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Peripheral Blood Eosinophils (peripheral + blood_eosinophil)
Selected AbstractsCurrent epidemiology of atopic dermatitis in south-eastern NigeriaINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 10 2004Edith N. Nnoruka MB Background, Atopic dermatitis (AD) is a common pruritic, eczematous skin disorder that runs a chronic and relapsing course. In Nigeria, it is currently on the increase, particularly amongst infants, and has created cost burdens for families. It occurs in association with a personal or family history of asthma, allergic rhinitis and conjunctivitis. Major and minor criteria exist as guidelines for arriving at a diagnosis of AD, and surveys from Western countries have shown that these features, in particular the minor features, vary with ethnicity and genetic background and can be used to aid diagnosis. African dermatologists have also voiced concern that the much used Hanifin criteria for diagnosis of AD may need some adaptation for use in Africa. Objective, To document the features and disease outcomes of AD seen amongst dermatology hospital patients in Enugu, south-eastern Nigeria, with a view to reflecting current features amongst Nigerian Blacks. Methods, A prospective study of AD patients seen over a 2-year period at a tertiary referral dermatology clinic (University of Nigeria Teaching Hospital, Enugu, Nigeria) was carried out. A total of 1019 patients aged between 4 weeks and 57 years were included in the study. Results, The prevalence of AD was 8.5%, which is much higher than the prevalence of AD reported in various parts of Nigeria 15 years ago. AD occurred before the age of 10 years in 523 (51.3%) patients, whilst 250 (24.5%) had onset after 21 years. The earliest age of onset in infants was in the first 6 weeks of life, and this was found in 129 patients (12.7%). Education and occupation of household heads were the most significant (P < 0.001) factors associated with seeking proper health care for the child's AD. Four hundred and forty-one (43.3%) patients presented with subacute atopic eczema and 326 (32%) patients with severe impeteginized eczema. Four hundred and twenty-five patients (41.7%) had at least one first-degree family member with AD (16.7%), allergic rhinitis (10.3%), asthma (14.6%) and allergic conjunctivitis (2.1%), while 55 (13.3%) of controls had a positive family history (P < 0.01) of allergy. A personal history of AD only, without concomitant respiratory allergies, was seen in 486 (47.7%) patients. The face was affected in 431 (42.3%) patients. Inverse distribution of a flexural rash was observed over the extensor aspect of the joints: the elbow in 502 patients (49.3%), the wrist joint in 183 patients (17.9%) and the knee joints in 354 patients (34.7). The commonly observed minor features included xerosis in 719 patients (71%), papular lichenoid lesions in 547 patients (54.1%), infraorbital folds in 498 patients (49.2%), palmar hyper linearity in 524 patients (51.8%) and raised peripheral blood eosinophils in 519 patients (51%), particularly for those with severe AD. Fissured heels, forehead lichenification, orbital darkening, nail pitting, sand paper-like skin lesions on the elbows/knees/lateral malleolli, knuckle dermatitis of the hands, palmar erythema and pitted keratolysis occurred more uncommonly as minor features. Infective complications were very common and included bacterial infections (folliculitis, impetiginized dermatitis and pyodermas) in 425 (41.7%) patients, fungal infections in 377 (37%) patients, parasitic infections (scabies) in 90 (8.8%) patients and viral infection (herpes simplex and molluscum contagiosum) in 29 (2.9%) patients. Thirteen of these atopics were also HIV positive. Aggravating factors most commonly reported included heat intolerance, excessive sweating, humidity, grass intolerance, thick woollen clothing and drug reactions. Only three patients had food intolerance. Three hundred and ten patients (30.4%) recalled their AD being worse in the hot humid periods and 383 (37.6%) could not recall any periods of relief or remission. Conclusions, The prevalence of AD amongst south-eastern Nigerian Blacks is on the increase, as in other areas, although it is still lower here than in other parts of the world. Many conventional minor features were found, but some occurred less frequently than in