Partial least squares and principal components analysis of wine vintage by high performance liquid chromatography with chemiluminescence detection

HPLC with acidic potassium permanganate chemiluminescence detection was employed to analyse 17 Cabernet Sauvignon wines across a range of vintages (1971–2003). Partial least squares regression analysis and principal components analysis was used in order to investigate the relationship between wine composition and vintage. Tartaric acid, vanillic acid, catechin, sinapic acid, ethyl gallate, myricetin, procyanadin B and resveratrol were found to be important components in terms of differences between the vintages

Digital droplet PCR for minimal residual disease assessment in Philadelphia-positive acute lymphoblastic leukemia by Immunoglobulin/T-cell receptor and BCR::ABL1 gene analysis. Preliminary comparative results.

Background. BCR::ABL1 transcript and immunoglobulin/T-cell receptor clonal gene rearrangements (IG/TR) can be used as biomarkers for minimal residual disease (MRD) monitoring in Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL). There is a growing interest in evaluating MRD using a “double-hit strategy”, especially in the adult setting, where data are lacking. Real-time quantitative polymerase chain reaction (RQ-PCR) is the gold standard for MRD monitoring. It has, however, intrinsic issues that digital droplet PCR (ddPCR) may overcome. Aims. To carry out a parallel MRD monitoring at early time points (TPs) in adult Ph+ ALL patients by both molecular targets and, for BCR::ABL1, by both RQ-PCR and ddPCR to determine the concordance between the MRD values. Materials and methods. Samples were obtained from 28 adults with newly diagnosed Ph+ ALL, enrolled in the ongoing phase III GIMEMA ALL2820 clinical trial (NCT04722848). At diagnosis, all patients underwent IG/TR marker screening. MRD monitoring was performed by RQ-PCR and ddPCR for BCR::ABL1 quantification and by ddPCR for IG/TR. MRD results were considered discordant in case of a difference greater than one log10 or in case of a positivity/negativity. Results. The comparison between MRD values obtained by RQ-PCR and ddPCR using the BCR::ABL1 transcript showed an excellent degree of correlation (R2=0.996). Concerning IG/TR, a marker was identified in 20/28 patients, whereas 8/28 (29%) were no marker (NM). Moreover, in 4 patients (20%) it was not possible to design a sensitive allele-specific oligonucleotide (ASO) (NA). Sixteen samples were evaluated using both biomarkers by ddPCR. Overall, 7/16 (44%) samples were concordant by both targets, having either highly positive (2/7) or negative (5/7) MRD values, while 9/16 (56%) were discordant. Among these, 2/9 were MRD-positive by both targets but outside the concordance range, in 7/9 IG/TR MRD monitoring was negative, while BCR::ABL1 MRD monitoring was positive (range 10-3-10-1). In the 12 NM and NA patients, BCR::ABL1 ddPCR analysis revealed a quantifiable MRD in 8 cases (range 10-2-10-1), 1 proved positive not-quantifiable (PNQ), 2 were MRD-negative and 1 was not evaluable. Finally, in the NM subset, there were no differences in the type of fusion proteins (p190/p210) and enrichment of additional genetic lesions (Fig. 1), while the median WBC count at diagnosis was lower than in the other cases (6.27 x 109/l for NM vs 16.37 x 109/l for patients with IG/TR markers). Conclusions. BCR::ABL1 ddPCR is a sensitive tool for MRD monitoring, at least comparable to RQ-PCR. At variance, at least at early TPs, the degree of concordance between BCR::ABL1 transcript and IG/TR is suboptimal. Noteworthy, although IG/TR is the most widely used biomarker in children, the rate of NM in adult Ph+ ALL is high, suggesting that the BCR::ABL1 transcript remains the most sensitive target. Cohort expansion and clinical correlations are ongoing