Peripheral blood lymphocyte subsets in healthy Turkish children

Immunophenotyping of peripheral blood lymphocyte subpopulations is essential for the diagnosis and follow-up of children with immunodeficiencies and other immune disorders. The relative size and absolute number distributions (median and 5-95%) of lymphocyte subsets, including cord blood (Coulter, EPICS-XL) were examined by flow cytometry in 190 healthy subjects from birth to 18 years of age with a view to obtaining normal reference values for Turkish children of the following age groups: cord blood (n:29), birth to 1 year (n:41), 1 to 2 years (n:30), 2 to 6 years (n:30), 6 to 10 years (n:30), and 10 to 18 years (n:30). The relative size of CD2+, CD3+CD16-56-, CD3+CD8+ T lymphocytes increased while the relative size and absolute counts of those together with CD3+CD4+ and CD19+, CD20+ B lymphocytes decreased with age. The percentage of CD3-CD16+56+ NK cells increased from 0-1 year to 10-18 years; however, absolute count of CD3-CD16+56+ NK cells remained stable and unchanged in all age groups. The relative size and absolute count of activation markers (CD3+CD25+ and HLADR+) decreased from 0-1 year through 10-18 years age group. This study has once more demonstrated that both the percentage and the absolute number of lymphocyte subsets in cord blood and peripheral blood of healthy infants and children changed with age. Therefore, comparison of results to those of age-matched healthy controls is of utmost importance in the reliable and accurate evaluation of lymphocyte subsets reflecting cellular immunity in children.     

IgG subclasses in healthy children and in children with frequent respiratory tract infections

A group of 130 children presenting with frequent respiratory tract infections was examined for serum levels of IgG-subclasses IgG1, IgG2, IgG3 and IgG4 using radial immunodiffusion according to Mancini. Additionally a control group of 175 children not prone to infections was investigated. Both, low and high levels compared to controls were observed for IgG3 and IgG4. 11.5% of the children with frequent airway infections had IgG3 values below 2 SD below the mean for age compared to 2.8% in the control group (p less than 0.01). Likewise a low IgG4 level was observed more frequently in children prone to airway infections (9.8% versus 2.8% in control; p less than 0.05). IgG4 was undetectable (level less than 3.4 mg/dl) in 5 of the 175 control children. Despite an accumulation of low or undetectable IgG3 or IgG4 levels in children with frequent respiratory tract infections, no correlation between low IgG subclass-levels and the degree of the individual disease could be detected. Based on this lack of a simple causal relationship between frequent respiratory tract infections and the finding of low or undetectable IgG-subclass levels, an immunoglobulin replacement therapy has to be considered with reserve.     

新菌灵与美欧卡霉素对照治疗小儿以呼吸道感染为主的疾病

目的探讨小儿呼吸道感染性疾病的药物治疗。方法呼吸道感染性疾病等患者５４例，随机分为治疗组和对照组。治疗组２７例，用新菌灵（ＣＸＭ－Ａ）治疗。＜５岁服ＣＸＭ－Ａ１２５ｍｇ，每日２次，＞５岁服ＣＸＭ－Ａ２５０ｍｇ。每日２次。对照组２７例，用美欧卡霉素治疗，剂量为每公斤体重３０ｍｇ，分（３～４）次口服。结果治疗组总有效率为９６％，而对照组为８１．４８％（Ｐ＜０．０５）。新菌灵治疗上呼吸道感染、气管炎及支气管炎、肺炎的有效率分别为１００％、１００％和５０％。结论新菌灵治疗小儿呼吸道感染性疾病效果优于美欧卡霉素。     

Antibiotic prescribing by primary care physicians for children with upper respiratory tract infections

OBJECTIVES: To determine if the rate of appropriate antibiotic use in the treatment of children with bronchitis, viral upper respiratory tract infections, sinusitis, otitis media, and pharyngitis has changed in recent years and to identify factors that are associated with the use of inappropriate antibiotic therapy. DESIGN: The National Ambulatory Medical Care Survey was used to examine the antimicrobial prescribing habits of physicians who provide primary care for children. Data were analyzed from 1995-1998. SETTING: Office-based physician practices. PARTICIPANTS: Pediatricians, family physicians, and generalists completing survey forms for patients younger than 18 years. MAIN OUTCOME MEASURE: The appropriate use of antibiotics for upper respiratory tract infections. RESULTS: Multivariate analyses were used to examine factors associated with the use of inappropriate antibiotics to treat either upper respiratory tract infections or bronchitis. Patients seen in 1998 and diagnosed as having upper respiratory tract infections were 0.69 (95% confidence interval, 0.59-0.81) times less likely to be treated with antibiotics compared with patients seen in 1995. Multivariate analyses were also used to assess factors associated with the use of antibiotics with a suboptimal therapeutic profile for the treatment of either sinusitis or otitis media. Children diagnosed as having either sinusitis or otitis media were 0.3 (95% confidence interval [CI], 0.16-0.48) times less likely to receive antibiotics with a suboptimal therapeutic effect in 1998 compared with 1995. CONCLUSIONS: Physicians are slowly improving their antibiotic prescribing patterns but the use of inappropriate antibiotics is still common. Almost half of patients with upper respiratory tract infections receive antibiotics.     

Lower respiratory tract infections in children

Lower respiratory tract infections-pneumonia, atypical pneumonia, bronchiolitis, and bronchitis-are responsible for much morbidity and mortality in the pediatric population. On a regular basis, pediatricians clinically diagnose these conditions and must make decisions regarding evaluation and treatment. The focus of this update is on new developments in the past year in the areas of epidemiology, etiology, diagnosis, treatment, and prevention of lower respiratory tract infections.     