other countries, which may be attributed to ethnicity. Further studies will be required to confirm the ethnic differences in these features of AD amongst Nigerians and other Africans, to clarify the features of AD that are peculiar to Africans. [source] Protection in lambs vaccinated with Haemonchus contortus antigens is age related, and correlates with IgE rather than IgG1 antibodyPARASITE IMMUNOLOGY, Issue 1 2000Kooyman Protection by vaccination with excretory,secretory products (ES) from Haemonchus contortus, containing predominantly proteins of 15 and 24 kDa, against an experimental challenge infection depends on the age of the sheep. Vaccinated sheep 9, 6 or 3 months of age were protected for 83%, 77% and ,34%, respectively. There was a significant difference in ES-specific serum IgE response but not in IgG1 response, after the last vaccination between the different age groups. In the protected 9-month-old animals, there was an increase up to 18 times the prevaccination levels, while the increase in the unprotected 3-month-old animals was at most 1.4 times. The 6-month-old animals showed an intermediate increase of approximately six times the prevaccination level. There was no correlation within the 9-month-old sheep between ES-specific IgE levels and protection, measured as worm burden. However, when the different age groups were combined, there was a positive correlation (r = 0.38) between protection and ES-specific IgE levels 1 week after the vaccination. At the end of the experiment, peripheral blood eosinophils and mast cell counts in abomasal tissue were also significantly higher in the vaccinated and challenged 9-month-old sheep than in the vaccinated and challenged 3-month-old or than in the 9-month-old sheep with challenge, but without vaccination. Increased serum IgE levels, eosinophilia and mucosal mast cell hyperplasia are the hallmarks of a Th2 response and were all demonstrated in protected, older sheep, but not in unprotected, younger sheep. [source] Selective priming of peripheral blood eosinophils in patients with idiopathic hypereosinophilic syndrome,APMIS, Issue 11 2006MARIA LAMPINEN The idiopathic hypereosinophilic syndrome (HES) is characterised by blood eosinophilia associated with organ involvement. Elevated numbers of blood neutrophils have been observed during episodes of active HES. However, an increased responsiveness of eosinophils to chemotactic and chemokinetic stimuli may explain the selective eosinophil infiltration of the tissue. We have studied the migratory responses of blood eosinophils and neutrophils from 9 patients with HES and from 13 healthy control subjects. Chemokinetic and chemotactic responses to factors acting on both cell types were analysed by means of a modification of the Boyden chamber technique. We found increased migratory responses of the eosinophils, but not of the neutrophils, from the patients with HES. Increased blood neutrophil counts in three of the patients did not coincide with alterations of the neutrophil migratory responses. Our finding of increased migratory responses of eosinophils from patients with HES towards non-specific chemoattractants suggests selective priming of eosinophils in this disease. Interleukin (IL)-5 has previously been shown to prime eosinophils for migratory responses, and successful anti-IL-5 therapy of patients with HES indicates an important role for this cytokine in the development of hypereosinophilia. [source] Characteristics of extrinsic vs. intrinsic atopic dermatitis in infancy: correlations with laboratory variablesBRITISH JOURNAL OF DERMATOLOGY, Issue 4 2006J-H. Park Summary Background, Atopic dermatitis (AD) has been divided into the extrinsic type (ADe) and the intrinsic type (ADi) according to the serum IgE levels and the presence or absence of allergen-specific IgE. Although previous studies have demonstrated differences in the various immunological parameters, the characteristics of AD in infancy have rarely been reported. Objectives, Our study was performed to analyse the correlations between the laboratory parameters of infantile ADe and ADi. Methods, We recruited 237 infants with AD and checked the SCORAD index, the number of peripheral blood eosinophils, the serum eosinophil cationic protein (ECP) levels, the total serum IgE levels and the specific serum IgE levels in all the patients. We also checked the serum