Determination of Myeloid Antigen Expression on Childhood Acute Lymphoblastic Leukaemia Cells: Discrepancies Using Different Monoclonal Antibody Clones

Prospective clinical studies including large numbers of patients have led to the conclusion that co-expression of myeloid antigens in childhood acute lymphoblastic leukaemia (My+ALL) does not have prognostic significance. However, reports of the frequency of My+ ALL in children vary widely across laboratories using different mAb clones and staining and analysing procedures. Taking two commonly accepted thresholds of positivity for myeloid antigens (20 and 30%), we analysed the immunoreactivity of the most widely employed mAb clones against CD13 (SJ1D1, L138 and My7) and CD33 (My9, P67.6 and D3HL60) and compared the proportions of My+ ALL detected by these clones in childhood ALL. The correlation between myeloid antigen expression and the presence of the t(12;21) translocation was analysed concomitantly in the same samples.

The percentage of ALL cases positive for myeloid markers varied significantly depending on the mAb clone and the positive threshold. Among patients with B-ALL, the proportion of CD13+ ALL was significantly lower using SJ1D1 than using L138 or My7, while the proportion of CD33+ ALL was significantly higher for My9 than for P67.6 or D3HL60. Analysis of the co-expression of CD13 and CD33 on B-ALL cells using combinations of mAb clones showed that this frequency was either underestimated by the SJ1D1/D3HL60 or overestimated by the L138/P67.6 and My7/My9 combinations. A correlation between CD13/CD33 positivity and the t(12;21) translocation was uniformly observed in B-ALL patients for a positive threshold of 30%, whereas SJ1D1/D3HL60 detected no correlation between t(12;21) and CD13/CD33 positivity when the threshold was lowered to 20%. These data show that the mAb clones commonly used to detect the CD13 and CD33 surface antigens have variable immunoreactivity against childhood ALL cells, which may partly explain the conflicting reports concerning the prognostic significance of myeloid antigen expression in paediatric ALL and its association with different translocations. The present findings may also be of clinical importance for therapeutic choices.     

Determination of myeloid antigen expression on childhood acute lymphoblastic leukaemia cells: discrepancies using different monoclonal antibody clones.

Prospective clinical studies including large numbers of patients have led to the conclusion that co-expression of myeloid antigens in childhood acute lymphoblastic leukaemia (My+ ALL) does not have prognostic significance. However, reports of the frequency of My+ ALL in children vary widely across laboratories using different mAb clones and staining and analysing procedures. Taking two commonly accepted thresholds of positivity for myeloid antigens (20 and 30%), we analysed the immunoreactivity of the most widely employed mAb clones against CD13 (SJ1D1, L138 and My7) and CD33 (My9, P67.6 and D3HL60) and compared the proportions of My+ ALL detected by these clones in childhood ALL. The correlation between myeloid antigen expression and the presence of the t(12;21) translocation was analysed concomitantly in the same samples. The percentage of ALL cases positive for myeloid markers varied significantly depending on the mAb clone and the positive threshold. Among patients with B-ALL, the proportion of CD13+ ALL was significantly lower using SJ1D1 than using L138 or My7, while the proportion of CD33+ ALL was significantly higher for My9 than for P67.6 or D3HL60. Analysis of the co-expression of CD13 and CD33 on B-ALL cells using combinations of mAb clones showed that this frequency was either underestimated by the SJ1D1/D3HL60 or overestimated by the L138/P67.6 and My7/My9 combinations. A correlation between CD13/CD33 positivity and the t(12;21) translocation was uniformly observed in B-ALL patients for a positive threshold of 30%, whereas SJ1D1/D3HL60 detected no correlation between t(12;21) and CD13/CD33 positivity when the threshold was lowered to 20%. These data show that the mAb clones commonly used to detect the CD13 and CD33 surface antigens have variable immunoreactivity against childhood ALL cells, which may partly explain the conflicting reports concerning the prognostic significance of myeloid antigen expression in paediatric ALL and its association with different translocations. The present findings may also be of clinical importance for therapeutic choices.     

