Search PubMed⌕ Search

Biomedical subjects

H Heimpel

Publications and source records attributed to H Heimpel.

At least 109 records · Page 6Linked to original sources
PubMed1993

Measurement of recipient-specific alloreactivity: is GVHD predictable?

Acute graft-versus-host disease (GVHD) is a serious complication of allogeneic bone marrow transplantation (BMT) from an HLA-identical sibling. There is no practical test before transplantation that gives sufficient information to predict the degree of allogeneic reactivity between HLA-identical siblings. We determined the frequency with which host-specific interleukin-2 (IL-2) -secreting donor T lymphocyte precursors (Tl-p) occurred in 16 pairs of HLA-identical siblings before they underwent marrow grafting. The results were correlated with the development of acute GVHD after BMT. We further analyzed the responding host (and donor) -specific Tl-p with respect to the cell surface phenotype, the influence of previous in vivo priming, and the MHC class restriction of minor histocompatibility (mH) antigen recognition. To investigate whether host-reactive Tl-p are involved in the induction of acute GVHD, we also examined the frequency of host-specific Tl-p at various time intervals after BMT in 14 patients with and without acute GVHD. High frequencies of host-specific Tl-p were detectable before BMT in 8 donors whose siblings later had severe (grade II or III) acute GVHD. Among the donors to 8 patients with mild (grade 0 or I) acute GVHD, low frequencies were found. Various T-cell subsets contributed to the responding Tl-p. The presence of host-specific Tl-p after BMT was significantly correlated with the development of serious (grade II or III) acute GVHD. We conclude that host-specific IL-2-secreting T cells are critically involved in the induction and maintenance of acute GVHD.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1993

Graft rejection by a population of primed CDw52- host T cells after in vivo/ex vivo T-depleted bone marrow transplantation.

We investigated a case of graft rejection after in vivo/ex vivo T-depleted BMT in a patient who had received a HVG-matched, GVH one locus-mismatched, MLC-negative graft from his cousin. In vivo/ex vivo T cell depletion was performed with Campath 1G (CP1G) and Campath 1M (CP1M), respectively. We identified a failure of CP1G to eradicate a CDw52- (Campath-negative) host T cell population as the main cause of treatment failure. The analysis also suggests that significant host-versus-donor reactivity prior to transplant, as detected by limiting dilution analysis, also contributed to graft rejection. The rejecting T cells were bifunctional in that they showed cytotoxic activity and were capable of inhibiting haemopoietic progenitor growth by producing inhibitory lymphokines.

Adult↗
PubMed1993

Frequency of bone marrow T cells responding to HLA-identical non-leukemic and leukemic stimulator cells.

Grafted immunocompetent cells are considered responsible for GVHD as well as for the elimination of residual leukemic cells ('graft-versus-leukemia reactivity', GVLR) in leukemic patients after allogeneic BMT. Clinical and experimental investigations have given contradictory answers to the question whether GVHD and GVLR are two manifestations of the same process or separate immunologic processes. We have addressed this question by analysing the primary in vitro response of BM-derived proliferating and cytotoxic T lymphocyte precursors (PTLp and CTLp) in HLA identical relative pairs (n = 17). PTLp frequency estimation reveals strong responses (> 1 in 5000) on non-leukemic as well as leukemic stimulation in a majority of cases. CTLp amount variably to 10-100% of the proliferating precursor cells. Preliminary specificity analyses show that on non-leukemic stimulation about 90% of colonies exhibit exclusive lysis of the non-leukemic target. At the same time, on leukemic stimulation, about 75% of cytolytic colonies are exclusively reactive against leukemic targets without crossreactivity against nonleukemic targets from the same patient. Our data show that primary in vitro responses in HLA identical sibling pairs may be as strong as those against allo MHC antigens. In addition CTL specifically lysing leukemic or non-leukemic targets may represent an in vitro model of the immunologic non-identity of GVHD and GVLR.

Bone Marrow↗
PubMed1993

Influence of graft-versus-host disease on the eradication of minimal residual leukemia detected by polymerase chain reaction in chronic myeloid leukemia patients after bone marrow transplantation.

