Molecular and cellular pediatrics最新文献

Background: B-cell acute lymphoblastic leukemia (B-ALL) is characterized by the malignant burgeoning of abnormal B-cell lymphoblasts. In recent years, the use of chimeric antigen receptor T-cell (CAR-T) therapy which targets CD19 antigen present on the surface of B-cells, has gained significant attention as a treatment option against aggressive and refractory forms of B-ALL. However, the loss of CD19 antigen on B-cell surface due to aberrant splicing under therapy pressure has been suggested as one of the main factors for the emerging CAR-T therapy resistance. The primary aim of this study was to elucidate the presence and characteristics of aberrant CD19 splicing patterns in pediatric B-ALL patients at the time of initial diagnosis stage.

Methodology: Herein, using RT-PCR based splice assays we have examined CD19 splicing patterns in 43 primary pediatric B-ALL patient samples spread across various subtypes, and investigated underlying mechanisms harboring aberrant splicing.

Results: We observe that CD19 isoform lacking exon 5-6 is present in ~ 55% of pediatric patients at the initial diagnosis stage itself. Our in-silico analysis identified splicing regulator MBNL1 as a potential modulator of CD19 exon 5-6 splicing. Subsequent qRT-PCR analysis in patient samples revealed that MBNL1 is overexpressed in patient samples exhibiting exon 5-6 skipping. Furthermore, our functional studies demonstrate that loss of MBNL1 in B-ALL cell line induces exon 5-6 skipping, thereby confirming its mechanistic role in CD19 splicing regulation.

Conclusions: Taken together, we for the first time report the existence of aberrantly spliced CD19 isoform lacking exon 5-6 in primary pediatric patients at the diagnosis stage. Our results suggest that this MBNL1 dysregulation contributes to this splicing event, potentially predisposing patients to resistance against CD19-directed immunotherapies.

Background: Acid sphingomyelinase deficiency (ASMD), also known as Niemann-Pick disease types A and B, is a rare autosomal recessive lysosomal storage disorder caused by SMPD1 mutations. It is characterized by sphingomyelin accumulation and a broad clinical spectrum ranging from severe neurodegeneration in type A to a milder visceral phenotype in type B. Intermediate forms (type A/B) show overlapping features of both subtypes.

Case presentation: We report a 6-month-old boy with ASMD type A/B who first presented with meningoencephalitis and a single seizure most likely secondary to an intercurrent viral infection rather than a primary disease manifestation. Subsequent evaluation revealed multiple systemic red-flag features including marked hepatosplenomegaly, severe growth failure, a cherry-red spot, macroglossia, dysmorphic facial features, recurrent pneumonia, and bilateral sensorineural hearing loss. Laboratory investigations demonstrated elevated liver enzymes and cerebrospinal fluid abnormalities, while auditory brainstem response confirmed the hearing impairment. Enzyme assay confirmed reduced ASM activity, and targeted SMPD1 genetic sequencing identified a homozygous frameshift mutation classified as pathogenic according to ACMG criteria, establishing the diagnosis of an intermediate ASMD phenotype.  CONCLUSION: This case highlights the diagnostic challenges posed by ASMD type A/B, particularly when the initial presentation mimics an acute infection. The overlap of coincidental infectious illness with systemic red-flag features, the clinical variability of intermediate phenotypes, and the rarity of the disorder all contribute to delayed recognition. These factors underscore the importance of maintaining a high index of suspicion and pursuing early metabolic and genetic testing in atypical pediatric presentations.

Trial registration: Not applicable.

Background: B-cell Acute Lymphoblastic Leukemia (B-ALL) remains an important cause of cancer-related death in children. Therefore, accurate identification at diagnosis of patients at high risk of relapse is crucial. In this context, long non-coding RNAs (lncRNAs) could be novel candidates with great potential. Hence, the aim of this study was to identify new prognostic biomarkers in pediatric B-ALL through an RNA sequencing (RNA-seq) approach that allows the detailed exploration of a wide range of lncRNAs.

Methods: Total RNA from two cohorts of B-ALL patients (C1 with 50 Spanish patients, and C2 with 72 Canadian patients) was sequenced with a depth of approximately 150 million paired-reads using Illumina technology. All protein coding and non-coding genes included in lncRNAKB annotation were studied to develop a gene expression-based 5-year Event Free Survival (EFS) prediction model.

Results: First, univariate Cox proportional hazards analyses identified 48 genes significantly associated with higher EFS risk in both cohorts. From these, ALASSO regression selected five genes, all of which are lncRNAs, as the most informative to develop the prediction model, which we have called surviBALL. Stratification of patients into three risk groups according to the surviBALL model revealed significantly poorer EFS in high-risk patients across C1, C2, and the integrated C1 + C2 cohort (P < 0.001). Validation in an independent cohort of 177 publicly available B-ALL samples confirmed surviBALL's prediction capacity (P = 2.80 × 10^- 4) and its independence of both subtype and MRD.

Conclusions: These findings suggest that surviBALL has the potential to complement current risk stratification approaches, particularly by identifying patients at high risk of relapse at diagnosis. As a hypothesis-generating proof of concept, this study highlights the promise of more personalized treatment strategies and warrants further validation in independent cohorts.

Background: This study aimed to identify GBA1 variants in Egyptian Gaucher disease (GD) patients residing in a region with high consanguinity and to correlate these genotypes with their clinical phenotypes.

