortality in patients who undergo marrow transplantation from unrelated donors. The extent to which unrecognized mismatching for alleles that encode DR1-DR18 contribute to the increased risk of acute GVHD and overall survival is unknown. We analyzed 364 patients and their HLA-A, B, DR serologically matched donors to determine whether molecular typing of DRB1 alleles can allow more accurate donor/recipient matching and thereby improve clinical outcome after marrow transplantation. DRB1 alleles were typed by sequence-specific oligonucleotide probe hybridization methods. Selected alleles were confirmed by DNA sequencing. Of the 364 pairs, 305 were matched and 59 were mismatched for DRB1. The probability of moderate to severe acute GVHD was .48 for the matched and .70 for the mismatched patients. Compared with mismatched patients, the estimated relative risk (RR) of GVHD for matched patients was .58 (95% confidence interval [CI], .40 to .85). DRB1 matching decreased the risk of transplant-related mortality (RR, .66; 95% CI, .44 to .97) and was associated with decreased overall mortality (RR, .71; 95% CI, .51 to 1.0). Therefore, matching DRB1 alleles of the donor and recipient decreases the risk of acute GVHD and improves survival after unrelated marrow transplantation. These results indicate that prospective matching of patients and donors for DRB1 alleles is warranted.

Adolescent↗
PubMed1995

A toxicity study of trimetrexate used in combination with cyclosporine as acute graft-versus-host disease prophylaxis in HLA-mismatched, related donor bone marrow transplants.

This study evaluated the acute toxicity of trimetrexate (TMTX) used in combination with cyclosporine (CsA) for prevention of acute graft-versus-host disease (GVHD) in patients undergoing allogeneic marrow transplantation from HLA-mismatched, related donors. TMTX has a mechanism of action similar to that of methotrexate (MTX); however, unlike MTX, TMTX is not primarily dependent on renal excretion. Patients were conditioned for transplant with cyclophosphamide, anti-thymocyte globulin, and total body irradiation. TMTX, 10 mg/m2 i.v., was administered on days 1, 3, 6, 11, 18, 25, 32, and 39 after transplant. CsA, 1.5 mg/kg i.v., was administered every 12 hr beginning on day-1. Eleven patients with hematologic malignancies or aplastic anemia (median age = 34 yr) received TMTX. Toxicity assessed included nausea, vomiting, fever, rash, time to myeloid and platelet engraftment, mucositis, and hepatic and renal dysfunction. Toxicity of TMTX was not different from that observed with MTX in a similar patient population. One patient died on day 16 before engraftment. The other 10 patients all engrafted and all developed acute GVHD at a median time of 11 days after transplant. The major manifestation of acute GVHD was in the skin, and all but one patient responded to primary therapy with corticosteroids. Seven patients have survived a median of 447 days after transplant. No significant toxicity from TMTX was observed. Further trials are warranted to define the role of TMTX in marrow transplantation.

Adolescent↗
PubMed1995

Quantitative determination of bone marrow transplant engraftment using fluorescent polymerase chain reaction primers for human identity markers.

We have developed a quantitative, nonisotopic method using variable number tandem repeat (VNTR) and short tandem repeat (STR) markers for monitoring donor cell engraftment in marrow transplant recipients. Posttransplant DNA from the recipient is amplified with fluorescent polymerase chain reaction (PCR) primers for polymorphic markers that distinguish donor alleles from recipient alleles. The fluorescent PCR products are then separated on agarose or acrylamide gels on the Applied Biosystems 373A Sequencer (Foster City, CA). Using GeneScan 672 software (Applied Biosystems) to analyze the separated alleles, we can correlate allele peak areas to the percentage of donor or recipient DNA. We quantitate engraftment in a mixed chimeric sample by mixing pretransplant recipient and donor DNAs in a range of percentages and amplifying the mixtures to produce a standard curve. By amplifying and analyzing the posttransplant sample DNA(s), we can determine the extent of engraftment by interpolating the percent peak area of the informative allele(s) from this standard curve. This approach provides a precision of measurement ranging, depending on the marker, from 3.5% to 8.0% (percent coefficient of variation) and an accuracy of engraftment determination ranging from 97% to 99%, with a sensitivity of detection of 1% donor or recipient DNA. We retrospectively analyzed a panel of 32 patients and found seven to be informative for some degree of mixed chimerism, indicative of either residual normal host cells or leukemic relapse. An analysis of different cell lineages obtained posttransplant showed different degrees of engraftment in myeloid and T-cell populations. In summary, this method can provide an accurate, quantitative assessment of mixed chimerism in patients posttransplant. Such information may be useful in the future in guiding early implementation of additional treatment designed to circumvent graft failure or suppress relapse.