To evaluate the remission quality of Philadelphia chromosome (Ph)-positive, BCR/ABL-positive CML patients after allogeneic bone marrow transplantation (BMT) we used the polymerase chain reaction (PCR) to detect BCR-ABL specific RNA in addition to Southern blotting, cytogenetic, and hematological investigation. Fifty-five bone marrow samples of 27 patients in clinical remission were studied by PCR, 0.5 to 99 months (median 8 months) after BMT. The median clinical follow-up of this cohort of patients is 24 months (1-109) after BMT. BCR-ABL transcripts could be detected in 16 out of 27 patients (59%). Risk factors for minimal residual leukemia (MRD) as defined by PCR were the kind of graft-versus-host disease (GvHD) prophylaxis (patients with T-cell-depleted grafts had a higher rate of MRD in comparison to patients treated with methotrexate/cyclosporin A) and the presence or absence of GvHD after BMT (patients without GvHD had a higher incidence of MRD than patients with GvHD). Moreover, the detection of minimal residual leukemia had prognostic significance. Out of 16 patients with minimal residual leukemia as detected by PCR, four patients relapsed clinically and two further cases relapsed cytogenetically. In contrast none of the patients lacking evidence of minimal residual leukemia relapsed. Serial PCR analysis may prove helpful in deciding about further therapeutic interventions (e.g. interferon therapy or adoptive immunotherapy) before leukaemic relapse becomes manifest after BMT.

Adult↗
PubMed1992

Host-specific interleukin-2-secreting donor T-cell precursors as predictors of acute graft-versus-host disease in bone marrow transplantation between HLA-identical siblings.

BACKGROUND: Acute graft-versus-host disease (GVHD) is a serious complication of allogeneic bone marrow transplantation from an HLA-identical sibling. There is no practical test before transplantation that gives sufficient information to predict the degree of allogeneic reactivity between HLA-identical siblings. METHODS: We determined the frequency with which host-specific interleukin-2-secreting donor T-cell precursors occurred in 16 consecutive pairs of HLA-identical siblings before they underwent marrow grafting. The results were correlated with the development of acute GVHD after transplantation. RESULTS: High frequencies of host-specific T-cell precursors (> or = 1 per 100,000) were detectable before transplantation in eight donors whose siblings later had severe (grade II or III) acute GVHD. Among the donors to eight patients with mild (grade 0 or 1) acute GVHD, low frequencies (< 1 per 100,000) were found. CONCLUSIONS: Analysis of the frequency of such cells before transplantation may be a useful predictor of severe acute GVHD in allogeneic bone marrow transplantation between HLA-identical siblings. It is possible that the patients at risk for serious acute GVHD after marrow grafting may benefit from some alternative form of immunosuppressive therapy.

Acute Disease↗
PubMed1992

[Severe tetraparesis as the first manifestation of a chronic lymphatic leukemia].

Uncertain gait and weakness on standing, progressing to flaccid paraparesis of both legs, developed in a 76-year-old woman. Proprioceptor reflexes of both legs were absent and there was pallaesthesia up to the pelvic rim. Electromyography pointed to polyneuritis. Administration of prednisone, 1 mg/kg daily for 10 days, was ineffective, as was one-time plasmapheresis. An incomplete tetraparesis developed. Blood white-cell count increased within 2 weeks by 10,400/microliters (52% lymphocytes) to 17,400/microliters. Blood smear, bone-marrow cytology and histology, as well as immunocytology, revealed lymphoplasmocytoid immunocytomas (chronic lymphocytic leukemia). Oral cytoreductive treatment was started with chlorambucil, 0.1 mg/kg daily, and prednisone, 100 mg daily. After 19 days the patient was able to walk with support, after 28 was walking unaided. Treatment was continued over eight cycles (14 days' treatment, 14 days' interval per cycle). 17 weeks after onset of treatment paraesthesias of the legs required renewed administration of chlorambucil, 0.1 mg/kg per day, for 3 months. The patient has now been free of symptoms during a follow-up period of 12 months.

Aged↗
PubMed1992

Thrombotic thrombocytopenic purpura in early pregnancy with maternal and fetal survival.

