Manuel Gómez-Choco

Catecholamines, infection, and death in acute ischemic stroke

Experimental studies have recently suggested that acute ischemia may facilitate the appearance of fatal infections as part of a brain-induced immunodepression syndrome. However, the mechanisms and neurological consequences of infections complicating acute ischemic stroke have received much less attention at the bedside. The incidence of infection and death after non-septic stroke was compared in this prospective study with longitudinal changes of cytokines, leukocytes, normetanephrine (NMN) and metanephrine (MN) in 75 consecutive patients. In multivariate analysis, infection, n = 13 (17%), was associated with the upper quartile of MN (OR 3.51, 95% CI 1.30-9.51), neurological impairment (NIHSS) on admission (OR 3.99, 95% CI 1.34-11.8), monocyte count (OR 1.78, 95% CI 1.13-2.79), and increased interleukin (IL)-10 (OR 1.54, 95% CI 1.00-2.38). Mortality at 3 months, n = 16 (21%), was associated with increased levels of NMN on admission (OR 2.34 95% CI 1.15-4.76), NIHSS score (OR 2.57, 95% CI 1.29-5.11), and higher IL-6 levels (OR 1.29, 95% 1.00-1.67). These findings suggest that acute ischemic stroke is associated with an early activation of the sympathetic adrenomedullar pathway that lowers the threshold of infection and increases the risk of death. Moreover, these findings are independent of the blood borne effects of pro- and anti-inflammatory cytokines, and circulating leukocytes.

Monocyte subtypes predict clinical course and prognosis in human stroke

The number of circulating monocytes increases after stroke. In this study, we assessed the time course and phenotype of monocyte subsets and their relationship with the clinical course and outcome in 46 consecutive stroke patients and 13 age-matched controls. The proportion of the most abundant ‘classical’ CD14highCD16 monocytes did not change after stroke, whereas that of CD14highCD16+ monocytes increased and CD14dimCD16+ monocytes decreased. CD14highCD16 + monocytes had the highest expression of TLR2, HLA-DR and the angiogenic marker, Tie-2; CD14dimCD16+ monocytes had the highest expression of costimulatory CD86 and adhesion molecule CD49d. Platelet-monocyte interactions were highest in CD14highCD16 monocytes and lowest in CD14dimCD16+ monocytes. In adjusted models, 1/CD14highCD16 monocytes were associated with poor outcome (OR: 1.38), higher mortality (OR: 1.40) and early clinical worsening (OR: 1.29); 2/CD14highCD16+ monocytes were inversely related to mortality (OR: 0.32); and 3/CD14dimCD16+ monocytes were inversely related to poor outcome (OR: 0.74) and infarction size (r= 0.45; P = 0.02). These results illustrate that the predominant monocyte subtype conveys harmful effects after stroke, which include stronger interaction with platelets. Alternatively, rarer subpopulations of monocytes are beneficial with a phenotype that could promote tissue repair and angiogenesis. Therefore, monitoring of monocyte subtypes may emerge as a useful tool at the bedside for stroke patients.

Uric Acid Levels Are Relevant in Patients With Stroke Treated With Thrombolysis

Background and Purpose— Uric acid (UA) is a neuroprotective antioxidant that improves the benefits of alteplase in experimental ischemia. However, it is unknown whether endogenous UA also influences the response to thrombolysis in patients with stroke. Methods— A total of 317 consecutive patients treated with thrombolysis were included in a prospective stroke registry. Demographics, laboratory data, neurological course, and infarction volume were prospectively collected. Excellent outcome was defined as achieving a modified Rankin Scale score <2 at 90 days. Binary and ordinal logistic regression models were used to analyze modified Rankin Scale score at 90 days. Results— UA levels were significantly higher in patients with an excellent outcome than in patients with a poor outcome (5.82 [1.39] versus 5.42 [1.81], P=0.029). In multivariate models, increased UA levels (OR, 1.23; 95% CI, 1.03 to 1.49; P=0.025) were associated with an excellent outcome and with an increased risk of shifting to a better category across the modified Rankin Scale (OR, 1.19; 95% CI, 1.04 to 1.38; P=0.014) independently of the effect of confounders. The levels of UA and the volume of final infarction were inversely correlated (r=−0.216, P<0.001) and the inverse correlation remained after adjustment for age, sex, and baseline National Institutes of Health Stroke Scale score (t value=−2.54, P=0.01). Significantly lower UA levels were found in patients with malignant middle cerebral artery infarction and parenchymal hemorrhage postthrombolysis. Conclusions— Increased UA serum levels are associated with better outcome in patients with stroke treated with reperfusion therapies. These results support the assessment of the potential neuroprotective role of the exogenous administration of UA in patients with stroke treated with thrombolysis.

