Healthier rhythm, healthier brain? Integrity of circadian melatonin and temperature rhythms relates to the clinical state of brain-injured patients.

BACKGROUND: Healthy circadian rhythmicity has been suggested to relate to a better state of brain-injured patients and to support the emergence of consciousness in patient groups characterized by a relative instability thereof such as patients with disorders of consciousness (DOC). METHODS: Going beyond earlier studies, a systems-level perspective was adopted and, using multilevel modelling, the joint predictive value of three indices of circadian rhythm integrity derived from skin temperature variations, melatoninsulfate secretion, and physical activity (wrist actigraphy) patterns was evaluated for the behaviourally assessed state [Coma Recovery Scale - Revised (CRS-R) score] of DOC patients [13 unresponsive wakefulness syndrome; seven minimally conscious (exit) state]. Additionally, it was assessed in a subset of 16 patients whether patients' behavioural repertoire (CRS-R score) varied (i) with time of day or (ii) offset from the body temperature maximum (BTmax ), i.e. when cognitive performance is expected to peak. RESULTS: The results reveal that better integrity of circadian melatoninsulfate and temperature rhythms relate to a richer behavioural repertoire. Moreover, higher CRS-R scores are, by trend, related to assessments taking place at a later daytime or deviating less from the pre-specified time of occurrence of BTmax . CONCLUSIONS: In conclusion, the results suggest that therapeutic approaches aimed at improving circadian rhythms in brain-injured patients are promising and should be implemented in hospitals or nursing homes. Beyond this, it might be helpful to schedule diagnostic procedures and therapies around the (pre-assessed) BTmax (≈4 pm in healthy individuals) as this is when patients should be most responsive.

Late age onset of amyotrophic lateral sclerosis is often not considered in elderly people.

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease causing an upper and lower motor neuron loss. It is neurology textbook knowledge that the mean age of onset is about 60 years. However, recent investigations show an increasing incidence in older persons. We therefore evaluated whether ALS is potentially not considered in elderly people with ALS symptoms, respectively, not recognized. MATERIALS AND METHODS: We included retrospectively all patients with ALS diagnoses after work-up that were admitted to our neurological and geriatric departments from 2007 to 2010 and collected their clinical data. The diagnosis of ALS was based on the El Escorial criteria. Patients were grouped into three categories according to age (<50, between 50 and 70, >70), and differences in clinical and/ or biographical factors were investigated. RESULTS: We identified 35 patients (18 men and 17 women) with a median age at onset of 71.5 years (range: 36-87 years). When establishing the diagnosis, 51% were older than 70 years, 40% (14/35) between 50 and 70, and only 9% younger than 50. Only in 46 per cent of patients who were sent to our departments with ALS symptoms ALS was considered by the referring physician. CONCLUSION: Late age onset of ALS seems to be more common than formerly assumed and is presumably under-recognized in elderly patients. ALS needs to be considered as a differential diagnosis in older patients. Potential factors accounting for older people being underdiagnosed with ALS relate to frequent presentation with symptoms like dysphagia, frailty or general weakness for other reasons.

Non-eosinophilic airway hyper-reactivity in mice, induced by IFN-γ producing CD4(+) and CD8(+) lung T cells, is responsive to steroid treatment.

Non-eosinophilic asthma is characterized by infiltration of neutrophils into the lung and variable responsiveness to glucocorticoids. The pathophysiological mechanisms have not been characterized in detail. Here, we present an experimental asthma model in mice associated with non-eosinophilic airway inflammation and airway hyper-responsiveness (AHR). For this, BALB/c mice were sensitized by biolistic DNA immunization with a plasmid encoding the model antigen ß-galactosidase (pFascin-ßGal mice). For comparison, eosinophilic airway inflammation was induced by subcutaneous injection of ßGal protein (ßGal mice). Intranasal challenge of mice in both groups induced AHR to a comparable extent as well as recruitment of inflammatory cells into the airways. In contrast to ßGal mice, which exhibited extensive eosinophilic infiltration in the lung, goblet cell hyperplasia and polarization of CD4(+) T cells into Th2 and Th17 cells, pFascin-ßGal mice showed considerable neutrophilia, but no goblet cell hyperplasia and a predominance of Th1 and Tc1 cells in the airways. Depletion studies in pFascin-ßGal mice revealed that CD4(+) and CD8(+) cells cooperated to induce maximum inflammation, but that neutrophilic infiltration was not a prerequisite for AHR induction. Treatment of pFascin-ßGal mice with dexamethasone before intranasal challenge did not affect neutrophilic infiltration, but significantly reduced AHR, infiltration of monocytes and lymphocytes as well as content of IFN-γ in the bronchoalveolar fluid. Our results suggest that non-eosinophilic asthma associated predominantly with Th1/Tc1 cells is susceptible to glucocorticoid treatment. pFascin-ßGal mice might represent a mouse model to study pathophysiological mechanisms proceeding in the subgroup of asthmatics with non-eosinophilic asthma that respond to inhaled steroids.