Thrombotic thrombocytopenic purpura (TTP) is a hematologic disorder which is clinically characterized by thrombocytopenia, microangiopathic hemolytic anemia, fever, neurologic symptoms, and cardiac and renal involvement. The pathogenic mechanisms of this disease are poorly understood. It is well known that TTP is associated with pregnancy and that prognosis for the mother and child is poor. We present the first case of a severe TTP diagnosed in the first trimester of pregnancy (13th week of gestation) with maternal survival and birth of a healthy child which required continuous and intensive treatment with plasma therapy until delivery. During a period of 24 weeks several attempts to discontinue plasma therapy failed because of continuous active disease, and it became evident that plasma infusions were not as effective as plasma exchanges. The fact that the patient entered into remission soon after delivery of a healthy child by cesarean section in the 37th gestational week shows that in this case pregnancy activated an unknown factor which does not cross the placenta and which can be removed by plasmapheresis.

Adult↗
PubMed1992

Cryopreserved autologous platelet transfusions in alloimmunized patients with acute leukemia.

Autologous platelets of 5 alloimmunized patients with acute leukemia in remission were cryopreserved with 5% dimethylsulfoxide in liquid nitrogen and retransfused in the following therapy-induced thrombocytopenic phase. The mean platelet recovery after freezing, thawing and washing was 85 +/- 6%. The mean corrected 1-hour increment in platelet counts was 11 (4-27) x 10(9)/l, i.e. 61% in comparison with fresh platelet transfusions in other patients. In vivo function of frozen platelets was documented by improvement of the posttransfusion bleeding time. Cryopreserved autologous platelets function hemostatically and can be used even for completely refractory patients and thus permit curative antileukemic therapy.

Adult↗
PubMed1992

ABO-incompatible bone marrow transplantation.

In the past 10 years 201 HLA-identical bone marrow transplantations (BMT) were performed with major ABO incompatibility in 41 (20%) and minor ABO incompatibility in 35 (18%) patients. ABO compatibility between donor and recipient showed no influence on granulocyte and platelet recovery after BMT. Erythrocyte reconstitution was significantly (p < 0.01) delayed for about 1 week in major ABO-incompatible BMT. In addition, a pure red cell aplasia lasting for 2-5 months occurred in 6 out of 21 blood group 0 patients who received transplants of group A. The rate of graft rejection, incidence of graft-versus-host disease as well as the leukemic relapse rate were similar in ABO-compatible and ABO-incompatible BMT. The probability of a 10-year survival after BMT is independent of ABO compatibility between donor and recipient.

ABO Blood-Group System↗
PubMed1992

Chronic myelogenous leukemia: recent developments in prognostic evaluation and chemotherapy. The German CML Study Group.

Recent developments in CML research are illustrated by the results of one large randomized multicenter study carried out by the German CML Study Group. From July 1983 to January 1991, a total of 703 CML patients were recruited; 624 patients were randomized to compare hydroxyurea and interferon alpha (IFN) with busulfan. The median survival of Ph+ patients by now is 3.95 years, that of Ph- patients 1.1 years. Some difference in survival is recognizable between the treatment arms, but this is not yet significant. Fewer adverse effects are being observed in the hydroxyurea group. Ph-negative patients tend to have lower white blood cell and platelet counts. Patients (164) were randomized to receive IFN. In 50 patients (30%) IFN had to be terminated because of adverse effects, therapy resistance, or other reasons. Reduction of the Ph-chromosome was observed in 20% of evaluable patients. In 3 patients complete cytogenetic remissions were observed. Clinically relevant neutralizing antibodies were detected in 9 cases. Prospectively evaluated age, organomegaly related symptoms, Karnofsky index, extramedullary manifestations, erythroblasts, and percent of circulating blasts proved to be of prognostic significance. A prognostic score (score 1) was determined and compared to Sokal's score. It is expected that the study results will allow statements as to the advantages or disadvantages of the use of busulfan, hydroxyurea and IFN in the treatment of CML as well as to the reliability of prognostic markers.

Bone Marrow Transplantation↗
PubMed1991

Treatment of aplastic anemia with antilymphocyte globulin and methylprednisolone with or without cyclosporine. The German Aplastic Anemia Study Group.

