Expression of AC133 vs. CD34 in acute childhood leukemias

AC133, a newly discovered antigen on human progenitor cells, demonstrating 5-transmembranous domains is expressed by 30-60% out of all CD34+ cells. Our aim therefore was to investigate the extent of human stem-/progenitor cells expressing AC133 antigen in umbilical cord blood, peripheral blood without or following an application of granulocyte-colony stimulating factor (rhG-CSF). The main task was the investigation of bone marrow aspirates derived from children suffering from newly diagnosed acute leukemias, as well as from patients with a relapse or during a complete remission. The determination of antigen expression was done by application of flow cytometry (FACScan analysis) and the usage of newly developed monoclonal antibodies (AC133/1 and AC133/2; Miltenyi Biotec GmbH) in combination with monoclonal antibody directed against CD34-antigens (HPCA-2; BD). Our studies till now show average percentages in umbilical cord blood derived from 43 newborns about 0.294 +/- 0.165% AC133+ vs. 0.327 +/- 0.156% CD34+ hematopoietic stem-/progenitor cells (HSPC). In peripheral blood from 11 healthy donors we verified up to 0.15% CD34+ as well as AC133+ HSPC's. The concentration of progenitor cells was found to be obviously higher in peripheral blood from children with various diseases (neuroblastoma, rhabdomyosarcoma, ALL/AML) and undergoing application with rhG-CSF in order to be prepared for PBSC-transplantation. In those cases we found up to 3.51% AC133+ cells as well as slightly higher values (3.94%) for CD34 antigens. Additionally we quantified 128 bone marrow (BM) samples for AC133+ and CD34+ cells. In 10 BM samples, derived from patients without any neoplasia, the CD34+ cells were about 0.03% and 1.49%, whereas AC133 values were up to 0.64%. Bone marrow aspirates from 53 children with acute leukemias at time of diagnosis (ALL: n = 41/AML: n = 12) have been immunophenotyped and leukemic blast cells have been proved for AC133- and CD34 antigen expression. 32/41 (78%) of lymphoblastic leukemic cells showed to be positive for CD34 antigen and 24/41 (58%) demonstrated AC133 antigens. Interestingly there were 2 ALL-patients with pathological blast cells positive for AC133 but lacking of any CD34 antigens. 42% (5/12) of investigated AML patients showed CD34+ phenotype, on the other hand there were only 25% (3/12) with AC133+ phenotype. Similar values were found in relapsed patients (n = 18). In BM samples from patients during complete remission (n = 47) we could detect percentages up to 5.55% for CD34 and up to 1.25% for AC133 positive stem-/progenitor cells. Such quite high data may be explained by occasionally application of rhG-CSF therapy. Our results till now lead to the conclusion, that it seems to be useful, to recruit quantification of CD34+ HPSC by additionally detecting AC133 antigens. This new stem cell marker (AC133) may be of great value in case of autologous peripheral blood stem cell transplantation (PBSCT) because it could be an alternative to the usual CD34+ MACS selection system.     

儿童急性淋巴细胞白血病免疫分型特征及其临床意义

目的：探讨急性淋巴细胞白血病（ALL）患儿的免疫分型及其与临床特征的关系。方法：139例ALL患儿为研究对象,取肝素抗凝的骨髓或静脉血2~3 mL,利用流式细胞仪进行免疫分型分析。结果：139例ALL患儿中,B-ALL 103例（74.1 %）,T-ALL 24例（17.3 %）,T/B双表型ALL 12例（8.6 %）。B-ALL主要表达的抗原有CD19（90.3%）、CD10（83.5%）、CD20（27.2%)。T-ALL主要表达的抗原有CD3（79.2%）、CD7（66.7%）、CD5（33.3%）。B/T-ALL主要表达的T系抗原有CD7（50.0%）、CD5（41.7%）;B系抗原有CD19（50.0%）、CD10（33.3%）。139例ALL患儿中,32例伴髓系抗原表达（My+）,主要表达的抗原有CD13、CD33、CD14、MPO等。139例ALL患儿中,31例表达CD34;而My+ ALL中CD34阳性表达（15.6%）明显低于My- ALL（24.3%）。139例ALL患儿中,82例表达HLA-DR。CD10、CD34、HLA-DR在标危、中危、高危型ALL中的表达差异有统计学意义。My+ ALL组性别、出血发生率与My- ALL组比较差异有统计学意义（P<0.05）。结论：免疫分型可正确区分儿童ALL的来源。CD10、CD34、HLA-DR抗原表达与ALL的临床分型有关。     