Assessment of a wireless headband for automatic sleep scoring.

PURPOSE: Classically, professional assessment of sleep is done in the sleep laboratory using whole-night polysomnography (PSG). However, given a misbalance between accredited sleep laboratories and the large amount of patients suffering from sleep disorders, only few receive appropriate diagnostic assessment. Recently, some low-cost home sleep scoring systems have been proposed, yet such systems are rarely tested scientifically. The aim of the present study was to evaluate the staging accuracy of the home sleep scoring system Zeo (Newton, MA, USA). METHODS: A final sample of 21 nights from ten subjects (aged 23-45) was digitally recorded with PSG as well as with the Zeo system. We compared scorings of Zeo (on an epoch-be-epoch basis) with the Somnolyzer 24 × 7 (an automatic staging algorithm), expert scorers as well as the freeware SleepExplorer. RESULTS: It was revealed that Zeo shows moderate overall agreement as compared to our study standard Somnolyzer 24 × 7 (κ = 0.56). The most obvious performance difference between Zeo and both other scoring approaches was stage wake (sleep onset latency + wake after sleep onset). While Zeo detected only 40.8 % of the study standard wake epochs, 70.1 % were detected by the expert scorers and 83.4 % by the SleepExplorer, respectively. CONCLUSIONS: Data suggest that the Zeo system produces acceptable sleep scoring for stage REM, light and deep sleep, with a specific weakness in correctly detecting waking periods.

Treatment of vertebral artery origin stenosis with a Pharos stent device: a single center experience.

Atherosclerotic stenosis of vertebral artery (VA) origin exceeding 70% severity accounts for one third of all vertebrobasilar strokes. For a period of one year the results of endovascular treatment of VA stenosis with the new Pharos stent device were assessed.Twenty-two patients with symptomatic VA stenosis were treated with the Pharos stent. Clinical status and stenosis grade were documented before treatment and 24 hours, one, three and twelve months after treatment via ultrasound and magnetic resonance tomography.All procedures proved to be technically successful without the occurrence of intra-procedural complications. During the observation period of more than one year, 55% of patients were documented with a mean stenosis degree of 60%: two (10%) of these patients showed a residual stenosis after angioplasty and nine patients (45%) an in-stent restenosis, whereas only two patients were documented with a hemodynamically relevant in-stent restenosis of 80%. These two patients were retreated with balloon dilatation. None of the patients showed neurological deterioration or new abnormalities at magnetic resonance tomography examination. Neither VA occlusion nor restenosis of the contralateral VA negatively affected the clinical outcome. An in-stent restenosis was developed by more female than male patients.VA origin stenting with the Pharos stent device is an effective treatment of stenosis. The good clinical results compared to the high restenosis rates have to be examined in further studies. Pin particular, it has to be determined whether the Pharos stent allows the vessel time for collateralization, whether double antiplatelet treatment prevents recurrent cerebrovascular events or whether merely the low restenosis degree is causative for the clinical outcome.

Cerebral localized marginal zone lymphoma presenting as hypothalamic-pituitary region disorder.

INTRODUCTION: Marginal zone B-cell lymphoma is a rare disease which can be considerably difficult to recognize and diagnose when signs of systemic involvement are absent. CASE PRESENTATION: We report the case of a 57-year-old woman with initial olfactory disturbance, followed by psychosis, diabetes insipidus and hypothalamic eating disorder as an uncommon clinical presentation of marginal zone B-cell lymphoma. CONCLUSION: Marginal zone B-cell lymphoma should be considered as a potential differential diagnosis in patients with hypothalamic disturbances.

Classification of Non-Aneurysmal Subarachnoid Haemorrhage: CT Correlation to the Clinical Outcome.

