Acute lymphoblastic leukemia in children: correlation of musculoskeletal manifestations and immunophenotypes

Purpose Studies on musculoskeletal manifestations (MSM) of childhood acute lymphoblastic leukemia (ALL) have yielded variable findings with regard to their clinical impact. We investigated the significance for differential diagnosis, treatment and outcome of musculoskeletal complaints as presenting symptoms of ALL, and their correlation with leukemia immunophenotypes, for which data is lacking. Methods Data on 783 children in the national study for childhood ALL between 1984 and 2003 were reviewed retrospectively. Statistical analysis examined possible relationships between MSM at the time of diagnosis and demographic and clinical data, biological features of leukemia (peripheral blood counts, immunophenotype and main cytogenetic aberration), response to initial prednisone treatment, and outcome. Results Of 765 children with data on orthopaedic complaints, 240 presented with MSM (31.4%). Among these children, B cell precursor (BCP) was much more common (209/576, 36.3%) than T cell ALL (25/176, 14.2%). Patients with MSM had lower white blood cell counts (WBC) (median of 9 vs. 20 × 10⁹/L, P < 0.001) and percentage of blast cells in the peripheral blood at diagnosis compared to those without (median of 27 vs. 53%, P < 0.001). Hepatomegaly and splenomegaly were less common in MSM group (67 vs. 53% <3 cm, P < 0.001, and 63 vs. 50% <3 cm, P < 0.001, respectively). Poor response to initial treatment with prednisone was recorded in 7.1% of patients with MSM versus 11.5% of those without (P = 0.086). The analysis revealed no independent effect of MSM on event-free survival (EFS), after correcting for differences in EFS related to immunophenotype or initial WBC. Conclusions MSM occur mostly in children with BCP ALL who present with less involvement of extramedullary organs, low peripheral blood blasts and white blood cells counts. These findings highlight the importance of including ALL in the differential diagnosis of MSM even in the presence of an apparently normal peripheral blood count. Our study also suggests that MSM are caused by leukemic cells with enhanced biological propensity to remain relatively confined within the intramedullary bone-marrow space.     

Marked improvement of delayed methotrexate-induced leukoencephalopathy treated with high-dose folinic acid

We report the case of a patient with delayed methotrexate (MTX)-induced leukoencephalopathy who showed a marked improvement both in clinical and neuroimaging findings after a high-dose of the active form of folinic acid (leucovorin) treatment. The patient developed progressive affective impairment accompanied by headache, nausea and vomiting after treatment with MTX during the chemotherapy for acute lymphoblastic leukemia, and diagnosed as delayed type MTX-induced leukoencephalopathy. After an intravenous injection of high-dose folinic acid (total 1920 mg), neurological deficits and white matter changes dramatically improved in a few weeks. Although delayed MTX-induced leukoencephalopathy may cause irreversible brain damage, an early treatment with high dose leucovorin may thus facilitate the marked improvement of clinical findings and white matter abnormalities.     

慢粒白血病abl癌基因表达的研究

选择分别位于ｂｃｒ／ａｂｌ嵌合基因的Ｍｂｃｒｌ第二外显子和ａｂｌ的第二外显子上的两条引物，对１８例慢粒白血病及２例急淋白血病标本进行逆转录ＰＣＲ（ＲＴ－ＰＣＲ）检测。结果：在１８例包括ｐｈ（＋）和ｐｈ（－）不同病期的慢粒白血病患者血中均检出ｂｃｒ／ａｂｌ嵌合基因的表达，其中１４例为Ｋ－２８型表达，１例为Ｌ－６型表达，３例为Ｋ－２８型，Ｌ－６型同时表达；２例急淋白血病标本中１例为Ｋ－２８型表达。研究结果表明，１．ｂｃｒ／ａｂｌ嵌合基因是慢粒白血病的一个重要分子生物学特征；２．ｐｈ（＋）和ｐｈ（－）慢粒白血病的分子生物学基础相同，即均有ｂｃｒ／ａｂｌ嵌合基因；３．至少部分急淋白血病与慢粒白血病有相同的分子生物学基础；４．ｂｃｒ的断裂点位置可能有一定的临床意义，但有待进一步研究；５．同时表达Ｌ－６型和Ｋ－２８型的情况多见于急变区，此现象提示体内可能同时有两类不同嵌合的白血病细胞或白血病急变期ｂｃｒ出现新的重排。     