Base Sequence↗
PubMed1995

A comprehensive approach for typing the alleles of the HLA-B locus by automated sequencing.

We describe an approach for typing alleles of the HLA-B locus by using automated sequencing technology. The exon 2 and exon 3 nucleotide sequence of each allele is determined directly from genomic DNA in two steps. In the first step, HLA-B exon 2, intron 2 and exon 3 sequences are amplified with one or two primer pairs out of a panel of 5 primer pairs that describe all known HLA-B alleles. In the second step, templates are sequenced in 5' and 3' orientations in a PCR assay that utilizes Taq polymerase to incorporate fluorescent dye-labeled nucleotides into each new strand synthesized. Gel electrophoresis of the labeled products is performed in an automated DNA sequencer. The derived sequences are aligned against reference sequences and each nucleotide position is evaluated for homology to consensus sequence. Using this strategy, the HLA-B allele sequence is directly ascertained with precision and efficiency. The automated sequencing strategy can be readily applied in the clinical laboratory as a practical tool for high resolution typing of HLA-B alleles.

Alleles↗
PubMed1995

Marrow transplantation from unrelated volunteer donors.

Marrow transplants from human leukocyte antigen (HLA)-compatible unrelated volunteer donors have become feasible for more than 30% of patients without a family match and have allowed long-term, disease-free survival in 15-65% of patients with a variety of hematological disorders. However, unrelated donor transplants have a higher incidence of graft failure and graft versus host disease (GVHD) than do HLA-matched sibling transplants. This increase may be due to disparities between donor and recipient for undetected HLA determinants or for non-HLA histocompatibility genes. Because of the large number of HLA loci and their high degree of polymorphism, fully compatible donors will not be found for most patients. Fortunately, a limited degree of HLA mismatch does not necessarily impair long-term survival in patients with hematologic malignancy. Current studies are defining the risk associated with mismatching for each histocompatibility locus and are developing methods for marrow transplantation that can decrease morbidity and improve survival despite genetic disparity between donor and recipient.

Bone Marrow Transplantation↗
PubMed1995

Phase II study of busulfan, cyclophosphamide and fractionated total body irradiation as a preparatory regimen for allogeneic bone marrow transplantation in patients with advanced myeloid malignancies.

A previous phase I dose escalation study determined that the maximum tolerated doses of busulfan and cyclophosphamide that could be combined with 12.0 Gy of total body irradiation were 7 mg/kg and 50 mg/kg, respectively. A phase II study of these three agents was carried out in 56 patients with advanced myeloid malignancies receiving allogeneic bone marrow transplants from HLA-identical donors. Cyclosporine with methotrexate or with prednisone was administered for prophylaxis against graft-versus-host disease. Grade 3 (n = 8) and 4 (n = 3) regimen-related toxicity occurred in 20% of patients, which was the maximum predicted from the phase I study. The 2-year actuarial probabilities of non-relapse mortality and relapse were 0.52 and 0.55, respectively. Fourteen patients survive, 12 in remission, 581-1761 days post-transplant. The actuarial probabilities of disease-free survival for patients with recurrent acute myeloid leukemia and advanced chronic myeloid leukemia at 2 years were 20% and 23%, respectively. When compared with our historical experience in patients receiving other treatment regimens, there was no apparent improvement in disease-free survival.

