All-
trans
retinoic acid (ATRA)-based therapy for acute promyelocytic leukemia (APL), a subtype of acute myeloid leukemia (AML), is the most successful example of differentiation therapy. Although ...ATRA can induce differentiation in some non-APL AML cell lines and primary blasts, clinical results of adding ATRA to standard therapy in non-APL AML patients have been inconsistent, probably due to use of different regimens and lack of diagnostic tools for identifying which patients may be sensitive to ATRA. In this study, we exposed primary blasts obtained from non-APL AML patients to ATRA to test for differentiation potential in vitro. We observed increased expression of differentiation markers, indicating a response to ATRA, in four out of fifteen primary AML samples. Three samples in which CD11b increased in response to ATRA had an inversion of chromosome 16 as well as the CBFB-MYH11 fusion gene, and the fourth sample was from a patient with
KMT2A
-rearranged, therapy-related AML. In conclusion, we identified a subgroup of non-APL AML patients with inv(16) and CBFB-MYH11 as the most sensitive to ATRA-mediated differentiation in vitro, and our results can help identify patients who may benefit from ATRA treatment.
Acute myeloid leukemia (AML) is characterized by arrested differentiation making differentiation therapy a promising treatment strategy. Recent success of inhibitors of mutated isocitrate ...dehydrogenase (IDH) invigorated interest in differentiation therapy of AML so that several new drugs have been proposed, including inhibitors of dihydroorotate dehydrogenase (DHODH), an enzyme in pyrimidine synthesis. Cytarabine, a backbone of standard AML therapy, is known to induce differentiation at low doses, but the mechanism is not completely elucidated. We have previously reported that 5-aminoimidazole-4-carboxamide ribonucleoside (AICAr) and brequinar, a DHODH inhibitor, induced differentiation of myeloid leukemia by activating the ataxia telangiectasia and Rad3-related (ATR)/checkpoint kinase 1 (Chk1) via pyrimidine depletion. In this study, using immunoblotting, flow cytometry analyses, pharmacologic inhibitors and genetic inactivation of Chk1 in myeloid leukemia cell lines, we show that low dose cytarabine induces differentiation by activating Chk1. In addition, cytarabine induces differentiation ex vivo in a subset of primary AML samples that are sensitive to AICAr and DHODH inhibitor. The results of our study suggest that leukemic cell differentiation stimulated by low doses of cytarabine depends on the activation of Chk1 and thus shares the same pathway as pyrimidine synthesis inhibitors.
All-trans retinoic acid (ATRA)-based treatment of acute promyelocytic leukemia (APL) is the most successful pharmacological treatment of acute myeloid leukemia (AML). Recent development of inhibitors ...of mutated isocitrate dehydrogenase and dihydroorotate dehydrogenase (DHODH) has revived interest in differentiation therapy of non-APL AML. Our previous studies demonstrated that 5-aminoimidazole-4-carboxamide ribonucleoside (AICAr) induced differentiation of monocytic cell lines by activating the ATR/Chk1 via pyrimidine depletion. In the present study, the effects of AICAr on the viability and differentiation of primary AML blasts isolated from bone marrow of patients with non-APL AML were tested and compared with the effects of DHODH inhibitor brequinar and ATRA.
Bone marrow samples were obtained from 35 patients and leukemia blasts were cultured ex vivo. The cell viability was assessed by MTT assay and AML cell differentiation was determined by flow cytometry and morphological analyses. RNA sequencing and partial data analysis were conducted using ClusterProfiler package. Statistical analysis was performed using GraphPad Prism 6.0.
AICAr is capable of triggering differentiation in samples of bone marrow blasts cultured ex vivo that were resistant to ATRA. AICAr-induced differentiation correlates with proliferation and sensitivity to DHODH inhibition. RNA-seq data obtained in primary AML blasts confirmed that AICAr treatment induced downregulation of pyrimidine metabolism pathways together with an upregulation of gene set involved in hematopoietic cell lineage.
AICAr induces differentiation in a subset of primary non-APL AML blasts, and these effects correlate with sensitivity to a well-known, potent DHODH inhibitor.
Objective
We explored damage occurrence in patients with childhood-onset SLE (cSLE) and aimed to predict the risk of organ damage occurrence in time.
Methods
The retrospective study included patients ...treated for cSLE at the Centre of Reference for Pediatric and Adolescent Rheumatology of the Republic Croatia over a 29-year period.
