Comparison of demographic features and prognosis between cardiogenic shock in patients with Chagas heart disease and other etiologies – Registry Of Acute Medical Emergencies in Brazil (ROAD)

Background

Chagas disease is a chronic, systemic, parasitic infection caused by Trypanosoma cruzi, and a common cause of heart failure (HF) in Latin America. The incidence can be as high as 14% in endemic areas. The prognosis seems to be worse than other causes of HF, with mortality of up to 20%/year. Mortality and prognosis during the acute decompensation, however, are less studied.

Purpose

Compare differences between cardiogenic shock (CS) in patients with HF caused by chronic Chagas heart disease (ChHD) and those caused by other etiologies (non-ChHD).

Methods

We performed a multicentric, prospective, observational study of patients admitted with CS at 3 emergency departments in Brazil between January 2015 and December 2019. Baseline characteristics and intrahospital outcomes were obtained. Statistical analysis: The primary outcome was combined intra-hospital events (death, stroke, acute renal failure and bleeding). Comparison between groups was performed through Chi-squared and Student's T-test and the multivariate analysis by logistic regression, being p<0.05 considered significant.

Results

856 patients with CS were included, 158 (18,5%) ChHD and 698 (81,5%) non-ChHD. Those with ChHD were younger (60.5±11.7 vs. 64.9±4.8 years old, p<0.0001), less often male (50.0 vs. 64.3%, p=0.001) and had lower prevalence of diabetes (20.9 vs. 36.2%, p<0.0001), hypertension (36.07 vs. 64.1%, p<0.0001), chronic obstructive pulmonary disease (1.9 vs. 7.8%, p=0.007) and dyslipidemia (14.6 vs. 36%, p<0.0001). The ejection fraction was lower in ChHD (26 + 7.3 vs. 30.4% + 11.4, p<0.0001) and they had more definitive pacemaker (17.3 vs. 6.8%, p<0.0001). At the admission, patients with ChHD had lower systolic blood pressure (91.3±20.6 vs. 98.8±25.9 mmHg, p=0.001) and were more symptomatic, with orthopnea (41.3 vs. 28.3%, p=0.004), dyspnea (75.3 vs. 57.3%, p<0.0001). Treatment in the first 24 hours was different, with less withdrawal of beta-blockers (51.2 vs. 63.9%, p=0.006) and more use dobutamine (80.4 vs. 66.2%, p<0.0001). Main cause of decompensation was progression of disease in 39.1% of ChHD versus 22.9% of non-ChHD (p<0.001). Decompensation seemed more severe with greater necessity of orotracheal intubation (30 vs. 14.5%, p<0.0001), intra-aortic balloon pump (27.9 vs. 7.5%, p<0.0001), bleeding (9.2 vs. 3.8%, p=0.012) and acute renal failure (46.7 vs. 35.8%, p=0.024). The primary outcome was observed in 57% of the non-ChHD and 71.5% of the ChHD (OR 0.578, 95% CI: 0.314–1.064, p=0.079). Also, there were no differences between intra-hospital mortality in patients with ChHD versus non-ChHD (37.3 vs. 32.7%, p=0.261).

Conclusion

To the best of our knowledge, this is the biggest registry with Chagasic patients in cardiogenic shock. They were younger and had less comorbidities, but were admitted with lower blood pressure, more symptoms and needed more inotropes in the first 24 hours. No difference in mortality or combined outcome was observed.

Funding Acknowledgement

Type of funding source: None

Neural cell response to multiple novel sites on laminin-1

The basement membrane protein laminin-1 is a potent stimulator of neurite outgrowth for a variety of neuronal cell types. Previous studies have identified neurite outgrowth activity in several distinct regions of the laminin-1 molecule. In this study, 545 overlapping 12- to 14-mer synthetic peptides, corresponding to most of the amino acid sequence of the alpha1, beta1, and gamma1 chains of laminin-1, were screened for cell attachment and neurite outgrowth activity using primary cultures of mouse cerebellar granule neurons and two neuronal cell lines. We identified 48 peptides derived from novel regions of the laminin-1 molecule that were positive for neural cell adhesion activity. Only the cerebellar cells were found to have true neurite outgrowth activity with certain of the peptides, whereas some peptides induced short spike-like process with the cell lines. Although 23 of these peptides were active on all 3 cell types screened, 25 others showed cell-type specificity in their activity. These studies show that (1) there are multiple and distinct sites on laminin-1 for cell adhesion and neurite-like outgrowth and (2) that there are neural cell-type-specific active domains. The multiple active sites found explains, in part, the potent activity of laminin-1 on neurite outgrowth.

