[Treatment of sudden hearing loss through Fibrinogen/LDL-apheresis. A prospective, randomized multicenter trial]. / Behandlung des Hörsturzes durch Fibrinogen-LDL-Apherese. Eine prospektive randomisierte Multizenterstudie.

INTRODUCTION: Sudden sensorineural hearing loss (SSHL) is thought to be of various origins. Disturbances of microcirculation, autoimmune pathology and viral infection are among the most likely causes. Acute reduction of plasma fibrinogen and serum LDL positively influences hemorheology and endothelial function and might thus be an effective therapy for SSHL. OBJECTIVE: To test the hypothesis that fibrinogen/LDL-apheresis is as effective or superior to conventional therapy with plasma expanders and prednisolone in the treatment of SSHL. DESIGN: controlled, prospective, randomized, multicenter trial. SETTING AND PATIENTS: 201 patients were recruited from 01/2000 to 6/2001 at the University Clinics of Munich, Berlin, Hamburg and Bochum. Inclusion criteria was sudden sensorineural hearing loss of unknown origin within 6 days of onset. INTERVENTIONS: Single fibrinogen/ LDL-apheresis infusion of prednisolone (250 mg, tapered by 25 mg daily), hydroxyethyl starch (500 ml, 6%) and pentoxifylin (400 mg/day). MAIN OUTCOMES: Improvement of pure tone thresholds 48 h after onset of therapy. RESULTS: Over all improvement of pure tone thresholds in the fibrinogen/ LDL-apheresis treated patients is slightly but not significantly better than in the standard therapy group. After 48 h, 50% speech perception in the fibrinogen/ LDL-apheresis group (21.6+/-20.1 dB) is significantly (p<0.034) better than in the standard group (29.3+/-29.4 dB). Patients with plasma fibrinogen levels of more than 295 mg/dl have a substantial and significantly (p<0.005) better improvement of speech perception (15.3+/-17.3 dB) than standard treated patients (6.1+/-10.4 dB). CONCLUSIONS: Fibrinogen/LDLapheresis is at least equally effective compared to prednisolone treatment in sudden hearing loss. Selected patients with plasma fibrinogen of more than 295 mg/dl improve significantly better when treated with fibrinogen/LDLapheresis.

Effect of IL-4, IFN-gamma and IL-12 on cytokine production from human CD45RA and CD45RO CD4 T cell precursors.

The aim of this study was to compare the effects of IL-4, IL-12 and IFN-gamma on the production of T helper-1 (Th1) and T helper-2 (Th2)-type cytokines from human peripheral blood 'naive' CD45RA and 'memory' CD45RO CD4 T cells. CD45RA or CD45RO CD4 T cells were cultured for 4 days with phorbol myristate acetate (PMA) and ionomycin and either IL-4, IFN-gamma or IL-12 and their ability to proliferate and secrete IFN-gamma and IL-4 determined. Purified CD45RO CD4 T cells stimulated with PMA and ionomycin secreted higher levels of IL-4 and IFN-gamma, as measured by ELISA, than CD45RA CD4 T cells which secreted little IL-4 or IFN-gamma. However, CD45RA and CD45RO CD4 T cells proliferated to the same extent and IL-4, IFN-gamma and IL-12 had no effect on this. IL-12 and IFN-gamma had no effect on the amount of IL-4 secreted by PMA and ionomycin-stimulated CD45RO CD4 T cells, but culture with IL-4 enhanced IL-4 production 7-fold. IL-12 increased the amount of IFN-gamma produced by CD45RO CD4 T cells 2- to 3-fold. Small amounts of IFN-gamma production were induced in CD4 CD45RA T cells by IL-12 and IFN-gamma. These results indicate: (1) that CD45RA cells cannot make significant amounts of IL-4 under the conditions used, (2) that CD45RO cells can produce both Th1 and Th2 cytokines immediately upon restimulation, (3) that IL-12 favours Th1 cytokine production in both CD45RA and CD45RO CD4 T cells, and (4) that IFN-gamma favours IFN-gamma production in CD45RA but not CD45RO cells.

Immune memory in CD4+ CD45RA+ T cells.

This study addresses the question of whether human peripheral CD4+ CD45RA+ T cells possess antigen-specific immune memory. CD4+ CD45RA+ T cells were isolated by a combination of positive and negative selection. Putative CD4+ CD45RA+ cells expressed CD45RA (98.9%) and contained < 0.1% CD4+ CD45RO+ and < 0.5% CD4+ CD45RA+ CD45RO+ cells. Putative CD45RO+ cells expressed CD45RO (90%) and contained 9% CD45RA+ CD45RO+ and < 0.1% CD4+ CD45RA+ cells. The responder frequency of Dermatophagoides pteronyssinus-stimulated CD4+ CD45RA+ and CD4+ CD45RO+ T cells was determined in two atopic donors and found to be 1:11,314 and 1:8031 for CD4+ CD45RA+ and 1:1463 and 1:1408 for CD4+ CD45RO+ T cells. The responder frequencies of CD4+ CD45RA+ and CD4+ CD45RO+ T cells from two non-atopic, but exposed, donors were 1:78031 and 1:176,903 for CD4+ CD45RA+ and 1:9136 and 1:13,136 for CD4+ CD45RO+ T cells. T cells specific for D. pteronyssinus were cloned at limiting dilution following 10 days of bulk culture with D. pteronyssinus antigen. Sixty-eight clones were obtained from CD4+ CD45RO+ and 24 from CD4+ CD45RA+ T cells. All clones were CD3+ CD4+ CD45RO+ and proliferated in response to D. pteronyssinus antigens. Of 40 clones tested, none responded to Tubercule bacillus purified protein derivative (PPD). No difference was seen in the pattern of interleukin-4 (IL-4) or interferon-gamma (IFN-gamma) producing clones derived from CD4+ CD45RA+ and CD4+ CD45RO+ precursors, although freshly isolated and polyclonally activated CD4+ CD45RA+ T cells produced 20-30-fold lower levels of IL-4 and IFN-gamma than their CD4+ CD45RO+ counterparts. Sixty per cent of the clones used the same pool of V beta genes. These data support the hypothesis that immune memory resides in CD4+ CD45RA+ as well as CD4+ CD45RO+ T cells during the chronic immune response to inhaled antigen.