interleukin (IL)-4 and IL-5 levels in 20 patients with ADe and in 20 with ADi. Results, This study showed many peculiar characteristics of infantile AD. In infancy, ADi was more prevalent than ADe. The eosinophil count, the ECP level and the SCORAD in ADi were lower than in ADe. Furthermore, a group of patients without characteristics of ADi or ADe could be identified. We tentatively classify this group as indeterminate type (ADind) and propose it as a separate entity. The clinical severity was well correlated with the eosinophil count and the serum ECP levels in ADe and ADi. Therefore these two parameters could be used as clinical severity markers in infancy. Infants are more allergic to food, and the variety of specific allergenic responses was connected with clinical severity. A higher eosinophil count, a higher ECP level and a higher detection rate of IL-5 in the peripheral blood of infants with ADe means that eosinophils have a more prominent role in ADe than in ADi. Conclusions, Infantile AD has many distinctive features in its laboratory variables as compared with AD in other age groups. Clinicians should recognize these facts when they deal with infants with AD, and further studies are warranted on the natural course of infantile AD. [source] A mechanism of benefit of soy genistein in asthma: inhibition of eosinophil p38-dependent leukotriene synthesisCLINICAL & EXPERIMENTAL ALLERGY, Issue 1 2008R. Kalhan Summary Background Dietary intake of the soy isoflavone genistein is associated with reduced severity of asthma, but the mechanisms responsible for this effect are unknown. Objective To determine whether genistein blocks eosinophil leukotriene C4 (LTC4) synthesis and to evaluate the mechanism of this effect, and to assess the impact of a 4-week period of soy isoflavone dietary supplementation on indices of eosinophilic inflammation in asthma patients. Methods Human peripheral blood eosinophils were stimulated in the absence and presence of genistein, and LTC4 synthesis was measured. 5-lipoxygenase (5-LO) nuclear membrane translocation was assessed by confocal immunofluorescence microscopy. Mitogen-activated protein (MAP) kinase activation was determined by immunoblot. Human subjects with mild-to-moderate persistent asthma and minimal or no soy intake were given a soy isoflavone supplement (100 mg/day) for 4 weeks. The fraction of exhaled nitric oxide (FENO) and ex vivo eosinophil LTC4 production were assessed before and after the soy isoflavone treatment period. Results Genistein inhibited eosinophil LTC4 synthesis (IC50 80 nm), blocked phosphorylation of p38 MAP kinase and its downstream target MAPKAP-2, and reduced translocation of 5-LO to the nuclear membrane. In patients with asthma, following 4 weeks of dietary soy isoflavone supplementation, ex vivo eosinophil LTC4 synthesis decreased by 33% (N=11, P=0.02) and FENO decreased by 18% (N=13, P=0.03). Conclusion At physiologically relevant concentrations, genistein inhibits eosinophil LTC4 synthesis in vitro, probably by blocking p38- and MAPKAP-2-dependent activation of 5-LO. In asthma patients, dietary soy isoflavone supplementation reduces eosinophil LTC4 synthesis and eosinophilic airway inflammation. These results support a potential role for soy isoflavones in the treatment of asthma. [source] Effects of inhaled ciclesonide on circulating T-helper type 1/T-helper type 2 cells in atopic asthmatics after allergen challengeCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2006T. Kawayama Summary Background The predominance of T-helper type 2 (Th2) lymphocytes is thought to underlie the pathogenesis of asthma. Allergen inhalation challenge in atopic asthmatic subjects is associated with decreased interferon-, (IFN-,) positive CD4+ and CD8+ lymphocytes in peripheral blood and induced sputum. Objective This study examined the effects of an inhaled corticosteroid on these previously described allergen-induced changes in circulating Th1 and Th2 lymphocytes. Methods Subjects were randomized to 7 days of placebo, 40 or 80 ,g ciclesonide in a crossover study. Airway responses and peripheral blood were measured before and after treatment, and 24 h after allergen challenge. Results Ciclesonide 40 and 80 ,g significantly attenuated the late response and sputum eosinophils at 8 h post-allergen (P<0.05). Circulating IFN-, positive CD4+ lymphocytes decreased after allergen