Chromosomal breakage tests in the differential diagnosis of Fanconi anemia and aplastic anemia

BACKGROUND

FA patients are hypersensitive to preconditioning of bone marrow transplantation.

OBJECTIVE

Assessment of the power of mitomycin C (MMC) test to assign FA patients.

METHODS

We analysed 195 patients with hematological disorders using spontaneous and two types of chromosomal breakage tests (MMC and bleomycin). In case of presumed Ataxia telangiectasia (AT), patients' blood was irradiated in vitro to determine the radiosensitivity of the patients.

RESULTS

Seven patients were diagnosed as having FA. The number of spontaneous chromosomal aberrations was significantly higher in FA patients than in aplastic anemia (AA) patients including chromatid breaks, exchanges, total aberrations, aberrant cells. MMC-induced ≥10 break/cell was 83.9 ± 11.4% in FA patients and 1.94 ± 0.41% in AA patients (p < .0001). The difference in bleomycin-induced breaks/cell was also significant: 2.01 ± 0.25 (FA) versus 1.30 ± 0.10 (AA) (p = .019). Seven patients showed increased radiation sensitivity. Both dicentric + ring, and total aberrations were significantly higher at 3 and 6 Gy compared to controls.

CONCLUSIONS

MMC and Bleomycin tests together proved to be more informative than MMC test alone for the diagnostic classification of AA patients, while in vitro irradiation tests could help detect radiosensitive-as such, individuals with AT.

[Pediatric cardiopulmonary resuscitation]

Our aim is to summarize the new European Resuscitation Council (ERC) 2021 guidelines on paediatric life support. In children, exhaustion of compensatory mechanisms in respiratory or circulatory failure leads to cardiac arrest. Recognition and treatment of children in critical condition are the most important element of its prevention. With the ABCDE approach, life-threatening problems can be identified and treated using simple interventions (bag-mask ventilation, intraosseous access, fluid bolus, etc.). Important new recommendations: 4-hand ventilation during bag-mask ventilation, target saturation of 94-98% during oxygen therapy, and fluid bolus of 10 ml/kg. In pediatric basic life support, if there is no normal breathing after 5 initial rescue breaths in absence of signs of life, chest compression should be initiated immediately using primarily two-thumb encircling method for infants. Recommended rate is 100-120/min, ratio of compression to ventilation is 15 : 2. Pediatric advanced life support is a teamwork. The structure of the algorithm is unchanged, high-quality chest compression is still a paramount. Recognition and treatment of potential reversible causes (4H-4T) and the decisive role of focused ultrasound are emphasized. New features: recommendation of 4-hand technique bag-mask ventilation, role of capnography, and age-dependent ventilatory rate in the case of continuous chest compression after endotracheal intubation. Drug therapy is unchanged, the fastest way to administer adrenaline during resuscitation is via intraosseous access. Treatment after return of spontaneous circulation decisively influences neurological outcome. Patient care is further based on the ABCDE scheme. Important goals are maintaining normoxia, normocapnia, avoiding hypotension, hypoglycemia, fever and use of targeted temperature management. Orv Hetil. 2023; 164(12): 463-473.

[Epidemiology of early infections after autologous hematopoietic stem cell transplantation. Analysis of data from 699 patients treated in a Hungarian centre]

Introduction: Autologous hemopoietic stem cell transplantation remains a promising therapy in certain malignant and non-malignant conditions. The procedure, however, will increase the risk of complications, most notably early and late infections. Aim: To analyze the frequency and spectrum of pathogens in early (<+100 days) post-transplant infections and to evaluate risk factors for mortality. Method: Prospectively collected data from 699 patients undergoing autologous hemopoietic stem cell transplantation between 2007 and 2014 at our center were retrospectively reviewed and analyzed. Results: The median age of 699 patients was 56 (interquartile range: 43-62) years, 54% (376) were male. 25 patients have been transferred to other centers and 19 patients were lost to follow up. Neutropenic fever occurred in 69.8% (488) of patients. In addition, 102 infectious episodes in 96 patients were identified. Most commonly bacteremia occurred (49 episodes) with a median onset of 7 (5-11) days. The majority (33/49) of bacteremias have been observed during the pre-engraftment period. Their incidence proved to be higher in patients with malignant lymphoma compared to individuals with plasma cell disorders (p = 0.0005, OR: 2.41, 95% CI: 1.49-3.99). 12 episodes of viral infections and 8 cases of proven or probable invasive mycoses have been identified. Among the 655 patients with complete follow up, 16 in-hospital deaths (2.4%) occurred, 8 of them were associated with infections. Survival was adversely affected by early infections (p = 0.0001). Conclusion: In autologous stem cell transplantation, microbiologically unconfirmed neutropenic fever is common. Documented early bacteremia, however, is infrequent. Lymphoma patients have a significantly higher chance to develop bloodstream infections compared to individuals with plasma cell disorders. Early infections decrease the chance of survival; thus, an effective prophylaxis and therapy remains of paramount importance. Orv Hetil. 2020; 161(3): 103-109.

