How to Manage Philadelphia-Positive Acute Lymphoblastic Leukemia in Resource-Constrained Settings

Recent studies have indicated that more than half of adult patients newly diagnosed with Ph+ ALL can now achieve a cure. However, determining the most suitable protocol for less-resourced settings can be challenging. In these situations, we must consider the potential for treatment toxicity and limited access to newer agents and alloSCT facilities. Currently, it is advisable to use less intensive induction regimens for Ph+ ALL. These regimens can achieve high rates of complete remission while causing fewer induction deaths. For consolidation therapy, chemotherapy should remain relatively intensive, with careful monitoring of the BCR-ABL1 molecular transcript and minimal residual disease. AlloSCT may be considered, especially for patients who do not achieve complete molecular remission or have high-risk genetic abnormalities, such as IKZF1-plus. If there is a loss of molecular response, it is essential to screen patients for ABL mutations and, ideally, change the TKI therapy. The T315I mutation is the most common mechanism for disease resistance, being targetable to ponatinib. Blinatumomab, a bispecific antibody, has shown significant synergy with TKIs in treating this disease. It serves as an excellent salvage therapy, aside from achieving outstanding results when incorporated into the frontline.

Association between convalescent plasma treatment and mortality in COVID-19: a collaborative systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX ).

METHODS

In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence.

RESULTS

A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis.

CONCLUSIONS

Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care.

Immunophenotype of acute lymphoblastic leukemia in minorities- analysis from the SEER database

Acute Lymphocytic Leukemia (ALL) is a malignancy that originates from immature lymphoid cells and is clinically established with flow cytometry through disease-specific markers. Variation between ethnic groups is an epidemiological aspect of ALL. Higher incidence rates have been observed in Latin American patients and ALL in Latinos carries a dismal prognosis. The cell of origin in ALL is derived from immature cells of either the B or T lineage. Most reported data among Latinos either exclusively looks at B cell precursor ALL or do not distinguish between subtypes. We used the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database to delineate the differences in incidence rates of B-ALL and T-ALL across ethnic groups in the United States. Data from SEER-18 was used to compare incidence rates of T-ALL and B-ALL. Due to the utilization of cytogenetics and subsequent changes in ICD coding over the years examined the most recent data reported from 2002 to 2017. We compared rates in Non-Hispanic Whites (NHWs), Latinos, Blacks and Asian-Pacific Islanders (API). Age-adjusted incidence rates per 100,000 person-years were calculated. The incidence rate of B-ALL in the Latino population was consistently higher than other race/ethnicities throughout the years, ranging from 1.0 per 100,000 in 2002 to 2.5 per 100,000 in 2017. Blacks had the lowest age adjusted incidence rate (AAIR) of B-ALL overall, with rates approximately one third of those found in Latinos and the highest AAIR of T-ALL with an AAIR of 0.5 per 100,000.

Mutational profile of ZBTB16-RARA-positive acute myeloid leukemia

Background

The ZBTB16‐RARA fusion gene, resulting from the reciprocal translocation between ZBTB16 on chromosome 11 and RARA genes on chromosome 17 [t(11;17)(q23;q21)], is rarely observed in acute myeloid leukemia (AML), and accounts for about 1% of retinoic acid receptor‐α (RARA) rearrangements. AML with this rare translocation shows unusual bone marrow (BM) morphology, with intermediate aspects between acute promyelocytic leukemia (APL) and AML with maturation. Patients may have a high incidence of disseminated intravascular coagulation at diagnosis, are poorly responsive to all‐trans retinoic acid (ATRA) and arsenic tryoxyde, and are reported to have an overall poor prognosis.

Aims

The mutational profile of ZBTB16‐RARA rearranged AML has not been described so far.

Materials and methods

We performed targeted next‐generation sequencing of 24 myeloid genes in BM diagnostic samples from seven ZBTB16‐RARA+AML, 103 non‐RARA rearranged AML, and 46 APL. The seven ZBTB16‐RARA‐positive patients were then screened for additional mutations using whole exome sequencing (n = 3) or an extended cancer panel including 409 genes (n = 4).

Results

ZBTB16‐RARA+AML showed an intermediate number of mutations per patient and involvement of different genes, as compared to APL and other AMLs. In particular, we found a high incidence of ARID1A mutations in ZBTB16‐RARA+AML (five of seven cases, 71%). Mutations in ARID2 and SMARCA4, other tumor suppressor genes also belonging to SWI/SNF chromatin remodeling complexes, were also identified in one case (14%).

Discussion and conclusion

Our data suggest the association of mutations of the ARID1A gene and of the other members of the SWI/SNF chromatin remodeling complexes with ZBTB16‐RARA+AMLs, where they may support the peculiar disease phenotype.