急性淋巴细胞白血病免疫分型的特点及其临床意义

目的为了探讨急性淋巴细胞白血病(ALL)各亚型免疫分型的特点及其临床意义。方法采用CD45/SSC双参数散点图设门,应用三色流式细胞术,对81例ALL的初诊患者骨髓标本进行免疫分型,并对其中45例进行核型分析。结果(1)B-ALL中CD19表达最常见(阳性率为100%),而T-ALL中CD5和CD7表达阳性率最高,均为90%;B-ALL和T-ALL都存在抗原交叉表达的现象;两组患者的完全缓解率(CR率)并无显著差异(P>0.05)。(2)伴髓系抗原表达的急性淋巴细胞白血病(My ALL)比较常见,本组达到39.5%,常累及B淋巴系统(占My ALL的84.4%);各髓系抗原中以CD13表达阳性率最高;此类患者的CR率较高,儿童CR率为72.2%,成人为78.6%。(3)急性杂合性白血病(HAL)的发病率为19.8%,以髓系、B系共同表达者居多;并且CD34表达阳性率较高(81.3%),该类患者CR率较低(儿童和成人分别为50%和40%)。(4)CD34在B-ALL,My ALL和HAL中表达阳性率较高,而T-ALL中少见(P<0.025)。结论免疫分型在诊断特殊类型的ALL(如HAL,My ALL)中具有显著优势;CD19和CD5诊断B-ALL和T-ALL的灵敏度较好,但特异性不高,存在抗原交叉表达;CD34和髓系抗原的表达与CR率无相关性,但在HAL,CD34的表达与CR率成负相关。     

成年人伴CD2表达B系急性淋巴细胞白血病免疫表型特征分析

 目的　了解成年人伴CD2表达B系急性淋巴细胞白血病（CD+2 B-ALL）的免疫表型特征,为临床诊断、治疗及预后判断提供依据。方法　应用流式细胞术及多种单克隆抗体检测18例成年人CD+2 B-ALL及68例CD-2 B-ALL患者的免疫表型,并对其结果进行分析比较。结果　CD+2 B-ALL的发病年龄明显小于CD-2 B-ALL,18例成年人CD+2 B-ALL的大部分表面标志物与CD-2 B-ALL相似,其中CD10表达水平[（73.78±26.67）%]高于CD-2 B-ALL[（52.84±35.25）%],差异有统计学意义（t＝2.35,P＜0.05）,CD33表达水平[（15.46±27.41）%]则低于CD-2 B-ALL[（31.15±27.72）%],差异有统计学意义（t＝2.16,P＜0.05）;所有B-ALL患者都高表达CD34,阳性表达率分别为72.2 %（13／18）和80.9 %（55／68）,差异无统计学意义（χ2＝0.64,P＞0.05）。CD+2 B-ALL的CD20阳性率明显低于CD-2 B-ALL,差异有统计学意义（χ2＝11.38,P＜0.05）。CD+2 B-ALL伴髓系抗原（CD13或CD33）表达率为44.4 %（8／18）,明显低于CD-2 B-ALL 的72.1 %（49／68）,差异有统计学意义（χ2＝4.86,P＜0.05）。结论　成年人CD+2 B-ALL与CD-2 B-ALL具有相似的免疫表型,主要来源于造血干细胞的恶性转化,CD+2 B-ALL伴髓系抗原（CD13、CD33）及CD20表达明显低于CD-2 B-ALL,提示成年人CD+2 B-ALL可能有较好的预后。     

Review of the incidence and clinical relevance of myeloid antigen-positive acute lymphoblastic leukemia

An increasing number of papers document cases of acute leukemia in which individual blast cells co-express markers normally restricted to a single cell lineage. Numerous terms are used to refer to cases with unscheduled expression of lineage-foreign proteins; the best defined categories were hybrid acute leukemia and acute mixed-lineage leukemia. The incidence of phenotypically variant acute leukemia varies with the quality and quantity of parameters used and the stringency of the criteria employed for its definition. Considerable interest has focused on acute lymphoblastic leukemia (ALL) cells expressing one or several myeloid lineage-associated antigens (My+ ALL), CD13, CD14, CD15, CD33, and CDw65. Owing to legitimate and cryptic expression on lymphoid cells, CD11b and CD15 reagents may not be considered as specific indicators of myeloid differentiation. The reported incidence ranged from 5 to 46% in 14 studies on My+ ALL, totalling 3817 patients. Several detailed reports documented a higher incidence of My+ ALL in adults (realistically in the range 10-20%) than in children (5-10%) and in B-lineage ALL as opposed to T-lineage ALL. My+ ALL cases are more likely to display unique cytogenetic [t(9;22), 11q23, 14q32] features than My-neg ALL. There appears to be no predominant expression of a single myeloid-associated antigen among those analyzed. As the morphological diagnosis of a leukemia subtype is often imprecise, some T-neg B-neg My+ ALL cases might actually contain FAB AML-M0 populations. While the expression of myeloid-associated antigens has no apparent prognostic significance in the majority of childhood ALL subtypes, in adults myeloid antigens seem to identify a high risk group of ALL patients with a poorer response to standard ALL therapy.     