The timing of testing influences skill retention after basic life support training: a prospective quasi-experimental study

BACKGROUND

Proper basic life support (BLS) is key in improving the survival of out-of-hospital cardiac arrest. BLS skills deteriorate in three to 6 months after training. One method to improve skill retention may be using the "testing effect" to test skills at the end of a BLS course. The aim of our study was to investigate whether either testing or the timing of such testing after BLS training have any influence on skill retention.

METHODS

This was a post-test only, partial coverage, prospective quasi-experimental study designed to evaluate a BLS training course among 464 fifth year medical students at Semmelweis University in the first semester of 2013/2014. Groups were systematically but non-randomly assigned to either a control group that took no exam or one of two experimental groups that took an exam (N = 179, NoExam group; N = 165, EndExam group - exam at the end of the BLS training; N = 120, 3mExam group - exam 3 months after the BLS training). The ability to perform ten prescribed essential BLS steps was evaluated during a skill retention assessment 2 months after the course in the NoExam, 2 months after the course (and the exam) in the EndExam and 5 months after the course (2 months after the exam) in the 3mExam group to measure skill retention and the effect of our intervention. Scores were calculated for each BLS step, and also summed up as a total score. We used Kruskal-Wallis test to assess differences in skill retention.

RESULTS

Overall, NoExam and EndExam groups showed similar skill retention. The mean total score (and many of the sub-scores) of students was significantly higher in the 3mExam group compared to both the NoExam and the EndExam groups, and there was no difference in the total score (and many of the sub-scores) of the latter two groups. The 3mExam group had less variability in total scores (and many of the sub-scores) than the other two groups.

CONCLUSION

Our study provides evidence that testing these skills 3 months after BLS training may be more effective than either testing immediately at the end of the course or no testing at all.

Antithymocyte Globuline Therapy and Bradycardia in Children

In antithymocyte globulin (ATG) treated patients occasionally bradycardia has been noticed. Therefore, we retrospectively analyzed the occurrence of bradycardia in ATG-treated children. Using medical records between 2007 and 2012 we identified children undergoing a combined therapy with ATG and glucocorticoids (ATG group, n = 22). The incidence of bradycardia was compared to that registered in children treated with glucocorticoids alone (glucocorticoid alone group, n = 21). Heart rates (HR) were registered before and on days 0-3, 4-7 and 8-14 after the ATG or steroid administration. The rate of bradycardic episodes was higher during ATG therapy than in the steroid alone group, while severe bradycardia occurred only in the ATG group (97 versus 32, p = 0.0037, and 13 versus 0, p = 0.0029, respectively). There was an interaction between the time and treatment group on HR (p = 0.046). Heart rates in ATG and steroid alone groups differed significantly on day 0-3 and day 4-7 (p = 0.046, p = 0.006, respectively). Within the ATG group HR was lower on days 4-7 compared to the days before and the days 8-14 values (p < 0.001, 95%CI: 0.020-0.074). These findings indicate that transient asymptomatic bradycardia is probably more common with ATG therapy than previously reported. HR should be closely monitored during and after ATG therapy.

