Search Results (1,571)

Recurrent pregnancy loss (RPL) is defined as the occurrence of two or more pregnancy losses before 20 weeks of gestation. RPL is a common medical condition among reproductive-age women, with approximately 23 million cases reported annually worldwide. Up to 5% of pregnant women may experience two or more consecutive pregnancy losses. Previous studies have investigated risk factors for RPL, including maternal age, uterine pathology, genetic anomalies, infectious agents, endocrine disorders, thrombophilia, and immune dysfunction. However, RPL is a disease caused by a complex interaction of genetic factors, environmental factors (e.g., diet, lifestyle, and stress), epigenetic factors, and the immune system. In addition, due to the lack of research on genetics research related to RPL, the etiology remains unclear in up to 50% of cases. Platelets play a critical role in pregnancy maintenance. This study examined the associations of platelet receptor and ligand gene variants, including integrin subunit beta 3 (ITGB3) rs2317676 A > G, rs3809865 A > T; fibrinogen gamma chain (FGG) rs1049636 T > C, rs2066865 T > C; glycoprotein 1b subunit alpha (GP1BA) rs2243093 T > C, rs6065 C > T; platelet endothelial cell adhesion molecule 1 (PECAM1) rs2812 C > T; and platelet endothelial aggregation receptor 1 (PEAR1) rs822442 C > A, rs12137505 G > A, with RPL prevalence. In total, 389 RPL patients and 375 healthy controls (all Korean women) were enrolled. Genotyping of each single nucleotide polymorphism was performed using polymerase chain reaction–restriction fragment length polymorphism and the TaqMan genotyping assay. All samples were collected with approval from the Institutional Review Board at Bundang CHA Medical Center. The ITGB3 rs3809865 A > T genotype was strongly associated with RPL prevalence (pregnancy loss [PL] ≥ 2: adjusted odds ratio [AOR] = 2.505, 95% confidence interval [CI] = 1.262–4.969, p = 0.009; PL ≥ 3: AOR = 3.255, 95% CI = 1.551–6.830, p = 0.002; PL ≥ 4: AOR = 3.613, 95% CI = 1.403–9.307, p = 0.008). The FGG rs1049636 T > C polymorphism was associated with a decreased risk in women who had three or more pregnancy losses (PL ≥ 3: AOR = 0.673, 95% CI = 0.460–0.987, p = 0.043; PL ≥ 4: AOR = 0.556, 95% CI = 0.310–0.997, p = 0.049). These findings indicate significant associations of the ITGB3 rs3809865 A > T and FGG rs1049636 T > C polymorphisms with RPL, suggesting that platelet function influences RPL in Korean women. Full article

Background: TNF receptor 1 (TNF-R1) mediates the proinflammatory and proapoptotic effects of TNF-alpha, with its soluble form predicting incident heart failure (HF). While there is evidence linking TNF pathway activation to cardiac dysfunction, the mechanisms involved remain unclear. This study aimed to investigate the association between TNF-R1, exercise capacity, and cardiac function in asymptomatic patients with hypertensive heart disease (HHD). Methods: We enrolled 80 patients (mean age 55 ± 12 years) with HHD and no clinical symptoms of HF (stages A and B). Echocardiography, including tissue Doppler and left atrial and left ventricular (LV) strain assessment, was performed at rest. Peripheral venous blood samples were collected to measure serum TNF-R1 concentration. Results: The study population was divided into two subsets based on the median exercise capacity (peak VO₂) value. Patients with higher VO₂ had lower serum TNF-R1 concentration and higher early peak mitral annular velocity (e’) and peak atrial longitudinal strain (PALS). After adjusting for other covariates, multivariable regression analysis identified TNF-R1 as an independent determinant of peak VO₂. Mediation analysis revealed that the relationship between TNF-R1 and peak VO₂ was mediated by LV diastolic function (PALS or e’), with a decrease in the beta coefficient after including mediator variables from 0.37 (p < 0.001) to 0.30 (p < 0.006) and 0.31 (p = 0.004), respectively. Conclusions: In patients with HHD, higher TNF-R1 levels are associated with lower exercise capacity, which may be mediated by impaired LV diastolic function. These findings might suggest a role of TNF signalling in early HF development, justifying further studies to evaluate TNF-R1 as a biomarker for risk of HF progression. Full article