challenge with placebo (P<0.05), and this was inhibited by 40 ,g ciclesonide treatment (P<0.05). There was no effect of allergen inhalation or ciclesonide on IL-4-positive CD4+ lymphocytes or IFN-, and IL-4-positive CD8high lymphocytes. The allergen-induced change of IFN-,/IL-4 ratio on CD4+ cells correlated with the allergen-induced change of peripheral blood eosinophils. Conclusions The results of this study suggest that attenuation of allergen-induced airway responses by ciclesonide may be mediated through regulation of IFN-,-positive CD4+ cells. [source] Increased expression of collagen receptors: ,1,1 and ,2,1 integrins on blood eosinophils in bronchial asthmaCLINICAL & EXPERIMENTAL ALLERGY, Issue 9 2006S. Bazan-Socha Summary Background Eosinophils are one of the major effector cells in bronchial asthma. Their infiltration of airways correlates with the asthma severity. Recruitment and activation of eosinophils are partially mediated by integrins ,4,1 and ,4,7. Collagens type I and IV constitute important components of extracellular matrix and vascular basement membrane, respectively. Therefore, collagen-binding integrins (,1,1 and ,2,1) may also play a role in eosinophil lung infiltration. Objective To evaluate the possible presence of ,1,1 and ,2,1 integrins on peripheral blood eosinophils from asthmatic subjects. Methods Collagen receptors were studied on eosinophils separated by immunomagnetic CD16-negative method from healthy donors (n=13) and patients with moderate persistent atopic bronchial asthma (n=15). Surface receptor identification was performed by flow cytometry and cell adhesion assay. Results Eosinophils isolated from the patients showed increased expression of both ,1,1 and ,2,1 integrins as compared with healthy controls. Moreover, adhesive function of eosinophils to collagen type IV was inhibited by snake venom disintegrins: viperistatin and obtustatin. These disintegrins contain KTS active motif and are specific inhibitors of ,1,1 integrin. Conclusion We demonstrated for the first time that collagen receptors: ,1,1 and ,2,1 integrins are overexpressed on the surface of peripheral blood eosinophils of asthmatic subjects. Further studies may reveal potential application of KTS-disintegrins or their structural analogs for therapy of bronchial asthma. [source] Levels of cysteinyl leukotriene receptor mRNA in human peripheral leucocytes: significantly higher expression of cysteinyl leukotriene receptor 2 mRNA in eosinophilsCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2001H. Mita Background Cysteinyl leukotrienes (CysLTs) have been implicated as important contributors in the pathophysiology of asthma and their biological effects are mediated by at least two distinct G-protein-coupled receptors. cDNA sequences of cysteinyl leukotriene receptor 1 (CysLTR1) and cysteinyl leukotriene receptor 2 (CysLTR2) have recently been elucidated. Objectives Our aim is to explore gene expression and the comparative expression of CysLTR1 mRNA and CysLTR2 mRNA in human peripheral blood leucocytes. Methods Gene expression of CysLTR1 and CysLTR2 mRNAs in human peripheral blood eosinophils, neutrophils, monocytes and T lymphocytes has been measured by competitive reverse transcription-polymerase chain reactions using RNA or DNA competitors. Results(a) When cellular levels of CysLTR1 mRNA were normalized to those of G3PDH mRNA, the relative concentration of CysLTR1 mRNA in eosinophils (43.8 ± 37.2, n = 29) was significantly higher than that in neutrophils (18.7 ± 23.3, n = 11), monocytes (0.93 ± 1.1, n = 10) and T lymphocytes (3.4 ± 2.4, n = 11). (b) When measured using each DNA competitor, mRNAs for both types of CysLTR coexisted in each type of leucocyte. The ratio of CysLTR1 mRNA to CysLTR2 mRNA was significantly lower in eosinophils (0.65 ± 0.42, n = 12) than in neutrophils (6.9 ± 4.9, n = 12), monocytes (1.8 ± 0.9, n = 10) and T lymphocytes (4.5 ± 5.7, n = 10). (c) Human umbilical vein endothelial cells expressed CysLTR2 mRNA, but not CysLTR1 mRNA. Conclusion These studies reveal that CysLTR1 mRNA and, in particular, CysLTR2 mRNA are abundantly expressed at high levels in eosinophils, raising the possibility that CysLTR2 may have an important physiological role in eosinophils and a CysLTR2 antagonist may be a good target for preventing signal transduction by CysLTs in eosinophils. [source] | |||||||||||||||||||