Brain-Derived Antigens in Lymphoid Tissue of Patients with Acute Stroke

In experimental animals, the presence of brain-derived constituents in cervical lymph nodes has been associated with the activation of local lymphocytes poised to minimize the inflammatory response after acute brain injury. In this study, we assessed whether this immune crosstalk also existed in stroke patients. We studied the clinical course, neuroimaging, and immunoreactivity to neuronal derived Ags (microtubule-associated protein-2 and N-methyl d-aspartate receptor subunit NR-2A), and myelin-derived Ags (myelin basic protein and myelin oligodendrocyte glycoprotein) in palatine tonsils and cervical lymph nodes of 28 acute stroke patients and 17 individuals free of neurologic disease. Stroke patients showed greater immunoreactivity to all brain Ags assessed compared with controls, predominantly in T cell zones. Most brain immunoreactive cells were CD68+ macrophages expressing MHC class II receptors. Increased reactivity to neuronal-derived Ags was correlated with smaller infarctions and better long-term outcome, whereas greater reactivity to myelin basic protein was correlated with stroke severity on admission, larger infarctions, and worse outcome at follow-up. Patients also had more CD69+ T cells than controls, indicative of T cell activation. Overall, the study showed in patients with acute stroke the presence of myelin and neuronal Ags associated with lymph node macrophages located near activated T cells. Whether the outcome of acute stroke is influenced by Ag-specific activation of immune responses mediated by CD69 lymphocytes deserves further investigation.

Effect of glatiramer acetate (Copaxone) on the immunophenotypic and cytokine profile and BDNF production in multiple sclerosis: a longitudinal study.

We assessed the effect of glatiramer acetate (GA) on the immunophenotypic and cytokine profile and the BDNF production by peripheral blood mononuclear cells, and their association with the clinical response in 19 naïve-treated MS patients prospectively followed-up after GA therapy. Two patients withdrew the therapy. After a median follow-up of 21 months, twelve were considered responders and five as non-responders. Non-responder patients had significant longer disease duration and a higher EDSS score at baseline. In the responder group, a significant decrease in the percentage of INF-gamma producing total lymphocytes, CD4+ and CD8+ T cells, and reduced percentage of IL-2 producing CD4+ and CD8+ T cells were observed at 12, 18 and 24 months. These changes were associated with a significant increase in the percentage of CD3+, CD4+ and CD4(+) CD45RA(+) T cells, and BDNF production from month 6 that remained significant throughout the study. We did not observe significant changes in the nonresponder group for any of the parameters studied. Our data suggest that GA treatment induces a downmodulation of proinflammatory cytokines associated with the regulation of the peripheral T cell compartment and with increased production of BDNF that might be related to the clinical response.

Outcomes of a contemporary cohort of 536 consecutive patients with acute ischemic stroke treated with endovascular therapy.

Background and Purpose— We sought to assess outcomes after endovascular treatment/therapy of acute ischemic stroke, overall and by subgroups, and looked for predictors of outcome. Methods— We used data from a mandatory, population-based registry that includes external monitoring of completeness, which assesses reperfusion therapies for consecutive patients with acute ischemic stroke since 2011. We described outcomes overall and by subgroups (age ⩽ or >80 years; onset-to-groin puncture ⩽ or >6 hours; anterior or posterior strokes; previous IV recombinant tissue-type plasminogen activator or isolated endovascular treatment/therapy; revascularization or no revascularization), and determined independent predictors of good outcome (modified Rankin Scale score ⩽2) and mortality at 3 months by multivariate modeling. Results— We analyzed 536 patients, of whom 285 received previous IV recombinant tissue-type plasminogen activator. Overall, revascularization (modified Thrombolysis In Cerebral Infarction scores, 2b and 3) occurred in 73.9%, 5.6% developed symptomatic intracerebral hemorrhages, 43.3% achieved good functional outcome, and 22.2% were dead at 90 days. Adjusted comparisons by subgroups systematically favored revascularization (lower proportion of symptomatic intracerebral hemorrhages and death rates and higher proportion of good outcome). Multivariate analyses confirmed the independent protective effect of revascularization. Additionally, age >80 years, stroke severity, hypertension (deleterious), atrial fibrillation, and onset-to-groin puncture ⩽6 hours (protective) also predicted good outcome, whereas lack of previous disability and anterior circulation strokes (protective) as well as and hypertension (deleterious) independently predicted mortality. Conclusions— This study reinforces the role of revascularization and time to treatment to achieve enhanced functional outcomes and identifies other clinical features that independently predict good/fatal outcome after endovascular treatment/therapy.

Multimodal CT-Assisted Thrombolysis in Patients With Acute Stroke A Cohort Study

Background and Purpose— The value of multimodal CT to assist thrombolysis has received little attention in stroke. Methods— We assessed prospectively the impact derived from the routine application of CT perfusion and CTA in patients with acute stroke treated consecutively with alteplase. The safety and efficacy of thrombolytic therapy were compared in 106 patients assisted with CT/CTA/CT perfusion (multimodal CT group) and 262 patients assisted without full multimodal brain imaging (control group) during a 5-year period (2005–2009). Results— Good outcome (modified Rankin scale score ≤2) at 3 months was increased in the multimodal group compared with controls (adjusted OR, 2.88; 95% CI, 1.50–5.52). Multimodal-assisted thrombolysis yielded superior benefits in patients treated beyond 3 hours (adjusted OR, 4.48; 95% CI, 1.68–11.98) than treated within 3 hours (adjusted OR, 1.31; 95% CI, 0.80–2.16; interaction test P=0.043). Mortality (14% and 15%) and symptomatic hemorrhage (5% and 7%) were similar in both groups. Conclusions— Multimodal CT use in routine clinical practice may heighten the overall efficacy of thrombolytic therapy in acute ischemic stroke. The benefits seem greater in patients treated >3 hours after stroke onset, but further randomized clinical trials are needed to confirm these findings.