Background/Objectives: Guidelines recommend patients with heart failure with reduced ejection fraction (HFrEF) receive four-pillar heart failure (4P-HF) therapy, which significantly reduces cardiac morbidity and mortality. However, implementing these guidelines effectively into clinical practice remains challenging. Methods: Patients with HFrEF on submaximal 4P-HF therapy were identified from a large, multicentre Cardiology network database using a natural language processing tool, supported by manual file review. A nurse-led, remotely delivered, medication uptitration program aimed to optimise therapy in this real-world cohort. Results: The final cohort included 2004 patients with a mean age of 72.7 ± 11.6 years. Utilisation of 4P-HF increased from 11.1% at baseline to 49.8% post intervention, and each individual medication class increased significantly post intervention (all p < 0.001). The largest increase was observed with the use of sodium–glucose cotransporter 2 inhibitors, which rose from 17.3% to 73.9%, followed by mineralocorticoid receptor antagonists (51.6% to 65.7%), beta-blockers (88.4% to 97.0%), and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/angiotensin receptor blocker–neprilysin inhibitors (89.8% to 96.4%). In patients on submaximal therapy, barriers were documented in all cases. Following medication optimisation, left ventricular ejection function (LVEF) improved significantly (38.5% ± 10.8% vs. 42.5% ± 11.7, p < 0.001). Conclusions: This nurse-led, remotely delivered, medication optimisation program significantly improved the adoption of 4P-HF therapy and LVEF in patients with HFrEF. The program demonstrates a practical, scalable solution for the optimisation of HFrEF therapy across a large healthcare network. Full article

Background/Objectives: Real-world evidence shows alarmingly suboptimal utilization of guideline directed medical therapy (GDMT) in heart failure with reduced ejection fraction (HFrEF). One of the barriers of GDMT implementation appears to be concerns about the potential development of drug-related adverse events (AEs), particularly in high-risk patients. This study aimed to evaluate whether advanced HFrEF (AHF) patients can be up-titrated safely and whether AHF predisposes individuals to the occurrence of putatively drug-related AEs. Methods: A total of 373 HFrEF patients with documented baseline, 2 months, and 12 months visits were analyzed for utilization and target dosages (TDs) of HF drugs. Successful up-titration and AEs were evaluated for different stages of HF reflected by N-terminal pro-B type natriuretic peptide (NT-proBNP) (<1000 pg/mL, 1000–2000 pg/mL, >2000 pg/mL). Results: A stepwise increase in HF medications was observed for all drug classes during follow-up. At 12 months, 73%, 75%, 62%, 86%, and 45% of patients received ≥90% of TDs of beta-blockers (BBs), renin–angiotensin system inhibitors (RASis), mineralocorticoid receptor antagonists (MRAs), sodium–glucose cotransporter-2 inhibitors (SGLT2 i), and triple-therapy, respectively. Predictors of successful up-titration in logistic regression were baseline HF drug TDs, estimated glomerular filtration rate (eGFR), and potassium, but not NT-proBNP or age. The development of AEs was rare, with hyperkalemia as the most common event (34% at 12 months). AEs were comparable in all stages of HF. However, the development of hyperkalemia was more frequent in patients with higher NT-proBNP and also accounted for most cases of incomplete up-titration. Conclusions: This study suggests that with dedicated protocols and frequent visits, GDMT can be successfully implemented across all stages of HFrEF, including patients with AHF. Full article

Endometriosis is a disorder characterized by the presence of endometrial tissue outside the uterus, leading to dyspareunia, chronic pelvic pain, dysuria, and infertility. The latter has been related to implantation failure associated with alterations in decidualization, a process regulated by sex hormones such as progesterone. Membrane progesterone receptor β (mPRβ) exhibits a lower expression in endometriotic tissues than in normal endometrial ones. However, the role of mPRβ in decidualization is unknown. This work aimed to investigate whether mPRβ plays a role in the decidualization of endometrial stromal cells (ESCs) derived from women with and without endometriosis. The mPR agonist OrgOD-2 induced the gene expression of key decidualization markers (insulin-like growth factor binding protein 1, prolactin, transcription factor heart and neural crest derivatives-expressed transcript 2, and fork-head transcription factor) in healthy ESCs, eutopic (uterine cavity), and ectopic (outside of the uterine cavity) ESCs from women with endometriosis. Notably, the expression of the decidualization markers was lower in endometriotic cells than in healthy endometrial ones. An siRNA mediated knockdown of mPRβ reduced the expression of decidualization-associated genes in ESCs treated with a decidualization stimuli, regardless of whether cells were derived from healthy women or those with endometriosis. Our data suggest that progesterone, through mPRβ activation, regulates the decidualization process in endometrial stromal cells from women with and without endometriosis. Full article