Management of acute promyelocytic leukemia: updated recommendations from an expert panel of the European LeukemiaNet

Since the comprehensive recommendations for the management of acute promyelocytic leukemia (APL) reported in 2009, several studies have provided important insights, particularly regarding the role of arsenic trioxide (ATO) in frontline therapy. Ten years later, a European LeukemiaNet expert panel has reviewed the recent advances in the management of APL in both frontline and relapse settings in order to develop updated evidence- and expert opinion-based recommendations on the management of this disease. Together with providing current indications on genetic diagnosis, modern risk-adapted frontline therapy, and salvage treatment, the review contains specific recommendations for the identification and management of the most important complications such as the bleeding disorder APL differentiation syndrome, QT prolongation, and other all-trans retinoic acid- and ATO-related toxicities, as well as recommendations for molecular assessment of the response to treatment. Finally, the approach to special situations is also discussed, including management of APL in children, elderly patients, and pregnant women. The most important challenges remaining in APL include early death, which still occurs before and during induction therapy, and optimizing treatment in patients with high-risk disease.

The emerging story of acute lymphoblastic leukemia among the Latin American population - biological and clinical implications

Higher incidence rates and poor outcomes have been reported among Latin American patients (Latinos) with acute lymphoblastic leukemia (ALL). Distinct patterns in recent genomic studies allude to a predisposing genetic component. In this review, we critically examine the increasing amount of empirical information on the epidemiology, outcomes and genomics of Latinos with ALL. We discuss the immense diversity within the Latino community and varying definitions of what is considered Latino, which pose an epidemiological challenge. Environmental factors have been evaluated as possible predisposing factors in the development of ALL but studies have produced conflicting results. In this review we describe chromosomal abnormalities and the specific genomic landscape in Latinos with ALL and their association with unfavorable prognosis, focusing on the higher frequency of Philadelphia chromosome-Like ALL. Recent data suggest an association between polymorphisms that are commonly found in indigenous Americans and high rates of ALL. The review compares the distribution of ALL throughout the various countries in Latin America in an attempt to shed some epidemiological light on the genetic ancestry of ALL. We additionally identify areas where research is warranted in efforts toward the advent of novel targeted agents that are relevant in improving outcomes within the Latino community.

Development and Evaluation of a Hematology-Oriented Clinical Research Training Program in Latin America

The objectives of the study were to describe the development of a patient-oriented clinical research training program in a low- or middle-income country (LMIC) setting, to describe perceived benefits of the program and barriers to application, and to make recommendations for future training programs. The program was developed by the American Society of Hematology in collaboration with Latin American stakeholders and clinical researchers. Session types were didactic, small group, and one-on-one faculty/participant dyad formats. Outcomes were assessed by quantitative surveys of trainees and qualitative feedback from both trainees and faculty members. The program is an annual 2-day course specifically for Latin American hematologists. Through course evaluations, all trainees described that the didactic sessions were relevant. All session types were useful for gaining knowledge and skills, particularly one-on-one meetings. The potential for networking was highly valued. Barriers to trainee applications were the concerns that skill level, proposed research program, and knowledge of English were not sufficiently strong to warrant acceptance into the course, and financial costs of attendance. We have described the development and initial evaluation of a clinical research training program in a LMIC setting. We learned several valuable lessons that are applicable to other research training programs.

Suppression of Myc oncogenic activity by ribosomal protein haploinsufficiency

The Myc oncogene regulates the expression of multiple components of the protein synthetic machinery, including ribosomal proteins, initiation factors of translation, Pol III, and rDNA1,2. An outstanding question is whether and how increasing the cellular protein synthesis capacity can affect the multi-step process leading to cancer. We utilized ribosomal protein heterozygote mice as a genetic tool to restore increased protein synthesis in Eμ–Myc/+ transgenic mice to normal levels and show that in this context Myc's oncogenic potential is suppressed. Our findings demonstrate that the ability of Myc to increase protein synthesis directly augments cell size and is sufficient to accelerate cell cycle progression independently of known cell cycle targets transcriptionally regulated by Myc. In addition, when protein synthesis is restored to normal levels, Myc overexpressing precancerous cells are more efficiently eliminated by programmed cell death. Our findings reveal a novel paradigm that links increases in general protein synthesis rates downstream of an oncogenic signal to a specific molecular impairment in the modality of translation initiation employed to regulate the expression of selective mRNAs. We show that an aberrant increase in cap-dependent translation downstream Myc hyperactivation specifically impairs the translational switch to internal ribosomal entry site (IRES)-dependent translation required for accurate mitotic progression. Failure of this translational switch results in reduced mitotic-specific expression of the endogenous IRES-dependent form of Cdk11 (p58-PITSLRE)3-5, which leads to cytokinesis defects and is associated with increased centrosome numbers and genome instability in Eμ–Myc/+ mice. When accurate translational control is re-established in Eμ–Myc/+ mice, genome instability is suppressed. Our findings reveal how perturbations in translational control provide a highly specific outcome on gene expression, genome stability, and cancer initiation that have important implications for understanding the molecular mechanism of cancer formation at the post-genomic level.

