Stephany Cares Huber

Chronic musculoskeletal disorders, including osteoarthritis, rheumatoid arthritis, and tendinopathies, converge on persistent synovial inflammation, matrix catabolism, and impaired repair. This review synthesizes molecular evidence that the cholinergic anti-inflammatory pathway (CAP), the efferent vagal arm of the inflammatory reflex, behaves as a rheostat of the musculoskeletal microenvironment. Activation of the α7 nicotinic acetylcholine receptor (α7nAChR) on macrophages, chondrocytes, osteoblasts, and synoviocytes suppresses nuclear factor-κB (NF-κB) and NLRP3 inflammasome signaling, downregulates MMP-1, MMP-3, and MMP-13, and reduces osteoblast RANKL production; effects on OPG and on the RANKL/OPG ratio under vagal stimulation remain uncharacterized, while favoring a pro-resolution M2-like macrophage program; context-dependent pro-inflammatory responses have also been reported. Bidirectional CAP and mesenchymal stromal cell (MSC) crosstalk indicates that MSCs both sense cholinergic cues and require an intact vagal arc for full immunomodulation. Along the gut–vagus–joint axis, dysbiosis and endotoxin translocation attenuate vagal signaling and amplify systemic inflammatory tone. Because orthobiologics such as platelet-rich plasma, bone marrow aspirate concentrate, and MSCs act within this milieu, cholinergic tone appears associated with the terrain that conditions their efficacy. Heart rate variability stratification and vagal neuromodulation may represent testable adjuncts, although prospective validation in orthobiologic populations remains absent. Preclinical and early clinical evidence is critically appraised throughout.

Introduction: Orthobiologics such as Platelet-Rich Plasma (PRP) and Injectable Platelet-Rich Fibrin (i-PRF) have emerged as promising tools in regenerative medicine. However, the lack of methodological standardization and the still limited comparative characterization between these products represent significant barriers to their optimized clinical application. This comparative laboratory study aimed to characterize and differentiate PRP and i-PRF, focusing on their cellular composition, obtained volume, and total Platelet-Derived Growth Factor (PDGF-BB) content. Materials and Methods: This study was conducted with 34 individuals meeting standard blood donation criteria. Peripheral blood samples were collected from all participants. PRP was obtained using a modified double-spin centrifugation protocol, whereas i-PRF was prepared using a modified low-speed centrifugation technique. Cellularity (platelet and leukocyte counts), final produced volume, and total PDGF-BB content were assessed using complete blood count analysis and an enzyme-linked immunosorbent assay (ELISA), respectively. Statistical analysis was performed using Linear Mixed Models (LMMs). Results: Both protocols resulted in significant increases in platelet and leukocyte concentrations compared to baseline values. PRP showed significantly higher platelet and leukocyte concentrations compared with i-PRF, as well as markedly higher PDGF-BB levels. In contrast, i-PRF yielded a substantially greater final volume and enabled a higher absolute delivery of total leukocytes, whereas PRP delivered a greater absolute number of platelets. In exploratory analyses, female sex, the presence of comorbidities, and increased abdominal circumference were associated with variations in product volume and cellular composition. Discussion: These findings indicate that PRP and i-PRF exhibit distinct biological profiles in terms of cellularity, volume, and total PDGF-BB content. Whether these laboratory differences translate into distinct clinical outcomes remains unknown. The results should therefore be viewed as hypothesis-generating: they suggest that PRP and i-PRF may not be interchangeable, and that future randomized clinical trials are needed to define product-specific indications based on the target tissue and desired biological mechanism.

Introduction: Orthobiologics such as Platelet-Rich Plasma (PRP) and Injectable Platelet-Rich Fibrin (i-PRF) have emerged as promising tools in regenerative medicine. However, the lack of methodological standardization and the still limited comparative characterization between these products represent significant barriers to their optimized clinical application. This comparative laboratory study aimed to characterize and differentiate PRP and i-PRF, focusing on their cellular composition, obtained volume, and concentration of Platelet-Derived Growth Factor (PDGF-BB). Materials and Methods: This study was conducted with 34 healthy individuals. Peripheral blood samples were collected from all participants. PRP was obtained using a modified double-spin centrifugation protocol, whereas i-PRF was prepared using a modified low-speed centrifugation technique. Cellularity (platelet and leukocyte counts), final produced volume, and PDGF-BB concentration were assessed using complete blood count analysis and enzyme-linked immunosorbent assay (ELISA), respectively. Statistical analysis was performed using Generalized Linear Models (GLM). Results: Both protocols resulted in significant increases in platelet and leukocyte concentrations compared to baselines values. PRP showed significantly higher platelet and leukocyte concentrations compared with i-PRF, as well as markedly higher PDGF-BB levels. In contrast, i-PRF yielded a substantially greater final volume and enabled a higher absolute delivery of total leukocytes, whereas PRP delivered a greater absolute number of platelets. Female Sex, presence of comorbidities, and increased abdominal circumference positively influenced product volume and cellular composition. Discussion: Although both PRP and i-PRF effectively concentrate blood-derived components, they present distinct biological profiles regarding cellularity, volume, and growth factor availability. These findings indicate that PRP and i-PRF are not interchangeable, and their clinical use should be guided by the target tissue, therapeutic mechanism, and evidence from randomized clinical trials.