Methodology: This descriptive study included 68 Egyptian patients diagnosed with GD. Diagnosis relied upon reduced β-glucocerebrosidase activity measured by tandem mass spectrometry from dried blood spots and confirmed by GBA1 single-gene sequencing. Clinical and laboratory information were gathered from patient records, and neurological evaluations were conducted by a neurologist.

Results: Thirty patients (44.1%) were classified as type 1 GD, three (4.4%) as type 2 GD, and 35 patients (51.5%) as type 3 GD. Variant analysis of the 136 alleles identified 19 different variants. The most prevalent mutant allele was c.1448T > C p.(Leu483Pro) (50.7%). Seven novel variants were documented: five homozygous missense variants, including c.263 C > T p.(Met88Thr), c.1331 A > G p.(Asp444Gly), c.1409 C > T p.(Ser470Phe), c.907 C > G p.(Leu303Val), c.1574G > A p.(Gly525Asp), two heterozygous missense variants: c.380 C > G p.(Ala127Gly) and c.453 + 2T > C. All carriers of these novel variants were phenotypically classified as type 1 GD. Genotype-phenotype correlations confirmed that the c.1226 A > G p.(Asn409Ser) variant was confined to type 1 GD, whereas c.1448T > C p.(Leu483Pro) was associated with types 2 and 3 GD.

Conclusion: Variant analysis of 136 alleles identified 19 GBA1 variants, including seven novel variants. These findings enhance genotype-phenotype correlations, provide genetic counseling, and enable customized molecular analyses for families at risk.

Background: Late preterm infants (34-36 weeks gestation) represent the majority of preterm births and are often assumed to follow similar postnatal growth trajectories as term infants. However, the postnatal hormonal environment and body composition development in this group remain underexplored. This prospective observational study aimed to analyze and compare growth, body composition, energy expenditure, hormonal, and metabolic responses in healthy late preterm and term infants in the first four months of life.

Results: Anthropometry, body composition, energy expenditure, metabolic biomarkers and growth factors were measured in 94 term infants (gestational age: 39.6 ± 1.3 weeks, birth weight 3330 ± 570 g) and 18 late preterm infants (35.0 ± 1.0 weeks, 2520 ± 660 g) at three time points (0-5, 55-65 and 115-125 days of life). The onset of fat mass accretion occurred directly after birth resulting in higher percent fat mass in late preterm infants in early life. Late preterm infants reached a similar percent fat mass approximately five weeks earlier in postmenstrual age than term infants. In contrast, fat-free mass developed along similar trajectories in both groups, indicating preserved lean tissue growth in late preterm infants. Energy expenditure doubled during the first two months and was closely linked to fat-free mass accretion. Insulin-like growth factor (IGF)-1 and IGF-2 levels increased postnatally, with slightly higher concentrations in late preterm infants. Increase of percent fat mass paralleled leptin and IGF levels in both groups. IGF-1 and IGF-2 levels were higher in formula-fed infants, supporting the influence of nutritional composition on growth-related hormonal regulation.

Conclusions: Birth may initiate changes in hormonal levels and acceleration of fat mass accrual, resulting in higher fat mass in late preterm-born infants at term age when compared to term-born infants. Next to hormonal shifts, these changes appear to be driven by nutritional factors in the early postnatal period. The results suggest that growth targets for late preterm infants may need to be reconsidered, particularly in the early postnatal period. Future studies should provide evidence on individual growth targets and nutritional guidelines for preterm infants to account for the physiological differences to term infants.

The new German Center for Child and Adolescent Health (DZKJ) founded as part of the German Centers for Health Research provides an unprecedented and unique opportunity for internationally outstanding research that contributes to the health and well-being of children and adolescents by creating a sustainable, multidisciplinary translational research center with a wide spectrum of clinical and scientific disciplines. The DZKJ attracts and motivates some of the best basic and clinical scientists in Germany inside and outside the field of pediatrics to jointly dedicate their research and creativity to unravelling the causes of both common and rare diseases and to developing innovative therapies and prevention strategies. All DZKJ partner sites will join forces for a pivotal, networked lighthouse for clinical and translational science in pediatrics in Germany and beyond.

Background: Thrombocytopenia is the most common hematologic manifestation of acid sphingomyelinase deficiency (ASMD). The introduction of enzyme replacement therapy (ERT) represents significant progress in the treatment landscape of this disorder. This study presents the largest pediatric case series of ASMD to date, providing valuable insights into the real-world application of ERT in affected children.

Methods: Ten children with ASMD (five with type B and five with type A/B) received ERT for one year. Growth parameters, complete blood counts, abdominal ultrasonography, liver function tests, lipid profiles, and neurological assessments were conducted at baseline and subsequently every three months. In addition, chest high-resolution computed tomography (HRCT) and dual-energy X-ray absorptiometry (DXA) were performed at baseline and repeated after one year.

Results: No serious infusion-related reactions (IAR) were recorded. However, one patient developed a mild urticarial rash, while another experienced pyrexia. Anemia was present in all children at baseline. A significant increase in hemoglobin levels starting at week 12 (p = 0.02) with peak levels observed at week 50. Thrombocytopenia was present in 60% of patients at baseline. Platelet counts did not show a significant change at week 12 (p = 0.3), but a significant increase was observed after 24 weeks (p = 0.0196), and counts peaked at week 50 (p = 0.0057). There was a significant reduction in liver and spleen sizes, as well as lipid profile parameters. In addition, gradual improvements were observed in interstitial lung disease scores and bone mineral densities throughout the study course.

Conclusion: Our findings indicate that olipudase alfa provides significant benefits in key hematological and visceral clinical outcomes in pediatric patients with ASMD.