To propose a new computed tomography (CT)-based classification system for nonaneurysmal subarachnoid haemorrhage (SAH), which predicts patients' discharge clinical outcome and helps to prioritize appropriate patient management. A 5-year, retrospective, two-centre study was carried out involving 1486 patients presenting with SAH. One hundred and ninety patients with nonaneurysmal SAH were included in the study. Initial cranial CT findings at admission were correlated with the patients' discharge outcomes measured using the Modified Rankin Scale (MRS). A CT-based classification system (type 1 e 4) was devised based on the topography of the initial haemorrhage pattern. Seventy-five percent of the patients had type 1 haemorrhage and all these patients had a good clinical outcome with a discharge MRS of 1. Eight percent of the patients presented with type 2 haemorrhage, 62% of which were discharged with MRS of 1 and 12% of patients had MRS 3 or 4. Type 3 haemorrhage was found in 10%, of which 16% had good clinical outcome, but 53% had moderate to severe disability (MRS 3 and 4) and 5% were discharged with severe disability (MRS 5). Six percent of patients presented with type 4 haemorrhage of which 42% of the patients had moderate to severe disability (MRS 3 and 4), 42% had severe disability and one-sixth of the patients died. Highly significant differences were found between type 1 (1a and 1b) and type 2 (p» 0.003); type 2 and type 3 (p » 0.002); type 3 and type 4 (p » 0.001). Haemorrhages of the type 1 category are usually benign and do not warrant an extensive battery of clinical and radiological investigations. Type 2 haemorrhages have a varying prognosis and need to be investigated and managed along similar lines as that of an aneurysmal haemorrhage with emphasis towards radiological investigation. Type 3 and type 4 haemorrhages need to be extensively investigated to find an underlying cause.

Classification of non-aneurysmal subarachnoid haemorrhage: CT correlation to the clinical outcome.

AIM: To propose a new computed tomography (CT)-based classification system for non-aneurysmal subarachnoid haemorrhage (SAH), which predicts patients' discharge clinical outcome and helps to prioritize appropriate patient management. METHODS AND MATERIALS: A 5-year, retrospective, two-centre study was carried out involving 1486 patients presenting with SAH. One hundred and ninety patients with non-aneurysmal SAH were included in the study. Initial cranial CT findings at admission were correlated with the patients' discharge outcomes measured using the Modified Rankin Scale (MRS). A CT-based classification system (type 1-4) was devised based on the topography of the initial haemorrhage pattern. RESULTS: Seventy-five percent of the patients had type 1 haemorrhage and all these patients had a good clinical outcome with a discharge MRS of

Antigen dose-dependent suppression of murine IgE responses is mediated by CD4(-)CD8(-) double-negative T cells.

BACKGROUND: The IgE response against protein antigens is profoundly influenced by the dose used for sensitization. OBJECTIVE: The aim of the study was to identify immune cells that are involved in antigen dose-dependent regulation of IgE formation. METHODS: Wild-type mice as well as T helper (Th)1-deficient IL-12p40(-/-) and IFN-gamma(-/-) mice were immunized by repeated intraperitoneal injection of either low doses (K01 mice) or high doses (K100 mice) of keyhole limpet haemocyanin adsorbed to aluminium hydroxide. Splenocytes of immunized mice were restimulated in vitro and antigen-dependent T cell proliferation and cytokine production were measured. The frequency of regulatory T cell subsets among splenocytes from K01 and K100 mice was compared using fluorocytometry and RT-PCR analysis. Splenocytes or T cell subpopulations were transferred into naïve mice and the effect of lymphocyte transfer on IgE production after priming of recipients with low antigen doses was determined. RESULTS: Specific IgE production was considerably impaired in K100 mice. Antigenic restimulation revealed hypoproliferation of K100 splenocytes and reduced production of Th2 cytokines IL-4, IL-5 and IL-13, but no induction of IFN-gamma production. Moreover, lymphocytes from K01 and K100 mice did not show significant differences in the expression of molecules associated with the phenotype or activity of conventional regulatory T cells. Transfer of splenocytes or purified T cells from K100 mice substantially suppressed the induction of IgE production in the recipients in an antigen- and isotype-specific manner. Neither CD4(+) nor CD8(+) T cells from K100 mice were able to inhibit IgE formation; instead, we identified CD4(-)CD8(-) double-negative T cells (dnT cells) as the principal T cell population, which potently suppressed IgE production. CONCLUSION: Our data demonstrate that CD4(-)CD8(-) dnT cells play a major role in the regulation of IgE responses induced by high antigen doses.