Deep venous thrombosis (DVT) is characterized by the formation of a thrombus within deep veins. The unmet need to identify new biomarkers and causal risk factors in DVT patients has led to the use of novel techniques, such as metabolite analyses. This study aimed to characterize metabolic alterations in acute DVT patients using ¹H-NMR spectroscopy and determine the persistence of these changes over a six-month follow-up. Metabolomics, particularly ¹H-NMR spectroscopy, was performed on serum samples from acute DVT patients (first 30 days from diagnosis) and healthy controls (HC). Additionally, 10 plasma markers were evaluated using a Luminex kit. A total of 30 patients, with a mean age of 44 ± 12.5 years, primarily women (9 males:21 females), were included. Acute DVT patients showed elevated inflammatory markers, such as IL-6, IL-8, PDGF-AB/BB, and P-selectin, which later decreased in the follow-up group. However, adhesion molecules like sVCAM-1 and sICAM-1 have increased after six months. Metabolomics analysis revealed significantly decreased levels of glutamine, glucose, and branched-chain amino acids (BCAAs), alongside increased lactate levels in acute DVT samples. Metabolomic profiles showed only partial normalization at follow-up, indicating persistent metabolic dysregulation. Overall, the reduced glucose metabolism and increased lactate levels indicate anaerobic metabolism, likely caused by tissue hypoxia due to impaired blood flow. Glutamine, essential for DNA, ATP, and protein synthesis, was notably reduced, potentially impairing endothelial cell proliferation and vascular repair. The presence of adhesion molecules in the follow-up group confirms persistent endothelial dysfunction. These findings suggest that metabolic and endothelial alterations may persist long after acute inflammation resolves in DVT patients. In conclusion, the persistence of metabolic dysregulation suggests chronic metabolic stress in these patients, potentially resulting from ongoing endothelial damage, low-grade inflammation, or altered mitochondrial function due to past tissue hypoxia.

Background: Transcutaneous Randomized Pulsed Radiofrequency (TCPRF-STP) is a non-invasive therapeutic approach increasingly explored for managing spine-related pain, particularly in cases involving disc herniations and degenerative spine conditions. Objectives: To evaluate the use of transcutaneous PRF-STP in the treatment of spine pathologies and its evolution in short-term follow-up. Methods: This case series examines the outcomes of three patients treated with TCPRF-STP for varying spine pathologies, including lumbar and cervical disc herniations, lumbar stenosis, and radiculopathy. All patients had previously undergone conventional conservative therapies without a satisfactory improvement and were unwilling or unable to undergo invasive procedures. The treatment involved the application of electromagnetic fields through adhesive skin patches at targeted sites. Patients underwent three sessions of TCPRF-STP, with follow-up assessments evaluating pain and MRI. Results: Transcutaneous PRF-STP showed notable reductions in pain (VAS 0 in most cases), improvements in movement, and the restoration of normal daily activities. Follow-up MRI scans demonstrated positive structural changes in the treated discs. Although long-term recurrence occurred in one case, the patient remained active without functional limitations. Conclusions: Transcutaneous PRF-STP offers a promising, minimally invasive alternative for patients seeking to avoid surgery, though further studies with larger cohorts and longer follow-up periods are necessary to establish more robust evidence of its efficacy. This technique could become an important adjunct in managing chronic spinal pain conditions, offering patients an option with minimal risk and hospital demands.

Transcutaneous Randomized Pulsed Radiofrequency (PRF-STP) is a non-invasive therapeutic approach increasingly explored for managing spine-related pain, particularly in cases involving disc herniations and degenerative spine conditions. This case series examines the outcomes of four patients treated with PRF-STP for varying spine pathologies, including lumbar and cervical disc herniations, lumbar stenosis, and radiculopathy. All patients had previously undergone conventional conservative therapies without satisfactory improvement and were unwilling or unable to undergo invasive procedures. Treatment involved the application of electromagnetic fields through adhesive skin patches at targeted sites, providing pain relief and functional improvement. Patients underwent three sessions of PRF-STP, with follow-up assessments showing significant reductions in pain (VAS 0 in most cases), improvement in movement, and restoration of normal daily activities. Follow-up MRI scans demonstrated positive structural changes in the treated discs. Although long-term recurrence occurred in one case, the patient remained active without functional limitations. PRF-STP offers a promising, minimally invasive alternative for patients seeking to avoid surgery, though further studies with larger cohorts and longer follow-up periods are necessary to establish more robust evidence of its efficacy. This technique could become an important adjunct in managing chronic spinal pain conditions, offering patients an option with minimal risk and hospital demands.

