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Background Erdheim-Chester Disease (ECD) is a clonal non-Langerhans histiocytosis, classified as a macrophage-dendritic cell neoplasm in the 2016 WHO classification. The exact cell of origin of ECD is unknown, although some limited evidence suggests that it arises from myeloid progenitors. Case presentation A 43-year-old patient, diagnosed with BRAF V600E mutated ECD, developed NPM1+/FLT3+ acute myeloid leukemia (AML) with wild-type BRAF, 15 months after the initial ECD diagnosis. The patient received intensive chemotherapy plus midostaurin, followed by midostaurin maintenance. Six months into maintenance, the patient remains in complete remission with low-level measurable residual disease, whereas ECD shows a sustained partial metabolic response. Molecular karyotype at several distinct timepoints, namely ECD diagnosis, AML diagnosis, and following treatment of AML, highlighted a molecular signature, indicative of a persistent, underlying clonal hematopoiesis. Conclusion This case report suggests that ECD and AML might represent an expansion of two distinct clones in a background of clonal hematopoiesis, indicating their shared origin. Moreover, molecular karyotype might serve as a strong, inexpensive tool for revealing clonal hematopoiesis in cases of negative targeted next-generation sequencing. Finally, the moderate response of ECD to midostaurin suggests that kinase inhibition might have a potential role in ECD treatment.

Η Οξεία Μυελογενής Λευχαιμία (ΟΜΛ) αποτελεί μια νόσο με μεγάλη ετερογένεια. Η αιτιολογία ανάπτυξης της νόσου δεν έχει πλήρως αποσαφηνιστεί, ωστόσο στην πολυσταδιακή πορεία της, φαίνεται να εμπλέκονται γενετικοί, επιγενετικοί και περιβαλλοντικοί παράγοντες. Σκοπός της παρούσας διδακτορικής διατριβής ήταν η διερεύνηση του ρόλου των πολυμορφισμών των γονιδίων αποτοξικοποίησης CYP2B6 (G516T, C777A, A785G), GSTP1 (A313G) και των γονιδίων επιδιόρθωσης RAD51 (G135C), XPD23 (Α23927C) και LIG4 (C26T) στην προδιάθεση εμφάνισης της ΟΜΛ. Επίσης, μελετήθηκε η συσχέτιση της μεθυλίωσης του υποκινητή του γονιδίου GSTP1 και ανάπτυξη της ΟΜΛ. Αναλύθηκαν 619 ασθενείς με ΟΜΛ και 430 υγιείς δότες. Η μεθοδολογία που ακολουθήθηκε περιλαμβάνει την κυτταρογενετική ανάλυση δειγμάτων μυελού των οστών ασθενών, τη γονοτυπική ανάλυση των προαναφερθέντων πολυμορφισμών και τον έλεγχο μεθυλίωσης του υποκινητή του γονιδίου GSTP1. Τα αποτελέσματα της παρούσας έρευνας ανέδειξαν τον πιθανό ρόλο των πολυμορφισμών G516T και A785G του γονιδίου CYP2B6 καθώς και των πολυμορφισμών A313G και C26T των γονιδίων GSTP1 και LIG4, αντίστοιχα, στην προδιάθεση ανάπτυξης ΟΜΛ. Αντιθέτως, ο πολυμορφισμός C777A του γονιδίου CYP2B6 καθώς και οι πολυμορφισμοί G135C, Α23927C των γονιδίων επιδιόρθωσης RAD51 και XPD23, αντιστοιχα, παρουσίασαν παρόμοια κατανομή συχνοτήτων μεταξύ ασθενών και μαρτύρων, γεγονός που υποδηλώνει ότι πιθανότατα η παρουσία των πολυμορφισμών αυτών δεν αυξάνουν τον κίνδυνο ανάπτυξης ΟΜΛ. Για το γονίδιο CYP2B6 πραγματοποιήθηκε και η δημιουργία των απλοτύπων για τους υπό μελέτη πολυμορφισμούς. Ενδιαφέρον παρουσιάζει το γεγονός τα άτομα που έφεραν τον απλότυπο TAG (συνύπαρξη των τριών μεταλλαγμένων γονοτύπων) έχουν 3-φορές μεγαλύτερη πιθανότητα ανάπτυξης της νόσου σε σύγκριση με τους μάρτυρες. Από τις μελέτες συσχετίσεων μεταξύ των γονοτύπων των υπό μελέτη γονιδίων με τα κυτταρογενετικά ευρήματα των ασθενών βρέθηκαν στατιστικά σημαντικές διαφορές υποδηλώνοντας έτσι το σημαντικό ρόλο των πολυμορφισμών στη δημιουργία ειδικών για την ΟΜΛ χρωμοσωμικών αλλοιώσεων. Επιπλέον, βρέθηκε ότι η μεθυλίωση του υποκινητή του γονιδίου GSTP1 απαντάται συχνότερα στους ασθενείς με δευτεροπαθή ΟΜΛ. Σύμφωνα λοιπόν με όλα τα παραπάνω, τα αποτελέσματα της παρούσας διδακτορικής διατριβής, μεμονωμένα ή συνδυαστικά, αναμένεται να συμβάλλουν στην κατανόηση του ρόλου των πολυμορφισμών γονιδίων αποτοξικοποίησης και επιδιόρθωσης στην προδιάθεση ανάπτυξης ΟΜΛ, στην εμφάνιση συγκεκριμένων κυτταρογενετικών αλλοιώσεων καθώς και στη σχεδίαση κατάλληλων εξατομικευμένων θεραπευτικών πρωτοκόλλων ανάλογα με το γενετικό υπόβαθρο των ασθενών.