急性淋巴细胞白血病免疫分型的特点及其临床意义(英文)

目的为了探讨急性淋巴细胞白血病(ALL)各亚型免疫分型的特点及其临床意义。方法采用 CD45/SSC 双参数散点图设门,应用三色流式细胞术,对81例 ALL 的初诊患者骨髓标本进行免疫分型,并对其中45例进行核型分析。结果 (1)B-ALL 中 CD19表达最常见(阳性率为100%),而 T-ALL 中 CD5和 CD7表达阳性率最高,均为90%;B-ALL 和 T-ALL 都存在抗原交叉表达的现象;两组患者的完全缓解率(CR 率)并无显著差异(P>0.05)。(2)伴髓系抗原表达的急性淋巴细胞白血病(My~+ ALL)比较常见,本组达到39.5%,常累及 B 淋巴系统(占 My~+ ALL 的84.4%);各髓系抗原中以 CD13表达阳性率最高;此类患者的 CR 率较高,儿童 CR 率为72.2%,成人为78.6%。(3)急性杂合性白血病(HAL)的发病率为19.8%,以髓系、B 系共同表达者居多;并且 CD34表达阳性率较高(81.3%),该类患者 CR 率较低(儿童和成人分别为50%和40%)。(4)CD34在 B-ALL,My~+ALL 和 HAL 中表达阳性率较高,而 T-ALL 中少见(P<0.025)。结论免疫分型在诊断特殊类型的 ALL(如 HAL,My~+ ALL)中具有显著优势;CD19和 CD5诊断 B-ALL 和 T-ALL 的灵敏度较好,但特异性不高,存在抗原交叉表达;CD34和髓系抗原的表达与 CR 率无相关性,但在 HAL,CD34的表达与 CR 率成负相关。     

CD13在费城染色体阴性急性B淋巴细胞白血病中的表达及其临床意义

目的 分析成年人和儿童急性B淋巴细胞白血病(B-ALL)的免疫表型,观察髓系抗原CD13的表达与费城染色体阴性(Ph-)B-ALL患者的临床特征、血液学特点和临床预后的关系.方法 采用多参数流式细胞术检测111例成年和32例儿童B-ALL患者免疫表型.结果 儿童与成年B-ALL患者CD13、CD33阳性表达率差异均无统计学意义[31.3 ％(10/32)比19.8 ％(22/111),18.8 ％(6/32)比29.7 ％(33/111),均P＞ 0.05].在Ph-B-ALL患者中,儿童CD13阳性表达率高于成年人[32.3％(10/31)比9.4％(6/64),P＜ 0.05].在儿童和成年Ph-B-ALL患者中,CD13+和CD13-患者的诱导完全缓解率和缓解时间差异均无统计学意义(均P＞ 0.05).在儿童Ph-B-ALL患者中,CD13+和CD13-患者的复发时间差异有统计学意义[(111±16)d比(683±57)d,P＜0.000 1].儿童和成年CD 13+Ph-B-ALL患者的复发时间差异亦有统计学意义[(111±16)d比(319± 16)d,P＜ 0.000 1].结论 在Ph-B-ALL患者中,儿童CD13阳性表达率明显高于成年人,CD13+ Ph-B-ALL患者尤其是儿童CD 13+ Ph-B-ALL患者更易复发.     

In vivo and in vitro expression of myeloid antigens on B-lineage acute lymphoblastic leukemia cells.