Adolescent↗
PubMed1995

Marrow transplants from unrelated donors.

Unrelated-donor transplants have been a realistic option for an increasing number of patients, and the results of these transplants are favorable for patients with good prognostic features. Timing of the transplant early in the course of disease, before malignant clones become resistant to therapy and while the patient remains in good clinical condition, is a critical variable. Further improvements in the safety and efficacy of unrelated-donor transplants will require new approaches to GVHD prevention, better supportive care, acceleration of immune reconstitution and facilitation of tolerance induction without loss of the graft-versus-leukemia effect.

Adult↗
PubMed1994

Marrow transplantation for chronic myeloid leukemia: a randomized study comparing cyclophosphamide and total body irradiation with busulfan and cyclophosphamide.

A prospective randomized study was conducted comparing two conditioning regimens for the treatment of patients with chronic myeloid leukemia in chronic phase by marrow transplantation from HLA identical siblings. Sixty-nine patients received 60 mg/kg of cyclophosphamide on each of 2 successive days followed by 6 fractions of total body irradiation each of 2.0 Gy (CY-TBI), and 73 patients received 16 mg/kg of busulfan delivered over 4 days followed by 60 mg/kg CY on each of 2 successive days (BU-CY). There was no significant difference between the CY-TBI and the BU-CY groups in the 3-year probabilities of survival (0.80 for both), relapse (0.13 for both), or event-free survival (CY-TBI, 0.68; BU-CY, 0.71) or in speed of engraftment or incidence of venocclusive disease of the liver. The 4-year probabilities of survival and event-free survival for patients transplanted within 1 year of diagnosis were 0.86 and 0.72, respectively, for each group. Significantly more patients in the CY-TBI group experienced major creatinine elevations. There was significantly more acute graft-versus-host disease in the CY-TBI group. Fever days, positive blood cultures, hospitalizations, and inpatient hospital days were significantly more common in the CY-TBI group than in the BU-CY group. In conclusion, the BU-CY regimen was better tolerated than, and associated with survival and relapse probabilities that compare favorably with, the CY-TBI regimen.

Adolescent↗
PubMed1994

Treatment of acute graft-versus-host disease with humanized anti-Tac: an antibody that binds to the interleukin-2 receptor.

Humanized anti-Tac is a genetically engineered human IgG1 monoclonal antibody specific for Tac, the alpha subunit of the interleukin-2 (IL-2) receptor, and blocks IL-2-dependent activation of human T lymphocytes. The safety, pharmacokinetics, and immunosuppressive activity of humanized anti-Tac were evaluated in 20 patients who developed acute graft-versus-host disease (GVHD) after allogeneic marrow transplantation. Patients had developed acute GVHD at 5 to 26 (median, 14) days after transplantation and had failed to respond to primary therapy with glucocorticoids. Sequential groups of 4 patients each received a single 1-hour infusion of antibody in escalating doses of 0.5, 1.0, or 1.5 mg/kg; 8 additional patients were then treated with 1.5 mg/kg. A second infusion of antibody was administered after 11 to 48 (median, 16) days in 8 patients who had transient improvement of GVHD after the first infusion. Acute side effects, limited to chills in 1 patient and diaphoresis in another, were observed during or shortly after the antibody infusion. Overall improvement of acute GVHD occurred in 8 patients, 6 of whom were treated with a single antibody infusion and 2 with two infusions. Four responses were complete and 4 were partial. Three additional patients had improvement in one organ but progression in another. Responses occurred in 9 of 16 cases with skin disease, 3 of 15 with liver disease, and 6 of 12 with gastrointestinal disease. Two patients survive at 529 and 645 days after antibody treatment. Two patients died after relapse of leukemia. Sixteen patients died of infection or organ failure between 5 and 211 (median, 55) days. The terminal elimination half-life of the antibody was 44 to 363 hours, with a harmonic mean of 79, 88, and 94 hours, respectively, for the three doses studied. Absolute peripheral blood T-lymphocyte counts remained unchanged during the 56 days after infusion of the antibody. A fraction of circulating T cells expressed the alpha chain of the IL-2 receptor that, in some patients, was bound by antibody in vivo up to 28 days after treatment. No patient developed a measurable antibody response to humanized anti-Tac. Humanized anti-Tac has a long half-life after intravenous injection in humans, superior to any rodent monoclonal antibody specific for human T cells, and does not appear to induce antibody formation in recipients of marrow transplants. Improvement of steroid-refractory GVHD in 40% of patients after only one or two antibody infusions indicates that humanized anti-Tac is immunosuppressive.