Laminin-1 and laminin-2 G-domain synthetic peptides bind syndecan-1 and are involved in acinar formation of a human submandibular gland cell line

The culture of human submandibular gland (HSG) cells on laminin-1 induces acinar differentiation. We identified a site on laminin involved in acinar differentiation using synthetic peptides derived from the C-terminal G-domain of the laminin alpha1 and alpha2 chains. The alpha1 chain peptide AG73 (RKRLQVQLSIRT) decreases the size of acini formed on laminin-1. Cells cultured with either AG73 or the homologous alpha2 chain peptide MG73 (KNRLTIELEVRT) form structures that appear acinar-like, but the cell nuclei are not polarized to the basal surface and no lumen formation occurs, indicating that additional sites on laminin are required for complete differentiation. The G-domain of laminin-1 contains both integrin and heparin binding sites, and anti-beta1-integrin antibodies disrupt acinar formation. Cell adhesion to the peptides and to E3, an elastase digest fragment of laminin-1 containing AG73, is specific, since other laminin peptides or EDTA do not compete the binding. Heparin and heparan sulfate decrease cell adhesion to AG73 and MG73 but anti-beta1-integrin antibodies have no effect. Treating the cell surface with heparitinase inhibits adhesion to both AG73 and MG73. We isolated cell surface ligands using both peptide affinity chromatography and laminin-1 affinity chromatography. Treating the material bound to the affinity columns with heparitinase and chondroitinase enriches for a core protein identified as syndecan-1 by Western blot analysis, thus identifying a syndecan-1 binding site in the globular domain of laminin-1 and laminin-2. In summary, multiple interactions between laminin and HSG cells contribute to acinar differentiation, involving both beta1-integrins and syndecan-1.

Laminin stimulates expression of two mitochondrial proteins during neurite outgrowth

Differential hybridization was utilized with mRNA from NG108-15 cells cultured on either tissue culture plastic or laminin for 4 hr to identify genes whose mRNA was increased by laminin, a potent stimulator of neurite outgrowth. Two of the 16 laminin-induced clones, cytochrome b and chargerin II, are mitochondrial proteins. Northern blotting confirmed that laminin increased the mRNA levels of cytochrome b and chargerin II several fold. Antibody to chargerin II stained both processes and cell bodies of the cerebellar Purkinje cells and localized in the mitochondria of NG108-15 cells, which also showed increased protein levels in the presence of laminin. In addition, higher levels of chargerin II protein were detected in the newborn brain compared to the adult. However, inhibitors of mitochondrial protein synthesis did not affect laminin-mediated neurite outgrowth. These data suggest that the increased synthesis of mitochondrial enzymes observed with laminin treatment may not be necessary for the formation of neurites.

Neurotoxicity of the human immunodeficiency virus type 1 tat transactivator to PC12 cells requires the Tat amino acid 49-58 basic domain

The acquired immunodeficiency syndrome (AIDS) frequently involves the central nervous system (CNS) and manifests as dementia due to encephalitis or diffuse neurodegeneration. Human immunodeficiency virus type 1 (HIV-1) proteins, potentially transported into the CNS by mononuclear inflammatory cells, have been implicated in the etiology of this HIV-1 associated neurological dysfunction. Here we investigate the neurotoxicity of the essential HIV-1 regulator protein Tat in vivo after microinfusion into the rat brain and in vitro using PC12, NG108-15, and GT17 neuronal cell lines. Infusion of either chemically synthesized Tat (Tat86) or recombinant Tat (rTat) into the striatal gray matter in Sprague-Dawley rats resulted in postural deviation ipsilateral to the infusion, a clinical presentation in rats associated with complete striatal dysfunction. Histologic examination 3 days after infusion revealed massive necrosis in the area of the distribution of the infusion. Infusion of heat denatured rTat, peptide Tat49-58, or peptide Tat57-86 did not result in clinically or histologically detectable brain damage. After 3 days incubation in vitro, the lethal dose for half (LD50) of PC12 cells due to rTat was 5 micrograms/ml. The LD50 for Tat86 under the same conditions was 10 micrograms/ml. Tat49-58 and Tat57-86 peptides were not toxic in vitro even at 10-fold higher doses. At 5 micrograms/ml, rTat was toxic to 100% of GT17 cells after 24 hr. At 5 micrograms/ml, Tat86 was toxic to 90% of the NG108-15 cells after 7 days of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)