Transcriptional targeting of dendritic cells for gene therapy using the promoter of the cytoskeletal protein fascin.

Strong cell-type-specific promoters are basic tools in gene therapy allowing for novel applications and focused strategies by transcriptionally targeting gene expression to selected cells. In immunotherapy, dendritic cells (DC) are of central importance, since they represent the principal inducers of immune responses. Here we describe isolation and use of the promoter of the murine actin-bundling protein fascin to target transcriptionally gene expression to cutaneous DC. Using the reporter gene enhanced green fluorescent protein (EGFP), we demonstrate that the fascin promoter mediates a strong antigen expression that is restricted to mature DC. DNA vaccination with antigen-encoding expression vectors under control of the fascin promoter using a gene gun resulted, consistently, in limited antigen expression by few directly transfected DC. Nevertheless, nearly as many antigen-specific CD8+ T cells directed against the encoded antigens EGFP and beta-galactosidase, respectively, were induced as with expression constructs under control of the ubiquitously expressed CMV promoter. This result impressively underlines the pivotal role of directly transfected DC in DNA vaccination. Immunization using the fascin promoter induced markedly lower levels of antigen-specific antibodies following single or repeated immunization. Thus, our DC-targeted DNA vaccination approach induces qualitatively distinct, predominantly cellular immune responses and provides new opportunities for immunotherapy.

Efficacy of recombinant adenovirus as vector for allergen gene therapy in a mouse model of type I allergy.

DNA-based immunization represents an attractive alternative approach to the current treatment of allergic diseases by specific immunotherapy with allergen extracts. In this study, we used a replication-deficient adenovirus vector (AdCMV), to examine the in vivo efficacy of preventive and therapeutic genetic immunization in a mouse model of type I allergy. Primary immunization with a recombinant adenovirus expressing the model antigen beta-galactosidase (AdCMV-(beta)gal) induced a Th1 immune response (predominance of IgG2a antibodies, high frequency of IFN-gamma producing T cells) and large numbers of cytotoxic T lymphocytes. Prophylactic vaccination with AdCMV-(beta)gal abolished the production of specific IgE following subsequent immunization with (beta)gal-protein, and skewed the Th2-biased immune response to a Th1-orientated response. In contrast, therapeutic administration of AdCMV-(beta)gal after priming with (beta)gal-protein neither significantly inhibited ongoing IgE production nor modulated a manifest Th2 immune response. Thus, allergen gene transfer via recombinant adenovirus represents an effective method to establish protection against the development of allergic disorders, but does not qualify as a therapeutic tool to interfere with ongoing high IgE production.

The role of NO in contact hypersensitivity.

Contact dermatitis or contact hypersensitivity (CHS) is a common T lymphocyte-mediated allergic disease characterized by local inflammatory skin reactions following contact with small reactive compounds called haptens. In common with other allergic processes, the development of contact dermatitis proceeds in two phases: a sensitization phase which occurs on first exposure to allergen, and an elicitation phase which occurs on subsequent exposure when the clinical manifestations of the disease are observed. This process is hapten-specific. While the pathophysiology of the sensitization phase is well characterized, our understanding of the elicitation phase is still incomplete, including the relative contribution of the different effector cells and mediators involved. Here we summarize current knowledge of the contribution of nitric oxide (NO) to skin inflammation with special focus on CHS. A number of inflammatory stimuli trigger expression of NO in human and animal skin, and topical application of an NO-releasing cream results in inflammation. Moreover, expression of the inducible isoform of nitric oxide synthase (iNOS) is induced in CHS and iNOS inhibitors injected intradermally suppress CHS responses. However, iNOS-deficient mice develop an aggravated CHS response late in the elicitation phase, suggesting that NO is involved in downregulation of CHS. Based on these data, we propose a comprehensive model of the role of NO in CHS.

Expression of the actin-bundling protein fascin in cultured human dendritic cells correlates with dendritic morphology and cell differentiation.

