Basic characteristics and safety of donation in related and unrelated haematopoietic progenitor cell donors - first 10 years of prospective donor follow-up of Swiss donors.

Since July 2007 prospective life-long follow-up (FU) for unrelated (URD) and related donors (RD) is mandatory in Switzerland and data on every allogeneic haematopoietic progenitor cell (HPC) donation are collected prospectively. We report the real-world experience of HPC donation during a 10-year study period (01.07.2007-30.06.2017) with basic characteristics and FU data. 1105 donors underwent 1155 HPC donation procedures. Eighty percent of first donations performed by 802 (73%) RDs and 303 (27%) URDs were peripheral blood stem cells (PBSC), 20% bone marrow (BM). Male donors were over-represented as URD (60% male vs 40% female). Main differences between RDs and URDs concerned age and pre-existing health disorders. RDs were significantly older at first donation (median age 48 years) compared to URD (34 years, p < 0.0001) and had more pre-existing health problems: 25% vs 9% in URD (p < 0.0001). No fatal complications occurred, collection related severe adverse events (SAE) after first donation were not significantly different between groups (RD 1.2%, URD 0.99%), incidence rates for neoplastic and autoimmune diseases did not exceed the rates of the general population. RDs are a more heterogeneous and potentially more vulnerable group, but if donor evaluation is performed appropriately, HPC donation is still safe.

Indication of spatially random occurrence of Chlamydia-like organisms in Bufo bufo tadpoles from ponds located in the Geneva metropolitan area.

Occurrence of bacteria belonging to the order Chlamydiales was investigated for the first time in common toad (Bufo bufo) tadpole populations collected from 41 ponds in the Geneva metropolitan area, Switzerland. A Chlamydiales-specific real-time PCR was used to detect and amplify the Chlamydiales 16S ribosomal RNA-encoding gene from the tails of 375 tadpoles. We found the studied amphibian populations to host Chlamydia-like organisms (CLOs) attributable to the genera Similichlamydia, Neochlamydia, Protochlamydia and Parachlamydia (all belonging to the family Parachlamydiaceae), Simkania (family Simkaniaceae) and Estrella (family Criblamydiaceae); additionally, DNA from the genus Thermoanaerobacter (family Thermoanaerobacteriaceae) was detected. Global autocorrelation analysis did not reveal a spatial structure in the observed CLOs occurrence rates, and association tests involving land cover characteristics did not evidence any clear effect on CLOs occurrence rates in B. bufo. Although preliminary, these results suggest a random and ubiquitous distribution of CLOs in the environment, which would support the biogeographical expectation 'everything is everywhere' for the concerned microorganisms.

Persistence of butterfly populations in fragmented habitats along urban density gradients: motility helps.

In a simulation study of genotypes conducted over 100 generations for more than 1600 butterfly's individuals, we evaluate how the increase of anthropogenic fragmentation and reduction of habitat size along urbanisation gradients (from 7 to 59% of impervious land cover) influences genetic diversity and population persistence in butterfly species. We show that in areas characterised by a high urbanisation rate (>56% impervious land cover), a large decrease of both genetic diversity (loss of 60-80% of initial observed heterozygosity) and population size (loss of 70-90% of individuals) is observed over time. This is confirmed by empirical data available for the mobile butterfly species Pieris rapae in a subpart of the study area. Comparing simulated data for P. rapae with its normal dispersal ability and with a reduced dispersal ability, we also show that a higher dispersal ability can be an advantage to survive in an urban or highly fragmented environment. The results obtained here suggest that it is of high importance to account for population persistence, and confirm that it is crucial to maintain habitat size and connectivity in the context of land-use planning.

Predictors of nonresponse to fluid restriction in hyponatraemia due to the syndrome of inappropriate antidiuresis.

BACKGROUND: Fluid restriction (FR), the first-line treatment for hyponatraemia due to the syndrome of inappropriate antidiuresis (SIAD), often does not lead to successful correction of hyponatraemia. Therefore, predictive markers of treatment response are desirable. We evaluated routinely measured serum (s) and urine (u) parameters, s-copeptin and s-mid-regional pro-atrial natriuretic peptide (s-MR-proANP), as possible predictors of FR response. METHODS: In this prospective observational study, we included patients with profound hyponatraemia (s-sodium <125 mmol L-1 ) due to SIAD. Patients were classified as FR responders (increase in s-sodium concentration of >3 mmol L-1 within 24 h) or nonresponders (increase of ≤3 mmol L-1 within 24 h). Initial laboratory parameters were compared between groups with logistic regression analysis. RESULTS: Of 106 SIAD patients analysed, 82 underwent treatment with FR; 48 (59%) patients showed a successful response to FR and 34 (41%) were considered nonresponders. High levels of u-sodium and u-osmolality were significantly associated with nonresponse to FR [odds ratio (OR) 15.0, 95% confidence interval (CI) 2.4-95.8, P = 0.004 and OR 34.8, 95% CI 1.2-1038.8, P = 0.041, respectively). The association of u-sodium and nonresponse remained significant also after adjustment for diuretic use. Lower levels of s-MR-proANP were associated with nonresponse (OR 0.03, 95% CI 0.003-0.3, P = 0.004), whereas s-copeptin was not significantly associated with response to FR. CONCLUSION: Easily measured laboratory parameters, especially u-sodium, correlate with therapeutic response and identify patients most likely to fail to respond to FR. Measurement of these parameters may facilitate early treatment choice in patients with SIAD.