The expression of myeloid antigens has been extensively examined using two-color analysis in 43 children with B-lineage acute lymphoblastic leukemia (ALL). On pre-culture cells, CD33 expression was frequently observed in CD19+, CD10- B-precursor ALL, and CD14 was expressed only on the cells from B-precursor ALL expressing CD19, CD10 and CD20, and B-ALL. After 2 or 3 days of culture without TPA, CD13 emerged on the cells from 21 of 29 patients irrespective of the presence or the absence of fetal calf serum in the culture. Of four patients with CD10+ B-precursor ALL, which showed no expression of CD13 after culture, two had T-cell associated antigens. Whereas the addition of TPA to the culture enhanced the expression of CD13 on the cells from acute non-lymphocytic leukemia (ANLL), TPA reduced the expression of this antigen on B-precursor cells. These findings suggest that the regulatory mechanism of CD13 expression may be different between B-precursor ALL and ANLL. Co-culture with cycloheximide mostly abrogated the induction of CD13, suggesting that CD13 expression was mainly dependent on de novo protein synthesis.     

CD13、CD33在BCR-ABL+急性淋巴细胞白血病患者骨髓中的表达及其与临床特征和预后的相关性

目的:探讨髓系抗原CD13、CD33在BCR-ABL+急性淋巴细胞白血病（acute lymphoblastic leukemia,ALL）患者骨髓中的表达及其与临床特征和预后的相关性。方法:应用实时荧光定量聚合酶链反应（real time quantitative-polymerase chain reaction,RQ-PCR）检测119例初诊ALL患者骨髓BCR-ABL表达水平。用流式细胞学检查检测ALL的抗原表达水平。对照分析单纯BCR-ABL+患者中CD13+和CD13-以及CD33+和CD33-患者在初次诱导缓解率（initial-induction remission rate,CR1）和总生存率（overall survival rate,OS）的区别。结果:在BCR-ABL+ 的ALL患者中,初诊时CD13+患者较CD13-患者具有较低的首次诱导缓解率,差异具统计学意义（P＜0.05）,但CD33+患者较CD33-患者首次诱导缓解率无统计学差异。CD13+组及CD33+的OS显著低于CD13-组及CD33-组（P＜0.05）。结论:BCR-ABL+ALL患者中CD13+及CD33+提示预后不良。     

Usefulness of a small scale indirect 125I-labelled protein A binding assay for detection of monoclonal antibodies against hematopoietic cell surface antigens

We describe a small-scale solid-phase indirect 125iodine protein A binding assay (IPA) and discuss its usefulness for detection of hematopoietic cell surface antigens and for screening hybridoma clones producing monoclonal antibodies (McAbs) against K562 cell surface antigens correlated with differentiation induced by 12-O-tetradecanoyl phorbol-13-acetate (TPA). This assay was performed in polystyrene Terasaki microtest plates instead of 96-well microtiter plates, using hematopoietic cells attached to the wells by air drying. This method facilitates washing procedures and reduces the radioactive waste. The specificity of this IPA method is as high as those of RIAs and ELISAs generally used. Titration curves of a McAb, My7, specific for CD13 on HL60 and TPA-treated HL60 (HL60-TPA) cells, were linear between the 10(-1) and 10(-4) dilutions. A difference in the CD13 expression between HL60 and HL60-TPA cells could be detected by both IPA and flow cytometry using My7 at 10(-1)-10(-3) dilutions. At the 10(-3) dilution, however, CD13 expressed on HL60 cells was detected by the IPA method but not by flow cytometry. These results show that the sensitivity of IPA is superior to that of flow cytometry. By screening hybridoma clones with this IPA method, we succeeded in producing three interesting and useful McAbs (21H73, 37G7 and 49C12) against K562 cell surface antigens whose expression was altered after the differentiation induced by TPA. We also demonstrated that the IPA method is suitable for cell surface marker analysis of leukemia cells freshly isolated from patients.     

急性白血病免疫表型分析及其临床意义

 目的 探讨急性白血病（AL）的免疫表型特点及其临床意义。方法 采用间接免疫荧光法检测分析107例AL患者的免疫表型。结果 CD33、CD13是急性髓系白血病（AML）中最有诊断价值的指标,CD14有助于AML-M4、AML-M5与其他亚型的区别。CD2、CD7是T淋巴细胞白血病（T-ALL）中最有诊断价值的指标,CD19、CD22是B淋巴细胞白血病（B-ALL）中最有诊断价值的指标。17例ALL患者伴髓系抗原（My+ALL）表达率为11.76 %,85例AML患者伴淋系抗原（Ly+AML）表达率为24.71 %。My+ALL和My-ALL患者的CR率分别为0和71.43 %,差异无统计学意义（P＞0.05）。Ly+AML和Ly-AML患者的CR率分别为33.33 %和80.95 %,差异有统计学意义（P＜0.01）。CD+34 AML和CD-34 AML患者的CR率分别为40.74 %和83.33 %,差异有统计学意义（P＜0.01）。HLA-DR+AML和HLA-DR-AML的CR率分别为48.15 %和79.63 %,差异有统计学意义（P＜0.01）。结论 免疫表型分析对AL的诊断以及治疗指导、预后判断等均具有重要意义。     

Expression pattern of hybrid phenotype in adult acute lymphoblastic leukemia.