Cancer is a leading cause of death, and the fibrinolytic system shows cooperative effects that facilitate the growth of tumors and the appearance of metastases. This prospective study aimed to evaluate the fibrinolytic potential in cancer patients and its association with mortality outcomes using the fluorometric method of simultaneous thrombin and plasmin generation. The study included 323 cancer patients and 148 healthy individuals. During the 12-month follow-up, 68 patients died. Compared to the control group, cancer patients showed alterations in thrombin production consistent with a hypercoagulability profile, and an increase in plasmin generation. Mortality risk was associated with two parameters of thrombin in both univariate and multivariable analysis: maximum amplitude (Wald 11.78, p < 0.001) and area under the curve (Wald 8.0, p < 0.005), while such associations were not observed for plasmin. In conclusion, this was the first study able to demonstrate the simultaneous evaluation of thrombin and plasmin generation in newly diagnosed untreated cancer patients. Patients with cancer have been observed to exhibit a hypercoagulable profile. During the study, two parameters linked to thrombin generation, MA and AUC, were identified and found to have a potential association with mortality risk. However, no associations were found with parameters related to plasmin generation.

Coagulation activation is a prominent feature of severe acute respiratory syndrome coronavirus 2 (COVID-19) infection. Activation of the contact system and intrinsic pathway has increasingly been implicated in the prothrombotic state observed in both sterile and infectious inflammatory conditions. We therefore sought to assess activation of the contact system and intrinsic pathway in individuals with COVID-19 infection. Baseline plasma levels of protease:serpin complexes indicative of activation of the contact and intrinsic pathways were measured in samples from inpatients with COVID-19 and healthy individuals. Cleaved kininogen, a surrogate for bradykinin release, was measured by enzyme-linked immunosorbent assay, and extrinsic pathway activation was assessed by microvesicle tissue factor–mediated factor Xa (FXa; MVTF) generation. Samples were collected within 24 hours of COVID-19 diagnosis. Thirty patients with COVID-19 and 30 age- and sex-matched controls were enrolled. Contact system and intrinsic pathway activation in COVID-19 was demonstrated by increased plasma levels of FXIIa:C1 esterase inhibitor (C1), kallikrein:C1, FXIa:C1, FXIa:α1-antitrypsin, and FIXa:antithrombin (AT). MVTF levels were also increased in patients with COVID-19. Because FIXa:AT levels were associated with both contact/intrinsic pathway complexes and MVTF, activation of FIX likely occurs through both contact/intrinsic and extrinsic pathways. Among the protease:serpin complexes measured, FIXa:AT complexes were uniquely associated with clinical indices of disease severity, specifically total length of hospitalization, length of intensive care unit stay, and extent of lung computed tomography changes. We conclude that the contact/intrinsic pathway may contribute to the pathogenesis of the prothrombotic state in COVID-19. Larger prospective studies are required to confirm whether FIXa:AT complexes are a clinically useful biomarker of adverse clinical outcomes.

Deep venous thrombosis (DVT) is associated with significant morbidity and mortality. Studies on changes in the level of metabolites could have the potential to reveal biomarkers that can assist in the early detection, diagnosis, monitoring of DVT progression, response to treatment, or recurrence of DVT. In this scenario, the metabolomic analysis can provide a better understanding of the biochemical dysregulations of thrombosis. Using an untargeted metabolomic approach through magnetic resonance spectroscopy and multi- and univariate statistical analysis, we compared 40 patients with previous venous thrombosis and 40 healthy individuals, and we showed important serum differences between patients and controls, especially in the spectral regions that correspond to glucose, lipids, unsaturated lipids, and glycoprotein A. Considering the groups depending on risk factors and the local of the previous episode (lower limbs or cerebral system), we also noticed differences in metabolites linked to lipids and lactate. Comparative analyses pointed to altered ratios of glucose/lactate and branched-chain amino acids (BCAAs)/alanine, which might be associated with the fingerprints of thrombosis. Although samples for metabolomic analysis were collected months after the acute episode, these results highlighted that, alterations can still remain and may contribute to a better understanding of the complications of the disease.