Dendritic cells are key players of the immune system as they efficiently induce primary immune responses by activating naive T cells. We generated human dendritic cells from CD14+ blood precursors and investigated expression of the actin-bundling protein fascin during maturation by western blotting, immunofluorescence, and cytofluorometry. Cells obtained by culture of CD14+ blood precursors in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4, which were only weakly positive for the maturation marker CD83, expressed low amounts of fascin. Addition of a cytokine cocktail including tumor necrosis factor alpha, interleukin-1beta, interleukin-6, and prostaglandin E2 induced maturation of the cells and enhanced fascin expression in parallel with CD83 expression. Isolated mature CD83+ cells displayed especially high fascin levels on western blots, as did gated CD83+ dendritic cells in cytofluorometry. Dendritic cells generated from CD34+ blood precursors expressed high levels of fascin as well. Confocal microscopy revealed that location of fascin within the cell was restricted to the area of the submembranous actin cytoskeleton and to the dendritic processes. Suppression experiments using antisense constructs of fascin hint at a retarded morphologic maturation of dendritic cells, supporting the view that fascin expression is pivotal for dendrite formation. Our data suggest that fascin could serve as a marker molecule to monitor the maturation state of in vitro generated dendritic cells for use in clinical trials.

Deficient cytokine response of human allergen-specific T lymphocytes from humanized SCID mice and reconstitution by professional antigen-presenting cells.

BACKGROUND: Hu-PBL-SCID mice generated by the transfer of PBMCs from atopic individuals may provide a physiologic in vivo model for investigating human responses to allergens and potential approaches toward immunotherapy. OBJECTIVE: This study was undertaken to investigate the functional activity and cytokine profile of human allergen-reactive T lymphocytes isolated from hu-PBL-SCID mice. METHODS: PBMCs from allergic individuals were coinjected with allergen into SCID mice. Human lymphocyte migration and phenotype were established by reverse transcription-PCR and immunohistochemistry, IgE levels in sera were determined, and the frequency of allergen-reactive cytokine-producing T lymphocytes was established. RESULTS: After immunization with allergen, specific IgE levels in hu-PBL-SCID sera were comparable with levels in donor sera. Although the majority of lymphocytes remained in the peritoneum, significant numbers of T lymphocytes were located in the spleen, where human IL-4, IL-5, and IFN-gamma messenger RNA expression was detected after stimulation with PHA and phorbol myristate acetate. Failure to induce cytokine production by human T lymphocytes isolated from the peritoneum and spleen of hu-PBL-SCID mice by allergen was reversed by stimulating with allergen in the presence of exogenously added IL-2 and antigen-presenting cells (APC), particularly CD14(+) monocytes. Under these conditions, allergen-reactive T cells expressed a T(H)2-like phenotype. CONCLUSIONS: These data suggest that, after initial activation and induction of antibody production, human T lymphocytes enter a state of unresponsiveness, arising from a loss of human professional APC, in hu-PBL-SCID mice. The use of hu-PBL-SCID mouse models in studies on therapeutic approaches for allergy may benefit from the additional transfer of human professional APC.

Consequences of antigen self-presentation by tumor-specific cytotoxic T cells.

CD8-positive cytotoxic T cells (CTL) recognize antigenic peptides in combination with major histocompatibility complex (MHC) class I molecules on the surface of syngeneic antigen presenting cells (APC). In the present paper we show that cells from tumor antigen-specific CTL clones present their cognate antigenic peptide to other CTL from the same clone. Inter-CTL peptide presentation resulted in activation of the cells of one CTL clone to MHC-unrestricted lysis of bystander cells. In contrast to the behaviour of this clone, another CTL clone did not lyse bystander cells after incubation with the cognate peptide, but was activated to self-destruction. The human herpes virus Epstein-Barr virus is involved in the pathogenesis of a broad spectrum of human neoplasias. Using freshly established non-clonal T cells with specificity for a peptide derived from an Epstein-Barr virus encoded antigen we found again lysis of MHC mismatched bystander cells as a consequence of inter-CTL peptide presentation, indicating that bystander lysis following antigen self-presentation is not a phenomenon restricted to long-term in vitro cultured T cell clones. The potential implications for immunosurveillance against cancer and for tumor escape mechanisms are discussed.

Maturation of epidermal Langerhans cells: increased expression of beta- and gamma-actin isoforms as a basis of specialized cell functions.

