Direct and indirect reference intervals of 25-hydroxyvitamin D: it is not a real vitamin D deficiency pandemic.

Introduction: Many studies report vitamin D (25-OH-D) deficiency, although there is no consensus among scientific societies on cut-offs and reference intervals (RI). The aim of this study is to establish and compare RI for serum 25-OH-D by direct and indirect methods. Materials and methods: Two studies were performed in Zaragoza (Spain). A retrospective study (N = 7222) between January 2017 and April 2019 was used for RI calculation by indirect method and a prospective study (N = 312) with healthy volunteers recruited in August 2019 and February 2020 for direct method. Seasonal differences were investigated. Measurements were performed on Cobas C8000 (Roche-Diagnostics, Basel, Switzerland) using electrochemiluminescence immunoassay technology. Results: Reference intervals (2.5-97.5 percentile and corresponding 95% confidence intervals, CIs) were as follows: by indirect method 5.6 ng/mL (5.4 to 5.8) - 57.2 ng/mL (55.2 to 59.8), in winter 5.4 ng/mL (5.2 to 5.7) - 55.7 ng/mL (53.6 to 58.4), while in summer 5.9 ng/mL (5.4 to 6.2) - 59.9 ng/mL (56.3 to 62.9). By direct method 9.0 ng/mL (5.7 to 9.5) - 41.4 ng/mL (37.6 to 48.0), in winter 7.4 ng/mL (3.9 to 8.6) - 34.6 ng/mL (30.6 to 51.5), while in summer 13.3 ng/mL (10.1 to 14.1) - 44.1 ng/mL (38.9 to 66.0). In both methods, RIs were higher in summer. A significant difference was observed in 25-OH-D median values between the two methods (P < 0.001). Conclusions: Reference interval calculation according to the studied area may be a useful tool to adapt the deficiency cut-offs for 25-OH-D. Our data support 25-OH-D values over 12.0 ng/mL for healthy population as sufficient, therefore current recommendations should be updated. In addition, differences in seasonality should be taken into account.

The balance between fitness advantages and costs drives adaptation of bacteriophage Qß to changes in host density at different temperatures.

Introduction: Host density is one of the main factors affecting the infective capacity of viruses. When host density is low, it is more difficult for the virus to find a susceptible cell, which increases its probability of being damaged by the physicochemical agents of the environment. Nevertheless, viruses can adapt to variations in host density through different strategies that depend on the particular characteristics of the life cycle of each virus. In a previous work, using the bacteriophage Qß as an experimental model, we found that when bacterial density was lower than optimal the virus increased its capacity to penetrate into the bacteria through a mutation in the minor capsid protein (A1) that is not described to interact with the cell receptor. Results: Here we show that the adaptive pathway followed by Qß in the face of similar variations in host density depends on environmental temperature. When the value for this parameter is lower than optimal (30°C), the mutation selected is the same as at the optimal temperature (37°C). However, when temperature increases to 43°C, the mutation selected is located in a different protein (A2), which is involved both in the interaction with the cell receptor and in the process of viral progeny release. The new mutation increases the entry of the phage into the bacteria at the three temperatures assayed. However, it also considerably increases the latent period at 30 and 37°C, which is probably the reason why it is not selected at these temperatures. Conclusion: The conclusion is that the adaptive strategies followed by bacteriophage Qß, and probably other viruses, in the face of variations in host density depend not only on their advantages at this selective pressure, but also on the fitness costs that particular mutations may present in function of the rest of environmental parameters that influence viral replication and stability.

Endocrine Evaluation and Homeostatic Model Assessment in Patients with Cornelia de Lange Syndrome.

Objective: The aim of this study was to expand knowledge about endocrine disorders in individuals with Cornelia de Lange syndrome (CdLS), a rare developmental genetic disorder with anomalies in multiple organs and systems. Methods: Hormone levels, clinical scores, anthropometric measurements, and molecular analysis were assessed in 24 individuals with CdLS. Results: Hyperprolactinemia was the most common endocrine disorder. Three patients showed subclinical hypothyroidism. In the gonadotropic axis, mildly delayed puberty was observed, as well as genital anomalies, such as cryptorchidism. Despite short stature, levels of insulin-like growth factor 1 and insulin-like growth factor-binding protein 3 were normal, on average. Three prepubertal individuals without risk factors had higher than normal values for the homeostatic model assessment of insulin resistance (HOMA-IR) and for insulinemia, suggesting insulin resistance. Furthermore, two adults had elevated BMIs associated with HOMA-IR values over the cut-off values. Conclusion: CdLS can lead to dysregulation of the endocrine system, particularly in patients with high HOMA-IR values and insulinemia who are at risk of insulin resistance. Therefore, clinical follow-ups with hormonal assessments are proposed for individuals with CdLS.

