Reduced plasma PCSK9 response in patients with bacteraemia is associated with mortality.

BACKGROUND: The proprotein convertase subtilisin/kexin type 9 (PCSK9) enzyme controls blood cholesterol levels by downregulating the expression of the low-density lipoprotein receptor (LDLR). Pathogenic lipids (e.g. lipopolysaccharide) are removed from the circulation by an LDLR/PCSK9-dependent mechanism; thus, it has been suggested that PCSK9 inhibitors may be beneficial in the treatment of infections. We measured plasma PCSK9 levels in patients with culture-positive bacteraemia and explored pathogen-dependent and infection site-dependent effects as well as correlations between patient characteristics and outcome. METHODS: Proprotein convertase subtilisin/kexin type 9 in the plasma was measured with an enzyme-linked immunosorbent assay from 481 patients with blood culture-positive infection on days 0 to 4 after admission to the emergency department. Patient outcome and clinical and laboratory data were gathered retrospectively from patient records. RESULTS: The plasma PCSK9 level was elevated equally in patients with Gram-positive or Gram-negative bacterial infections; particularly high levels were seen in patients with a lower respiratory tract infection and Streptococcus pneumoniae bacteraemia. PCSK9 levels showed a significant positive correlation with C-reactive protein (CRP) level. Bacteraemia patients with liver disease or a history of alcohol abuse had significantly lower levels of plasma PCSK9. Reduced PCSK9 plasma responses in patients were significantly associated with mortality at days 7, 28 and 90. CONCLUSION: Proprotein convertase subtilisin/kexin type 9 is upregulated in blood culture-positive infections. Plasma PCSK9 resembles acute-phase proteins; its expression is induced during an infection, reduced in liver disease and correlates positively with CRP level. We have shown that PCSK9 levels are lower in patients with a fatal prognosis.

Plasma cell-free DNA and qSOFA score predict 7-day mortality in 481 emergency department bacteraemia patients.

BACKGROUND: A few studies have shown that both quick Sequential Organ Failure Assessment (qSOFA) score and cell-free DNA (cfDNA) have potential use as a prognostic marker in patients with infection. We studied these two markers alone and in combination to identify those emergency department (ED) patients with the highest risk of death. METHODS: Plasma cfDNA level was studied on days 0 to 4 after admittance to the ED from 481 culture-positive bloodstream infection cases. The qSOFA score was evaluated retrospectively according to Sepsis-3 definitions. The primary outcome was death by day 7. RESULTS: CfDNA on day 0 was significantly higher in nonsurvivors than in survivors (2.02 µg mL-1 vs. 1.35 µg mL-1 , P < 0.001). CfDNA level was high (>1.69 µg mL-1 ) in 134 (28%) of 481 cases, and the qSOFA score was ≥2 in 128 (28%) of 458 cases. High cfDNA and qSOFA score ≥2 had 70% and 77% sensitivity and 76% and 76% specificity in predicting death by day 7, respectively. High cfDNA alone had odds ratio (OR) of 7.7 (95% CI 3.9-15.3) and qSOFA score ≥2 OR of 11.6 (5.5-24.3), but their combination had OR of 20.3 (10.0-41.4) in predicting death by day 7 when compared with those with low cfDNA and qSOFA score <2. Amongst the five cases with the highest cfDNA levels, there were three patients with severe disseminated intravascular coagulation. CONCLUSION: CfDNA and qSOFA score can be used independently to identify those bacteraemia patients at high risk of death, and combining these two markers gives additional advantage.

The relationship between antenatal risk characteristics, place of delivery and adverse delivery outcome in rural Malawi.

OBJECTIVE: To describe and compare the frequency of antenatally identified maternal 'risk' characteristics, place of delivery and occurrence of delivery complications. METHODS: A prospective cohort study of 780 pregnant women completing antenatal follow-up at a rural health center in Malawi. RESULTS: Three-quarters of the subjects had at least one commonly accepted risk characteristic. Only 30% of these women, and 22% of those with no risk characteristics, delivered in a modern health facility. Four women died, 127 experienced other delivery complications and there were 52 perinatal deaths. The 'at-risk' classification had over 80% sensitivity but less than 30% specificity to predict delivery complications or perinatal deaths. The positive predictive values were as low as 20% for delivery complications and 7% for perinatal mortality. Most individual 'risk' characteristics were not associated with adverse delivery outcomes, even when adjusted for the place of delivery. CONCLUSIONS: Antenatal risk identification failed to promote safe deliveries because of a poor predictive value of the 'risk' variables and the failure of the identified 'at-risk' individuals to deliver in modern health facilities.