糖皮质激素受体高、低亲和力位点在急性淋巴细胞性白血病治疗中的意义

研究了１０例正常人和２９例急性淋巴细胞性白血病（急淋）患者外周血糖皮质激素受体高、低亲和力结合位，或（ＧＣＲＨ、ＧＣＲＬ），利用Ｒｕ３８４８６对ＧＣＲＬ进行封闭，对部分患者ＧＣＲＨ、ＧＣＲＬ在激素联合化疗前后水平的变化进行了动态观察。结果表明，正常对照组ＧＣＲＨ、ＧＣＲＬ分别为４６０８±１８８９位点／细胞和１３５２３８±８８５０９位点／细胞，两者相关良好。急淋患者ＧＣＲＨ、ＧＣＲＬ分别为６０５２±３８８８位点／细胞和１２６４０５±１０２１３３位点／细胞，经过糖皮质激素药物联合化疗后，其水平分别为３６１６±１９６２位点／细胞和１４３５９７±１１２２８９位点／细胞，ＧＣＲＨ下降明显（Ｐ＜０．０１），下降率为４０．３％；而ＧＣＲＬ化疗前后差异不显著（Ｐ＞０．０５）。提示ＧＣＲＬ在介导糖皮质激素联合化疗疗效的维持中起重要的作用。     

Immunophenotyping of childhood acute lymphoblastic leukemia in Saudi Arabia: Second look

Geographical variations in the incidence of disease are of considerable theoretical and practical importance. It has been claimed that the distribution of acute lymphoblastic leukemia (ALL) phenotypes in Saudi Arabia is different from that recorded in the Western literature. One hundred and twelve (112) patients under 15 years of age, diagnosed as ALL between January 1992 and May 1994 had immunophenotypes performed on their blast cells. Common ALL (cALL) together with pre-B-ALL, formed 86.5% of the total; B-cell 3%, T-cell 6% and null cell 4.5%. These figures are not significantly different from the Western literature. A previous claim from this institution in 1990, that both null and B-cell ALL were significantly increased compared with elsewhere, is not supported by the present figures. Age and sex distribution, and FAB classification, L1 77%, L2 20% and L3 3%, were also of the same order as described elsewhere and, in particular, there was no increase in the frequency of L3 subtype.     

急性淋巴细胞性白血病的细胞遗传学研究

对40例中国人急性淋巴细胞白血病(急淋)进行了细胞遗传学的研究,发现正常核型为40%,染色体数量异常占42.5%,染色体结构异常为17.5%,特异染色体异常包括有t(9;22)(q34;q11),t(4;11)(q21;q23)和t(8;14)(q24;q32)及环状染色体等.分析了2例急淋患者初发和复发时核型的变化,显示复发时有附加异常。研究认为细胞形态学,免疫表型和细胞遗传学的联合分析(MIC)有助于急淋的诊断和分型。此外,细胞遗传学检查对于急淋白血病的预后具有重要意义。     

Ultrastructural myeloperoxidase activity and expression of myeloid-associated antigens in acute lymphoblastic leukemia

Ultrastructural myeloperoxidase (MPO) activity and myeloid-associated antigen (MyAg) expression were investigated in 12 adult patients with acute lymphoblastic leukemia (ALL). Ultrastructural MPO was detected by 3 different methods. Immunophenotyping was performed by flow cytometry, using a series of monoclonal antibodies. Ultrastructural MPO-positive blast cells were detected in 6 patients (50%). In 5 of these 6 patients, the methods detecting both MPO and platelet peroxidase (PPO) activities found MPO-positive blast cells more frequently than those detecting MPO activity alone. In 2 patients (17%), at least one kind of MyAg was positive. Ultrastructural MPO activity was detected more frequently than MyAg expression in ALL patients. This method of detecting PPO and MPO is recommended for detection of ultrastructural MPO-positive ALL.