Background/aim PON1 gene has an executive role in antioxidant defense, protecting cells from genotoxic factors. Q192R and L55M PON1 polymorphisms reduce catalytic activity of the encoded protein. These polymorphisms were studied in 300 chronic lymphocytic leukemia (CLL) patients and 106 healthy donors. They were also associated with patients' cytogenetic findings, to investigate their possible implication in CLL pathogenesis. Materials and methods SNP genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Karyotypic analysis was also performed by chromosome G-banding analysis and fluorescence in situ hybridization. Results Genotypic and allelic distribution of Q192R polymorphism showed a statistically significant higher frequency of mutant genotypes and mutant alleles in patients compared to controls. The same observation was noted in patients with abnormal karyotypes and those carrying abn14q32 and del(6q). A statistically increased frequency for the mutant allele was also revealed in patients with del(11q). On the contrary, L55M polymorphism showed a similar distribution between patients and controls. Conclusion Q192R polymorphism plays a role in CLL predisposition and the formation of specific chromosomal aberrations.

Mutations of ASXL1 are early events in acute myeloid leukemia (AML) leukemogenesis and have been associated with unfavorable prognosis. In this study, we investigated the type and frequency of ASXL1 mutations in a large cohort of patients with de novo or secondary AML (s-AML) and looked for correlations with cytogenetic findings and disease features. ASXL1 mutations were associated with older age, s-AML and higher peripheral leukocytosis. We observed more frequent co-occurrence of ASXL1 mutations with trisomy 8 and chromosome 11 aberrations but a negative correlation with myelodysplastic syndromes (MDS)-related cytogenetic abnormalities, especially -5/del(5q) and -7/del(7q). ASXL1 mutations were also found in other genetically defined AML subgroups such as those with t(9;22), inv(3)/t(3;3), t(8;21) or t(15;17); however, none of our inv(16) cases carried ASXL1 mutations. We detected two previously unreported ASXL1 mutations, p.IIe593Val and p.Cys688Tyr. Our findings suggest that ASXL1 mutations tend to cluster with specific clinical and cytogenetic profiles of AML patients.

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in adults and is characterized by the presence of specific cytogenetic abnormalities. CLL research has been focused on epigenetic processes like gene promoter methylation of CpG islands. In the present study, the methylation status of the RAD21 gene is studied and associated with cytogenetic findings in CLL patients in order to investigate its possible implication in CLL pathogenesis and the formation of CLL chromosomal abnormalities.