Mid-regional pro-atrial natriuretic peptide and the assessment of volaemic status and differential diagnosis of profound hyponatraemia.

BACKGROUND: Hyponatraemia is common and its differential diagnosis and consequent therapy management is challenging. The differential diagnosis is mainly based on the routine clinical assessment of volume status, which is often misleading. Mid-regional pro-atrial natriuretic peptide (MR-proANP) is associated with extracellular and cardiac fluid volume. METHODS: A total of 227 consecutive patients admitted to the emergency department with profound hypo-osmolar hyponatraemia (Na < 125 mmol L(-1) ) were included in this prospective multicentre observational study conducted in two tertiary centres in Switzerland. A standardized diagnostic evaluation of the underlying cause of hyponatraemia was performed, and an expert panel carefully evaluated volaemic status using clinical criteria. MR-proANP levels were compared between patients with hyponatraemia of different aetiologies and for assessment of volume status. RESULTS: MR-proANP levels were higher in patients with hypervolaemic hyponatraemia compared to patients with hypovolaemic or euvolaemic hyponatraemia (P = 0.0002). The area under the curve (AUC) to predict an excess of extracellular fluid volume, compared to euvolaemia, was 0.73 [95% confidence interval (CI) 0.62-0.84]. Additionally, in multivariate analysis, MR-proANP remained an independent predictor of excess extracellular fluid volume after adjustment for congestive heart failure (P = 0.012). MR-proANP predicted the syndrome of inappropriate antidiuresis (SIAD) versus hypovolaemic and hypervolaemic hyponatraemia with an AUC of 0.77 (95% CI 0.69-0.84). CONCLUSION: MR-proANP is associated with extracellular fluid volume in patients with hyponatraemia and remains an independent predictor of hypervolaemia after adjustment for congestive heart failure. MR-proANP may be a marker for discrimination between the SIAD and hypovolaemic or hypervolaemic hyponatraemia.

Vertical and horizontal photobiont transmission within populations of a lichen symbiosis.

Lichens are widespread symbioses and play important roles in many terrestrial ecosystems. The genetic structure of lichens is the result of the association between fungal and algal populations constituting the lichen thallus. Using eight fungus- and seven alga-specific highly variable microsatellite markers on within-population spatial genetic data from 62 replicate populations across Europe, North America, Asia and Africa, we investigated the contributions of vertical and horizontal transmission of the photobiont to the genetic structure of the epiphytic lichen Lobaria pulmonaria. Based on pairwise comparisons of multilocus genotypes defined separately for the mycobiont and for the photobiont, we inferred the transmission mode of the photobiont and the relative contribution of somatic mutation and recombination. After constraining the analysis of one symbiont to pairs of individuals with genetically identical symbiotic partners, we found that 77% of fungal and 70% of algal pairs were represented by clones. Thus, the predominant dispersal mode was by means of symbiotic vegetative propagules (vertical transmission), which dispersed fungal and algal clones co-dependently over a short distance, thus shaping the spatial genetic structure up to distances of 20m. Evidence for somatic mutation generating genetic diversity was found in both symbionts, accounting for 30% of pairwise comparisons in the alga and 15% in the fungus. While the alga did not show statistically significant evidence of recombination, recombination accounted for 7.7% of fungal pairs with identical algae. This implies that, even in a mostly vegetatively reproducing species, horizontal transmission plays a role in shaping the symbiotic association, as shown in many coral and other symbioses in nature.

Prognostic value of procalcitonin in community-acquired pneumonia.

The prognostic value of procalcitonin (PCT) levels to predict mortality and other adverse events in community-acquired pneumonia (CAP) remains undefined. We assessed the performance of PCT overall, stratified into four predefined procalcitonin tiers (< 0.1, 0.1-0.25, > 0.25-0.5, >0.5 µg·L⁻¹) and stratified by Pneumonia Severity Index (PSI) and CURB-65 (confusion, urea >7 mmol·L⁻¹, respiratory frequency ≥ 30 breaths·min⁻¹, systolic blood pressure < 90 mmHg or diastolic blood pressure ≤ 60 mmHg, and age ≥ 65 yrs) risk classes to predict all-cause mortality and adverse events within 30 days follow-up in 925 CAP patients. In receiver operating characteristic curves, initial PCT levels performed only moderately for mortality prediction (area under the curve (AUC) 0.60) and did not improve clinical risk scores. Follow-up measurements on days 3, 5 and 7 showed better prognostic performance (AUCs 0.61, 0.68 and 0.73). For prediction of adverse events, the AUC was 0.66 and PCT significantly improved the PSI (from 0.67 to 0.71) and the CURB-65 (from 0.64 to 0.70). In Kaplan-Meier curves, PCT tiers significantly separated patients within PSI and CURB-65 risk classes for adverse events prediction, but not for mortality. Reclassification analysis confirmed the added value of PCT for adverse event prediction, but not mortality. Initial PCT levels provide only moderate prognostic information concerning mortality risk and did not improve clinical risk scores. However, PCT was helpful during follow-up and for prediction of adverse events and, thereby, improved the PSI and CURB65 scores.