Acute lymphoblastic leukemia subtypes in Israel: the Sheba medical center experience

Direct association of socio-economic status with T-cell acute lymphoblastic leukaemia in children

Lymphoblasts from 186 consecutive untreated children <18 years were analysed by flow cytometry in Brazil. Socio-economic status was defined by family income; undernourishment by height and weight for age standardised z scores below -1.28. The observed frequencies were precursor-B (pre-B) CD10 positive acute lymphoblastic leukaemia (ALL) (CD10+) 65%, pre-B CD10 negative (CD10-) 13%, and T-ALL 18%. The typical incidence peak at age 2-5 years was observed among the CD10 positive cases. Nutritional variables were not associated with immunophenotypes. Low monthly per capita income was associated with T-immunophenotype (P=0.024). In conclusion, a direct association between unfavourable socio-economic status and the T-phenotype indicates a potential role of socio-economic factors on the genesis of ALL in children, thus confirming indirect data of the international literature.

T-cell acute lymphoblastic leukemia in Israel: clinical and laboratory features

T-cell acute lymphoblastic leukemia (ALL) comprises a third of the cases of childhood ALL in Israel. This high proportion of T-ALL is most probably due to a deficiency in pre-B/common ALL. The T-ALL patients had significantly worse 4-yr survival compared to standard risk or non-T high risk patients. In view of these special epidemiologic and clinical features a study of the immunophenotype of all consecutive cases of T-ALL and T-non Hodgkin's lymphoma (NHL) observed in our medical center was performed. Twenty-eight ALL and 3 NHL patients were studied and their cells characterized using a panel of monoclonal antibodies, TdT reactivity and E-rosette formation. Assays of the activities of adenosine deaminase (ADA) and purine nucleoside phosphorylase (NP) were also performed. Based on the surface antigen expression, the tumor cells could be classified into one of the three known developmental stages of T cells. It was found that the immunophenotype of the T-ALL cases in Israel was similar to that observed in other countries. Considerable heterogeneity of surface antigen expression was found and in a number of cases the phenotype analysis was not easily reconciled with models of T-cell ontogeny. The activities of ADA and NP were correlated with the developmental stage, as defined by the surface antigenic expression. Contrary to observations on normal T-cells, where ADA activity decreases and NP activity increases as T-cells mature and differentiate, this was not found in the malignant T cells. These findings as well as the existence of atypical immunophenotypes suggest that the leukemic T cell has an abnormal gene expression.

Pattern of subtypes of acute lymphoblastic leukemia in India

Leukemic cells from 124 acute lymphoblastic leukemia (ALL) and 31 chronic lymphatic leukemia (CLL) were examined for sheep erythrocyte receptor (E), surface immunoglobulin (SIg) and their reactivity with a panel of monoclonal antibodies recognizing specific surface antigens including pan-T, Common ALL and Ia antigens. In acute lymphatic leukemia, 33% of patients reveal T-cell receptor associated with higher age group, mediastinal mass and high WBC count. Common ALL was predominant between 2 and 9-yr age group. Among chronic lymphatic leukemia, 2 patients were found to be T-CLL while 29 revealed presence of SIg. Ia antigen was detected in 44.4% of ALL and 64% fo CLL patients. The pattern of surface marker observed in our series may be related to our life style, socio-economic and environmental factors.

The epidemiology of childhood acute lymphoblastic leukemia and non-Hodgkin's lymphoma in Israel between 1976 and 1981

n epidemiologic survey of childhood acute lymphoblastic leukemia (ALL) and non-Hodgkin's lymphoma (NHL) occurring in Israel, Judea, Samaria and the Gaza Strip between the years 1976 and 1981, revealed 205 cases of ALL and 69 of NHL. The mean annual incidence of lymphatic malignancies was 3.1/10(5) in the Israeli Jews, 2.3/10(5) in the Israeli Arabs and 2.5/10(5) in the Gaza Strip. In the Jewish population there was a peak in the incidence of lymphatic malignancies at the 2-5 years age group, while in the Israeli Arabs this was less prominent. There were no significant differences in the incidence or type of lymphatic malignancies in the various Jewish or Arab groups but there was a trend for a high leukemia to lymphoma ratio (LLR) in the patients from the Gaza Strip. A relatively higher LLR was observed in families of a high socioeconomic status, but it did not reach statistical significance. T-cell ALL comprised about a third of the typed ALL cases. A high proportion of the patients with ALL belonged to the high-risk category: 46% of the Jewish children and 76% of the Gaza Strip children. White blood cell count above 100,000/mm3 were found at presentation in 36.7% of the Gaza Strip patients but only in 9.4% of the Jewish patients. In spite of that, the survival at 4 years of the Jewish and Arab patients was similar. However, the patients with T-cell ALL had a significantly worse survival than the standard risk or the non-T high-risk group: 43.3 +/- 9.7, 66.6 +/- 7.1 and 63.6 +/- 10.4%, respectively. Compared to a previous study conducted in this country in the sixties it appears that the epidemiologic differences that were observed at that time between the various Jewish ethnic groups have practically disappeared.

Results of treatment of high risk childhood acute lymphoblastic leukemia

Sixteen children with high risk acute lymphoblastic leukemia (ALL) who had one or more of the following risk factors: white cell count over 50 X 10(9)/liter, mediastinal mass, age under 2 or over 10 years, extramedullary involvement, or T-cell markers, were treated by a new protocol. All attained complete remission and 11 are still in their continuous first remission for 6-53 months. High activity of adenosine deaminase (ADA) in the leukemic cells seems to be an independent risk factor, as in the high ADA level group, 4 out of 7 patients relapsed and died, while none of the 8 patients with low ADA levels relapsed or died.