160例儿童急性白血病免疫表型分析

目的　免疫表型可以确定细胞的来源和分化阶段 ,是急性白血病的重要生物学特征。该文了解儿童急性白血病 (AL)抗原表达规律、分布情况并探讨其临床意义。方法　采用流式细胞术直接或间接免疫荧光法检测 1 6 0例儿童AL的免疫表型。结果　 1 6 0例AL中 ,急性淋巴细胞白血病 (ALL) 1 1 2例 ,急性髓细胞白血病(AML) 4 8例。 1 1 2例ALL中 ,T系ALL 1 2例 (1 0 .7% ) ;B系ALL(不包括成熟B ALL) 93例 (83.0 % )。ALL中 ,1 3.8%有髓系抗原表达 ,以CD33阳性最常见 ;AML中 ,4 0 %有淋系抗原表达 ,以CD7阳性率最高。儿童AML淋系抗原表达阳性率高于儿童ALL髓系抗原表达 (P <0 .0 1 )。CD1 4在儿童M 4和M 5的表达频率为 77.8%。B系ALL中CD34阳性率 5 8.5 %。AML中 ,CD34的表达频率为 5 5 .3% ,其中M1和M 2的CD34阳性率为 76 .5 % ,高于其它AML病人的CD34阳性率 (4 3.3% ) ,P <0 .0 5。HLA DR抗原在M 3的表达频率为 1 1 .1 % ,低于其它类型AML病人的HLA DR阳性率 (76 .3% ) ,P <0 .0 1。B系ALL中 ,CD34表达与FAB分型、起病时白细胞数、髓外侵润情况均无关 (P >0 .0 5 ) ;CD34-组婴幼白血病发生率 (1 7.6 % )高于CD34+ 组 (4 .2 % ) ,P <0 .0 5。结论　HLA DR阴性对于M3的诊断具有一定参考价值。     

Mucosal T cells recovered from mice after infection with respiratory syncytial virus display a memory/activation phenotype

Pgp-1 expression was studied as a marker of memory/activation on systemic and mucosal T cells of BALB/c and C57BL/6 mice after infection with respiratory syncytial virus (RSV), using two-color dual fluorescence flow cytometry employing anti-L3T4 (CD4), anti-Ly2 (CD8), and anti-Pgp-1 (CD44) monoclonal antibodies. Pgp-1 was expressed in relatively low densities on T cells of C57BL/6 mice, allowing differentiation of a dual population of Pgp-1¹⁰ and Pgp-1^hi T cells after antigenic stimulation in vivo. On the contrary, T cells of BALB/c mice were uniformely Pgp-1^hi, making this mouse strain less suitable for studies with this marker. In blood and spleen consistently more CD8⁺ than CD4⁺ T cells were Pgp-1^hi, while in BAL more CD4⁺ than CD8⁺ T cells were Pgp-1^hiAfter primary but not after secondary infection, CD4⁺ Pgp-1^hi T cells increased significantly in the blood and spleen. After secondary infection both CD4⁺ Pgp-1^hi and CD8⁺ Pgp-1^hi T cells increased in the BAL. It is hypothesized that after primary infection systemic RSV-specific T cells acquire an activation/memory phenotype as characterized by an enhanced expression of Pgp-1, resulting in a faster and stronger influx of these cells in the lungs after secondary infection.     

High proportion of leukemic stem cells at diagnosis is correlated with unfavorable prognosis in childhood acute myeloid leukemia