Adult↗
PubMed1994

[Traumatic superior orbital fissure syndrome].

A 7-year old boy was referred owing to suspicion of a lesion of the lacrymal canal, after having been hit on his head by a bale of straw weighing 400-500 kilos. The patient developed a fissura orbitalis superior syndrome (FOSS), despite the fact that radioscopy could not prove any fracture or other lesions to explain the case. FOSS is a rarely reported syndrome. There is no treatment, normally there will be a complete recovery in the course of three to four months.

Child↗
PubMed1994

Unrelated donor or autologous marrow transplantation for treatment of acute leukemia.

High-dose chemoradiotherapy followed by marrow transplantation from an HLA-matched sibling donor is curative for patients with acute leukemia. Autologous marrow transplantation has been used with success for some patients without such a sibling. Alternatively, the option of performing a transplant from an HLA-matched unrelated donor has been made possible by the recent development of large registries of HLA-typed volunteers. The purpose of this study was to compare the outcomes for patients with advanced leukemia treated by unrelated or autologous marrow transplantation. Forty-three patients with acute myeloid or lymphoid leukemia were transplanted from a closely HLA-matched unrelated donor. Results were compared with those of a disease-, disease-stage-, and age-matched cohort of 77 patients treated with autologous marrow transplantation at the same institution during the same period. Myeloid reconstitution with peripheral granulocyte counts greater than 10(9)/L was achieved in 93% of unrelated recipients and 70% of autologous recipients at a median of 24 and 36 days after transplantation, respectively (P = .0001). The cumulative proportions of patients discharged alive (79% v 77%) and times from transplant to first hospital discharge (35 v 34 days) were not different between unrelated and autologous recipients (P = .65). For patients transplanted in complete remission, relapse occurred after transplantation in 27% of the unrelated and in 55% of the autologous recipients (P = .08). For patients transplanted in relapse, the corresponding posttransplant relapse rates were 48% and 63%, respectively (P = .72). Forty percent of unrelated recipients and 28% of autologous recipients died in remission. Leukemia-free survivals were 33% for unrelated and 25% for autologous recipients transplanted in remission (P = .45), and 12% for unrelated and 5% for autologous recipients transplanted in relapse (P = .75). Unrelated donor transplants appear no less effective than autologous transplants to achieve long-term survival and may be more effective in eradicating leukemia in patients who have failed conventional chemotherapy. Further studies are warranted to assess the relative effectiveness of unrelated and autologous transplantation performed earlier in the course of the disease.

Adolescent↗
PubMed1994

Rheumatoid factor, HLA-DR4, and allelic variants of DRB1 in women with recent-onset rheumatoid arthritis.

OBJECTIVE: To examine the relationship of rheumatoid factor (RF) to HLA-DR4 and alleles of DRB1 in women with recent-onset rheumatoid arthritis (RA). METHODS: Incident cases of RA were identified as part of a prospective, population-based case-control study. HLA typing was completed for 246 cases meeting criteria for definite or classic RA. RESULTS: One hundred thirty-six patients (55%) were positive for DR4, and 130 (53%) were RF positive. DR4 was found to be strongly associated with seropositivity (odds ratio 4.1, P < 0.0001). Patients with a shorter interval from RA onset to RF testing had a higher frequency of seropositivity than those with a longer interval (< or = 18 months 60%, > 18 months 33%). Further analysis of patients who had RF testing within 18 months of RA onset showed that the frequency of seropositivity was significantly greater among DR4-positive patients who had the shared sequence stretch of DR beta 1 associated with RA susceptibility (76% RF positive) than among DR1-positive patients who had this sequence (45% RF positive) (odds ratio 3.8, P = 0.01). Moreover, the frequency of seropositivity among DR1-positive patients with the sequence did not differ from that among all patients without the shared sequence (47%) (odds ratio 0.9, P = 0.8). CONCLUSION: HLA-DR4 is strongly associated with seropositivity in women with recent-onset RA. The amino acid sequence of DR beta 1 that is associated with susceptibility to RA and is shared between DR4 and DR1 appears not to be the primary determinant of seropositivity in these women.

