Alterations in acute-phase reactants (CRP, rheumatoid factor, complement, Factor B, and immune complexes) following an ultramarathon

Abstract

Objectives. The human body initiates an acute phase response (APR) in response to a wide range of homeostatic disturbances. This complex series of reactions serves to activate repair processes and prevent ongoing tissue damage. An important aspect of the APR is the de novo synthesis of acute phase proteins (APP), many of which have not been thoroughly investigated. Main outcome measures.Alterations in CRP (C-reactive protein), C1est, C3, C4, C6, rheumatoid factor (RF) and Factor B were determined before and after an ultramarathon. Data were analysed using a one-way analysis of variance comparing values to pre-exercise levels. Significance was set at p < 0.05.Design. Venepunctures were performed on athletes participating in an ultramarathon (90 km) 24 hours before, immediately post-exercise (IPE), and 3h, 24h and 72h after the race. Serum was stored at -80°C until analysed. CRP levels in serum were assessed using the N Latex CRP kit. The levels of circulating immune complexes (CIC) were determined using particle-enhanced nephelometry. Complement proteins C1est, C3, C4 and RF were measured using laser nephelometry. C6 and Factor B were determined by radial immunodiffusion. Results. CRP was significantly elevated IPE (58%), 3hpost (77%), 24h post (87%) and 72h post (69%). Pre-race CRP levels were above the normative range (5.10 ± 3.08 mg/l), C6 was significantly elevated (p < 0.05) at 24h post (7.8%) and 72h post (8.8%) exercise. Factor B was significantly elevated (p < 0.05) at 72h post exercise (12.8%). RF was significantly elevated at 72h post exercise (6.7%). Conclusion.Significant increases in selected acutephase reactants occur several days after the exercise event. In addition, as indicated by elevated resting levels of CRP, the athletes began the race with some degree of inflammation, presumably as a result of the cumulative training and racing mileage in preparation for the ultramarathon.

Effect of Aerobic and Anaerobic Exercise on the Complement System of Proteins in Healthy Young Males

“…Mashiko et al [22] reported a similar post-game observation in rugby players. In contrast to our findings for the Beep test, the levels of C3 and C4 after short-term maximal exercise rapidly returned to baseline values [40,54], but they stayed slightly lowered after an ultramarathon [55]. When analyzing the runners, Smith et al reported that short-term aerobic exercise triggers the activation of C3 and C4 complement components and subsequent increase in C3a and C4a [56].…”

Non-allergic activation of eosinophils after strenuous endurance exercise

“…The acute phase response (APR) to muscle/tissue damage, specifically the activation of complement components C3, C4 and C5 fragments, may be a possible mechanism for activating eosinophils. 13 Submitted data from the present study have shown that the same ultramarathon caused an APR and an increase in complement, 38 and this may have played a role in the non-allergic activation of eosinophils.…”

C-reactive protein - biological functions, cardiovascular disease and physical exercise

“…25,40,45 Although there is general consensus regarding the induction of an acute-phase inflammatory response following strenuous, unaccustomed or prolonged bouts of exercise, there is some degree of uncertainty surrounding the precise stimuli responsible for this response. The majority of authors have attributed the rise in inflammatory markers following physical activity to muscle damage.…”

“…Increases in CRP have been observed following acute strenuous, prolonged bouts of running, 40 triathlon, 16,47 bench stepping 12 and anaerobic exercise. 26 Since eccentrically based exercise is more commonly associated with muscle damage, and CRP serves to bind damaged cells, it seems reasonable to assume that this type of activity would be associated with pronounced elevations in CRP.…”