In acute myeloid leukemia (AML), the leukemia-initiating cell is found within the CD34(+)/CD38(-) cell compartment. Over the last years evidence grew that AML is initiated and propagated by leukemic stem cells (LSCs). Conceivably, these most immature leukemia cells are more resistant to therapy and subsequently initiate relapse. The authors studied 17 patients with childhood AML treated according to the AML-BFM 98/04 protocol. At diagnosis, the authors determined the characteristic immunophenotype of the leukemic cells by flow cytometry and investigated the expression of CD34, CD38, and CD45 to define a population of immunophenotypically immature cells (CD34(+)/CD38(-)/CD45(-/low)) enriched for LSCs in many cases of AML. The authors compared the fraction of this population of all myeloid cells at diagnosis with event-free survival. Kaplan-Meier analysis revealed significant higher event free survival of patients with low CD34(+)/CD38(-)/CD45(-/low) cell proportion (<0.68%) compared to patients with high burden of this population (>0.83%; log-rank P < .04). This correlation was not found for the total number of CD34(+) cells. This is the first study to show that a higher proportion of immature CD34(+)/CD38(-)/CD45(-/low) blasts at diagnosis correlates with unfavorable prognosis in childhood AML. The results suggest that a large CD34(+)/CD38(-)/CD45(-/low) population reflects a higher fraction of LSCs, leading to increased chemotherapy resistance and elevated relapse rate. Thus the initial frequency of CD34(+)/CD38(-)/CD45(-/low) cells may serve as a prognostic marker in pediatric AML. Future treatment in childhood AML should specifically target this immature population as well as the mature blast population.     

Phenotypic changes of T-lymphocyte subsets induced by interleukin-12 and interleukin-15 in umbilical cord vs. adult peripheral blood mononuclear cells

The decreased incidence of graft-vs.-host disease found following umbilical cord blood (CB) transplantation, and the increased susceptibility of newborns to infections, have been attributed, in part, to functional and phenotypic immaturity of neonatal T cells. We investigated the phenotypic changes of CB T cells induced by two immunoregulary cytokines, interleukin (IL)-12 and IL-15, alone or in combination. Adult peripheral blood (APB) mononuclear cells (MNCs) were also tested for comparison. Prior to culture, the percentages of CD3⁺ CD8⁺, CD3⁺ CD25⁺, and CD3⁺ CD56⁺ cells were significantly lower in CB MNCs than in APB MNCs. IL-15, but not IL-12, significantly increased CD3⁺ CD8⁺ expression among the CB MNCs after 1 week of culture. Combining IL-12 and IL-15, however, resulted in decreased CB CD3⁺ CD8⁺ expression compared with IL-15 alone. The percentage of CD3⁺ CD25⁺ cells in CB MNCs spontaneously increased in the absence of cytokines, while that of CD3⁺ CD56⁺ cells in CB MNCs could not be enhanced with cytokines. In contrast, the percentages of CD3⁺ CD25⁺ and CD3⁺ CD56⁺ cells among the APB MNCs could be increased with IL-12, IL-15, and further with IL-12 and IL-15 combined. Thus, different patterns of T-cell subset changes were demonstrated between CB MNCs and APB MNCs in response to IL-12 and/or IL-15. These data may serve as a foundation for using cytokine therapy in newborns and children receiving CB transplants.     

以缺血性脑卒中为主要表现的儿童获得性免疫缺陷综合征1例

对2019年1月苏州大学附属儿童医院重症医学科收治的1例以缺血性脑卒中为主要表现的获得性免疫缺陷综合征患儿的临床资料进行回顾性分析。患儿,男,6岁4个月,既往有血小板减少性紫癜和反复呼吸道感染病史。主诉"右侧肢体乏力10余天"。头颅磁共振成像提示双侧额顶叶较广泛异常信号伴左侧丘脑、外囊软化灶形成。血常规示白细胞4.88×10⁹/L,淋巴细胞比例0.291,淋巴细胞计数1.42×10⁹/L,血红蛋白99 g/L,血小板23×10⁹/L。淋巴细胞亚群:CD3⁺84.1%,CD3⁺CD4⁺0.2%,CD3⁺CD8⁺61.4%,CD4⁺/CD8⁺0,CD3-CD19⁺9.2%,CD3-CD₁₆₊₅₆⁺6.1%,CD₁₉⁺CD₂₃⁺5.8%。输血前检查:人类免疫缺陷病毒(HIV)(⁺),余阴性。患儿父母双方均为HIV感染患者。本病例提示神经系统受累症状在HIV感染中并不少见,且脑卒中是HIV感染患儿出现临床局灶性神经功能缺损的最常见原因。高危患儿出现其他神经受累表现或认知改变,须尽早完善头颅磁共振检查。     

