Variant Of Acute Promyelocytic Leukemia Research Articles

Promyelocytic Blast Crisis of Chronic Myelogenous Leukemia:A Rare Subtype Associated With Disseminated Intravascular Coagulation

Two patients with chronic myelogenous leukemia (CML) developed blast crisis that morphologically appeared to be the microgranular variant of acute promyelocytic leukemia. This represented 8% of CML patients developing blast crisis from 1984 to 1993. Cytogenetic studies revealed translocation 15;17 in addition to translocation 9;22 that had been documented at initial diagnosis. Both patients had evidence of disseminated intravascular coagulation at the onset or during treatment of blast crisis, which was not documented in any other patients with CML blast crisis. One patient died of sepsis during intensive chemotherapy. The second returned to a chronic phase of the disease after therapy. Although rare, a promyelocytic blast crisis of CML can occur which, as in de novo acute promyelocytic leukemia, has a propensity to produce disseminated intravascular coagulation.

All-transretinoic acid followed by intensive chemotherapy gives a high complete remission rate and may prolong remissions in newly diagnosed acute promyelocytic leukemia: a pilot study on 26 cases

We entered 26 patients with newly diagnosed acute promyelocytic leukemia (APL) in a pilot study of all-transretinoic acid (ATRA) followed by intensive chemotherapy. Median age was 46 (range 25 to 63). No patient presented with leukocytes > 10 x 10(9)/L or had the microgranular APL variant. Cytogenetic analysis (25 patients) found a t(15;17) in 24 cases. Patients were scheduled to receive ATRA (45 mg/m2/d) until complete remission, followed by an intensive daunorubicin (DNR) + Ara C course (“4 + 7” course), then three “2 + 5” DNR + Ara C courses and maintenance chemotheapy. However, the “4 + 7” course was administered in emergency if hyperleukocytosis rapidly developed to prevent leukostasis. Twenty-five patients (96%) achieved CR, 14 with ATRA alone and 11 after the addition of the “4 + 7” course on day 2 to 30 of treatment, because leukocytes rapidly increased (9 cases), because of resistance to ATRA (1 case), and development of organomegaly (1 case). The remaining patient died on day 6, from CNS bleeding. Apart from hyperleukocytosis, side effects were usually moderate. In the 11 patients who could be studied in vitro, a very good correlation was found between in vivo and vitro differentiation and proliferation of APL blasts with ATRA. Three patients were allografted after the “4 + 7” course. Four patients did not receive this course but received the subsequent “2 + 5” courses and maintenance. The remaining patients followed the scheduled protocol. Three patients relapsed after 8, 11, and 15 months (including one allografted patient). Two patients died in CR, after 6 and 17 months. The other 20 patients remained in CR after 18+ to 34+ months (median 21). Actuarial disease free interval (DFI) and event free survival (EFS) were 87% and 77%, respectively, after 18 months. These results were compared to those obtained in our previous APL 84 trial with chemotherapy alone in newly diagnosed APL (after excluding patients included in this trial who presented with hyperleukocytosis). In APL 84 trial, the CR rate was 76%, the actuarial DFI and EFS were 59% and 48% after 18 months, respectively. Differences with the pilot study of ATRA followed by chemotherapy were significant for DFI (P = .02), EFS (P = .006), but not for CR rate (P = .08). Although this is a historical comparison, these results suggest that ATRA followed by chemotherapy may prove superior to chemotherapy alone in newly diagnosed APL, by slightly increasing the CR rate, but perhaps more importantly by reducing the relapse rate.(ABSTRACT TRUNCATED AT 400 WORDS)

All-Transretinoic Acid Followed by Intensive Chemotherapy Gives a High Complete Remission Rate and May Prolong Remissions in Newly Diagnosed Acute Promyelocytic Leukemia: A Pilot Study on 26 Cases

We entered 26 patients with newly diagnosed acute promyelocytic leukemia (APL) in a pilot study of all-transretinoic acid (ATRA) followed by intensive chemotherapy. Median age was 46 (range 25 to 63). No patient presented with leukocytes > 10 x 10(9)/L or had the microgranular APL variant. Cytogenetic analysis (25 patients) found a t(15;17) in 24 cases. Patients were scheduled to receive ATRA (45 mg/m2/d) until complete remission, followed by an intensive daunorubicin (DNR) + Ara C course ("4 + 7" course), then three "2 + 5" DNR + Ara C courses and maintenance chemotheapy. However, the "4 + 7" course was administered in emergency if hyperleukocytosis rapidly developed to prevent leukostasis. Twenty-five patients (96%) achieved CR, 14 with ATRA alone and 11 after the addition of the "4 + 7" course on day 2 to 30 of treatment, because leukocytes rapidly increased (9 cases), because of resistance to ATRA (1 case), and development of organomegaly (1 case). The remaining patient died on day 6, from CNS bleeding. Apart from hyperleukocytosis, side effects were usually moderate. In the 11 patients who could be studied in vitro, a very good correlation was found between in vivo and vitro differentiation and proliferation of APL blasts with ATRA. Three patients were allografted after the "4 + 7" course. Four patients did not receive this course but received the subsequent "2 + 5" courses and maintenance. The remaining patients followed the scheduled protocol. Three patients relapsed after 8, 11, and 15 months (including one allografted patient). Two patients died in CR, after 6 and 17 months. The other 20 patients remained in CR after 18+ to 34+ months (median 21). Actuarial disease free interval (DFI) and event free survival (EFS) were 87% and 77%, respectively, after 18 months. These results were compared to those obtained in our previous APL 84 trial with chemotherapy alone in newly diagnosed APL (after excluding patients included in this trial who presented with hyperleukocytosis). In APL 84 trial, the CR rate was 76%, the actuarial DFI and EFS were 59% and 48% after 18 months, respectively. Differences with the pilot study of ATRA followed by chemotherapy were significant for DFI (P = .02), EFS (P = .006), but not for CR rate (P = .08). Although this is a historical comparison, these results suggest that ATRA followed by chemotherapy may prove superior to chemotherapy alone in newly diagnosed APL, by slightly increasing the CR rate, but perhaps more importantly by reducing the relapse rate.(ABSTRACT TRUNCATED AT 400 WORDS)