Early Increase in Complement Terminal Pathway Activation Marker sC5b-9 Is Predictive for the Development of Thrombotic Microangiopathy after Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT)-associated thrombotic microangiopathy (TA-TMA) is a multifactorial complication, and its prediction is largely unresolved. Our aim was to analyze changes of complement profile after HSCT to identify potential markers of TA-TMA development. Thirty-three consecutive pediatric patients (9.6 ± 4.4 years old) who underwent allogeneic HSCT due to malignant (n = 17) or nonmalignant (n = 16) indications were included in this study. Graft-versus-host disease (GVHD) was diagnosed using Glucksberg criteria, viral reactivation was monitored, 5 different TA-TMA diagnostic criteria were applied, and all important clinical and laboratory parameters of TA-TMA activity were registered. Complement pathway activities, components and terminal pathway activation marker (sC5b-9) levels were systematically measured before transplantation and on days 28, 56, and 100 after HSCT. During the first 100 days after HSCT, 1 of 33 patients died (day 50, multiple organ failure), whereas 10 subjects met the criteria for TA-TMA, typically on day 61 (range, 16 to 98 days). TA-TMA was preceded by acute GVHD in 3 of 10 patients, by viral reactivation in 2 of 10, or by both in 4 of 10 cases. Baseline sC5b-9 levels did not differ in patients without (200 [interquartile range, 144 to 266] ng/mL), or with (208 [interquartile range, 166 to 271] ng/mL) subsequent TA-TMA; however, on day 28 significant differences were observed (201 [interquartile range, 185 to 290] ng/mL versus 411 [interquartile range, 337 to 471] ng/mL; P = .004). Importantly, all 10 patients with TMA showed increase in sC5b-9 level from baseline level to day 28, whereas in patients without TMA the same tendency was observed for only 9 of 23 patients (P = .031). No additional complement parameters were closely associated with the development of TA-TMA. Development of TA-TMA occurred in 30% of our patients, typically after GVHD and/or viral reactivation. However, early raise of sC5b-9 activation marker was predictive for later development of TA-TMA, and should therefore be considered as an alarming sign necessitating a careful monitoring of all TA-TMA activity markers. Further studies enrolling a higher number of patients are necessary to determine if terminal pathway activation is an independent predictor of TA-TMA.

[Changes in diagnostic criteria of thrombotic microangiopathy after stem cell transplantation]

Hematopoietic stem cell transplantation associated thrombotic microangiopathy is a multifactorial complication, and has variable incidence in study populations due to different diagnostic criteria. The diversity of activity parameters, like elevated laktát-dehidrogenáz, hematological parameters and kidney function are not specific variables after stem cell transplantation. Dysregulation of the classical and alternative pathway can play an important role in the pathomechanism of thrombotic microangiopathy, but the understanding of the role of complement activation under transplantation conditions requires further investigation. Monitoring of complement parameters, including terminal complement pathway activation complex during transplantation may help physicians to improve diagnostic strategy, to evaluate therapeutical options and to predict and follow up efficacy of complement blockade methods and supportive therapy. This review focuses on the development of diagnostic criteria and therapeutical options in thrombotic microangiopathy, and presents some preliminary findings while using different diagnostic criteria in pediatric patients. Orv Hetil. 2017; 158(27): 1043-1050.

Subgroups of Paediatric Acute Lymphoblastic Leukaemia Might Differ Significantly in Genetic Predisposition to Asparaginase Hypersensitivity

L-asparaginase (ASP) is a key element in the treatment of paediatric acute lymphoblastic leukaemia (ALL). However, hypersensitivity reactions (HSRs) to ASP are major challenges in paediatric patients. Our aim was to investigate genetic variants that may influence the risk to Escherichia coli-derived ASP hypersensitivity. Sample and clinical data collection was carried out from 576 paediatric ALL patients who were treated according to protocols from the Berlin—Frankfurt—Münster Study Group. A total of 20 single nucleotide polymorphisms (SNPs) in GRIA1 and GALNT10 genes were genotyped. Patients with GRIA1 rs4958351 AA/AG genotype showed significantly reduced risk to ASP hypersensitivity compared to patients with GG genotype in the T-cell ALL subgroup (OR = 0.05 (0.01–0.26); p = 4.70E-04), while no such association was found in pre-B-cell ALL. In the medium risk group two SNPs of GRIA1 (rs2055083 and rs707176) were associated significantly with the occurrence of ASP hypersensitivity (OR = 0.21 (0.09–0.53); p = 8.48E-04 and OR = 3.02 (1.36–6.73); p = 6.76E-03, respectively). Evaluating the genders separately, however, the association of rs707176 with ASP HSRs was confined only to females. Our results suggest that genetic variants of GRIA1 might influence the risk to ASP hypersensitivity, but subgroups of patients can differ significantly in this respect.