Background: Peritoneal dissemination in colorectal cancer (CRC) is associated with poor prognosis due to limited efficacy of current therapeutic strategies. The cholinergic receptor nicotinic beta 2 subunit (CHRNB2), a component of the acetylcholine receptor, has been implicated in other malignancies, but its role in CRC remains unknown. Methods: This study evaluated the expression and function of CHRNB2 in CRC. CHRNB2 mRNA levels were quantified by qRT-PCR in cell lines and clinical specimens. Functional assays were conducted using CRC cell lines with high CHRNB2 expression, in which CHRNB2 was knocked down by shRNA. Cell proliferation, migration, and invasion were assessed in vitro. In vivo effects were evaluated using subcutaneous and peritoneal xenograft models. The impact of CHRNB2 monoclonal antibody (mAb) treatment on CRC cell proliferation was also examined. Clinical correlations were assessed between CHRNB2 expression and clinicopathological features, including recurrence patterns. Results: CHRNB2 expression varied among CRC cell lines, with the highest levels observed in LOVO cells. CHRNB2 knockdown significantly inhibited proliferation, migration, and invasion in vitro and suppressed tumor growth in vivo. CHRNB2 mAb treatment reduced cell proliferation. Clinically, high CHRNB2 expression correlated with a significantly higher cumulative rate of peritoneal recurrence, but not with recurrence in the liver, lungs, or lymph nodes. Multivariate analysis identified high CHRNB2 expression and T4 tumor depth as independent predictors of peritoneal recurrence. Conclusions: CHRNB2 promotes the malignant phenotype of CRC, particularly in peritoneal dissemination. These findings suggest that CHRNB2 may serve as a novel diagnostic biomarker and therapeutic target for CRC with peritoneal metastasis. Full article

Monkeypox virus (MPXV) has caused 148,892 confirmed cases and 341 deaths from 137 countries worldwide, as reported by the World Health Organization (WHO), highlighting the urgent need for effective vaccines to prevent the spread of MPXV. Traditional vaccine development is low-throughput, expensive, time consuming, and susceptible to reversion to virulence. Alternatively, a reverse vaccinology approach offers a rapid, efficient, and safer alternative for MPXV vaccine design. Here, MPXV proteins associated with viral infection were analyzed for immunogenic epitopes to design multi-epitope vaccines based on B-cell, CD4+, and CD8+ epitopes. Epitopes were selected based on allergenicity, antigenicity, and toxicity parameters. The prioritized epitopes were then combined via peptide linkers and N-terminally fused to various protein adjuvants, including PADRE, beta-defensin 3, 50S ribosomal protein L7/12, RS-09, and the cholera toxin B subunit (CTB). All vaccine constructs were computationally validated for physicochemical properties, antigenicity, allergenicity, safety, solubility, and structural stability. The three-dimensional structure of the selected construct was also predicted. Moreover, molecular docking and molecular dynamics (MD) simulations between the vaccine and the TLR-4 immune receptor demonstrated a strong and stable interaction. The vaccine construct was codon-optimized for high expression in the E. coli and was finally cloned in silico into the pET21a (+) vector. Collectively, these results could represent innovative tools for vaccine formulation against MPXV and be transformative for other infectious diseases. Full article

