Rhesus Factor Modulation of Effects of Smoking and Age on Psychomotor Performance, Intelligence, Personality Profile, and Health in Czech Soldiers

Abstract

BackgroundRhesus-positive and rhesus-negative persons differ in the presence-absence of highly immunogenic RhD protein on the erythrocyte membrane. This protein is a component of NH3 or CO2 pump whose physiological role is unknown. Several recent studies have shown that RhD positivity protects against effects of latent toxoplasmosis on motor performance and personality. It is not known, however, whether the RhD phenotype modifies exclusively the response of the body to toxoplasmosis or whether it also influences effects of other factors.Methodology/Principal FindingsIn the present cohort study, we searched for the effects of age and smoking on performance, intelligence, personality and self-estimated health and wellness in about 3800 draftees. We found that the positive effect of age on performance and intelligence was stronger in RhD-positive soldiers, while the negative effect of smoking on performance and intelligence was of similar size regardless of the RhD phenotype. The effect of age on four Cattell's personality factors, i.e., dominance (E), radicalism (Q1), self-sentiment integration (Q3), and ergic tension (Q4), and on Cloninger's factor reward dependency (RD) was stronger for RhD-negative than RhD-positive subjects, while the effect of smoking on the number of viral and bacterial diseases was about three times stronger for RhD-negative than RhD-positive subjects.ConclusionsRhD phenotype modulates the influence not only of latent toxoplasmosis, but also of at least two other potentially detrimental factors, age and smoking, on human behavior and physiology. The negative effect of smoking on health (estimated on the basis of the self-rated number of common viral and bacterial diseases in the past year) was much stronger in RhD-negative than RhD-positive subjects. It is critically needed to confirm the differences in health response to smoking between RhD-positive and RhD-negative subjects by objective medical examination in future studies.

Toxoplasmosis-Associated Difference in Intelligence and Personality in Men Depends on Their Rhesus Blood Group but Not ABO Blood Group

“…The fourth study has reported opposite relation of toxoplasmosis with Cattell's ego strength, praxernia, and ergic tension and Cloninger's cooperativeness in RhD-positive and RhD-negative blood donors [29]. The latter study also indicates that RhD phenotype might play an important role not only in the toxoplasmosis-associated differences but also in the age-associated differences in specific personality traits.. Another recent study shows that RhD phenotype could also play a role in correlations of age and smoking with psychomotor performance, intelligence and health of draftees [47]. The results of the current study are in an agreement with the already published data.…”

“…It must be reminded, however, that the ABO blood group system rather than the Rhesus factor system was nearly always examined in these studies, see [61]–[64]. Our results imply that in future behavioural studies the attention should be focused not only on the ABO system but also on RhD phenotype and that important confounding variables, especially Toxoplasma infection and smoking [47] should be controlled.…”

Does the prevalence of latent toxoplasmosis and frequency of Rhesus-negative subjects correlate with the nationwide rate of traffic accidents?

“…While the prevalence of RhD-negative subjects in Caucasian populations is about 16%, it is much lower in the population of people of Asian and African origin (Mourant 1954). It must be admitted, however, that RhD-negative individuals are subject to stronger negative effects of aging and smoking on health estimated on the basis of the self-rated number of common viral and bacterial diseases in the past year, regardless of Toxoplasma infection status, and that RhD positivity probably protects against a broader spectrum of negative factors than just the Toxoplasma infection (Flegr et al 2010(Flegr et al , 2012. A possible physiological mechanism of physiological and behavioural effects of RhD phenotype that was based on RhD negativity-associated anoxia in certain parts of nervous system was suggested by Prandota (2012).…”

Physical and Mental Health Status in Toxoplasma-Infected Women before and 3 Years after They Learn about Their Infection: Manipulation or Side-Effects of Impaired Health?

“…Rh positive and Rh negative subjects express different sensitivity to the effects of latent toxoplasmosis on psychomotor performance (Flegr et al, 2008c(Flegr et al, , 2012aNovotná et al, 2008) cognitive performance (Flegr et al, 2012a(Flegr et al, , 2013, personality profile (Cattell, 1972;Flegr et al, 2010Flegr et al, , 2012aFlegr et al, , 2013, and mental health (Holub et al, 2011) and also differ in their health status and the incidence of certain disorders Flegr, 2016), but see (Halmin et al, 2017). Many effects of toxoplasmosis are much stronger in Rh negative subjects and some can be detected only in them (Flegr et al, 2009;Kaňková et al, 2010).…”