婴幼儿常见下呼吸道感染性疾病与淋巴细胞亚群变化关系的研究

目的 探讨淋巴细胞亚群在儿童常见下呼吸道感染支气管炎、支气管肺炎和毛细支气管炎中的变化及临床意义。方法 选取111 例支气管炎、418 例支气管肺炎和83 例毛细支气管炎患儿为疾病组,同期健康婴幼儿235 例为对照组,用流式细胞仪检测各组淋巴细胞亚群。结果 支气管炎组总T 淋巴细胞、CD3⁺CD8⁺细胞低于对照组(P<0.05)。支气管肺炎组总T 淋巴细胞和CD3⁺CD8⁺ 细胞低于对照组、Th 和CD4/CD8 高于对照组,且Th 比例高于支气管炎组;与轻症肺炎组相比,重症肺炎组总T 淋巴细胞降低而B 淋巴细胞升高(P<0.05)。毛细支气管炎组Th 细胞和CD4/CD8 高于对照组、CD3⁺CD8⁺ 细胞低于对照组(P<0.01)。与对照组比,3 组下呼吸道感染患儿的B 淋巴细胞增高、NK 细胞比例降低(P<0.05)。结论 细胞免疫功能紊乱或低下以及体液免疫功能亢进参与了婴幼儿下呼吸道感染的发生和发展,并且变化程度与疾病类型及病情程度有关。     

Reactive thrombocytosis in children with upper urinary tract infections

The relationship between reactive thrombocytosis and the level of urinary tract infections was studied in 48 children. Platelets were counted before, during and after treatment. Reactive thrombocytosis was noticed in 74% of children with upper and in 14% with lower urinary tract infections. A significant rise in the platelet count presented in another five children (15%) with upper urinary tract infections. Conclusion: Reactive thrombocytosis was found almost exclusively in the renal parenchymal infections, usually during the recovery phase.     

Association of recurrent upper respiratory tract infections with low production of oxygen intermediates in children

ObjectivesUpper respiratory tract infections in children generally have significant morbidity and mortality. There is little data available about functional immaturity of the immune system and the child's susceptibility to infections at the beginning of their lives, thus, justifying a more specific immunological analysis.MethodAnalysis of hemograms and innate and adaptive immune responses in 95 children between age 1 to 6 years with episodes of recurrent respiratory infections (test group n = 39) and without these episodes (control group n = 56) was carried out. The production of reactive oxygen intermediates by peripheral blood cells stimulated by phorbol myristate acetate was analyzed. Additionally, the number of B lymphocytes, auxiliary T lymphocytes, and cytotoxic cells was determined using flow cytometry.ResultsResults from both groups did not show statistically significant differences in red blood cells, total leukocytes count, and the differential neutrophils, eosinophils, basophils, lymphocytes, and monocytes count. The analysis of the number of B lymphocytes, auxiliary T lymphocytes (LTCD4), and cytotoxic cells (LTCD8) also did not show any difference between both groups. However, the production of radical oxygen intermediates was significantly reduced in the test group as compared to the control group (p < 0.05).ConclusionsThere was no difference in the analysis of hemograms, leukograms, or the number of lymphocytes, LTCD4, LTCD8, or LTCD19. The reduced production of oxygen intermediates in the affected group suggests that these children's microbicide capacity is compromised, which may be related to their recurrent respiratory infections.     

Chlamydia pneumoniae in children with acute respiratory tract infections

Children seeking medical attention for acute respiratory tract infections were investigated for evidence of Chlamydia pneumoniae infection. Blood samples were obtained from 367 children. Nasopharyngeal or throat swabs for PCR analysis (polymerase chain reaction) were taken from 360 children. Serology was found to be useful for diagnosis of infection only in children aged 5 y. Using PCR, a prevalence of 8 and 10% of C pneumoniae was found in male and female children aged < 2 y; 17 and 19%, respectively, in the age group 2-4 y and 32 and 21%, respectively, in the age group 5–16 y. We conclude that Chlamydia pneumoniae is a common finding in young children with respiratory tract infections. Younger children were more often found to have a moderate disease, but may have been ill for a long period.     

Isoprinosine does not protect against frequent respiratory tract infections in childhood

Isoprinosine, an in vitro immuno-enhancing agent principally acting by stimulating T-lymphocytes, is one of a number of agents sometimes used in an attempt to prevent recurrent respiratory infections in children, although there are no formal trials for this particular drug. We performed a placebo-controlled double-blind trial to assess the efficacy of isoprinosine (50 mg/kg per day) for 6 weeks followed by 50 mg/kg per day twice weekly for 6 weeks in the prevention of frequent acute respiratory tract infections in 102 children aged 4–8 years. A total of 43 children treated with isoprinosine and 41 with placebo finished the study. Despite a transient increase in the total number of CD3+, CD4+ and CD8+ T-lymphocytes after 6 weeks of daily isoprinosine treatment, there was no difference in the number and length of duration of acute respiratory infections, number of antibiotic courses and number of days with cough, pharyngitis, rhinitis and increased body temperature (≥37.0°C and ≥38.0°C). There were no changes in markers of T- or B-lymphocyte activation (CD25, HLA-DR, CD45RA/RO, CD23). Conclusion Attempts at immunomodulation using isoprinosine in the dose and for the duration used may increase the total numbers of both CD4 and CD8 T-lymphocytes but is ineffective in prevention of respiratory tract infections in childhood. Received: 12 February 1998 / Accepted in revised form: 22 June 1998