Lymphocyte subsets and cytokines in adenoviral infection in children

To determine the distribution of major blood lymphocyte subsets we evaluated blood lymphocytes by flow cytometry in adenovirus-infected infants aged 30–730 d. In addition, interleukin-1-receptor antagonist, interleukin-10 and transforming growth factor-β1 were measured in serum by enzyme-linked immunosorbent assay. According to clinical parameters, mechanical ventilation and outcome, infections were classified as moderate ( n = 15), severe ( n = 11) and fatal ( n = 12). Controls were 13 healthy children. In severe and fatal infection, T cells (CD5⁺/CD19^-), NK effectors (CD16⁺), CD4⁺ T subset and B1 subset of B lymphocytes (CD5⁺/CD19⁺) were all significantly decreased. CD8⁺ cells were decreased in severe but not fatal cases. There was no difference in serum values of interleukin-10; however, fatal cases had high interleukin 1-receptor antagonist values. Interestingly, patients with moderate infection showed significantly increased values of transforming growth factor-β1. These results demonstrate that life-threatening adenoviral infection is associated with marked abnormalities in blood lymphocyte and cytokine profile.     

Increased bronchoalveolar lavage CD8 lymphocyte subset population in wheezy infants

Episodes of wheezing are very common in infancy but, despite their high prevalence, their mechanism is still poorly understood. To better understand the airway inflammation of wheezing infants, we examined cells of the bronchoalveolar lavage (BAL), focusing on the phenotype of lymphocytes and macrophages by using cytofluorimetry. Twenty-one wheezers (mean age 15.4 months) and seven non-wheezers (mean age 24.1 months) were studied. BAL was collected at fiberoptic bronchoscopy. Total and differential cell counts were similar in both populations. Eosinophils were not detected in the BAL fluid. The cell-surface markers CD2, CD3, CD4, CD7, CD8, CD19, and CD45 were studied for the lymphocyte sub-population analysis. The cell-surface markers CD14, CD54, CD62L, and human leucocyte antigen (HLA)-DR were studied for the macrophage sub-population analysis. A significant increase in the CD8⁺ lymphocyte population (p = 0.03) was observed in wheezers (median 43.1%, 25–75% percentile: 30.1–54.9%), as compared to non-wheezers (median 29.3%, 25–75% percentile: 13.5–34.7%). A significantly (p = 0.04) decreased expression of HLA-DR (mean fluorescence intensity [MFI]) was detected in the macrophage population of the wheezers (median MFI, 7,016; range 2135–7986), as compared to non-wheezers (median MFI, 8,369; range: 6478–8860). The results of the present study suggest that viral infection may have induced a CD8⁺ response in BAL cells.     

Equal frequency of TEL/AML1 rearrangements in children with acute lymphoblastic leukemia with and without Down syndrome

Constitutional trisomy 21 is the most prominent predisposing factor to childhood leukemia, whereas the t(12;21)(p13;q22) with its molecular genetic counterpart, the TEL/AML1 fusion gene, is the most common acquired chromosomal rearrangement in childhood B-cell precursor (BCP) acute lymphoblastic leukemia (ALL). Thus, it was somewhat surprising that according to the currently available literature the incidence of TEL/AML1⁺ BCP ALL is extremely low in patients with Down syndrome (DS). To further investigate this issue in a population-based fashion, the authors retrospectively assessed the number of DS patients with a TEL/AML1⁺ ALL in two consecutive Austrian ALL multicenter trials. Accordingly, they were able to analyze 8 of 10 individuals with DS and a BCP ALL, two of whom who suffered from a TEL/AML1⁺ leukemia. Based on this observation they concluded that individuals with BCP leukemia and a constitutional trisomy 21 may have similar likelihood to have a TEL/AML1 rearrangement as BCP ALL patients without this specific predisposing factor.     

