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Biomedical subjects

U Posch

Publications and source records attributed to U Posch.

6 recordsLinked to original sources
PubMed2006

Targeting human immunodeficiency virus type 1 with antibodies derived from patients with connective tissue disease.

During the budding process, human immunodeficiency virus (HIV) acquires several cellular proteins from the host. Thus, antibodies against self antigens found in sera patients with autoimmune disorders may cross react with host-derived or the HIV-specific proteins gp120 and gp41 on the viral envelope and probably neutralize HIV infection. To verify this hypothesis, 88 sera from HIV negative patients suffering from systemic lupus erythematosus (SLE) and other autoimmune disorders were analysed for cross reacting antibodies against HIV-1 by Western blot and FACS analysis indicating that antibodies cross-react with epitopes expressed on HIV infected or non-infected cells. Virus capture assays revealed that HIV-1(IIIB) was directly recognized by 60% of sera from patients with autoimmune disorders. Sera were also tested in HIV neutralization assays with stimulated T cells. Reduction of the viral load by patient sera correlated with their reactivity in Western blot analysis. Complement further enhanced the reduction of viral titres, although no complement-mediated lysis was observed. These data suggest a possible protective role of auto-antibodies against HIV infection in lupus patients.

Adolescent↗
PubMed2005

Severe thrombocytopenia due to host-derived anti-HPA-1a after non-myeloablative allogeneic haematopoietic stem cell transplantation for multiple myeloma: a case report.

BACKGROUND AND OBJECTIVES: Host- or donor-derived alloimmune thrombocytopenia can develop after non-myeloablative allogeneic haematopoietic stem cell transplantation (HSCT). We report the first case of host-derived HPA-1a antibodies. CASE REPORT: A 52-year-old male patient received HSCT from his human leucocyte antigen (HLA)-A, -B, -C, -DR identical brother after reduced intensity conditioning. Bilinear engraftment around day 12 was accompanied by a continuous decrease of platelet counts. We investigated for platelet antibodies because of a progressive decline of platelet counts and refractoriness to platelet transfusions. METHODS: The patient's serum was tested by enzyme-linked immunosorbent assay (ELISA), a solid phase assay and monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay. Recipient's DNA from the time before HSCT and donor's DNA were genotyped for human platelet antigens. RESULTS: Serum obtained on day 15 after HSCT reacted strongly with the donor's platelets due to host-derived anti-HPA-1a- and anti-HLA I antibodies. Serum samples from days 39, 45 and 65 after HSCT contained only anti-HLA I; no antibodies were detectable on day 149. Platelet counts increased on day 20 spontaneously. The decrease of the antibodies accompanied by the increase of the platelet counts suggests progressive elimination of residual host cells. CONCLUSIONS: The HPA-1a antibodies affected thrombopoietic engraftment and the success of platelet transfusions.

Antigens, Human Platelet↗
PubMed2000

HLA patterns in patients with nasal polyposis.

The etiology of nasal polyposis is still unknown, although risk factors include Aspirin intolerance, asthma, cystic fibrosis and primary ciliary dyskinesia. We studied frequencies of HLA A, B, DR and DQ in patients with nasal polyposis in order to determine a possible genetic component in the multifactorial pathogenesis of nasal polyps. Previous work has suggested an association of HLA-A1B8 with nasal polyposis and Aspirin intolerance. We investigated 89 patients with nasal polyposis, 11 of whom had Aspirin-intolerance, 19 asthma and 22 allergies to inhalation allergens. HLA patterns of these patients were compared to the ones of 1,070 healthy controls. No significant association of HLA-A1B8 was found with nasal polyps in the Aspirin-sensitive subgroup of our patients, but a significant association was seen with HLA-A74 and nasal polyposis.

Aspirin↗
PubMed1996

[Autologous blood donation with preliminary erythropoietin stimulation].

Low basal hemoglobin and functional iron deficiency are the limiting factors in autologous blood donation program. Treatment with recombinant human erythropoietin can increase the volume of autologous blood and makes donation of > or = 3 units possible-even in patients with low basal hemoglobin. Best results are obtained if stimulation begins already one week before first donation.

Anemia, Iron-Deficiency↗