Objectives In bronchopulmonary dysplasia (BPD), direct exposure to oxygen therapy can damage the pulmonary epithelium via oxidative stress. The NAD(P)H:quinone oxidoreductase 1 (NQO1) enzyme detoxifies genotoxic products of oxidative stress. The corresponding gene is subject to an inactivating single-nucleotide polymorphism (C 609 T), which reduces detoxifying ability. The aim of this study was to investigate whether the C 609 T NQO1 inborn gene polymorphism is associated with an increased risk of BPD. Study Design Peripheral blood samples from 119 premature neonates ≤ 32 weeks of gestational age (42 BPD and 77 non-BPD) were used for DNA extraction. NQO1 genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism method. Results A significantly higher frequency of the NQO1 polymorphism was observed in BPD neonates compared with neonates without BPD. All neonates with ≤ 1,000 g birth weight who carried the mutant allele in heterozygous or homozygous state developed BPD. None of the BPD nonaffected group neonates with ≤ 1,000 g birth weight carried the NQO1 polymorphism. Conclusion The higher incidence of NQO1 mutants among BPD neonates as well as the presence of the mutant allele in all neonates with ≤ 1,000 g who developed BPD provided the first evidence for a possible pathogenetic role of the C 609 T polymorphism in BPD susceptibility due to the reduction or loss of NQO1 enzymatic activity.

Acute myeloid leukemia (AML) is a clinically and genetically heterogeneous disease and the most common acute leukemia in adults. Many genotoxic factors have been accused for AML development but onl...

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in adults and is characterized by the presence of specific cytogenetic abnormalities. CLL research has been focused on epigenetic processes like gene promoter methylation of CpG islands. In the present study, the methylation status of the RAD21 gene is studied and associated with cytogenetic findings in CLL patients in order to investigate its possible implication in CLL pathogenesis and the formation of CLL chromosomal abnormalities.

Objectives Antioxidant response plays a key role in bronchopulmonary dysplasia (BPD) pathogenesis. The glutathione-S-tranferases pi 1 (GSTP1) and cytochrome P450 (CYP) detoxification enzymes protect cells from oxidative damage. The aim of the study was to investigate whether the A313G GSTP1 and G516T CYP2B6 inactivating polymorphisms could be associated with BPD susceptibility. Study Design To test this hypothesis, we conducted a case–control study enrolled 138 premature neonates ≤32 weeks of gestational age; of the 138, 46 developed BPD and 92 did not develop BPD. Genomic deoxyribonucleic acid was extracted from neonates' peripheral blood and was used as template for GSTP1 and CYP2B6 genotyping using the real-time polymerase chain reaction method. Results Our report provides evidence for a possible pathogenetic role of the G516T CYP2B6 polymorphism in BPD susceptibility. Although no differences in the frequencies of the GSTP1 variant genotypes were noticed between premature neonates who developed BPD and neonates who did not develop BPD, a significantly higher frequency of the GSTP1 polymorphism was observed in extremely low birth weight infants. Despite the small sample size, it is very interesting the fact that all neonates ≤1,000 g carrying the homozygous mutant GSTP1 genotype developed BPD. Conclusion Our results underscore the significance of both CYP2B6 and GSTP1 polymorphisms in modulating the risk of BPD.

CYP2B6 is a polymorphic detoxification gene which plays a vital role in the degradation of genotoxic compounds. In this study we hypothesized that inadequate detoxification due to CYP2B6 polymorphisms may contribute to AML. To evaluate the potential impact of CYP2B6 polymorphisms on AML development and induction of its specific chromosomal abnormalities we studied C 777 A and A 785 G polymorphisms for the first time in AML. Furthermore, we investigated the co-existence of the above polymorphisms with G 516 T polymorphism to determine the CYP2B6 high-risk haplotypes in AML susceptibility. Our study included 619 AML patients and 430 healthy donors. Concerning C 777 A CYP2B6 polymorphism, no significant difference was found between patients and controls. However, A 785 G CYP2B6 polymorphism showed a statistically higher frequency of the variant genotypes in patients (48.2%), mainly in secondary AML patients (49.1%) than in controls (26.1%). Moreover, an increased frequency of the variant genotypes was found in those with abnormal karyotypes, especially with −7/del(7q), −5/del(5q), +8, inv(16) and t(8;21). The combination of the three CYP2B6 polymorphisms (G 516 T, C 777 A & A 785 G) revealed seven haplotypes. Four out of six haplotypes with at least one mutant allele were significantly associated with an increased risk for AML. Interestingly, T 516 A 777 G 785 haplotype, where the three mutant alleles co-existed, had ~3-fold increased risk to be found in patients than controls. The association between haplotypes and cytogenetic aberrations revealed a positive correlation between specific CYP2B6 haplotypes and AML cytogenetic abnormalities. Our data suggest that A 785 G CYP2B6 gene polymorphism and specific CYP2B6 haplotypes may contribute to AML and its specific chromosomal aberrations.