Background Measurement of α-fetoprotein (AFP) concentrations in the serum of infants is useful for the management of testicular germ cell tumors, hepatoblastoma and hepatocellular carcinoma. Here, we provide a critical review of the available information about pediatric reference intervals (RI), focusing on their utility in interpreting AFP as an aid for cancer diagnosis. Content Evidence sources in the available literature were critically appraised. Out of 3873 retrieved papers, 24 were finally selected and carefully inspected, and six of them overcame exclusion criteria (i.e. methodological limitations in the study design, statistical gaps, drawbacks in traceability of the AFP assay to higher order materials and/or biased reporting of AFP results). Preterm and term infants up to the 3rd month of life exhibited the highest average AFP concentrations, but the attempt of defining RI by data pooling and partitioning for age intervals was impeded by the wide variability of data. The inability of defining robust RI in the first months of life made difficult, if not impossible, using upper reference limits for ruling out malignancies with a single AFP result. Evaluating the behavior of AFP concentrations 5 days from the baseline result, if this exceeds risk thresholds partitioned for age, according to the formula Xt=X0*2−t/HL (where: t=days elapsed for AFP retest; HL=AFP half-life according to age; X0=AFP baseline concentration, and Xt=predicted AFP concentration at day 5), could give a better information. Summary Novel studies defining AFP RI in infants based on robust methodology are warranted to improve the interpretation of AFP results in pediatric oncology. In the meantime, algorithms based on both serum AFP absolute concentrations and HL may aid in cancer diagnosis.

Several authors have recently claimed an excess in serum folate test ordering, suggesting phasing out it from clinical use. According to studies performed in countries undergoing folic acid fortification policies, it is indeed no more cost-effective to test folate in the face of deficiency prevalence < 1%. In this paper, we sought to evaluate request appropriateness, analytical issues, and cost-effectiveness of serum folate determination for clinical purposes in the European context, considering if evidence retrieved in fortified countries may be generalized. Studies performed in non-fortified countries have generally reported a suboptimal folate intake and suggest a remarkable prevalence of folate deficiency. Our internal data suggest that ~ 20%-25% of the subjects undergoing serum folate test are at risk for deficiency. However, a reliable evaluation of the risk for deficiency implies the knowledge of all issues related to the total testing process of folate measurement as well as the identification of the appropriate population in which to perform the test. The cost-effectiveness of the test is maximized when the request is oriented to subjects suggestive/at risk for deficiency, becoming low if the test is used as a screening tool or for monitoring of vitamin intake/supplementation. Because the individual folate status has a key role in ensuring normal development, physiologic growth, and maintenance of optimal health, the evaluation of its serum levels has to be retained in the clinical use in non-fortified countries, boosting for more appropriate request, and evidence from countries following fortification policies should be cautionary interpreted.

Introduction The correctness of the results of automated platelet analysis is still highly debated. The aim of this multicenter study, conducted according to international guidelines, was to verify the analytical performance of nine different types of hematology analyzers (HAs) in the automated platelet analysis. Methods Four hundred eighty‐six peripheral blood samples (PB), collected in K3EDTA tubes, were analyzed by ABX Pentra, ADVIA2120i, BC‐6800, BC‐6800 Plus, Cell‐DYN Sapphire, DxH800, XE‐2100, XE‐5000, XN‐20 with PLT‐F App. Within‐run imprecision and between‐run imprecision were carried out using PB and material control, respectively. The carryover, low limit of quantification (LoQ), and the PB stability were evaluated. Results The carryover was absent for all HAs. The LoQ of PLT ranged between 2.0 (Cell‐Dyn Sapphire) and 25.0 × 109/L (ADVIA 2120i), while immature platelet fraction (IPF) ranged between 1.0 (XN‐20) and 12.0 × 109/L (XE‐5000). The imprecision (%CV) increases as the platelet count decreases. No HAs showed desirable CVAPS for PLT counts less than 50.0 × 109/L, with the exception of Cell‐DYN Sapphire (CV 3.0% with PLT‐O mean value of 26.7 × 109/L), XN‐20 (CV 2.4% with PLT‐F mean value of 21.5 × 109/L), and BC‐6800 Plus (CV 1.9% with PLT‐O mean value of 26.5 × 109/L). The sample stability ranged between under two hours for MPV by ADVIA2120i and 8 hours for other PLT parameters and HAs. Conclusion The findings of this study may provide useful information regarding carryover, precision, and stability of platelet counts and parameters, especially in thrombocytopenic samples. Moreover, the stability of sample for platelet analysis is conditioned by the HA and by temperature and storage time.

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