The response to IV rt‐PA in very old stroke patients

The use of rtPA in stroke patients aged >80 years remains controversial and it is debated whether there are sex‐based differences in the response to rtPA. We assessed the clinical value of thrombolytic therapy in patients aged >80 years (elderly group) in comparison with a non‐elderly group, and evaluated the existence of sex differences in the response to rtPA. All consecutive patients (n = 157) treated with rtPA were prospectively assessed since July 2001, including 49 elderly patients who fulfilled the National Institute of Neurological Disorders and Stroke (NINDS) criteria. Changes of the National Institute of Health Stroke Scale (NIHSS) score at 1 h, 24 h, and 7 days after rtPA administration, favourable outcome at day 90 [(modified Rankin Scale) mRS 0–1, or 2 if mRS = 2 before the stroke], symptomatic bleedings, and death rates were compared between elderly and non‐elderly patients. Using logistic regression, baseline NIHSS score [odds ratio (OR) 0.59, 95% confidence interval (CI) 0.41–0.84] was an independent predictor of favourable outcome, but not sex (OR 0.72, 95% CI 0.33–1.56), or age >80 years (OR 0.74, 95% CI 0.32–1.70). The rates of clinical improvement, mortality, or symptomatic CNS bleeding were also unrelated to age and sex. In conclusion, the response to IV rtPA is not impaired in elderly stroke patients and male and female are equally responsive.

Course of matrix metalloproteinase-9 isoforms after the administration of uric acid in patients with acute stroke: a proof-of-concept study

Oxidative stress as well as expression and activity of matrix metalloproteinase 9 (MMP-9) are rapidly enhanced after cerebral ischemia. The magnitude of these effects is related to stroke outcome. In human stroke, the extent of oxidative stress correlates well with increased MMP-9 expression. The aim of this study was to evaluate whether treatment with the antioxidant molecule uric acid (UA) decreased the levels of MMP-9 in stroke patients treated with rtPA. The patients were part of a pilot, double-blind, randomized, vehiclecontrolled study of patients with acute stroke treated with rtPA (< 3 h) and randomized to receive an intravenous infusion of UA (n = 16) or vehicle (n = 8). Total matrix metalloproteinase (tMMP)-9 and active (aMMP-9) levels were measured in serum at baseline (< 3 h), at the end of study treatment infusion (< 5.5 h), and at 48 hours. Total MMP-9 and aMMP-9 increased very early after stroke onset in patients allocated vehicle after rtPA therapy. Lower increments of aMMP-9 were associated with better outcome at 3 months. UA treatment was associated with reduced levels of aMMP-9 at T1 (p < 0.02) in multivariate models adjusted for age, NIHSS score, and baseline aMMP-9 levels. The decline of aMMP-9 attained after UA administration supports further clinical assessment of UA therapy in patients with acute stroke.

BR serine/threonine kinase 2: a new autoantigen in paraneoplastic limbic encephalitis.

We describe a new antigen, BR serine/threonine kinase 2 (BRSK2), identified by an antibody present in the serum of a patient with limbic encephalitis and small-cell lung cancer (SCLC). Patients serum immunolabeled the neuronal cytoplasm and, less intense, the neuropil of rat brain but did not immunoreact with other rat tissues with the exception of testis. Immunoblots of rat brain homogenate identified several immunoreactive bands in the range of 88-82 kDa and a weaker broad band of 47-43 kDa. Probing a rat hippocampus expression library with the patients serum resulted in the isolation of BR serine/threonine kinase 2 (BRSK2), a protein (also know as SAD1B kinase) preferentially expressed in the brain and testis and implicated in neuronal polarization as well as synaptic development. Eluted IgG from the BRSK2 clone gave a similar immunolabeling than the patients serum by immunohistochemistry and immunoblot of rat brain and testis. BRSK2 antibodies reacted with two SCLC from patients without paraneoplastic neurological syndromes. No anti-BRSK2 antibodies were found in the serum of 50 patients with SCLC without PNS, 19 with limbic encephalitis without onconeural antibodies, 50 with anti-Hu antibodies and several paraneoplastic neurological syndromes, including 14 with limbic encephalitis, and 160 with a variety of non-paraneoplastic neurological syndromes. Our study suggests BRSK2 may be an autoantigen involved in the pathogenesis of SCLC-associated limbic encephalitis.