In familial Alzheimer’s disease (FAD), presenilin 1 (PSEN1) E280A cholinergic-like neurons (ChLNs) induce aberrant secretion of extracellular amyloid beta (eAβ). How PSEN1 E280A ChLNs-eAβ affects microglial activity is still unknown. We obtained induced microglia-like cells (iMG) from human peripheral blood cells (hPBCs) in a 15-day differentiation process to investigate the effect of bolus addition of Aβ42, PSEN1 E280A cholinergic-like neuron (ChLN)-derived culture supernatants, and PSEN1 E280A ChLNs on wild type (WT) iMG, PSEN1 E280A iMG, and sporadic Alzheimer’s disease (SAD) iMG. We found that WT iMG cells, when challenged with non-cellular (e.g., lipopolysaccharide, LPS) or cellular (e.g., Aβ42, PSEN1 E280A ChLN-derived culture supernatants) microenvironments, closely resemble primary human microglia in terms of morphology (resembling an “amoeboid-like phenotype”), expression of surface markers (Ionized calcium-binding adapter molecule 1, IBA-1; transmembrane protein 119, TMEM119), phagocytic ability (high pHrodo™ Red E. coli BioParticles™ phagocytic activity), immune metabolism (i.e., high generation of reactive oxygen species, ROS), increase in mitochondrial membrane potential (ΔΨm), response to ATP-induced transient intracellular Ca²⁺ influx, cell polarization (cluster of differentiation 68 (CD68)/CD206 ratio: M1 phenotype), cell migration activity according to the scratch wound assay, and especially in their inflammatory response (secretion of cytokine interleukin-6, IL-6; Tumor necrosis factor alpha, TNF-α). We also found that PSEN1 E280A and SAD iMG are physiologically unresponsive to ATP-induced Ca²⁺ influx, have reduced phagocytic activity, and diminished expression of Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) protein, but when co-cultured with PSEN1 E280A ChLNs, iMG shows an increase in pro-inflammatory phenotype (M1) and secretes high levels of cytokines IL-6 and TNF-α. As a result, PSEN1 E280A and SAD iMG induce apoptosis in PSEN1 E280A ChLNs as evidenced by abnormal phosphorylation of protein TAU at residue T205 and cleaved caspase 3 (CC3). Taken together, these results suggest that PSEN1 E280A ChLNs initiate a vicious cycle between damaged neurons and M1 phenotype microglia, resulting in excessive ChLN death. Our findings provide a suitable platform for the exploration of novel therapeutic approaches for the fight against FAD. Full article

Liver cirrhosis is a chronic progressive disease marked by the transition from a compensated to a decompensated stage, associated with severe complications. Central to this progression is portal hypertension, which results from increased intrahepatic vascular resistance and endothelial dysfunction, as well as splanchnic vasodilation and an augmented circulatory state. Non-selective beta-blockers (NSBBs) remain the standard of care for portal hypertension, reducing portal pressure by lowering cardiac output via beta-1 receptor blockade and decreasing splanchnic blood flow through beta-2 receptor antagonism. However, clinical application of NSBBs is often hindered by adverse effects such as bradycardia, hypotension, and fatigue, alongside inconsistent efficacy in certain patient populations. Such limitations have driven the search for alternative therapeutic strategies and effective biomarkers for identifying non-responders. Beta-3 adrenergic receptor agonists have emerged as promising candidates, acting through distinct mechanisms, different from NSBBs. By stimulating nitric oxide release from endothelial cells, beta-3 agonists induce selective vasodilation without negatively impacting cardiac function, potentially overcoming the limitations of traditional therapies. This review discusses the molecular pathways of NSBBs, their clinical role and limitations, introduces potential novel biomarkers, and highlights the growing evidence supporting beta-3 receptor agonists as novel and targeted treatments for portal hypertension. Full article

This study aimed to investigate the tyrosine kinase inhibitor Nintedanib and its potential role in reversing epithelial–mesenchymal transition (EMT) induced by transforming growth factor beta 2 (TGF-β2) in retinal pigment epithelial (RPE) cells, along with its therapeutic potential using a mouse model of subretinal fibrosis. We hypothesized that the blockade of angiogenesis promoting and fibrosis inducing signaling using the receptor tyrosine kinase inhibitor Nintedanib (OfevTM) can prevent or reverse EMT both in vitro and in our in vivo model of subretinal fibrosis. Primary human retinal pigment epithelial cells (phRPE) and adult retinal pigment epithelial cell line (ARPE-19) cells were treated with TGF-β210 ng/mL for two days followed by four days of Nintedanib (1 µM) incubation. Epithelial and mesenchymal phenotypes were assessed by morphological examination, quantitative real-time polymerase chain reaction(qPCR) (ZO-1, Acta2, FN, and Vim), and immunocytochemistry (ZO-1, vimentin, fibronectin, and αSMA). Metabolites were measured using luciferase-based assays. Extracellular acidification and oxygen consumption rates were measured using the Seahorse XF system. Metabolic-related genes (GLUT1, HK2, PFKFB3, CS, LDHA, LDHB) were evaluated by qPCR. A model of subretinal fibrosis using the two-stage laser-induced method in C57BL/6J mice assessed Nintedanib’s therapeutic potential. Fibro-vascular lesions were examined 10 days later via fluorescence angiography and immunohistochemistry. Both primary and ARPE-19 RPE stimulated with TGF-β2 upregulated expression of fibronectin, αSMA, and vimentin, and downregulation of ZO-1, consistent with morphological changes (i.e., elongation). Glucose consumption, lactate production, and glycolytic reserve were significantly increased in TGF-β2-treated cells, with upregulation of glycolysis-related genes (GLUT1, HK2, PFKFB3, CS). Nintedanib treatment reversed TGF-β2-induced EMT signatures, down-regulated glycolytic-related genes, and normalized glycolysis. Nintedanib intravitreal injection significantly reduced collagen-1+ fibrotic lesion size and Isolectin B4+ neovascularization and reduced vascular leakage in the two-stage laser-induced model of subretinal fibrosis. Nintedanib can induce Mesenchymal-to-Epithelial Transition (MET) in RPE cells and reduce subretinal fibrosis through metabolic reprogramming. Nintedanib can therefore potentially be repurposed to treat retinal fibrosis. Full article

