Procalcitonin as an early indicator of outcome in sepsis: a prospective observational study.

This study explores the role of procalcitonin (PCT) in predicting the outcome of sepsis. In a prospective multicentre observational investigation, blood was sampled within 24 h of onset of sepsis in 1156 hospitalised patients; 234 were in the intensive care unit (ICU) at the point of presentation of sepsis while 922 were not. PCT was estimated in serum by the ultrasensitive Kryptor assay in a double-blinded fashion. Among patients outside the ICU, mortality was 8% in those with PCT ≤0.12 ng/mL but 19.9% in those with PCT >0.12 ng/mL [P<0.0001, odds ratio (OR) for death: 2.606; 95% confidence interval (CI): 1.553-4.371]. Among patients whose sepsis presented in ICU, mortality was 25.6% in those with PCT ≤0.85 ng/mL but 45.3% in those with PCT >0.85 ng/mL (P=0.002; OR for death: 2.404; 95% CI: 1.385-4.171). It is concluded that PCT cut-off concentrations can contribute to predicting the outcome of sepsis and might be of particular value in identifying patients who would benefit from ICU admission.

Crystals of monosodium urate monohydrate enhance lipopolysaccharide-induced release of interleukin 1 beta by mononuclear cells through a caspase 1-mediated process.

OBJECTIVE: Recent studies suggest that crystals of monosodium urate (MSU), deposited in joints of patients with acute gouty arthritis, activate the NACHT domain, leucine-rich repeat and pyrin domain-containing protein (NALP)3 inflammasome. In the present study we have investigated whether production of proinflammatory cytokines by crystals was exacerbated during costimulation with Toll-like receptor (TLR) ligands. METHODS: Mononuclear cells of 22 healthy donors were stimulated by various concentrations of MSU crystals in the absence or presence of lipopolysaccharide (LPS), Pam3Cys and flagellin. Production of tumour necrosis factor alpha (TNFalpha), interleukin (IL)1 beta and IL6, as well as the intracellular concentrations of proIL1 beta were measured by ELISA. mRNA transcripts of TNFalpha and IL1 beta were assessed by real-time PCR. Stimulation experiments were also performed with peripheral blood mononuclear cells (PBMCs) of one patient carrying a NALP3 mutation. RESULTS: MSU induced a moderate release of IL1 beta and IL6, but not of TNFalpha. Urate crystals amplified IL1 beta production stimulated by the TLR4 ligand LPS, while no synergy was apparent for IL6 production. In addition, no synergy between urate crystals and Pam3Cys (TLR2 ligand) or flagellin (TLR5 ligand) was apparent. The synergy between urate crystals and LPS was directed at the level of the NALP3 inflammasome, as it was present only when active IL1 beta was measured, but not at the level of IL1 mRNA or proIL1 beta. The synergy between LPS and MSU crystals ceased to exist in the presence of a caspase 1 inhibitor. CONCLUSIONS: MSU crystals act in synergy with LPS for the induction of enhanced release of IL1 beta. Increased cleavage of proIL1 beta by urate-activated caspase 1 is proposed as the underlying mechanism.

Early apoptosis of blood monocytes is a determinant of survival in experimental sepsis by multi-drug-resistant Pseudomonas aeruginosa.

Apoptosis of blood monocytes was studied in experimental sepsis by multi-drug-resistant Pseudomonas aeruginosa. Thirty-six rabbits were used, divided into the following groups: A (n = 6), sham; B (n = 6), administered anaesthetics; and C (n = 24), acute pyelonephritis induced after inoculation of the test isolate in the renal pelvis. Blood was sampled at standard time intervals for estimation of tumour necrosis factor (TNF)-alpha and isolation of monocytes. Half the monocytes were incubated and the other half was lysed for estimation of the cytoplasmic activity of caspase-3 by a kinetic chromogenic assay. No animal in groups A and B died; those in group C were divided into two subgroups, CI (n = 8) with present activity of caspase-3 of blood monocytes at 3.5 h and CII (n = 16) with absent activity. Their median survival was 2.0 and 3.5 days, respectively (P = 0.0089). Ex vivo secretion of TNF-alpha from monocytes was higher by monocytes of subgroup CII than subgroup CI at 3.5 h (P = 0.039) and of group A than CII at 48 h (P = 0.010). Median change of caspase-3 activity between 3.5 and 24 h of sampling was 56.1 and -5.8 pmol/min per 10(4) cells for subgroups CI and CII (P = 0.040), respectively. Respective changes between 3.5 and 48 h were 28 981.0 and 0 pmol/min per 10(4) cells (P = 0.036). Early induction of apoptosis in blood monocytes is of prime importance for the survival of the septic host and might be connected to changes of monocyte potential for the secretion of TNF-alpha.

Altered innate and adaptive immune responses in patients with hidradenitis suppurativa.

BACKGROUND: The clinical improvement of hidradenitis suppurativa reported in a small number of patients with antitumour necrosis factor (anti-TNF)-alpha therapies supports the hypothesis for an altered immune response in these patients. OBJECTIVES: To evaluate the state of the innate and adaptive immune responses in patients with hidradenitis suppurativa. METHODS: Fifty-three patients and six healthy controls were studied. Blood was sampled and subpopulations of lymphocytes were analysed by flow cytometry; monocytes were isolated and their function was evaluated from the concentrations of TNF-alpha and interleukin (IL)-6 in supernatants of cell cultures after triggering with endotoxins (lipopolysaccharides). TNF-alpha and IL-6 were estimated by an enzyme immunoassay. RESULTS: CD3/CD8 lymphocytes were lower in patients with involvement of the perineum than in controls; patients with involvement of the breast had higher levels of natural killer (NK) cells than controls. A negative correlation was found between years lapsing since initial presentation of lesions of hidradenitis and the percentage of NK cells. Monocytes isolated from healthy volunteers were more active for the secretion of TNF-alpha and IL-6 than those of patients with hidradenitis suppurativa. CONCLUSIONS: A reduction in the percentage of NK cells over time and a lower monocyte response to triggering by bacterial components is observed in patients with hidradenitis suppurativa. Further research is needed to clarify if these changes are connected to an autoimmune mechanism in the pathogenesis of hidradenitis suppurativa.