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The idea that alterations in the brain immunomodulation are critical for Alzheimer's disease (AD) pathogenesis provides the most integrative view on this cognitive disorder, considering that converging research lines have revealed the involvement of inflammatory processes in AD. We have proposed the damage signal hypothesis as a unifying scheme in that release of endogenous damage/alarm signals, in response to accumulated cell distress (dyslipidemia, vascular insults, head injury, oxidative stress, iron overload, folate deficiency), is the earliest triggering event in AD, leading to activation of innate immunity and the inflammatory cascade. Inflammatory cytokines play a dual role, either promoting neurodegeneration or neuroprotection. This equilibrium is shifted toward the neurodegenerative phenotype upon the action of several risk factors that trigger innate damage signals that activate microglia and the release of tumor necrosis factor-alpha, interleukin-6, and some trophic factors. In this neuroimmunomodulatory hypothesis we integrate different risk factors with microaglial activation and the resulting neuronal alterations and hyperphosphorylations of tau protein. The progression of AD, with slowly increasing damage in brain parenchyma preceding the onset of symptoms, suggests that tissue distress triggering damage signals drives neuroinflammation. These signals via toll-like receptors, receptors for highly glycosylated end products, or other glial receptors activate sensors of the native immune system, inducing the anomalous release of cytokines and promoting the neurodegenerative cascade, a hallmark of brain damage that correlates with cognitive decline.

AimsTo compare primary percutaneous coronary intervention (pPCI) and fibrinolysis in very old patients with ST-segment elevation myocardial infarction (STEMI), in whom head-to-head comparisons between both strategies are scarce.Methods and resultsPatients ≥75 years old with STEMI <6 h were randomized to pPCI or fibrinolysis. The primary endpoint was a composite of all-cause mortality, re-infarction, or disabling stroke at 30 days. The trial was prematurely stopped due to slow recruitment after enroling 266 patients (134 allocated to pPCI and 132 to fibrinolysis). Both groups were well balanced in baseline characteristics. Mean age was 81 years. The primary endpoint was reached in 25 patients in the pPCI group (18.9%) and 34 (25.4%) in the fibrinolysis arm [odds ratio (OR), 0.69; 95% confidence interval (CI) 0.38–1.23; P = 0.21]. Similarly, non-significant reductions were found in death (13.6 vs. 17.2%, P = 0.43), re-infarction (5.3 vs. 8.2%, P = 0.35), or disabling stroke (0.8 vs. 3.0%, P = 0.18). Recurrent ischaemia was less common in pPCI-treated patients (0.8 vs. 9.7%, P< 0.001). No differences were found in major bleeds. A pooled analysis with the two previous reperfusion trials performed in older patients showed an advantage of pPCI over fibrinolysis in reducing death, re-infarction, or stroke at 30 days (OR, 0.64; 95% CI 0.45–0.91).ConclusionPrimary PCI seems to be the best reperfusion therapy for STEMI even for the oldest patients. Early contemporary fibrinolytic therapy may be a safe alternative to pPCI in the elderly when this is not available.Clinicaltrials.gov # NCT00257309.

Virtually none of the hypotheses on Alzheimer's disease (AD) pathogenesis address the earliest events that trigger the molecular alterations that precede cerebral degeneration and account for the diversity of risk factors that converge on a well-defined disease phenotype. We propose that long-term activation of the innate immune system by an individual array of risk factors constitutes a unifying mechanism leading to the triggering of an inflammatory cascade that converges in cytoskeletal alterations (tau aggregation, paired helical filament formation) as a previously hypothesized final common pathway in AD. The key pathogenic phenomena consist in the long-term, maladaptive activation of innate immunity-triggering receptors -such as the toll-like and advanced glycation end-products receptors, and others located in the microglial membrane -by seemingly heterogeneous risk factors such as hyperlipidemia, hyperglycemia, oxidative stress, head injury, amyloid oligomers, etc. Our hypothesis provides a unifying mechanism that explains both the diversity of risk factors acting over long periods of time and the individual response to such insults. This formulation is amenable to both empirical testing and implementation into therapeutic strategies that may lead to effective prevention of AD as well as other disorders in which impaired regulation of the innate immunity is the unifying cause of the condition.