Prevalence and Mortality of Patients with Palliative Needs in an Acute Respiratory Setting. / Prevalencia y mortalidad de pacientes con necesidades paliativas en una planta de Neumología. Estudio prospectivo.

INTRODUCTION: NECPAL is a tool for identification of patients with advanced chronic disease in need of palliative care. The main objective of the study is to know the prevalence of patients with palliative needs in an acute respiratory ward in a Spanish tertiary hospital using NECPAL. A second objective of the study is to know the annual mortality rate of these patients. MATERIALS AND METHODS: Cross sectional study and prospective monitoring of a cohort identified as palliative patients with the NECPAL tool for 12 months. Patient identification was performed in patients admitted to the respiratory ward of our hospital for longer than 3 days. We have assessed the annual vital status (deceased or not deceased) of patients and have recorded demographics, clinical and functional data, as well as the use of healthcare resources. RESULTS: We monitored a cohort of 363 patients. Of them, 87 patients (24.3%) (IC 95% 19-30) were identified as NECPAL positive. 60% of patients (n = 64) died within 12 months of their admission. There was no significant difference in the mortality ratio of oncologic versus non oncologic patients. In a multivariable analysis, mortality was associated with demand by patients or relatives for palliative care and with the presence of specific disease progression markers or indicators. CONCLUSIONS: prevalence of patients with palliative needs in acute respiratory wards is high (one out of four patients). 60% of the patients identified as NECPAL positive in our cohort died in the first 12 months. Training of healthcare professionals as well as availability of appropriate resources are indispensable factors to improve care of this population.

Plasma procalcitonin measured by time-resolved amplified cryptate emission (TRACE) in liver transplant patients. A prognosis marker of early infectious and non-infectious postoperative complications.

BACKGROUND: Elevated procalcitonin (PCT) levels are observed after major surgery, such as orthotopic liver transplantation (OLTx). The aim of this observational study was to evaluate PCT kinetics during the first 5 following days after surgery to establish the prognostic value of PCT changes in the outcome of OLTx, and to predict medical, technical and infectious complications. PCT was also evaluated in the differential diagnosis of infection vs. rejection. METHODS: A total of 64 OLTx were performed in 58 patients; they were split into two groups: with and without complications. Out of these patients, 18 developed infection, and nine rejection. PCT was measured before and during surgery, 12 h after transplantation and daily for the 5 following days. PCT was also measured the day when infection or rejection was diagnosed, and on the previous day. PCT was determined by time-resolved amplified cryptate emission (TRACE) technology. RESULTS: PCT elevation began at 12 h after surgery, reaching a peak on the 1st day in both groups. Significantly higher PCT concentrations were found in the group of patients developing complications, on the 5 postoperative days. It was found that a 24 h PCT value higher than 1.92 microg/L increased by 9.1-time-fold the risk of complications. When infection was diagnosed, a second peak of PCT was observed, but no PCT elevation was shown in rejection. CONCLUSIONS: Daily monitored PCT provides valuable information about the early outcome of OLTx.

Umbilical cord blood serum procalcitonin by Time-Resolved Amplified Cryptate Emission (TRACE) technology: reference values of a potential marker of vertically transmitted neonatal sepsis.

BACKGROUND: Neonatal infection remains a major diagnostic problem because of non-specific clinical signs and symptoms, as well as low sensitivity and specificity of routine laboratory tests. C-reactive protein (CRP), white blood cell count, absolute neutrophil count and immature/total neutrophil ratio are the most widely used tests in the diagnosis of sepsis and provide useful information, but none of these has demonstrated to be reliable in detecting all septic infants. Procalcitonin (PCT) has been suggested as a potentially useful laboratory test performed in umbilical cord blood when perinatal bacterial sepsis is under investigation. METHODS: In this study, the reference interval for umbilical cord blood serum PCT was established for the first time by Time-Resolved Amplified Cryptate Emission (TRACE) technology. RESULTS: The reference interval for PCT in umbilical cord blood serum ranged from 0.04 to 0.43 microg/L in 168 non-infected newborn infants (95% CI 0.02-0.06 and 0.35-0.60 microg/L, respectively). Cord blood serum PCT correctly classified one infected patient out of 90 newborn infants at risk of vertically transmitted sepsis and identified another neonate as a potentially infected patient despite having negative blood cultures. However, cord blood CRP misclassified 21 out of the 90 patients as infected neonates. CONCLUSIONS: Cord blood PCT measured by TRACE is a potentially more useful early marker of neonatal sepsis than cord blood CRP.