Hungarian Immunology

[Neonatal activation of interferon-γ in macrophages]

ERDŐS Melinda, MARÓDI László

MARCH 20, 2002

Hungarian Immunology - 2002;1(01)

[Each individual passes through developmental or transient immunodeficiency due to the immaturity of the immune system in early childhood, expecially in the neonatal period. Therefore, neonates contract infections by intracellular and extracellular microorganisms more easily than older children and adults, and develop more severe disease with a high mortality rate. A number of abnormalities in the neonate’s host defense systems have been described suggesting that the immune system at birth functionally differs from that in adults. Neonatal T and B cells show decreased reactivity to antigens and mitogens and have deficienct IgM-IgG isotype switching. Newborns have decreased functional capacities of the hemolytic complement system. Under the same in vitro and in vivo conditions neonatal granulocytes show functional deficiency earlier than adult cells. Effector mechanisms of the cell-mediated immunity involve activation of macrophages by T helper1 cytokines, particularly interferon- γ (IFN-γ). IFN-γ is the most important macrophage-activating cytokine in vivo. Neonatal T cells express lower levels of IFN-γ and macrophages are hyporesponsive to activation by this cytokine. This deficiency may be explained by decreased phosphorilation of STAT1 despite comparable expression of STAT1 protein in neonatal and adult macrophages.]



Further articles in this publication

Hungarian Immunology

[In memoriam professor Gyula Petrányi]


Hungarian Immunology

[Anti-inflammatory effects of high-dose intravenous immunoglobulin therapy in immunothrombocytopenic purpura]

ERDŐS Melinda, MARÓDI László

Hungarian Immunology

[2nd C1-esterase inhibitor deficiency workshop, April 2001, Budapest]

FARKAS Henriette, VARGA Lilian, HARMAT György, FÜST György

Hungarian Immunology

[Patomechanism of hereditary angioneurotic oedema and provoking factors of oedematous attacks]

FARKAS Henriette

[The author describes the genetic background of hereditary angioneurotic edema, an autosomal dominant disorder. The pathomechanism of edemaformation and the significance of major mediator substances are explained along with clinical manifestations and their management. A special emphasis is placed on prophylaxis, the mainstay of which is the elimination of precipitating factors. The latter include mechanical trauma, diagnostic and therapeutic interventions performed in the cephalic-cervical region, mental stress, and sex hormones. The effect of endocrine therapies, ACE inhibitors, and infections - Helicobacter pylori in particular - on the natural course of the disease is also discussed.]

Hungarian Immunology

[Relevances of anti-CD44 immunotherapy for cellular biology]

GÁL István, GLANT T. Tibor, MIKECZ Katalin

[INTRODUCTION - The CD44 molecule - the physiologic hialuronic acid receptor - is one of key mediators that direct the traffic of leukocytes into inflamed tissues. When applied in animal models of autoimmune arthritis, parenteral anti-CD44 antibody treatment exerts a dramatic antiinflammatory effect, but at high doses also a leukopenic effect. The goal of the present work is to elucidate the cellular basis of these phenomena. METHODS - In this study the authors used Western blot, immunoprecipitation, cell adhesion studies, flow chamber system studies (leukocyte rolling) and fluorescence microscopy following fluorescent labeling of actin cytoskeleton. RESULTS - Adhesion of CD44-expressing leukocytes to immobilized hialuronic acid does not result marked changes in cellular morphology. When incubated on immobilized anti-CD44 antibody, however, these cells spread, reorganize the actin cytoskeleton, and they adhere strongly to the surface. Studying the mechanisms of signal transduction, the authors found that engagement of CD44 with anti- CD44 antibody results in its enhanced association with numerous cytoskeletal regulator proteins, including ezrin, ankyrin, spectrin and focal adhesion kinase, thereby increasing the interaction between the cytoskeleton and the plasma membrane. Strong adhesion of the cells to immobilized anti-CD44 also prevents the rolling movement of these cells, mediated by CD44-hialuronic acid interactions, which precedes the extravasation of leukocytes to sites of inflammation. CONCLUSION - These results may provide insight into the antiinflammatory mechanisms of anti- CD44 antibody treatment. Based on these results and results published by other investigators, anti- CD44 antibodies may be uselful in the immunotherapy of rheumatic diseases.]

All articles in the issue

Related contents

Clinical Neuroscience

[The evaluation of paroxysmal events in neonates and infants]

NAGY Eszter, FARKAS Nelli, HOLLÓDY Katalin

[Introduction - Differential diagnosis of neonatal and infantile seizures based only on inspection poses a challenge even for specialists. Aims - To investigate the evaluations of neonatal and infantile paroxysmal events based only on inspection. Research question - Is there any difference in the opinion of neonatologists, paediatric neurologists and neurologists about the assessment of common paroxysmal events in infancy? Patients and methods - Video recordings about paroxysmal movements of 15 neonates or infants (aged 2 days- 5 months) were displayed for 47 paediatric neurologists, 35 neonatologists and nurses working in Neonatal or Perinatal Intensive Care Units and 43 neurologists. They had to decide without knowing the past medical history or EEG results whether events presented were epileptic or nonepileptic in nature. Results - Answers of neonatologists and paediatric neurologists were correct in 67% of cases (824/1230), no significant difference was found between their results. The largest uncertainty was in the judgement of discrete hand movements and very rapid clonus with epileptic origin, they were judged correctly by only one third of participants. The result of neurologists was only slightly, but not significantly different from that of paediatric neurologists. Conclusion - In most cases, the correct diagnosis of neonatal and infantile paroxysmal events requires video-EEG recording. No significant difference was revealed between the evaluation of neonatologists and paediatric neurologists about the differential diagnosis of movements. The ongoing cooperation of paediatric neurologists and neurologists going back to several decades facilitates the shaping of a common perspective.]

