Lymphocytic Leukaemias, Acute and Chronic

Multiplex acute leukemia cytosensing using multifunctional hybrid electrochemical nanoprobes at a hierarchically nanoarchitectured electrode interface

We have developed a robust, nanobiotechnology-based electrochemical cytosensing approach with high sensitivity, selectivity, and reproducibility toward the simultaneous multiplex detection and classification of both acute myeloid leukemia and acute lymphocytic leukemia cells. The construction of the electrochemical cytosensor involves the hierarchical assembly of dual aptamer-functionalized, multilayered graphene-Au nanoparticle electrode interface and the utilization of hybrid electrochemical nanoprobes co-functionalized with redox tags, horseradish peroxidase, and cell-targeting nucleic acid aptamers. The hybrid nanoprobes are multifunctional, capable of specifically targeting the cells of interest, amplifying the electrochemical signals, and generating distinguishable signals for multiplex cytosensing. The as-assembled electrode interface not only greatly facilitates the interfacial electron transfer process due to its high conductivity and surface area but also exhibits excellent biocompatibility and specificity for cell recognition and adhesion. A superstructured sandwich-type sensor geometry is adopted for electrochemical cytosensing, with the cells of interest sandwiched between the nanoprobes and the electrode interface. Such an electrochemical sensing strategy allows for ultrasensitive, multiplex acute leukemia cytosensing with a detection limit as low as ~350 cells per mL and a wide linear response range from 5 × 10(2) to 1 × 10(7) cells per mL for HL-60 and CEM cells, with minimal cross-reactivity and interference from non-targeting cells. This electrochemical cytosensing approach holds great promise as a new point-of-care diagnostic tool for early detection and classification of human acute leukemia and may be readily expanded to multiplex cytosensing of other cancer cells.

DNA and RNA determination in 111 cases of childhood acute lymphoblastic leukaemia (ALL) by flow cytometry: correlation of FAB classification with DNA stemline and proliferation

Flow cytometry with acridine orange was used in 111 cases of childhood acute lymphoblastic leukaemia (ALL) to determine simultaneously DNA index, cell cycle distribution and cellular RNA content in bone marrow samples. The overall incidence of DNA aneuploidy in the population was 40%. Significantly higher incidence of DNA aneuploidy was present in the L2 (70.6%) as compared to the L1 (34.1%) group (P = 0.007), using the FAB classification. No difference in the frequency of normal and abnormal DNA stemlines was found between newly diagnosed and relapsed patients. The L2 group had significantly higher proliferation (S phase = 12.4%) than L1 (S phase = 5.8%) (P = 0.01), but RNA content was not significantly different. The aneuploid group had significantly more (P = 0.01) cases with L2 morphology (28.6%) compared to the diploid group (8%) and proliferation was higher in DNA aneuploid (S-phase = 9.5%) compared to DNA diploid (S-phase = 4.7%) leukaemias. Likewise, RNA content was significantly higher in aneuploid than in diploid ALL (P = 0.006). These correlations between morphology, cell kinetics and DNA index elucidate biological properties of leukaemic cells with potentially prognostic value.

A 14q+ chromosome in a malignant lymphoma in a patient with Down's syndrome

A 17-year-old Japanese boy with Down's syndrome developed leukemic lymphosarcoma; histology of a lymph node biopsy revealed a malignant lymphoma, of the poorly differentiated lymphocytic (ML-PDL) or possibly lymphoblastic type (ML-LB). The Giemsa-banding technique for chromosome analysis revealed the karyotype of the lymphoma cells to be 47, XY, + 21, 14q+. A chromosome study of PHA-stimulated lymphocytes showed a 21-trisomic pattern, i.e., 47, XY, + 21. The 14q+ marker was a product of a translocation in which the long arm of chromosome No. 8 (probable break at band q11) was translocated to the long arm of a No. 14 at band q32, which is a region usually affected in various types of lymphomas. Two normal No.8 chromosomes were present. Thus, the lymphoma cells were partially trisomic for chromosome No. 8.

Chromosome studies in acute lymphoblastic leukaemia (ALL)

Chromosome banding studies of the bone marrow were performed in 35 adult (greater than 14 years) patients with acute lymphoblastic leukaemia (ALL). Surface marker analysis was done in 24 of these and revealed 4 B-ALL, 5 T-ALL and 15 non-T non-B ALL. Most patients were studied at diagnosis before any treatment. A clonal karyotypic abnormality was found in 16 patients (46 %) initially. A Philadelphia chromosome was found in 3 patients, all belonging to the non-T non-B group. 5 patients, who all had blast cells with morphologic characteristics of Burkitt type L, were found to have bone marrow cells with a 14q + marker chromosome. In at least 4 cases this was due to a t(8;14). The cytogenetic findings showed some correlation to the ALL subgroup, but not to the response to treatment or the prognosis.