We examined the expression of hybrid phenotype in 236 adults with acute lymphoblastic leukemia (ALL; 188 B-lineage ALL and 48 T-lineage ALL). In B-lineage ALL, myeloid antigen (mAg) CD15 was concentrated in CD10-CD20- cases (49%); CD13 (42%); and CD33 (43%) in CD10+CD20- cases. This trend had no correlation with the presence of Ph1 or t(4;11) chromosomal abnormality. T-cell antigen CD2, CD4, and CD7 was seen in four, four, and two cases, respectively, and CD4+ and CD7+ cases commonly expressed CD13 and/or CD33 (CD13/CD33). In T-lineage ALL, expression of mAg, CD11b (47%), CD13 (38%), CD15 (28%), and CD33 (51%) was restricted to CD3- cases. B-cell antigen CD19 was found in two cases with CD7 solely as T-cell antigen, and these cases possessed CD13/CD33. CD21 was detected in three cases with CD3. In whole ALL, CD13/CD33 was associated closely with the presence of stem-cell antigen CD34, and in T-lineage ALL, CD13/CD33 had a significant correlation with additional stem-cell features, such as HLA-DR, multidrug resistance 1 (MDR1) and c-kit gene expression. Our results suggest that immature ALL cells frequently express B+M+, T+M+, and occasionally B+T+M+ phenotype; that B+T+M- phenotype is extremely rare; and that mAg expression in B-lineage ALL is complicated as compared to T-lineage ALL.     

Aberrant antigen expression detected by multiparameter three color flow cytometry in intermediate and high grade B-cell lymphomas.

The aberrant expression of antigens (Ag) in lymphoproliferative disorders may cause a diagnostic problem when single parameter immunohistochemical assays are performed on frozen or paraffin sections because coexpression by relevant cells is not determined. This aberrant expression also raises the question as to whether mixed lineage (biphenotypic) lymphoid proliferations exist. Marrow (6) and extramedullary (20) tissues from 26 patients with diffuse, intermediate and high grade, B-cell lymphomas (IWF E=1, F=1, G=19, H=1 and J=4) were analyzed with 19 markers using 3-color flow cytometry. The percentages (%) of patients with double Ag coexpression in at least 20% of the CD19+ or CD20+ lymphoma cells were: stem cell (SC) Ag: CD10 = 58 and CD34 = 15; T-cell Ag: CD2 = 38, CD5 = 19 and CD7 = 19; myeloid (My) Ag: CD13 = 19 and CD33 = 8. The corresponding % with unusual triple Ag coexpression in at least 10% of the CD19+ B-cells were SC+T+ Ag: CD10CD2 = 50, CD10CD5 = 27, CD10CD7 = 38, CD34CD2 = 31, CD34CD5 = 19 and CD34CD7 = 27; T+T+ Ag: CD2CD5 = 35, CD2CD7 = 42 and CD5CD7 = 31; T+My+ Ag: CD2CD13 = 35 and CD2CD33 = 12; and My+My+ Ag: CD13CD33 = 12. Ten of 12 lymphomas tested showed clonal immunoglobulin (Ig) heavy chain gene rearrangements in the absence of clonal T-cell receptor (TCR) gene rearrangements. None (0%) of the My Ag positive cases showed immunoreactivity for myeloperoxidase. We conclude that the anomalous T and My Ag expression seen in the above B-cell lymphomas is not indicative of mixed lineage proliferation but represents the aberrant expression of these antigens by the malignant cells.     