Clinical Neuroscience

Positive airway pressure normalizes glucose metabolism in obstructive sleep apnea independent of diabetes and obesity

KABELOĞLU Vasfiye, SENEL Benbir Gulçin, KARADENIZ Derya

The relationship among obstructive sleep apnea syndrome (OSAS), type 2 diabetes mellitus (DM2) and obesity is very complex and multi-directional. Obesity and increased visceral fat are important perpetuating factors for DM2 in patients with OSAS. On the other hand, OSAS itself leads to obesity by causing both leptin and insulin resistance as a consequence of activation of the sympathetic nervous system. Risk for developing DM2 further increases in patients with OSAS and obesity. Data regarding effects of positive airway pressure (PAP) therapy, gold standard treatment for OSAS, on glycemic control were inconsistent due to variability in duration of and adherence to PAP therapy. In our cohort study we investigated effects of PAP treatment on glucose metabolism in normal-weighted non-diabetic OSAS patients, in obese non-diabetic OSAS patients, and in OSAS patients with DM2. We prospectively analyzed 67 patients diagnosed with OSAS and documented to be effectively treated with PAP therapy for three months. Apnea-hypopnea index was highest in the diabetic group, being significantly higher than in the normal-weighted group (p=0.021). Mean HOMA values were significantly higher in obese (p=0.002) and diabetic group (p=0.001) than normal-weighted group; the differences were still significant after PAP therapy. HbA1c levels were significantly higher in diabetic group compared to those in normal-weighted (p=0.012) and obese (p=0.001) groups. After PAP treatment, decrease in HbA1c levels were significant in normal-weighted (p=0.008), obese (p=0.034), and diabetic (p=0.011) groups. There was no correlation with the change in HbA1c levels and age (p=0.212), BMI (p=0.322), AHI (p=0.098) or oxygen levels (p=0.122). Our study showed that treatment of OSAS by PAP therapy offers beneficial effect on glucose metabolism, not only in diabetic patients, but also in obese and normal-weighted OSAS patients. Although data regarding overall effects of PAP therapy on glycemic control present contradictory results in the literature, it should be emphasized that duration and adherence to PAP therapy were main determinants for beneficial outcome of treatment.

Clinical Neuroscience

A case with reversible neurotoxicity induced by metronidazole

EREN Fulya, ALDAN Ali Mehmet, DOGAN Burcu Vasfiye, GUL Gunay, SELCUK Hatem Hakan, SOYSAL Aysun

Background - Metronidazole is a synthetic antibiotic, which has been commonly used for protozoal and anaerobic infections. It rarely causes dose - and duration - unrelated reversible neurotoxicity. It can induce hyperintense T2/FLAIR MRI lesions in several areas of the brain. Although the clinical status is catastrophic, it is completely reversible after discontinuation of the medicine. Case report - 36-year-old female patient who had recent brain abscess history was under treatment of metronidazole for 40 days. She admitted to Emergency Department with newly onset myalgia, nausea, vomiting, blurred vision and cerebellar signs. She had nystagmus in all directions of gaze, ataxia and incompetence in tandem walk. Bilateral hyperintense lesions in splenium of corpus callosum, mesencephalon and dentate nuclei were detected in T2/FLAIR MRI. Although lumbar puncture analysis was normal, her lesions were thought to be related to activation of the brain abscess and metronidazole was started to be given by intravenous way instead of oral. As lesions got bigger and clinical status got worse, metronidazole was stopped. After discontinuation of metronidazole, we detected a dramatic improvement in patient’s clinical status and MRI lesions reduced. Conclusion - Although metronidazole induced neurotoxicity is a very rare complication of the treatment, clinicians should be aware of this entity because its adverse effects are completely reversible after discontinuation of the treatment.

Clinical Neuroscience

[Immunomodulatory treatment in multiple sclerosis ]


[During the past decade, several disease-modifying agents have been established and have become available for the treatment of multiple sclerosis. The disease-modifying agents could be grouped into immunomodulatory and immunosuppressive therapies altering the long-term course of multiple sclerosis. Therapy is now available for relapsing-remitting, secondary progressive and progressive-relapsing multiple sclerosis. Different disease-modifying agents became also available for the treatment of relapsing-remitting multiple sclerosis in Hungary which makes the therapeutic decision difficult. This overview might help to give an answer for different questions in the management of multiple sclerosis: Which agent to choose? When to initiate the therapy? Which dose to apply? Are the drugs safe? How long to treat the patients with immunomodulatory drugs? We give a review from the literature to assess the efficacy of disease-modifying therapies and to compare the data from phase three trials of interferon β1b, two preparations of interferon β1a or glatiramer acetate for the treatment of multiple sclerosis. We analyzed the efficacy and safety of these agents on physical, inflammatory and cognitive measures of disease activity. Comparison of study results indicated similar effects of immunomodulatory agents on relapse-related and inflammatory measures in relapsing multiple sclerosis. Interferon β1a slowed the progression of disability in relapsing multiple sclerosis. One interferon β1a preparation (intramuscularly injected) demonstrated efficacy in slowing progression of cognitive dysfunction. The interferons reduced relapses at early phase of secondary progressive multiple sclerosis, but their efficacy have not yet been proven in the later phase of secondary progressive multiple sclerosis without relapses. Mitoxantrone demonstrated efficacy in slowing the progression of disability in secondary progressive multiple sclerosis. All of the disease modifying agents are safe and tolerable, if the indication is correct and the patients are strictly controlled.]