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Biomedical subjects

Heidrun Ullrich

Publications and source records attributed to Heidrun Ullrich.

4 recordsLinked to original sources

Treatment of colon and lung cancer patients with ex vivo heat shock protein 70-peptide-activated, autologous natural killer cells: a clinical phase i trial.

PURPOSE: The 14 amino acid sequence (aa(450-463)) TKDNNLLGRFELSG (TKD) of heat shock protein 70 (Hsp70) was identified as a tumor-selective recognition structure for natural killer (NK) cells. Incubation of peripheral blood lymphocyte cells with TKD plus low-dose interleukin 2 (IL-2) enhances the cytolytic activity of NK cells against Hsp70 membrane-positive tumors, in vitro and in vivo. These data encouraged us to test tolerability, feasibility, and safety of TKD-activated NK cells in a clinical Phase I trial. EXPERIMENTAL DESIGN: Patients with metastatic colorectal cancer (n = 11) and non-small cell lung cancer (n = 1) who had failed standard therapies were enrolled. After ex vivo stimulation of autologous peripheral blood lymphocytes with Hsp70-peptide TKD (2 microg/ml) plus low-dose IL-2 (100 units/ml), TKD was removed by extensive washing, and activated cells were reinfused i.v. The procedure was repeated for up to six cycles, applying a dose escalation schedule in 4 patients. RESULTS: The percentage of activated NK cells in the reinfused leukapheresis products ranged between 8 and 20% of total lymphocytes, corresponding to total NK cell counts of 0.1 up to 1.5 x 10(9). Apart from restless feeling in 1 patient and itching in 2 patients, no negative side effects were observed. Concomitant with an enhanced CD94 cell surface density, the cytolytic activity of NK cells against Hsp70 membrane-positive colon carcinoma cells was enhanced after TKD/IL-2 stimulation in 10 of 12 patients. Concerning tumor response, 1 patient was in stable disease during therapy by formal staging criteria and another patient showed stable disease in one metastases and progression in another. CONCLUSIONS: Reinfusion of Hsp70-activated autologous NK cells is safe. Immunological results warrant additional studies in patients with lower tumor burden.

Adult↗

Improved treatment of sudden hearing loss by specific fibrinogen aphaeresis.

The etiology of sudden sensorineural hearing loss is still unclear and is thought to result from disturbances of microcirculation, infectious causes, or autoimmune disorders. So far standard therapy did not show clear improvement over spontaneous remission rate, which is assumed to be about 50% [Nakashima et al., Acta. Otolaryngol. Stockh. 514:14-16, 1994; Schuknecht and Donovan, Arch. Otorhinolaryngol. 243:1-15, 1986; Harris and Sharp, Laryngoscope 100:516-524, 1990; Mayot et al., Clin. Immunol. Immunopath. 68:41-45, 1993; Gussen, Ann. Otol. Rhinol. Laryngol. 85:94-100, 1976]. Elevated blood viscosity due to high fibrinogen levels is supposed to cause decreased cochlear blood flow and thus initiate sudden hearing loss. The specific lowering of fibrinogen immediately decreases plasma viscosity exactly to the desired extent and should lead to improved cochlear blood flow [Suckfüll et al., Acta. Otolaryngol 119:763-766, 1999; Suckfüll, Lancet 360:1811-1817, 2002; Walch et al., Laryngol. Rhino. Otol. 75:641-645, 1996; Suckfüll et al., Otol. Neurotol. 23:309-311, 2002]. In a prospective uncontrolled pilot study on 36 patients with unilateral sudden onset sensorineural hearing loss (SHL) we tried to establish that 1-3 specific fibrinogen aphaereses alone improve recovery of hearing and that it is possible to lower fibrinogen to the target of 80-100 mg/dl without important side effects. Pure tone audiometry was carried out immediately before and after each aphaeresis as well as at 2 and 4 weeks and 6 months after treatment. Sixteen patients recovered spontaneously before undergoing fibrinogen adsorption. All 20 aphaeresis patients improved during immunoadsorption; in 60% of patients auditory thresholds returned to normal after the first immunoadsorption and treatment could be discontinued, in another 20% of patients complete recovery was reached after 4 weeks. The mean plasma fibrinogen concentration of the 20 patients before the first aphaeresis session was 308.1 +/- 51.5 mg/dl. Immediately after the first treatment session, the fibrinogen concentration was lowered to 100.7 +/- 25.3 mg/dl (P < 0.001). The second and third sessions also showed highly significant reductions in plasma fibrinogen. No important side effects were seen. In conclusion, specific fibrinogen adsorption is a promising new treatment modality that should be tested in a prospective, randomized controlled trial in patients with sudden hearing loss.

Adsorption↗

New trends in specific immunoadsorption.

Plasma exchange is widely accepted to remove pathogenic substances from patients' blood that cannot be eliminated otherwise like cholesterol in severe forms of familial hypercholesterolaemia or immunoglobulins and circulating immune complexes (CIC) in many autoimmune disorders. But dilution of other plasma proteins, as well as side effects and costs of substitution fluids, limit its efficiency. In immunoadsorption, the pathogen is bound specifically, generally no substitution fluids are needed and plasma can be conducted over the immunoadsorption columns as often as needed to achieve any reduction that one aims at, in some instances below the detection limit (e.g. HLA-antibodies in transplantations). The frequency of aphaereses is determined by the speed of the patients' improvement and the rebound of the eliminated substance, which can in some disorders be slowed down or stopped by concomitant immunosuppression. Generally, immunoadsorption is used in patients, where less expensive and demanding treatment options have failed, like severe hypercholesterolaemia, autoimmune disorders or hyperviscosity syndromes.

Autoantibodies↗

Lipoprotein (a) downregulates lysosomal acid lipase and induces interleukin-6 in human blood monocytes.

The association of elevated lipoprotein (a) (Lp(a)) with an increased risk for coronary events is clearly established. This increased risk may in part be due to the activation of monocytes as major cells involved in atherogenesis. High concentrations of plasma Lp(a) were shown to influence the gene expression of human blood monocytes and in the present study we demonstrate a reduced abundance of the lysosomal acid lipase (LAL) mRNA in monocytes of patients with coronary disease and selective Lp(a) hyperlipidemia. This is also supported by in vitro studies where purified Lp(a) but not low-density lipoprotein (LDL) was shown to downregulate mRNA levels of the LAL in control monocytes. A correlation of Lp(a) serum levels and the proinflammatory cytokine IL-6 was recently also described. Therefore, we investigated whether Lp(a) is capable to enhance the release of this acute phase cytokine from human blood monocytes. Purified Lp(a) led to an increased secretion of IL-6, but not TNF-alpha arguing against a general activation of these cells. The association of reduced LAL activity with the premature development of coronary artery disease has been demonstrated in patients with hypercholesterolemia, and in the present study we show for the first time that LAL expression is suppressed in monocytes from patients with Lp(a) hyperlipidemia and by purified Lp(a). In addition, increased levels of IL-6 also predict future cardiovascular events and IL-6 secretion was also induced by purified Lp(a).

Cells, Cultured↗