Pre-analytical considerations for microRNA quantification in childhood leukemia research

MicroRNAs (miRNAs) have gained significant attention as potential biomarkers in childhood leukemia, offering insights into diagnosis, prognosis, and therapeutic targeting. However, the clinical translation of miRNA biomarkers faces several challenges, including inconsistencies in results caused by methodological differences, sample processing variability, and a lack of standardized normalization techniques. In addition, miRNA profiles are highly cell-specific, with unique signatures for different blood cell types and leukemic blasts, reflecting their distinct biological roles and disease states. Pre-analytical factors are critical in ensuring the accuracy and reproducibility of miRNA quantification. The selectively enriched and highly stable exosomal miRNAs have shown great promise for studying intercellular communication and disease-specific miRNAs. The selection of the analytical matrix should align with the specific objectives of the research or diagnostic application. Addressing technical challenges and recording potential confounding variables (e.g., age, gender, ethnicity, body mass index, menstrual cycle, fasting, circadian rhythm, comorbidities, medications, smoking, and physical activity) are essential to enhancing the reproducibility and reliability of miRNA biomarkers.

This review aims to highlight the challenges facing miRNA quantification in childhood leukemias, scrutinizing all relevant pre-analytical issues, including the preferred specimen source, leukemic blast type and count, the selection of suitable blood components, the impact of time and freeze-thaw cycles, collection, processing, and storage variables.

Further research is needed to standardize methodologies and expand our understanding of miRNA interaction networks, ultimately advancing the application of miRNAs in childhood leukemia research.