Adolescent↗
PubMed1994

A novel HLA-A*8001 allele identified in an African-American population.

HLA polymorphism varies among different racial origins. Certain antigens are restricted to a particular ethnic group, suggesting that genetic events might have generated further unique polymorphism following racial diversification. In this study, we have identified and characterized a novel HLA-A allele, officially designated A*8001. The class I molecule, HLA-AXBG, encoded by this allele could not be defined by commonly available HLA antisera. We have identified two alloantisera that appear to be monospecific for this new antigen. The observed frequency of AXBG antigen specificity is 2% in African Americans among the total of 254 tested, but it has not been found in 305 Caucasians tested. IEF and cDNA sequencing analyses on multiple individuals revealed that AXBG antigen defined by the two antisera are encoded by an identical HLA-A*8001 allele and it has a number of unique amino acid residues that have not been observed among other HLA-A alleles but are known to occur in certain human nonclassic class I genes and nonhuman primate class I genes. The ability to identify the new HLA-AXBG antigen will improve the precision of HLA-A typing in black populations and enable us to match a patient with a donor for this otherwise undefined antigen in transplantation.

Alleles↗
PubMed1994

Effect of HLA incompatibility in marrow transplantation from unrelated and HLA-mismatched related donors.

Transplants from related donors who share one HLA haplotype and are variably matched with the recipient for HLA-A, B, or DRB1 loci on the unshared haplotype are associated with increased risks of graft failure and graft-versus-host disease (GVHD) that correlate with the degree of HLA mismatch. Survival, however, is not necessarily inferior if recipient incompatibility is limited to one HLA locus. Available methods for post-transplant immunosuppression have not allowed similar success with transplants incompatible for two or three HLA loci. GVHD incidence and severity can be decreased by depletion of donor T cells from the marrow inoculum. However, the potential benefit is offset by increased graft failure and leukemia relapse with no improvement in survival. Since fewer than 30% of the patients in North America or Europe have an HLA-matched sibling and less than 5% have a one HLA-locus mismatched relative, most candidates for an allogeneic marrow transplant are in need of an unrelated donor. As of October 1993, the National Marrow Donor Program (NMDP) has accrued more than 1 million volunteers typed for HLA-A and B, including 200,000 typed for HLA-DR, and has provided donors for more than 2000 transplants. The probability of finding an HLA-A, B, DR match at the initial search has increased from 10-15% in 1987, to 50-55% in 1992. An additional 12% of patients will find a match when available HLA-A and B matched donors are typed for DR, and 20% of patients have a one HLA-locus incompatible unrelated donor. Through an international network of regional registries a search for an unrelated donor can now be conducted among 1.7 million volunteers worldwide. Unrelated donor transplants have allowed long-term disease-free survival of patients with a variety of hematological disorders. When compared to HLA-matched sibling transplants, unrelated donor transplants are associated with an increase in the incidence of graft failure and GVHD. Such an increase may be due to undetected HLA disparities or to non-HLA-linked histocompatibility genes. At our center patients with CML in chronic phase, the most common indication for unrelated donor transplantation, have a 50-55% probability of survival 2-6 years after an unrelated donor transplant, whereas patients with aplastic or refractory anemia have a 25-35% probability of survival.(ABSTRACT TRUNCATED AT 400 WORDS)

Bone Marrow Transplantation↗