Epidermal Langerhans cells (LC) represent immature dendritic cells. During in vitro culture in the presence of keratinocytes they mature into potent immunostimulatory cells for naive T cells. This process is thought to simulate in vivo maturation of LC following activation by antigen contact. Maturation of LC is accompanied by morphological alterations. Applying a differential screening procedure we isolated differentially expressed cDNAs involved in the maturation events including cDNAs of the cytoskeletal actin isoforms beta- and gamma-actin. Stronger signals with hybridization probes derived from cultured LC compared with probes derived from freshly isolated LC indicate upregulation of actin expression. Upregulated expression of actin was confirmed by RT-PCR, Western blot and immunofluorescence analysis. Staining with fluorescence-labelled phalloidin that selectively binds to polymerized F-actin, indicates an increase in F-actin levels in cultured LC. Thus our data show that maturation of LC, which involves formation of dendritic structures and movement of formerly immobile cells, is accompanied by augmented expression of actin and formation of additional actin filaments. Furthermore, actin mRNA, often used as reference to assess mRNA amounts for Northern blotting or competitive RT-PCR because of its high and ubiquitous expression, is an inappropriate standard for the analysis of LC and DC.

[Methods for monitoring of therapeutic efficacy in immunotherapy of allergic rhinitis]. / Möglichkeiten zur Beurteilung des Therapieerfolges bei einer Immuntherapie bei Rhinitis allergica.

Efficacy monitoring of immunotherapy (IT) is performed to adjust the therapy according to the patient's reactions, to collect data for scientific studies and to evaluate the efficacy of IT. A decrease of allergy symptoms and of drug use are the main parameters. For this, allergy diaries are most suitable. Pollen exposition should be monitored with Burkhard traps. Wheal and flare reactions in skin tests can be measured by visual inspection with quantification of the diameter on transparent foils or by means of laser scanners. Nasal provocation testing leads to subjective and objective (rhinomanometry, acoustic rhinometry) results. A change in the threshold concentration of allergen, which is needed to provoke a positive test reaction, can be used to evaluate the success of an IT. Additionally, systemic or local side-effects should be carefully revealed. Cytologic measures can be achieved by nasal lavages. Cotton samplers, cytology brushes and suction techniques are used to collect cells and nasal secretions. Early and late allergic reactions can be evaluated. Specific cell activation markers like ECP or tryptase are useful parameters in nasal secretions. T-lymphocyte subpopulations and T-cell-lymphokine-profiles can be detected. During IT, a change from a dominating TH2-cytokine-profile to a dominating TH1-cytokine-profile can be seen. For the reason of their expense, those methods are restricted to scientific investigations and only rarely used for routine diagnostics.

[Theories on the mode of action of desensitization]. / Theorien zur Wirkweise der Hyposensibilisierung.

Specific immunotherapy (SIT) has been practised successfully for about 80 years. In classic immunotherapy, an allergen-extract is repeatedly injected subcutaneously in increasing doses. A large number of clinically controlled studies have proved the efficacy of this kind of immunotherapy, while its mode of action is not precisely known yet. A successful SIT leads to an impairment of allergic symptoms (symptom score), and a concordant decrease in drug use. Furthermore, a reduced reactivity in specific dermal, nasal and bronchial provocation tests is induced as well as a diminished unspecific reagibility in the affected tissues. Several studies showed reduced values for allergen-specific IgE (serum) that followed an initial increase. A reduced immigration of eosinophils was found, both after provocation with allergen and during the pollen season, as well as diminished values of markers for the activity of eosinophils, e.g. eosinophil cationic protein (ECP). Also, a reduced allergen-induced histamine-liberation from mast cells and basophils has been reported. The underlying mechanism for these effects of SIT might be a reorientation of the allergen-induced lymphokine-production to a dominant TH1-cytokine-profile. Because the relation between the quantity of IL-4 and its regulator IFN-gamma controls the extent of IgE-synthesis by B-cells, the reorientation leads to a diminished production of IgE. IFN-gamma inhibits the differentiation of TH2-cells; by this less TH2-cells are present to help B-cells to produce IgE-antibodies, and to induce the differentiation of mast cells and basophils as well as immigration, differentiation and activation of eosinophils. Thus, the positive effects of SIT can be explained by the reorientation T-cell lymphokine profile. The mechanism under discussion for explaining this reorientation include: 1) an increased differentiation of allergen-specific CD4+ precursor-cells or a reorientation of established TH2-cells to the production of IFN-gamma, 2) the differentiation of IFN-gamma-producing CD8+ T-cells and of T-cells with receptors for T-cell-antigenes of the gamma, delta-type; and 3) the induction of an energy in TH2-cells.