Coronary artery disease (CAD) constitutes a major contributor to morbidity, mortality and healthcare burden worldwide. Recent innovations in imaging modalities, pharmaceuticals and interventional techniques have revolutionized diagnostic and treatment options, necessitating the reevaluation of established drug protocols or the consideration of newer alternatives. The utilization of beta blockers (BBs) in the setting of acute myocardial infarction (AMI), shifting from the pre-reperfusion to the thrombolytic and finally the primary percutaneous coronary intervention (pPCI) era, has become increasingly more selective and contentious. Nonetheless, the extent of myocardial necrosis remains a key predictor of outcomes in this patient population, with large trials establishing the beneficial use of beta blockers. Computed tomography coronary angiography (CTCA) has emerged as a highly effective diagnostic tool for delineating the coronary anatomy and atheromatous plaque characteristics, with the added capability of MESH-3D model generation. Induction and preservation of a low heart rate (HR), regardless of the underlying sequence, is of critical importance for high-quality results. Landiolol is an intravenous beta blocker with an ultra-short duration of action (t1/2 = 4 min) and remarkable β1-receptor specificity (β1/β2 = 255) and pharmacokinetics that support its potential for systematic integration into clinical practice. It has been increasingly recognized for its importance in both acute (primarily studied in STEMI and, to a lesser extent, NSTEMI pPCI) and chronic (mainly studied in elective PCI) CAD settings. Given the limited literature focusing specifically on landiolol, the aim of this narrative review is to examine its pharmacological properties and evaluate its current and future role in enhancing both diagnostic imaging quality and therapeutic outcomes in patients with CAD. Full article

Holothuria scabra has long been acknowledged in traditional medicine for its therapeutic properties. The transforming growth factor-beta (TGF-β) superfamily is crucial in regulating cellular processes, including differentiation, proliferation, and immune responses. This study marks the first exploration of the gene expression localization, sequence conservation, and functional roles of H. scabra TGF-β proteins, specifically activin (HolscActivin), inhibin (HolscInhibin), and the TGF-β receptor (HolscTGFBR), across various organs. In situ hybridization indicated that HolscActivin and HolscInhibin are expressed in the intestine, respiratory tree, ovary, testis, and inner body wall. This suggests their roles in nutrient absorption, gas exchange, reproduction, and extracellular matrix remodeling. Notably, HolscTGFBR demonstrated a similar tissue-specific expression pattern, except for its absence in the respiratory tree. Bioinformatics analysis reveals that HolscTGFBR shares significant sequence similarity with HomsaTGFBR, especially in regions essential for signal transduction and inhibition. Molecular docking results indicate that HolscActivin may promote receptor activation, while HolscInhibin functions as a natural antagonist, reflecting the signaling mechanisms of human TGF-β proteins. Interestingly, cross-species ternary complex docking with human TGF-β receptors further supports these findings, showing that HolscActivin moderately engages the receptors, whereas HolscInhibin exhibits strong binding, suggestive of competitive inhibition. These results indicate that H. scabra TGF-β proteins retain the structural and functional features of vertebrate TGF-β ligands, supporting their potential applications as natural modulators in therapeutic and functional food development. Full article