抗CD47抗体联合阿糖胞苷靶向治疗NOD/SCID小鼠单核细胞白血病的研究

目的：探讨CD47在急性髓细胞白血病NOD/SCID小鼠模型中的预后意义及靶向治疗的最佳策略。方法：将分选的CD34+CD38-白血病干细胞（leukemia stem cells, LSCs）移植入NOD/SCID小鼠体内,建立小鼠急性单核细胞白血病模型;抗人CD47单克隆抗体单独或联合阿糖胞苷治疗白血病小鼠7~14 d,并进行疗效分析。将LSCs与小鼠巨噬细胞在含抗CD47单克隆抗体的培养液中共培养,观察CD47对巨噬细胞吞噬LSCs能力的影响。结果：THP-1细胞中存在CD34+CD38- LSCs,比例约为0.12%±0.06%,将分选后的CD34+CD38- LSCs（比例高达97.0%±1.7%）移植入NOD/SCID小鼠后成功建立白血病模型。体内实验表明,阿糖胞苷（7 d）联合抗CD47单克隆抗体（14 d）治疗后,白血病小鼠外周血和骨髓中CD33+CD45+白血病细胞下降最明显（P<0.01）,生存时间明显长于其它各组。体外共培养2 h后,抗CD47单克隆抗体组吞噬指数（76.9%±12.2%）明显高于抗CD45单克隆抗体组（7.60%±2.4%,P<0.01）。结论：CD47高表达是急性髓细胞白血病的预后不良因素。阿糖胞苷联合抗CD47单克隆抗体可有效杀灭普通白血病细胞和白血病干细胞,对彻底治愈急性髓细胞白血病具有重要临床意义。     

儿童急性B系淋巴细胞性白血病有效抗原组合及其临床应用探讨

目的 探讨使用流式细胞术(FCM)检测儿童急性B系淋巴细胞性白血病(B-lineageacute lymphoblastic leukemia,B-ALL)各有效抗原组合的发生频率及其与临床预后顺素相关性.方法 对289例初发B-ALL患儿的骨髓标本进行每组4个抗原,共9个抗原组合检测,统计各有效抗原组合的发生频率并与国外报告进行比较,分析各抗原组合在临床预后因素分组中的分布差异.结果 (1)327例初发B-ALL患儿中,289例存在至少1组可用于微小残留病(minimal residual disease,MRD)检测的有效抗原组合,其覆盖率为88.4%.(2)不同有效抗原组合的发生频率不同,以TdT组频率最高,为70.59%.(3)部分有效抗原组合与临床表型以及治疗反应相关,CD58组和TdT组与良好预后因素相关,而CD66c组和CD38组与不良预后因素相关.结论 B-ALL不同有效抗原组合的发生频率不同,在中国患儿中的表达与国外报道有差异.TdT组有高表达频率,可作为简化的MRD检测目标组合.发生频率较高的4个抗原组合可以为无初发时MRD记录的患儿的疗效评估和治疗强度调整提供一定的参考依据.部分有效抗原组合对临床预后产生影响,可能为B-ALL的个体化治疗提供参考依据.     

Both allergen-specific CD4 and CD8 Type 2 T cells decreased in asthmatic children with immunotherapy

Allergen-specific immunotherapy (IT) has been used for the treatment of atopic diseases since the turn of this century. The precise working mechanisms, however, remain to be clarified. The aim of this study was to investigate the role of particular subsets of allergen-specific T cells in the non-atopic individuals, untreated asthmatic children and the asthmatic children receiving immunotherapy. We collected peripheral blood from 16 untreated asthmatic children and 17 asthmatic children receiving immunotherapy over one and half years. All the patients were sensitive to mite allergen. Peripheral blood mononuclear cells (PBMC) were isolated and, in vitro , stimulated with crude mite extract to enrich the mite-specific T-cell population. After 14 days, the enriched mite-specific T cells were stimulated with phorbol-12-myristate-13-acetate (PMA) and ionomycin for intracellular detection of cytokines such as IFN-γ, IL-4 in CD4⁺ and CD8⁺ T lymphocytes. The data here demonstrated that the levels of mite-specific IgG4 and IgA increased significantly in asthmatic children after immunotherapy. In addition, both IL-4 expressing CD4⁺ and CD8⁺ T cells were significantly lower in asthmatic children after immunotherapy compared with those of before treatment and the normal control (p < 0.05). In contrast, the frequency of IFN-γ expressing CD4⁺ and CD8⁺ T cells did not significantly differ between untreated and SIT-treated groups. All these data suggested that decreased Type 2 CD4⁺ and CD8⁺ T cells might be closely correlated with the regulatory mechanisms of immunotherapy.     

