Effect of BNT162b2 mRNA booster vaccination on VO2 max in recreational athletes: A prospective cohort study.

Background and Aims: The goal of the present study was to systematically evaluate the effect of a booster vaccination with the BNT162b2 messenger RNA (mRNA; Pfizer-BioNTech®) vaccine on maximum oxygen uptake (VO2 max), potential signs of (peri)myocarditis, and sports participation. Methods: Recreational athletes who were scheduled to undergo booster vaccination were evaluated with transthoracic echocardiography, serum measurements of high-sensitivity C-reactive protein(hsCRP) and high-sensitivity troponin I, and a bicycle cardiopulmonary exercise test (CPET) with serum lactate evaluation before the booster vaccine administration. Seven days postvaccination the test battery was repeated. Additionally, the subjects were asked to fill in a questionnaire on side effects and a subjective evaluation of their relative training volume and intensity as compared to the weeks before vaccination. Results: A group of 42 analysed athletes showed a statistically significant 2.7% decrease in VO2 max after vaccination (mean standard error of mean pre: 48.6 (1.4) ml/kg/min; post: 47.3 (1.4) ml/kg/min; p = 0.004). A potentially clinically relevant decrease of 8.6% or more occurred in 8 (19%) athletes. Other CPET parameters and lactate curves were comparable. We found no serological or echocardiographic evidence of (peri)myocarditis. A slight but significant increase in hsCRP was noted 1 week after vaccination. Side effects were mild and sports participation was generally unchanged or mildly decreased after vaccination. Conclusion: In our population of recreational endurance athletes, booster vaccination with the BNT162b2 mRNA vaccine resulted in a statistically significant decrease in VO2max 7 days after vaccination. The clinical impact hereof needs to be further determined. No major adverse events were observed.

Study protocol: a single-blind, multi-center, randomized controlled trial comparing dynamic intraligamentary stabilization, internal brace ligament augmentation and reconstruction in individuals with an acute anterior cruciate ligament rupture: LIBRƎ study.

BACKGROUND: The current gold standard for the treatment of an anterior cruciate ligament (ACL) rupture is reconstruction with tendon graft. Recently, two surgical ACL repair techniques have been developed for treating an acute ACL rupture: Dynamic Intraligamentary Stabilization (DIS, Ligamys®) and Internal Brace Ligament Augmentation (IBLA, InternalBrace™). We will conduct a single-blind, multi-center, randomized controlled trial which compares DIS, IBLA and reconstruction for relative clinical efficacy and economic benefit. METHODS: Subjects, aged 18-50 years, with a proximal, primary and repairable ACL rupture will be included. DIS is preferably performed within 4 weeks post-rupture, IBLA within 12 weeks and reconstruction after 4 weeks post-rupture. Patients are included in study 1 if they present within 0-4 weeks post-rupture and surgery is feasible within 4 weeks post-rupture. Patients of study 1 will be randomized to either DIS or IBLA. Patients are included in study 2 if they present after 4 weeks post-rupture and surgery is feasible between 5 and 12 weeks post-rupture. Patients of study 2 will be randomized to either IBLA or reconstruction. A total of 96 patients will be included, with 48 patients per study and 24 patients per study arm. Patients will be followed-up for 2 years. The primary outcome is change from baseline (pre-rupture) in International Knee Documentation Committee score to 6 months post-operatively. The main secondary outcomes are the EQ-5D-5 L, Tegner score, Lysholm score, Lachman test, isokinetic and proprioceptive measurements, magnetic resonance imaging outcome, return to work and sports, and re-rupture/failure rates. The statistical analysis will be based on the intention-to-treat principle. The economic impact of the surgery techniques will be evaluated by the cost-utility analysis. The LIBRƎ study is to be conducted between 2018 and 2022. DISCUSSION: This LIBRƎ study protocol is the first study to compare DIS, IBLA and ACL reconstruction for relative clinical efficacy and economic benefit. The outcomes of this study will provide data which could aid orthopaedic surgeons to choose between the different treatment options for the surgical treatment of an acute ACL rupture. TRIAL REGISTRATION: This study is registered at ClinicalTrials.gov; NCT03441295. Date registered 13.02.2018.

Acute exercise-induced response of monocyte subtypes in chronic heart and renal failure.

PURPOSE: Monocytes (Mon1-2-3) play a substantial role in low-grade inflammation associated with high cardiovascular morbidity and mortality of patients with chronic kidney disease (CKD) and chronic heart failure (CHF). The effect of an acute exercise bout on monocyte subsets in the setting of systemic inflammation is currently unknown. This study aims (1) to evaluate baseline distribution of monocyte subsets in CHF and CKD versus healthy subjects (HS) and (2) to evaluate the effect of an acute exercise bout. Exercise-induced IL-6 and MCP-1 release are related to the Mon1-2-3 response. METHODS: Twenty CHF patients, 20 CKD patients, and 15 HS were included. Before and after a maximal cardiopulmonary exercise test, monocyte subsets were quantified by flow cytometry: CD14(++)CD16(-)CCR2(+) (Mon1), CD14(++)CD16(+)CCR2(+) (Mon2), and CD14(+)CD16(++)CCR2(-) (Mon3). Serum levels of IL-6 and MCP-1 were determined by ELISA. RESULTS: Baseline distribution of Mon1-2-3 was comparable between the 3 groups. Following acute exercise, %Mon2 and %Mon3 increased significantly at the expense of a decrease in %Mon1 in HS and in CKD. This response was significantly attenuated in CHF (P < 0.05). In HS only, MCP-1 levels increased following exercise; IL-6 levels were unchanged. Circulatory power was a strong and independent predictor of the changes in Mon1 (ß = -0.461, P < 0.001) and Mon3 (ß = 0.449, P < 0.001); and baseline LVEF of the change in Mon2 (ß = 0.441, P < 0.001). CONCLUSION: The response of monocytes to acute exercise is characterized by an increase in proangiogenic and proinflammatory Mon2 and Mon3 at the expense of phagocytic Mon1. This exercise-induced monocyte subset response is mainly driven by hemodynamic changes and not by preexistent low-grade inflammation.

Chronic exertional compartment syndrome of the forearm in motocross racers: findings on MRI.

INTRODUCTION: The purpose of this prospective study was to demonstrate the findings of MRI in motocross racers with chronic exertional compartment syndrome (CECS) of the forearm. MATERIALS AND METHODS: Racers with proven CECS and without CECS and male individuals not involved in strenuous activities with the forearm were included. Signal intensity (SI) and signal-to-noise ratio (SNR) obtained before and after exercise were compared (D-SNR). RESULTS: Magnetic resonance imaging after exercise showed an increase in SI and SNR in the muscles on T2-WI. The SI increase was obvious in the flexor digitorum superficialis (FDS) and profundus (FDP) in all CECS patients. In addition, a minor SI and SNR increase in the extensor carpi radialis longus (ECRL) was noted. In the non-symptomatic group of motocross racers, there was only a minor increase in SI and the SNR, which was similar in the FDP and ECRL muscles. In the untrained individuals a remarkable increase in the SI and SNR of the FDS/FDP-ECRL was noted. This increased SI and SNR was not present in the majority of non-symptomatic racers. CONCLUSION: Post-exertional MRI produces significant findings in CECS of the forearm. The motocross racers without post-exertional oedema in the FDP/FDS had no CECS.