Microgranular variant of acute promyelocytic leukemia in children.

The microgranular variant (M3v) of acute promyelocytic leukemia (APL) rarely has been reported in a pediatric series of acute nonlymphoblastic leukemia (AnLL). We reviewed the clinical and biologic features of childhood M3v cases in our AnLL series. From January 1970 to January 1991, 11 children with M3v were admitted and treated at our center. A diagnosis was made according to French-American-British (FAB) criteria. Morphologic examination, cytochemical analysis, and immunophenotyping were performed by a single pathologist. From January 1984, the diagnosis was confirmed by cytogenetic and, subsequently, by molecular analysis on frozen material. In our series, the overall incidence of children with APL was unusually high, 31.2% of the AnLL and M3v constituted one case in every four cases of APL. Even restriction of the analysis to the time when either cytogenetic and DNA studies confirmed the diagnosis, the incidence did not change. The immunophenotype of M3v cases was identical to that described for the hypergranular type, but an unexpected association of CD2 with M3v was shown. The onset was characterized by marked hyperleukocytosis (median WBC count, 87 x 10(9)/L) unlike classic APL. Disseminated intravascular coagulation (DIC) was always present and severe. Hyperleukocytosis and DIC were responsible for the high incidence of deaths for hemorrhagic events in the first days after onset (eight of 11 patients). In our experience, for unknown reasons, M3v may occur in childhood more than generally was considered. The clinical course and prognosis seem worse in M3v than in typical APL cases.

Identification of DNA Rearrangements at the Retinoic Acid Receptor-α (RAR-α) Locus in All Patients With Acute Promyelocytic Leukemia (APL) and Mapping of APL Breakpoints Within the RAR-α Second Intron: for the Italian Cooperative Study Group “GIMEMA”

Seventy patients with acute promyelocytic leukemia (APL) were characterized at the DNA level using genomic retinoic acid receptor-alpha (RAR-alpha) probes on Southern blot experiments. Sixty-two cases were defined as M3 according to the French-American-British (FAB) criteria, and eight had a diagnosis of microgranular or variant (M3v) APL. The use of two restriction enzymes and three probes exploring the second intron of the RAR-alpha gene allowed us to detect specific abnormal DNA fragments in every case, with clustering of rearrangements within the 20-kb intronic region between RAR-alpha exons II and III. A more detailed mapping of APL breakpoints was performed in 52 cases in which three EcoRI subregions of the RAR-alpha second intron were analyzed with corresponding probes. Comparison of clinical and hematological features in the three subgroups of patients with distinct RAR-alpha breakpoints did not show significant differences regarding age, peripheral blood (PB) counts, presence of coagulopathy, or FAB classification (M3 v M3v). Interestingly, a significant difference was observed in the M/F ratio of the three subgroups, with a higher incidence of rearrangements at the 5' end of the RAR-alpha second intron in female patients, and more frequent 3' breakpoints in males. The results of this study indicate that a unique genomic alteration consistently occurs on the 17q- derivative of the APL specific t(15;17) aberration. Moreover, the clinical relevance of RAR-alpha gene analysis both at diagnosis and in follow-up studies is further emphasized.

Identification of DNA rearrangements at the retinoic acid receptor- alpha (RAR-alpha) locus in all patients with acute promyelocytic leukemia (APL) and mapping of APL breakpoints within the RAR-alpha second intron. Italian Cooperative Study Group "GIMEMA"

Seventy patients with acute promyelocytic leukemia (APL) were characterized at the DNA level using genomic retinoic acid receptor- alpha (RAR-alpha) probes on Southern blot experiments. Sixty-two cases were defined as M3 according to the French-American-British (FAB) criteria, and eight had a diagnosis of microgranular or variant (M3v) APL. The use of two restriction enzymes and three probes exploring the second intron of the RAR-alpha gene allowed us to detect specific abnormal DNA fragments in every case, with clustering of rearrangements within the 20-kb intronic region between RAR-alpha exons II and III. A more detailed mapping of APL breakpoints was performed in 52 cases in which three EcoRI subregions of the RAR-alpha second intron were analyzed with corresponding probes. Comparison of clinical and hematological features in the three subgroups of patients with distinct RAR-alpha breakpoints did not show significant differences regarding age, peripheral blood (PB) counts, presence of coagulopathy, or FAB classification (M3 v M3v). Interestingly, a significant difference was observed in the M/F ratio of the three subgroups, with a higher incidence of rearrangements at the 5′ end of the RAR-alpha second intron in female patients, and more frequent 3′ breakpoints in males. The results of this study indicate that a unique genomic alteration consistently occurs on the 17q- derivative of the APL specific t(15;17) aberration. Moreover, the clinical relevance of RAR-alpha gene analysis both at diagnosis and in follow-up studies is further emphasized.