BACKGROUND AND METHODS: Immunosuppression is the most effective treatment for patients with aplastic anemia, except for bone marrow transplantation. The best results are achieved with antilymphocyte globulin or cyclosporine. Patients have been treated successfully with a combination of both agents, but there has been no controlled evaluation of its efficacy. We conducted a randomized, multicenter trial in 84 patients not eligible for bone marrow transplantation, comparing treatment with antilymphocyte globulin and methylprednisolone (41 patients--the control group) with antilymphocyte globulin, methylprednisolone, and cyclosporine (43 patients--the cyclosporine group). RESULTS: At three months significantly more patients in the cyclosporine group had a complete or partial remission in response to treatment than did patients in the control group (65 percent vs. 39 percent, P less than 0.03); this difference was confirmed at six months (70 percent vs. 46 percent, P less than 0.05). The superior results of the regimen including cyclosporine were most evident in the patients with severe or very severe aplastic anemia, whose response rate at six months was 65 percent, as compared with 31 percent of such patients in the control group (P less than 0.02). Granulocyte and hemoglobin levels became normal in most patients who responded, but platelet counts continued to be subnormal in 61 percent of the patients. Ten of 52 patients with responses (3 in the cyclosporine group and 7 in the control group) relapsed 4 to 37 months after treatment. The actuarial survival of all patients at 41 months is 64 percent in the cyclosporine group and 58 percent in the control group (P = 0.16); among the patients with severe or very severe disease, survival is 80 percent and 44 percent, respectively (P = 0.077). Cyclosporine had substantial but reversible side effects. CONCLUSIONS: Immunosuppressive treatment of aplastic anemia with antilymphocyte globulin, methylprednisolone, and cyclosporine appears to be more effective than a regimen of antilymphocyte globulin and methylprednisolone without cyclosporine and may thus represent a treatment of choice for patients who are not eligible for bone marrow transplantation.

Adult↗
PubMed1991

Functional criteria for staging and treatment of hairy cell leukemia.

The determination of clinical stage in hairy cell leukemia is hampered by the lack of common criteria. Furthermore, clinical stages in which the disease should be treated have not yet been defined. In this paper we propose common criteria for the clinical staging of all hairy cell leukemia patients (treated or untreated), as well as for the assessment of responses to therapy. These criteria are absence or presence of disease-related symptoms and disease progression. Based on these criteria we propose that hairy cell leukemia patients in the most favorable stage of the functional system, non-symptomatic Stable Disease (nsSD), do not require treatment. Only in patients with disease-related symptoms and/or signs of disease progression is treatment justified and necessary. No symmetry was observed between the functional stages and Jansen's stages. For evaluation of responses to treatment, our stages were more sensitive than the Leeds criteria. Experimental evidence enables the differentiation of patients with non-symptomatic stable disease from those with symptomatic and/or progressive disease.

Adult↗
PubMed1991

[Multicenter prospective controlled study of therapy of chronic myeloid leukemia. Comparison of busulfan, hydroxyurea and interferon alpha (April 1990 status)].

In a multicenter study it is being determined, whether the use of hydroxyurea or of interferon alpha instead of busulfan prolongs the chronic phase of Philadelphia-positive CML. Additional goals are the examination, whether the types of disease evolution and the terminal phases differ between the treatment groups, and the prospective recognition of prognostic criteria for the duration of the chronic phase of CML. By September 5, 1990, 593 CML-patients had been randomized, 221 for busulfan, 228 for hydroxyurea and 144 for interferon alpha. The average age is about 51 years. By April 30, 1990, 106 patients had reached the end of the chronic phase, 126 had died. The median survival of Philadelphia-positive patients was 3.95 years, that of all patients 3.75 years. The median observation time of all patients was 1.34 years (mean 1.60 years). At present, no significant difference in survival is recognizable between the three treatment arms, although fewer adverse effects have been observed in the hydroxyurea arm.

Busulfan↗
PubMed1990

Essential thrombocythemia in two sisters originating from different stem cell levels.

We report the rare occurrence of essential thrombocythemia (ET) in two sisters. In one patient, the clinical phenotype of the disease evolved from ET to polycythemia vera (PV) after 4 years of follow-up. Clonal hematopoiesis was established in both cases by X-chromosomal inactivation analysis using a DNA polymorphism of the phosphoglycerate-kinase (PGK) gene. Cell separation studies suggested a common ancestor for granulocytes, monocytes, and T lymphocytes in one patient; however, in her sister, monoclonality could only be demonstrated convincingly for the granulocyte fraction. Our data indicate that ET may originate from heterogenous stem cell levels.

Aged↗