Circulating irisin levels are lower in patients with either stable coronary artery disease (CAD) or myocardial infarction (MI) versus healthy controls, whereas follistatin and activin A levels are higher and can discriminate MI from CAD with similar to CK-MB accuracy.

BACKGROUND: Several myokines are produced by cardiac muscle. We investigated changes in myokine levels at the time of acute myocardial infarction (MI) and following reperfusion in relation to controls. METHODS: Patients with MI (MI Group, n=31) treated with percutaneous coronary intervention (PCI) were compared to patients with stable coronary artery disease (CAD) subjected to scheduled PCI (CAD Group, n=40) and controls with symptoms mimicking CAD without stenosis in angiography (Control Group, n=43). The number and degree of stenosis were recorded. Irisin, follistatin, follistatin-like 3, activin A and B, ALT, AST, CK and CK-MB were measured at baseline and 6 or 24h after the intervention. RESULTS: MI and CAD patients had lower irisin than controls (p<0.001). MI patients had higher follistatin, activin A, CK, CK-MB and AST than CAD patients and controls (all p≤0.001). None of the myokines changed following reperfusion. Circulating irisin was associated with the degree of stenosis in all patients (p=0.05). Irisin was not inferior to CK-MB in predicting MI while folistatin and activin A could discriminate MI from CAD patients with similar to CK-MB accuracy. None of these myokines was altered following PCI in contrast to CK-MB. CONCLUSIONS: Irisin levels are lower in MI and CAD implying that their production may depend on myocadial blood supply. Follistatin and activin A are higher in MI than in CAD suggesting increased release due to myocardial necrosis. They can predict MI with accuracy similar to CK-MB and their role in the diagnosis of MI remains to be confirmed by prospective large clinical studies.

Artificial nutrition and intestinal mucosal barrier functionality.

The gastrointestinal tract has a major role in digestion and absorption of nutrients while playing a leading role in defense of the body. It forms a shield against the invasion of various microorganisms or their products (e.g. antigens, toxins) and therefore it is important to establish its integrity and functionality. That depends on the route of administration and the composition of the artificial nutrition. This study concentrates on the influences of different kinds of artificial nutrition in the functionality of the intestinal mucosal barriers. It seems that full macromolecular solutions of enteral nutrition ensure an adequate mucous immune response, while a lack of nutritional stimulus in the lumen leads rapidly to a dysfunction of gastric-associated lymphatic tissue and mucosal immune system. This dysfunction renders the patients susceptible to infections in distant organs, hospital pneumonia, and multiorgan failure of non-infectious etiology. In patients with indication of total parenteral nutrition administration, addition of bombesin or glutamine preserves mucosal immune response and may limit the adverse effects.

Long-term treatment of osteoporosis: safety and efficacy appraisal of denosumab.

Denosumab is a fully human monoclonal antibody to the receptor activator of nuclear factor-κB ligand (RANKL), a member of the tumor necrosis factor receptor superfamily essential for osteoclastogenesis. Denosumab treatment is associated with a rapid, sustained, and reversible reduction in bone turnover markers, a continuous marked increase in bone mineral density at all sites, and a marked decrease in the risk of vertebral, hip, and nonvertebral fractures in women with postmenopausal osteoporosis. Therefore, it could be considered as an effective alternative to previous bisphosphonate treatment as well as first-line treatment of severe osteoporosis. Cost-effectiveness studies support this suggestion. In addition, denosumab seems to be the safest treatment option in patients with impaired renal function. Denosumab is characterized by reversibility of its effect after treatment discontinuation, in contrast with bisphosphonates. Large-scale clinical trials, including the extension of FREEDOM trial for up to 5 years, are reassuring for its safety. However, given its brief post-market period, vigilance regarding adverse events related to putative RANKL inhibition in tissues other than bone, as well as those related to bone turnover oversuppression, is advised.

Denosumab and bisphosphonates: rivals or potential "partners"? A "hybrid" molecule hypothesis.

Bisphosphonates are well established as the treatment of choice for disorders of excessive bone resorption, including osteoporosis. They bind bone mineral with high affinity and through internalization by the resorbing osteoclasts, affect their function and survival. Receptor activator of nuclear factor-κB ligand (RANKL) is a cytokine essential for osteoclast differentiation, activation, and survival. Denosumab, a human monoclonal antibody that neutralizes RANKL, constitutes a promising antiresorptive agent for osteoporosis treatment. However, its presumable interaction with the immune system could adversely affect immune response resulting in increased risk of infections. We hypothesize that bisphosphonates could serve as a vehicle for the delivery of denosumab selectively to the skeleton. Thus, the effect on the immune system could be minimized, along with a potential increase in the antiresorptive efficacy, as a result of the combined action of denosumab and the bisphosphonate on the earlier and later stages of osteoclast life, respectively.