Minimal residual disease in acute myeloid leukemia in children--standardization and evaluation of immunophenotyping in the AML-BFM-98 study

BACKGROUND: Minimal residual disease is a prognostic factor in AML. However, the impact on treatment stratification is not established. The AML-BFM 98 MRD study started in 1/2000 in order to evaluate, standardize and establish immunophenotyping in AML in children. METHODS: In a first phase the participating laboratories in Muenster, Goettingen, Vienna and Prague agreed on identical antibody-panels and standardized procedures of sample processing, analysis and data management. The consensus panel was evaluated and adapted to 3- and 4-color flowcytometry. The complete panel was applied to each follow-up sample in orderto minimize the risk offalse negative results due to the loss or shift of antigens during treatment, a known phenomenon in myeloid blasts. Between 1/2000 and 9/2001 165 of 198 protocol patients were analysed at diagnosis, in 149 children at least two follow-up samples were available. RESULTS: Three kinds of immunophenotypes could be defined. Asynchronous expression of stem cell and myeloid antigens i. e. CD34/CD117 combined with CD13/CD15 had a low specificity because precursors in regenerating or normal bone marrow expressed this pattern in 0.47 % (0.1 to 1.5 %). The aberrant co-expression of stem cell antigens and lymphatic antigens such as CD7 or CD2 showed a median level of specificity (0.07 % (0.04 to 0.19 %). Aberrant expression ofstem cell antigens combined with B-lymphatic (CD19, CD10) or NK-cell antigen (CD56) showed the best specificity. The maximal level in normal bone marrow was 0.05 %. Sensitivity of different immunophenotypes was evaluated by diluting known leukemic blasts in regenerating bone marrow. Minimal level of sensitivity was found to be at 10 (-3) to 5 x 10 (-4). According to these data highiy specific immunophenotypes could be detected in 33 %, median specificity was seen in 71 % and low specificity was seen in 88 % of the protocol patients. Two laboratories analyzed simultaneously 17 samples of children with AML from diagnosis and during therapy. A high correlation of blast quantification could be demonstrated (correlation r (2) = 0.98; blasts < 5 % r (2) = 0.91). In addition, two independent explorers quantified the raw data of 16 samples. All results correlated well (r (2) = 0.97; blasts < 5 % r (2) = 90.94). Conclusion: The prospective study phase, started 1/2002, aims to test the impact of MRD diagnostics as an independent prognostic factor in AML in children. This might facilitate future treatment stratification and consequently optimize outcome.     

Increased Ig-null B lymphocytes in the peripheral blood of pediatric solid organ transplant recipients with elevated Epstein-Barr viral loads

Abstract:  In this study, the characteristics of Ig-null B cells in high viral load carriers were examined by four-color flow cytometry. The frequency of Ig-null B cells in patients with high, low or undetectable virus loads was found that while patients with a high load had more Ig-null cells, these cells were also present in the low and undetectable load groups. As Ig-null cells from patients with no viral load were EBV-negative, EBV infection was not absolutely required for the generation or survival of Ig-null cells. Ig-null cells were CD19⁺, sIg^-, CD5⁻, CD10⁻, CD27⁻, CD23⁻, CD38⁻, and CD69⁻ with variable surface expression of CD20 and CD40. Ig-null cells did not have a proliferating cell phenotype (Ki67^-) and a high proportion were HLA class I^- and class II^-. Virus copy number in CD19⁺ Ig-null cell populations may be much higher than in CD19⁺ Ig⁺ cell populations. EBV infected Ig-null cells were common in blood specimens from pediatric solid organ transplant recipients and infected Ig-null cells may pose potential problems for immunotherapies that target infected B cells directly.     

T Cell Activation and T Cell Receptor Variable Region Gene Usage in Measles

T cell activation and T cell receptor variable (V) regions were studied with monoclonal antibodies in peripheral blood lymphocytes from 22 patients with measles. Increased (> 5%) activated T cells (HLA-DR⁺ CD3⁺ cells) were noted in 14 of the 22 patients. Elevations of Vβ5⁺ and Vβ8 + T cells were observed in two and four patients, respectively, and appeared to be associated with T cell activation. The duration of fever was significantly prolonged in those with increased (> 10%) activated T cells (p < 0.01). These results suggest that T cell activation and the preferential expansion of Vβ8⁺ and Vβ5⁺ T cells are associated with the pathogenic process of measles.     

