Biological and clinical features of B-precursor childhood acute lymphoblastic leukemia showing CD2 and/or E-rosette co-expression.

BACKGROUND: Co-expression of the T-associated marker CD2 or E-rosette in non-T acute leukemia has rarely been reported. In this paper the incidence of such co-expression, together with its biologic features and clinical relevance, was evaluated in a large series of childhood "common" acute lymphoblastic leukemia (cALL) cases. METHODS: This analysis was performed retrospectively on 306 cases of childhood non-T ALL. CD2 and/or E-rosette co-expression with other non-T markers was usually shown by a clear overlap between the percentages of T and non-T markers, by the great difference between positivity for CD2 or E-rosette and other T markers, and by double staining for CD2 and CD10 in one case. Two cases were further studied by a panel of nine different CD2 monoclonal antibodies (MAbs) representative of different epitopes. DNA analysis for the configuration of Ig and TCR genes (beta, gamma, and delta locus) was carried out in three cases. RESULTS: Eleven out of 306 cases (3.6%) showed CD2 and/or E-rosette co-expression in otherwise typical cALL. Data obtained in two cases with the use of nine different CD2 Mabs showed a different pattern of reactivity between leukemic B cells and normal T cells. The configuration of Ig and TCR genes was compatible with B-lineage ALL. CONCLUSIONS: CD2 and/or E-rosette co-expression was observed in a small subset of acute leukemias showing immunophenotypic and genotypic features of B-lineage ALL. A pattern of reactivity different from that seen in normal T cells was observed in the two cases tested with a large panel of CD2 MAbs. No association was found with other known prognostic factors, and 8 of these 11 patients have been in first continuous remission for 36-93 months.

B-cell acute lymphoblastic leukemia (B-ALL): a report of 17 pediatric cases.

BACKGROUND AND METHODS: B-cell acute lymphoblastic leukemia (B-ALL) presents FAB L3 morphology and surface Ig, CD19, CD20, CD24. This pattern may show some morphological and immunological heterogeneity. Seventeen pediatric cases of B-ALL at onset, treated in twelve AIEOP Centers (Italian Association for Pediatric Hematology and Oncology), are presented. RESULTS AND CONCLUSIONS: Clinical and hematological features were characterized by low WBC counts at presentation, high M/F ratio, older age and association with extramedullary involvement. The overall survival curve at 78 months is 40%. All patients showed blasts positive for surface Ig (sIg), DR, CD19, and CD24. Ten/17 cases presented the classical features of B-ALL: FAB L3 morphology, sIg+ restricted to light chains, CD20+, cytoplasm mu (c mu)-, CD10-, TdT-. The remainder showed some differences in this pattern, such as non-L3 morphology (3 cases), absence of CD20 (3 cases), CD10+ (4 cases), TdT+ (3 cases), c mu+ (1 case), lack of surface light chains (1 case). This rare ALL subset seems to be characterized by a high phenotype heterogeneity, indicating various degrees of differentiation.

Co-expression of myeloid antigens in childhood acute lymphoblastic leukaemia: relationship with the stage of differentiation and clinical significance.

Co-expression of myeloid antigens on the leukaemic blast cells was evaluated in 532 children with a diagnosis of acute lymphoblastic leukaemia (ALL). Using a panel of monoclonal antibodies belonging to CD11b, CD13, CD14, CD15 and CD33 an overall incidence of 4.3% was found, with values ranging between 1.8% for CD14 and 6.1% for CD15. When the data were further dissected, a significantly higher incidence of co-expression was noted in null-ALL (15/70 cases = 21.4%), compared to cases expressing a more mature immunophenotype, i.e. common-ALL (7/394 cases = 1.7%) and T-ALL (1/68 cases = 1.4%) (P less than 0.001). In null-ALL, 9/15 patients were infants, five of whom with the t(4;11); two further children also had a t(4;11). The clinical outcome of the 23 cases which co-expressed myeloid antigens was unfavourable. Only two of the 15 null-ALL, two of the seven common-ALL and the unique case with T-ALL are in fact in persistent first remission between 19 and 93 months from diagnosis. Though the overall incidence of childhood ALL expressing myeloid antigens is low, the evidence that this co-expression may be related to an unfavourable clinical course and that it more frequently occurs in null-ALL, particularly in the first year of life, suggests that the routine assessment of myeloid antigens may allow to identify a subgroup of childhood ALL with a poor clinical outcome.

The use of amniotic FSH levels in resolving a discrepancy between fetal chromosomal and phenotypic sex.

We report a case in which a discrepancy emerged between the prenatal diagnosis of female chromosomal sex and male sex at ultrasound examination. The FSH dosage performed on an amniotic fluid sample previously stored confirmed the male phenotype of the fetus. The effectiveness of the AF-FSH level dosage in prenatal diagnosis was taken into consideration.