Acute Promyelocytic Leukemia in Children: a Report on Eleven Cases.

We report 11 children (aged less than 20 years) with acute promyelocytic leukemia (APL), who represented 14% of our total number of patients with APL. There were 8 girls and 3 boys and the median age was 13.5 (range 3-19). Extramedullary leukemia was present in only 1 patient and hyperleukocytosis in 3 patients. Cytologically, 9 patients had "classical" APL, and 2 had the microgranular variant APL. Translocation (15;17) was present in all 4 karyotyped patients. Disseminated intravascular coagulation was seen in 8 patients at diagnosis, and was triggered by chemotherapy in 2 other cases. Induction chemotherapy was daunorubicin (DNR) alone in 6 patients, DNR + Ara C in 4 and zorubicin + Ara C in the remaining case. All patients received heparin during induction. Seven patients (64%) achieved complete remission (CR), 2 had resistant leukemia and 2 died during induction. Among the complete remitters, one received no further therapy and relapsed after 4 months, and another died of an unrelated cause after 4 weeks, while still in CR. The 5 others all relapsed after 3 to 13 months. Median survival was 5.5 months. Disease free survival (DFS) was significantly shorter than in our adult APL patients treated with the same regimens. APL is a rare disease in children and our results suggest that it may be associated with short remissions, especially when compared with adult APL. This could justify therapeutic reinforcement in these cases, such as allogeneic bone marrow transplantation, whenever possible, after CR has been achieved.

Microgranular promyelocytic leukemia: a multiparameter examination.

Six cases of microgranular variant acute promyelocytic leukemia (M3v) were studied by use of a multiparameter approach including morphology, cytochemistry, flow cytochemistry, flow cytometry, cytogenetics, and gene rearrangement. Three of six cases demonstrated both myeloid and monocytoid associated surface markers by flow cytometry. One of six cases had strong alpha-naphthyl-butyrate esterase (alpha-NBE) activity in addition to myeloperoxidase activity. There was no correlation between percentage of positive monocytoid surface markers and intensity of cytoplasmic alpha-NBE activity. Four of six cases also had a T-cell-associated surface antigen. Further studies indicated that the T-cell markers appeared to be on the promyelocytes and that the T-B receptor gene was not rearranged. Similarly, cytogenetics studies indicated only one clonal abnormality t(15q+; 17q-). Whether these cases represent true "lineage infidelity" remains to be answered. Future important studies are needed on normal hematopoietic progenitor cells at early stages of development and childhood to study lineage-specific characteristics and to determine whether co-expression normally exists during early development.

Pseudo-Chediak-Higashi Anomaly in a Case of Acute Myeloid Leukemia: Electron Microscopic Studies

The formation and fine structure of giant granules in neutrophil promyelocytes of a patient with a variant of acute myelogenous leukemia were investigated by electron microscopy. The patient presented with large lymph nodes and disseminated intravascular coagulation (DIC). By light microscopy, numerous giant granules, resembling those of Chediak-Higashi syndrome (CHS), were present, but Auer bodies could not be found. By electron microscopy, these giant granules were seen to be formed by fusion of azurophilic granules, as in CHS; however, they were different from the large granules of CHS, since they contained numerous microcrys-talline structures like those of Auer bodies. However, the crystalline cores of these granules exhibited a periodicity different from that of Auer bodies of acute pro-myelocytic leukemia. This clinical and hematologic syndrome (giant granules, enlarged lymph nodes, and DIC may represent a variant of acute promyelocytic leukemia.

Pseudo-Chediak-Higashi anomaly in a case of acute myeloid leukemia: electron microscopic studies

The formation and fine structure of giant granules in neutrophil promyelocytes of a patient with a variant of acute myelogenous leukemia were investigated by electron microscopy. The patient presented with large lymph nodes and disseminated intravascular coagulation (DIC). By light microscopy, numerous giant granules, resembling those of Chediak- Higashi syndrome (CHS), were present, but Auer bodies could not be found. By electron microscopy, these giant granules were seen to be formed by fusion of azurophilic granules, as in CHS; however, they were different from the large granules of CHS, since they contained numerous microcrystalline structures like those of Auer bodies. However, the crystalline cores of these granules exhibited a periodicity different from that of Auer bodies of acute promyelocytic leukemia. This clinical and hematologic syndrome (giant granules, enlarged lymph nodes, and DIC may represent a variant of acute promyelocytic leukemia.