伴髓系抗原表达的高危儿童急淋白血病临床生物学特征及长期预后分析

目的分析髓系抗原阳性(My+)的儿童高危急性淋巴细胞白血病(ALL)的临床生物学特征及长期预后关系。方法采用流式细胞仪直接免疫荧光法及RT-PCR法分别检测2001年8月至2003年3月在我院收治的初诊高危112例ALL患儿的髓系抗原及融合基因的表达,对其预后进行了中位时间达76个月的长期观察。结果髓系抗原的表达率为30.4%,B系ALL表达髓系抗原多于T系ALL,差异有显著性意义(P=0.019)。My+ALL患儿携带TEL-AML1融合基因者多于My-ALL患儿(P=0.049),My+ALL与My-ALL患儿在临床特点以及疗效等方面两组之间差异无显著性意义。结论高危ALL无论有无髓系抗原的表达其疗效无显著性差异,髓系抗原阳性表达在高危儿童ALL时不能作为预后不良的因素。     

23例儿童T系急性淋巴细胞白血病的生物学特征分析

目的：探讨儿童T细胞急性淋巴细胞白血病(T-ALL)的生物学性状及临床意义。方法：对初诊的23例儿童T-ALL患儿进行免疫分型、染色体、融合基因检测。结果：免疫分型中T系抗原以CD3阳性率最高,其次为CD7、CD5;B系抗原以CD19阳性率最高。23例中4例伴髓系抗原表达,阳性率达17%。CD34、HLA-DR表达阳性率分别为17%、22%。cCD3和cCD79的阳性表达率为100%和96%。8例行染色体检查,其中1例为超二倍体;1例为Ph+染色体。融合基因检测：5例中2例MLL基因重排异常,1例为SIL/TAL1阳性。CD3的表达与T-ALL首次化疗完全缓解率有关。结论：免疫分型分析是诊断T-ALL的重要手段, 但T-ALL免疫表型存在一定的异质性。对于儿童T-ALL的治疗预后评估,应结合细胞遗传学及分子遗传学进行综合判断。［中国当代儿科杂志,2010,12（8）：605-608］     

Case report of common variable immunodeficiency with functional T-helper defect and reduced CD4+ LAM−1 T cells

A 10 year-old boy presenting with an empyema and a previous medical history of recurrent and disseminated infections was investigated immunologically. The serum immunoelectrophoresis showed hypogammaglobulinaemia. The in vitro lymphocyte proliferation to T-cell mitogens (PHA and Con A) was diminished and the response to a T-dependent B cell mitogen (PWM) was severely diminished. Phenotypic analysis of his lymphocytes with monoclonal antibodies revealed normal CD3⁺, CD4⁺ and CD8⁺ cells with a normal CD4: CD8 ratio. Double immunofluorescence with Leu 8 antibody revealed a selective deficiency of the CD4⁺ LAM 1⁻ subset. Co-culture experiments between patient's B cells and supernatants from normal T cells showed that the patient's B cells could secrete Ig in vitro. We suggest that the Leu 8 monoclonal antibody may be useful in defining abnormalities in the regulatory subsets of T lymphocytes and that these abnormalities may be relevant in the pathogenesis of common variable immunodeficiency.     

Expression of chemokine receptor CX3CR1 in infants with respiratory syncytial virus bronchiolitis

Respiratory syncytial virus (RSV) glycoprotein G mimics fractalkine, a CX₃C chemokine, which mediates chemotaxis of leukocytes expressing its receptor, CX₃CR1. The aim of this study was to examine the relationship between RSV infection and expression of perforin and IFN- γ in CX₃CR1-expressing peripheral blood CD8⁺ T cells. Samples were collected from infants with RSV bronchiolitis, both in the acute and convalescence phase (n = 12), and from their age- and sex-matched healthy controls (n = 15). Perforin expression and IFN- γ secretion in CX₃CR1⁺ CD8⁺ T cells were assessed by four-color flow cytometry. The NF- κ B p50 and p65 subunit levels were also determined as markers of RSV-induced inflammation. Study results showed perforin and CX₃CR1 expression to be significantly lower in the convalescent phase of infected infants than in healthy controls. There was no significant difference in IFN- γ secretion and NF- κ B binding activity between two time-points in RSV-infected infants, or when compared with healthy controls. Infants with prolonged wheezing had lower acute-phase CX₃CR1 levels in peripheral blood. These data indicate existence of an event persisting after acute RSV infection that is able to modulate effector functions of cytotoxic T cells, and also link disease severity with CX₃CR1 expression.