替尼泊苷联合方案治疗交叉表达双系相关抗原急性白血病的临床研究

目的 :探讨替尼泊苷联合方案治疗交叉表达淋系和髓系抗原急性白血病的化疗疗效。方法 :应用替尼泊苷联合阿糖胞苷、环磷酰胺、长春地辛及泼尼松组成 TA或 TA+COP方案 ,治疗伴淋系抗原表达的急性髓细胞白血病 (L y+ AML) 2 4例和伴髓系抗原表达的急性淋巴细胞白血病(My+ AL L) 1 7例。结果 :完全缓解 (CR)率为 5 6 .1 % (2 3/ 4 1 ) ,总有效率为 80 .5 % (33/ 4 1 )。与常规方案 (DA、VDL P)诱导疗效相比有显著性差异 (P<0 .0 1 )。其中 L y+ AML 的 CR率为 5 8.3% ,总有效率为 79.2 % ;My+ AL L 的 CR率为 5 2 .9% ,总有效率为 82 .4 %。复治性 L y+ AML / My+ AL L 总有效率为 72 .7% (8/ 1 1 )。两种方案的骨髓抑制明显 ,毒副作用能够耐受。结论 :L y+ AML 和 My+ AL L不宜采用常规诱导缓解方案 ,TA和 TACOP方案宜作为此类患者的首选治疗方案     

Immunophenotypic changes induced on human HL60 leukaemia cells by 1alpha,25-dihydroxyvitamin D3 and 12-O-tetradecanoyl phorbol-13-acetate

1alpha,25-Dihydroxyvitamin D3 (1,25D3) induces HL60 cells to acquire a monocyte-like phenotype, while cells treated with 12-O-tetradecanoyl phorbol-13-acetate (TPA) resemble macrophages. Using a microarray of 82 CD antibodies, 24 cluster of differentiation (CD) antigens were detected on HL60 cells. 1,25D3 induced the following antigens in decreasing order of the change: CD14, CD11c, CD11b, CD54, CD86, CD38 and CD66c, with repression of CD117, CD71, CD95, CD45 and CD64. TPA induced the following antigens in decreasing order of the change: CD11c, CD9, CD11b, CD54, CD38, CD45RO and CD66c, with repression of CD4, CD117, CD95, CD71 and CD64. The results presented provide a basis for monitoring differentiation therapy of myeloid leukaemias in patients.     

Clinical Significance of Co-expression of Aberrant Antigens in Acute Leukemia: A Retrospective Cohort Study in Makah Al Mukaramah,Saudi Arabia

Background: Aberrant phenotypes in acute leukemia have variable frequency and their prognostic andpredictive relevance is controversial, despite several reports of clinical significance. Aims: To determinethe prevalence of aberrant antigen expression in acute leukemia, assess clinical relevance and demonstrateimmunophenotype-karyotype correlations. Materials and Methods: A total of 73 (40 AML and 33 ALL) newlydiagnosed acute leukemia cases presenting to KAMC, Kingdom of Saudi Arabia, were included. Diagnosis wasbased on WHO criteria and FAB classification. Immunophenotyping by flow cytometry, conventional karyotypingand fluorescence in situ hybridization for gene rearrangements were performed. Results: Aberrant antigens weredetected in 27/40 (67.5%) of AML and in 14/33 (42.4%) in ALL cases. There were statistically significant higherTLC in Ly+ AML than in Ly-AML (p=0.05) and significant higher blast count in ALL with aberrant antigensat presentation and day 14 (p=0.005, 0.046). There was no significant relation to clinical response, relapse freesurvival (RFS) or overall survival (p>0.05), but AML cases expressing ≥2 Ly antigens showed a lower medianRFS than those expressing a single Ly antigen. In AML, CD 56 was expressed in 11/40. CD7 was expressed in7/40, having a significant relation with an unfavorable cytogenetic pattern (p=0.046). CD4 was expressed in 5/40.CD19 was detected in 4/40 AML associated with M2 and t (8; 21). In ALL cases, CD33 was expressed in 7/33and CD13 in 5/33. Regarding T Ag in B-ALL CD2 was expressed in 2 cases and CD56 in 3 cases. Conclusions:Aberrant antigen expression may be associated with adverse clinical data at presentation. AML cases expressing≥2 Ly antigens may have shorter median RFS. No specific cytogenetic pattern is associated with aberrant antigenexpression but individual antigens may be related to particular cytogenetic patterns. Immunophenotype-karyotypecorrelations need larger studies for confirmation.     

Acute T-lymphoblastic leukemia relapsed with the character of myeloid/natural killer cell precursor phenotype: a case report.