Impaired control of IRES-mediated translation in X-linked dyskeratosis congenita

The DKC1 gene encodes a pseudouridine synthase that modifies ribosomal RNA (rRNA). DKC1 is mutated in people with X-linked dyskeratosis congenita (X-DC), a disease characterized by bone marrow failure, skin abnormalities, and increased susceptibility to cancer. How alterations in ribosome modification might lead to cancer and other features of the disease remains unknown. Using an unbiased proteomics strategy, we discovered a specific defect in IRES (internal ribosome entry site)-dependent translation in Dkc1(m) mice and in cells from X-DC patients. This defect results in impaired translation of messenger RNAs containing IRES elements, including those encoding the tumor suppressor p27(Kip1) and the antiapoptotic factors Bcl-xL and XIAP (X-linked Inhibitor of Apoptosis Protein). Moreover, Dkc1(m) ribosomes were unable to direct translation from IRES elements present in viral messenger RNAs. These findings reveal a potential mechanism by which defective ribosome activity leads to disease and cancer.

Management of APL in Developing Countries: Epidemiology, Challenges and Opportunities for International Collaboration

Acute promyelocytic leukemia (APL), a relatively rare hematologic malignancy, is highly curable with current treatment strategies. However, these strategies may be unavailable in countries with limited resources. A review of records in several Latin American countries revealed that approximately 30% of deaths among children and adults with APL were caused by early complications associated with the disease or its treatment. Further, APL accounts for 20% to 25% of cases of AML in these countries, consistent with the previous observation of increased incidence of APL in Latin Americans. The lack of population-based registries in developing countries has made it difficult to determine the real incidence of APL. Moreover, APL appears to have other unique epidemiologic characteristics, including association of primary APL with an increased body mass index at diagnosis and association of secondary APL with breast cancer. To facilitate the development of local capacity and implement effective treatment of APL in developing countries, the International Committee of the American Society of Hematology has assembled a working group to formulate treatment guidelines based on evidence from clinical trials results in the developed world but adapted to local resources. It is hoped that uniform treatment, careful documentation of specific outcome data, and ongoing monitoring of treatment efficacy and toxicity will improve the cure rate and provide biologic and epidemiologic information about APL in developing countries. This initial demonstration project may be joined by other countries, providing a framework for additional clinical investigation in this highly curable form of leukemia.

Intracranial Castleman’s disease presenting as hypopituitarism

Castleman's disease is an atypical lymphoproliferative disorder that may present as a localized or multicentric form. The involvement of the central nervous system is rare. We describe here a case of Castleman's disease with involvement of the hypothalamus and meninges, presenting as hypopituitarism. Radiological and clinical pathological features are emphasized and a review of the literature is presented.

Dyskeratosis congenita and cancer in mice deficient in ribosomal RNA modification

Mutations in DKC1 cause dyskeratosis congenita (DC), a disease characterized by premature aging and increased tumor susceptibility. The DKC1 protein binds to the box H + ACA small nucleolar RNAs and the RNA component of telomerase. Here we show that hypomorphic Dkc1 mutant (Dkc1m) mice recapitulate in the first and second generations (G1 and G2) the clinical features of DC. Dkc1m cells from G1 and G2 mice were impaired in ribosomal RNA pseudouridylation before the onset of disease. Reductions of telomere length in Dkc1m mice became evident only in later generations. These results suggest that deregulated ribosome function is important in the initiation of DC, whereas telomere shortening may modify and/or exacerbate DC.

Isolation and partial characterization of a polypeptide from Phoneutria nigriventer spider venom that relaxes rabbit corpus cavernosum in vitro

The venom of the Brazilian spider Phoneutria nigriventer was fractionated using a C18 microBondapack reverse-phase high-performance liquid chromatography column. The resulting fractions were assayed in the rabbit perfused corpus cavernosum tissue to identify those fractions responsible for the corpus cavernosum relaxation. Two fractions (A and B) with retention times of 18.1 and 36.7 min, respectively, induced relaxation of corpus cavernosum strips. Fraction A was selected for further biochemical characterization. Repurification of this fraction revealed the presence of a polypeptide (named PNV4) which migrates in sodium dodecyl sulphate-polyacrylamide gel electrophoresis as a single band consistent with a mol. wt close to 16,600. The amino acid composition of PNV4 showed the presence of 147 residues, a high content of Cys and a calculated mol. wt of 17,213 + Trp. The N-terminal amino acid sequence of PNV4 determined for its first 48 residues was AELTSCFPVGHECDGDASNCNCCGDDVYCGCGWGRWNCKCKVADQSYA.

Isolation of a polypeptide from Phoneutria nigriventer spider venom responsible for the increased vascular permeability in rabbit skin

Fractionation of Phoneutria nigriventer venom by Sephadex G-10 followed by ion-exchange chromatography yields a fraction (fraction XIII) which increases microvascular permeability in rabbit skin in vivo by activating the tissue kallikrein-kinin system. One polypeptide (PNV3) with the ability to increase microvascular permeability in the rabbit skin in vivo was isolated from fraction XIII and biochemically characterized. PNV3 has 132 amino acid residues with a calculated mol. wt of 14,475. This polypeptide showed the following N-terminal sequence: AVFAIQDQPC. Amino acid analysis indicated the presence of six disulfide bridges and a high content of Glx (20%). Pairwise comparison of PNV3 amino acid sequence with 27 other spider venom polypeptides and proteins indicated that PNV3 presents high similarity (60-70%) with other toxins (Tx2.1, Tx2.5 and Tx2.6) isolated from P. nigriventer venom.