In interaction with gender a common CYP3A4 polymorphism may influence the survival rate of chemotherapy for childhood acute lymphoblastic leukemia

CYP3A4 has an important role in the metabolisms of many drugs used in acute lymphoblastic leukemia (ALL) therapy; still, there are practically no publications about the role of CYP3A4 polymorphisms in ALL pharmacogenomics. We genotyped eight common single-nucleotide polymorphisms (SNPs) in the CYP3A4 and CYP3A5 genes in 511 children with ALL and investigated whether they influenced the survival of the patients. We involved additional 127 SNPs in 34 candidate genes and searched for interactions with respect to the survival rates. Significant association between the survival rates and the common rs2246709 SNP in the CYP3A4 gene was observed. The gender of the patients and the rs1076991 in the MTHFD1 gene strongly influenced this effect. We calculated new risk assessments involving the gender-rs2246709 interaction and showed that they significantly outperformed the earlier risk-group assessments at every time point. If this finding is confirmed in other populations, it can have a considerable prognostic significance.

Candidate gene association study in pediatric acute lymphoblastic leukemia evaluated by Bayesian network based Bayesian multilevel analysis of relevance

Background

We carried out a candidate gene association study in pediatric acute lymphoblastic leukemia (ALL) to identify possible genetic risk factors in a Hungarian population.

Methods

The results were evaluated with traditional statistical methods and with our newly developed Bayesian network based Bayesian multilevel analysis of relevance (BN-BMLA) method. We collected genomic DNA and clinical data from 543 children, who underwent chemotherapy due to ALL, and 529 healthy controls. Altogether 66 single nucleotide polymorphisms (SNPs) in 19 candidate genes were genotyped.

Results

With logistic regression, we identified 6 SNPs in the ARID5B and IKZF1 genes associated with increased risk to B-cell ALL, and two SNPs in the STAT3 gene, which decreased the risk to hyperdiploid ALL. Because the associated SNPs were in linkage in each gene, these associations corresponded to one signal per gene. The odds ratio (OR) associated with the tag SNPs were: OR = 1.69, P = 2.22x10^-7 for rs4132601 (IKZF1), OR = 1.53, P = 1.95x10^-5 for rs10821936 (ARID5B) and OR = 0.64, P = 2.32x10^-4 for rs12949918 (STAT3). With the BN-BMLA we confirmed the findings of the frequentist-based method and received additional information about the nature of the relations between the SNPs and the disease. E.g. the rs10821936 in ARID5B and rs17405722 in STAT3 showed a weak interaction, and in case of T-cell lineage sample group, the gender showed a weak interaction with three SNPs in three genes. In the hyperdiploid patient group the BN-BMLA detected a strong interaction among SNPs in the NOTCH1, STAT1, STAT3 and BCL2 genes. Evaluating the survival rate of the patients with ALL, the BN-BMLA showed that besides risk groups and subtypes, genetic variations in the BAX and CEBPA genes might also influence the probability of survival of the patients.

Conclusions

In the present study we confirmed the roles of genetic variations in ARID5B and IKZF1 in the susceptibility to B-cell ALL. With the newly developed BN-BMLA method several gene-gene, gene-phenotype and phenotype-phenotype connections were revealed. We showed several advantageous features of the new method, and suggested that in gene association studies the BN-BMLA might be a useful supplementary to the traditional frequentist-based statistical method.

[Pharmacokinetic analysis of high-dose methotrexate treatments in children with hematologic malignancies]

Monitoring the pharmacokinetic parameters of different anticancer drugs is necessary because they might have several side effects.

AIM

Pharmacokinetic and toxicity evaluation of high-dose methotrexate treatments in children with acute lymphoblastic leukemia.

PATIENTS AND METHODS

43 children (28 boys, 15 girls, mean age: 7.03 years) in 147 cases were treated with 5 g/m2/24h MTX according to ALL-BFM 1995 and 2002 protocols. Methotrexate and 7-hydroxi-methotrexate levels were measured with high pressure liquid chromatography at 24, 36, 48 hours. Authors registered the development of hepatotoxicity, nephrotoxicity, grade III/IV oral mucositis.

RESULTS

Therapeutic methotrexate serum concentrations (30-100µmol/l) were achieved in 72.5% of the cases. Repeated treatments resulted similar serum levels. Hepatotoxicity and hypoproteinemia occurred in 17% and in 48.9% of the cases. There was significant correlation between serum 7-hydroxi-methotrexate and creatinine levels (p<0.05).

CONCLUSION

5 g/m2 methotrexate resulted reliable therapeutic serum levels with mild and reversible toxicity. 7-hydroxi-methotexate measurements might be more useful than methotrexate levels to detect toxicity.