Interleukin-1 beta(IL-1β) is the major driving force in neuroinflammation. Here, we report on (i) the role of (IL-1β) in activating a signaling cascade that leads to proliferation and metastasis in glioblastoma cancer pathogenesis as well as (ii) the therapeutic role for IL-1 Receptor Antagonist (IL-1RA) and Tolcapone against untoward aspects of tumor pathogenesis. Here, we report that IL-1β treatment at 50 ng/mL for 48 h increased proliferation and metastasis by 30-fold (p ≤ 0.05), leading to the formation of clones of rapidly dividing cancer cells, leading to the formation of organized glial fibrillary acid protein (GFAP)-immunoreactive, clone-like structures with protruding spikes. Further, IL-1β treatment significantly increased the expression of mRNA levels of the IL-1β-driven pathway TLR-MyD88-NF-κB-TNFα and IL-6 (p ≤ 0.05). IL-1β also increased autophagy via elevation of mRNA and protein levels of cathepsin B, LAMP-2, and LC3B. In contrast, IL-1RA and Tolcapone inhibited this proliferation and the expression of these mRNAs and proteins, inhibiting autophagy by downregulating these autophagy proteins and inducing apoptosis by upregulating the expression of pro-apoptotic proteins like caspase-8 and caspase-3. IL-1β and its receptor can be targeted for successful anticancer therapy, as shown here with the use of IL-1RA and/or Tolcapone. Full article

Emerging evidence suggests a bidirectional relationship between gut microbiota, melatonin synthesis, and breast cancer (BC) development in hormone receptor-positive patients (HR+HER2+ and HR+HER2-). This study investigated alterations in gut microbiota composition, the serum serotonin–N-acetylserotonin (NAS)–melatonin axis, fecal short-chain fatty acids (SCFAs) and beta-glucuronidase (βGD) activity, and serum zonulin in HR+ BC patients compared to healthy controls. Blood and fecal samples were analyzed using mass spectrometry for serotonin, NAS, melatonin, and SCFAs; ELISA for AANAT, ASMT, 14-3-3 protein, and zonulin; fluorometric assay for βGD activity; and 16S rRNA sequencing for gut microbiota composition. HR+ BC patients exhibited gut dysbiosis with reduced Bifidobacterium longum and increased Bacteroides eggerthii, alongside elevated fecal βGD activity, SCFA levels (e.g., isovaleric acid), and serum zonulin, indicating increased intestinal permeability. Serum serotonin and N-acetylserotonin (NAS) levels were elevated, while melatonin levels were reduced, with a higher NAS/melatonin ratio in BC patients. AANAT levels were increased, and ASMT levels were decreased, suggesting disrupted melatonin synthesis. Bifidobacterium longum positively correlated with melatonin and negatively with βGD activity, while Bacteroides eggerthii showed a positive correlation with βGD activity. These findings suggested that gut microbiota alterations, disrupted melatonin synthesis, microbial metabolism, and intestinal permeability may contribute to BC pathophysiology. The NAS/melatonin ratio could represent a potential biomarker, necessitating further mechanistic studies to confirm causality and explore therapeutic interventions. Full article

Long-COVID (LC) is characterized by diverse and persistent symptoms, potentially mirroring different molecular pathways. Recent data might offer that one of them is mediated by functional autoantibodies (fAAb) targeting G protein-coupled receptors (GPCR). Thus, the aim of this study was to investigate the clinical phenotype of patients with LC in relation to their GPCR-fAAb seropositivity. The present study recruited 194 patients with LC and profiled them based on self-reported symptoms. GPCR-fAAb seropositivity was identified by using a cardiomyocyte bioassay, testing the presence and functionality of the AAbs. Logistic regression, clustering, and decision tree analyses were applied to examine associations between GPCR-fAAb profiles and self-reported symptoms considering age and gender. The most prevalent GPCR-fAAbs in patients with LC were fAAB targeting the β2 adrenergic receptor (β2-fAAb, 92.8%), the muscarinergic M2 receptor (M2-fAAb, 87.1%), the Angiotensin II type 1 receptor (AT1-fAAb, 85.6%), and angiotensin (1–7) Mas receptor (MAS-fAAb, 85.6%). β2-fAAb showed a significant relation with dizziness, lack of concentration, and POTS, while Endothelin Type A receptor functional autoantibody (ET-A-fAAb) was significantly related to deterioration of pre-existing neurological disorders. Statistical analysis indicated a strong positive correlation between M2- and β2-fAAb; as in addition, an association of β2-fAAb and gender was observed to one of the major clinical symptoms (fatigue/PEM), a critical impact of GPCR-fAAb on LC-pathogenesis can be assumed. Summing up, the present data show that specific GPCR-fAAb are associated with distinct clinical phenotypes. Especially, the combination of M2- and β2-fAAb seemed to be essential for the LC-phenotype with a combination of fatigue/PEM and lack of concentration as major clinical symptoms. Full article