Results
The disease development of 97 patients (77 females) with cSLE was examined. The median (Q1, Q3) follow-up time was 6.5 (2.3, 12.0) years. SDI was determined at 5 time points (6, 12, 24, 36 months, and last follow-up). Thirty-eight patients (48%) had organ damage at the last follow-up. Prepubertal group of patients showed higher SLEDAI scores at the disease onset, while post-pubertal group had significantly lower proportion of patients with relapses. We estimated the time from the first symptom to the moment of damage and our findings suggest that it is unlikely that organ damage will occur in 50% of patients in the first 6 years since the diagnosis. The number of 2019 ACR/EULAR classification criteria at the time of diagnosis associated with SDI determined after 1 year of the follow-up period. The patients who received higher doses of glucocorticoids accumulated damage faster and mycophenolate mofetil was found to be a more frequent therapy in patients with SDI ≥3.
Conclusion
Knowing that damage will most likely happen after the first 6 years after diagnosis in 50% of patients enables physicians to better predict damage occurrence. High number of 2019 ACR/EULAR criteria and treatment with glucocorticoids in childhood-onset SLE are associated with damage accrual and these findings could enable us to detect patients which should be closely monitored for higher risk of damage development.
•We found no clinical consequences of delaying ocrelizumab due to COVID-19 pandemics.•Positive correlation between the time of lymphocyte sampling and levels of CD19+ B cells was found for patients ...who received only one prior ocrelizumab cycle.•The delay in dosing of ocrelizumab was an independent predictor of repopulation of B cells.
To evaluate clinical and laboratory effects of delaying ocrelizumab infusions during the COVID-19 pandemics in people with multiple sclerosis (pwMS).
We have retrospectively searched our electronic database and identified 33 pwMS who had a delay in treatment due to COVID-19 pandemics. The following data were extracted: age, sex, multiple sclerosis (MS) phenotype: relapsing-remitting (RRMS) or primary progressive multiple sclerosis (PPMS), disease duration, Expanded Disability Status scale (EDSS), previous disease modifying therapy (DMT), number of ocrelizumab cycles prior to the lockdown, dates of first ocrelizumab infusion, last ocrelizumab infusion prior to the lockdown and delayed ocrelizumab infusion after the lockdown. Flow cytometry results, relapses and EDSS progression prior to the delayed ocrelizumab infusion after the lockdown were extracted.
The mean time between two ocrelizumab infusion during the lockdown was 7.72±0.64 (range 6.07 to 8.92) months. The mean time between last ocrelizumab infusion and the lymphocyte sampling prior to post COVID infusion was 6.59±0.95 (range 5.18 to 8.49) months. In this period, none of the studied patients had a relapse. In a multivariable linear regression analysis, time from last ocrelizumab infusion to lymphocyte sampling prior to the next infusion was the only significant predictor for CD19+ B cells count, when corrected for the number of previous ocrelizumab cycles and MS phenotype (RRMS or PPMS) (B=7.981, 95% C.I. 3.277-12.686, p=0.002).
We have not shown clinical consequences of delaying ocrelizumab due to COVID-19 pandemics. However, the delay in dosing of ocrelizumab was an independent predictor of repopulation of B cells.
The aim of this study was to compare for the first time IL-6 (Interleukin 6), testosterone (T) and estradiol (E) levels, their ratio (E/T), micronucleus (MN), and nuclear bridge (NB) frequency ...between newborns with regard to their mother's residency and diet. Our results should enable an assessment of the possible environmental endocrine effects and interaction between biomarkers, pointing to possible associated health risks.
Fifty full-term newborns of both sexes, whose mothers were healthy and not occupationally exposed to any known carcinogen, were analyzed. All of the mothers filled in a detailed questionnaire.
The results showed significantly higher levels of E in newborns of mothers with agricultural residency than those born by mothers with urban residency. Significantly, lower levels of E were measured in newborns of mothers who drank milk and carbonated beverages more frequently. Testosterone was significantly higher in boys of mothers with agricultural residency than from mothers with urban residency. Residence and other parameters had no impact on the difference in MN frequency. IL-6 levels were higher in newborns of mothers with agricultural residency. NB levels were significantly associated with E. A significant association between E levels and IL-6 was found.
Our results were the first to show a significant impact of the mother's agricultural residency and diet on their newborns' sex hormone and IL-6 levels and their association.