The leukemic lymphoblasts of a patient expressed CD7, CD13, CD33, CD34, HLA-DR and cytoplasmic CD3varepsilon. He was diagnosed with acute lymphoblastic leukemia (ALL), and successfully treated with a conventional chemotherapy for ALL. The disease relapsed three times, and the character of the cells gradually altered, i.e. CD56 expression increased and CD13, CD7 and cCD3 epsilon decreased. The phenotype of the relapsed ALL was, therefore, compatible with myeloid/natural killer cell precursor acute leukemia (M/NK-AL). Some of M/NK-AL may be closely related with T/myeloid-biphenotypic pro-T blasts, and both types of acute leukemia may develop a tendency to express myeloid antigens, and they may belong to the category of immature T lymphoid precursors.     

急性髓细胞白血病微分化型流式细胞术免疫分型分析

目的探讨流式细胞术（FCM）检测免疫表型在诊断急性髓细胞白血病微分化型（AML—M0）中的意义。方法采用多色FCM分析14例AML—M0病例的各相关抗原表达情况。结果14例AML—M0中,仅1例依据骨髓细胞形态学作出诊断,其余13例均依靠FCM作出明确诊断。在AML—M0中,髓系抗原CD33 14例（100％）表达阳性,CD13和CD117 9例（64％）表达阳性,CD34和HLA—DR12例（86％）表达阳性,一般成熟髓系相关抗原如CD16、CD10、CD14等均阴性,B和T淋巴细胞特异抗原如CD79a和CD3均为阴性,少数原始细胞表达细胞内髓过氧化物酶（MPO）、TdT。常常表达一些淋系但并不特异的抗原如CD7、CD2或CD19,但比淋巴细胞白血病表达的荧光强度弱。结论FCM免疫分型在AML—M0诊断中至关重要。     

Characterization of myeloid leukemias with monoclonal antibodies 3C5 and MY9

The expression of two membrane antigens identified by the monoclonal antibodies (McAb) My9 and 3C5 has been investigated in cells from 80 acute leukemias. My9 was positive in the blasts of 33 out of the 38 (87 per cent) cases of acute myeloid leukemia (AML) tested, regardless of FAB subtype, and in 13 of 18 (72 per cent) cases of chronic granulocytic leukemia (CGL) in myeloid blast crisis. The reactivity of 3C5 was confined to myeloblastic (M1) AML, 85 per cent of cases, and to lymphoblastic leukemia (ALL) of B-lineage, 70 per cent of cases, including CGL in lymphoid transformation. My9 was negative in ALL except for an unusual case. The phenotype My9+, 3C5+ was seen exclusively in M1 (69 per cent) and M2 (14 per cent) AML. Ultrastructural analysis with the immunogold method in combination with the myeloperoxidase (MPO) reaction showed that expression of My9 increased in parallel with MPO activity whereas 3C5 was expressed mainly in myeloblasts with little MPO content. We conclude that the use of these two McAb will contribute to the diagnosis and classification of AML and may throw some light to the pathogenesis of biphenotypic acute leukemias, including TdT + AML.     

G-CSF Receptors on the Surface of Ph1-positive Acute Lymphoblastic Leukemia (ALL) Cells with Myeloid Surface Antigens: ALL Cells with Myeloid Antigens have Myeloid Function

We treated a patient with acute lymphoblastic leukemia (ALL) whose lymphoblasts at onset showed Ph¹ chromosome and expressed on their surface both precursor B-cell antigens (CD 19 and CD10) and myeloid antigens (CD13 and CD33). The blast cells from this patient showed enhanced ³H-thymidine (³H-TdR) uptake and monocytic differentiation when cultured with either granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage CSF (GM-CSF). The specific binding of ¹²⁵I-labeled G-CSF was also demonstrated. These observations imply that the Ph¹-positive ALL blasts with myeloid surface antigens have myeloid characteristics both phenotypically and functionally.

The disease was resistant to an ALL-oriented regimen but responded to the acute non-lymphocytic leukemia (ANLL)-oriented regimen, but relapses occurred. The cells at the first relapse had exclusively lymphoid markers while those at the second relapse bore myeloid markers; both showed G-CSF binding properties. The expression of G-CSF receptors on the surface of these blasts and responsiveness to G- and GM-CSF may explain the poor prognosis of such patients. All this evidence provides insight into the origin of these blasts.