Volumetric absorptive microsampling (VAMS) is a novel approach that allows single-drop (10 μL) blood collection. Integration of VAMS with mass spectrometry (MS)-based untargeted metabolomics is an attractive solution for both human and animal studies. However, to boost the use of VAMS in metabolomics, key pre-analytical questions need to be addressed. Therefore, in this work, we integrated VAMS in a MS-based untargeted metabolomics workflow and investigated pre-analytical strategies such as sample extraction procedures and metabolome stability at different storage conditions. We first evaluated the best extraction procedure for the polar metabolome and found that the highest number and amount of metabolites were recovered upon extraction with acetonitrile/water (70:30). In contrast, basic conditions (pH 9) resulted in divergent metabolite profiles mainly resulting from the extraction of intracellular metabolites originating from red blood cells. In addition, the prolonged storage of blood samples at room temperature caused significant changes in metabolome composition, but once the VAMS devices were stored at − 80 °C, the metabolome remained stable for up to 6 months. The time used for drying the sample did also affect the metabolome. In fact, some metabolites were rapidly degraded or accumulated in the sample during the first 48 h at room temperature, indicating that a longer drying step will significantly change the concentration in the sample. KeywordsMetabolomics; Volumetric absorptive microsampling; Mass spectrometry ✉ Giuseppe Paglia beppepaglia@gmail.com. Compliance with ethical standardsThis study was performed in accordance with the ethical standards. The local ethics committee (Comitato etico del comprensorio sanitario di Bolzano) approved the study, and all participants provided written informed consent.

Additional studies are needed to confirm the promising effect of PLT-gel for the treatment of osteoradionecrosis.

Background and Objectives The role of pre-donation blood pressure (BP) as independent contributor to post-donation vasovagal reactions (VVRs) is still debated. Differences between a liberal (i.e., inclusion of hypotensive donors) and a restrictive policy (i.e., not accepting hypotensive donors) should be investigated. This study aims to investigate the consequences of a liberal policy in development of VVRs after whole-blood donations. Materials and MethodsWe compared the incidence of VVRs between 2015 (restrictive policy) and 2016 (liberal policy) and the associated risk factors. We evaluated respectively 22 789 vs. 21 676 blood donations obtained from 18 001 blood donors (12 501 donated in both years). ResultsComparing the results we obtained between 2015 and 2016, donations showed an overlap of the cohorts. Two hundred fifteen VVRs (incidence rate 0Á48%) were observed, 104 (0Á46%) of which in 2015, and 111 (0Á51%) in 2016. A preliminary univariate analysis showed that donors with systolic BP <110 mm Hg had a two-fold risk of VVRs compared to normotensive donors (VVR/donation rate of 0Á99% vs. 0Á46%; P = 0Á001). The subsequent multivariable logistic regression model showed that VVRs were highly associated with weight, site of collection, age and number of donations, excluding a role for systolic and diastolic BP.Conclusion A liberal pre-donation BP policy seems to be safe for blood donors. Our analysis confirms that older donors with higher body-weight who already had donated blood are unlikely to experience VVRs.

It is generally assumed that chronic lymphocytic leukemia of B cell origin (B-CLL) is characterized by the presence of surface membrane immunoglobulins (SmIg) and by the absence of cytoplasmic immunoglobulins (CyIg). In a variable number of cases SmIg are not detectable because of their low density on the cellular surface. Because a constant presence of CyIg in 20 subjects suffering from B-CLL has been reported recently, we reexamined 15 SmIg-negative and 10 SmIg- positive B-CLL patients by SmIg and CyIg determinations. We used a direct immunofluorescence method on peripheral blood mononuclear cells for the detection of SmIg and, after fixation, for CyIg. CyIg were detectable in 24 out of 25 cases, with a fluorescence intensity ranging from weak to moderate. The existence of frequent negative results for CyIg determination in B-CLL reported in the literature probably depends on the low sensitivity of the method used. We conclude that CyIg determination is useful in phenotyping every B-CLL patient, especially SmIg-negative ones.

The HLA-C*16:97 allele was found in multiple donors from the Bone Marrow Registry in South Tyrol.