In this study, we aimed to assess the prevalence of uncommon staining patterns found during testing for the presence of antinuclear antibodies (ANA) and to determine their association with certain ...antibodies and clinical diagnoses. Presence of ANA and the staining pattern was determined in 10955 samples using indirect immunofluorescence (IIF) on HEp-2 cells. ANA-positive samples were assessed for presence of 14 specific antibody types using a microbead based system. Demographic data (age, sex) and clinical diagnoses were collected from the referral documentation. Particular staining patterns were then compared with a representative comparison group comprised of samples with common staining patterns using these criteria. There were 22 patterns present in less than 3% of samples each and these were jointly present in 42.43% of ANA-positive samples. Specific antibodies were found in proportions similar to the comparison group (46.06%) and varied significantly between patterns. Likewise, there were significant differences in antibody distribution in particular patterns. Some patterns were associated with presence of rheumatic diseases or inflammatory arthropathies, while in others there was a concurrent diagnosis of liver disease, or a neoplastic process. Many of the uncommon IIF patterns have distinctive characteristics that warrant further investigation in order to determine their role in diagnosing various diseases, not limited only to the illnesses of the rheumatic spectrum. IIF on HEp-2 cells remains an irreplaceable method because of the diversity of ANA, only a number of which can be detected using other standardised methods.
Acute myeloid leukemia (AML) is a malignant hematopoietic disease with poor clinical course and outcome. There is a constant need for new prognostic factors that could facilitate patient risk ...stratification. The aim of our research was to determine the phosphorylation levels of phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK) pathways in leukemic cells, their relation to P-glycoprotein (P-gp) expression/activity and their prognostic significance in adult de novo AML. A total of 118 patients with AML were enrolled in the study. In a multivariate Cox regression analysis we found that P-gp activity and Akt phosphorylation were independent poor prognostic factors of overall survival (OS). In contrast, phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2) represented a favorable prognostic factor of OS and relapse-free survival (RFS). A negative correlation between P-gp activity and p38 phosphorylation level was found, implying a possible role of this MAPK pathway in P-gp regulation. In addition, we found correlation between Akt and p38 phosphorylation levels, indicative of co-activation of two signaling cascades in AML.
Acute lymphoblastic leukemia (ALL) is a malignant disease of lymphoid precursors. According to immunophenotype, it is further subdivided into precursor B cell ALL and precursor T cell ALL, with ...precursor B cell ALL being much more common both in children and adults. Lineage switch from one lymphoid lineage to another during the course of the disease is extremely rarely reported. Here, we describe a case of a child who initially presented as a precursor B-ALL but 15 years later and after two successfully treated relapses of the original ALL presented with early T cell precursor leukemia. Although it was considered as a relapse, it could be interpreted as a case of secondary leukemia, which can be explained as a consequence of treatment as well as a constitutional feature of an individual. Also, it draws attention to the possibility that hematopoietic cells, and in that context also leukemic cells, are much more plastic and capable of reprogramming than previously thought.
Composite mature B-cell lymphoproliferative neoplasms are rare entities characterized by the simultaneous presence of two or more distinctive B-cell derived monoclonal malignancies. This ...retrospective study used multiparametric flow cytometric analysis aimed at immunophenotypic profiling of composite mature B-cell lymphoproliferative neoplasms in a cohort of 413 subsequent patients with de novo leukemic B-cell chronic lymphoproliferative disorders diagnosed in our institution during a 30-month period. Biclonality was found in 16 (3.9 %) patients. The vast majority (88 %) of the cases had one of the clones phenotypically corresponding to chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Only when composite cases were categorized by phenotype of the non-CLL/SLL malignant population did we find a statistically significant (
P
= 0.001) higher frequency of biclonality among cases with hairy cell leukemia (22 %). Biclonal cases had the overall B-cell membrane
κ
to
λ
ratio within the normal range (median, 1.9; reference interval 0.5–4.0), making recognition of malignancy somewhat challenging. Our analysis strategy was therefore based on the detection of aberrant B-cell phenotypes, with subsequent confirmation of the monoclonal nature of neoplastic clones with regards to light chain restriction analysis. Discrimination of the coexisting clones in biclonal cases was possible on the basis of the expression of other antigen(s) (63 %), light scatter properties (44 %), different surface light chain restriction (69 %) and/or pattern of expression (44 %). The most informative cell surface antigens proved to be CD22, CD20, surface IgM, and CD23. In conclusion, historic
κ
/
λ
ratio is not a reliable approach and is a poor measurement for the detection of composite lymphomas. More creative analysis techniques should be utilized for this purpose.
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