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Review
. 2022 Dec 20;12(1):22.
doi: 10.3390/jcm12010022.

The Assessment of Immune Fitness

Joris C Verster  1   2 , Aletta D Kraneveld  1 , Johan Garssen  1   3
Affiliations
Review

The Assessment of Immune Fitness

Joris C Verster et al. J Clin Med. .

Abstract

Immune fitness (i.e., adequate functioning of the immune system) is essential to maintain health, prevent and resolve disease, and improve quality of life. This article provides an overview of how to assess immune fitness. It discusses how a single-item rating scale can be used to assess immune fitness. The scale can be used in conjunction with a single "yes" or "no" question asking whether the individual is experiencing reduced immune fitness. Retrospective assessments can be complemented with the Immune Status Questionnaire (ISQ) to provide more insight into the type and frequency of experiencing specific immune-related complaints. Momentary assessments of immune fitness can be complemented with biomarker measurements in body fluids. As individuals may be unaware of systemic inflammation (e.g., biomarker concentrations outside the normal range), it remains critical to combine immune fitness assessments with biomarker measurements of immune functioning.

Keywords: ISQ; assessment; biomarkers; immune fitness; immune functioning; single-item scale.

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Conflict of interest statement

Over the past 3 years, J.C.V. has acted as a consultant/advisor for Eisai, KNMP, Mentis, Red Bull, Sen-Jam Pharmaceutical, and Toast! A.D.K. has held research grants from H2020, Nutricia-Danone, Netherlands Center of Translational Research, Lung Fund, SGF/Health Holland, and NWO. J.G. is a part-time employee of Nutricia Research and received research grants from Nutricia Research Foundation, Top Institute Pharma, Top Institute Food and Nutrition, GSK, STW, NWO, Friesland Campina, CCC, Raak-Pro, and EU.

Figures

Figure 1
Figure 1
Relationship between general health and immune fitness. General health and immune fitness were both scored on a single-item rating scale ranging from 0 (very poor) to 10 (excellent). Data for n = 4272 individuals, taken from references [7,8,9,10,11,12].
Figure 2
Figure 2
Assessment of immune fitness.
Figure 3
Figure 3
Retrospective assessments of immune fitness. The immune fitness of n = 254 Utrecht University students was assessed with a single-item scale ranging from 0 (very poor) to 10 (excellent). The assessed time periods were 15 March 2019–11 May 2020 (Lockdown 1), 12 May 2020–31 October 2020 (No lockdown), and 1 November 2020–1 April 2021 (Lockdown 2). Means and standard errors (SE) are shown. Differences between the time periods were considered statistically significant if p < 0.0083 (applying Bonferroni’s correction for multiple comparisons). Data were taken from Hendriksen et al. [5,22].
Figure 4
Figure 4
Assessment of reduced immune fitness.
Figure 5
Figure 5
Reduced immune fitness. Shown are the distribution (A) and percentages (B) of individuals reporting normal or reduced immune fitness. Data for n = 4272 individuals, taken from references [7,8,9,10,11,12].
Figure 6
Figure 6
Correlation between the single-item immune fitness scale and the ISQ. Spearman’s correlation is depicted (red line). Dot sizes are proportional to the number of individuals. Abbreviation: ISQ = Immune Status Questionnaire. Data from n = 3748 individuals, taken from references [10,11,12,13,16,33,34,38].
Figure 7
Figure 7
Assessment of immune fitness. Characteristics of immune-related complaints (e.g., severity and duration) are shown in white ovals. Depending on the ability to cope, these characteristics determine immune fitness (indicated by a black arrow). In addition, immune-related complaints can be associated with systemic inflammation (indicated by a black arrow). The red arrows indicate which domains are assessed by the IFQ/ISQ (type and frequency of immune-related complaints), biomarkers (systemic inflammation), and the global (based on a single item) assessment (immune fitness). Abbreviations: IFQ = Immune Function Questionnaire, ISQ = Immune Status Questionnaire.
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References

    1. Unwin N., Alberti K.G.M.M. Chronic non-communicable diseases. Ann. Trop. Med. Parasitol. 2006;100:455–464. doi: 10.1179/136485906X97453. - DOI - PubMed
    1. Ogoina D., Onyemelukwe G.C. The role of infections in the emergence of noncommunicable diseases (NCDs): Compelling needs for novel strategies in the developing world. J. Infect. Public Health. 2009;2:14–29. doi: 10.1016/j.jiph.2009.02.001. - DOI - PMC - PubMed
    1. World Health Organization Noncommunicable Diseases. [(accessed on 30 March 2022)]. Available online: https://www.who.int/news-room/fact-sheets/detail/noncommunicable-diseases.
    1. Kiani P., Balikji J., Kraneveld A.D., Garssen J., Bruce G., Verster J.C. Pandemic preparedness: The importance of adequate immune fitness. J. Clin. Med. 2022;11:2442. doi: 10.3390/jcm11092442. - DOI - PMC - PubMed
    1. Hendriksen P.A., Garssen J., Bijlsma E.Y., Engels F., Bruce G., Verster J.C. COVID-19 lockdown-related changes in mood, health and academic functioning. Eur. J. Investig. Health Psychol. Educ. 2021;11:1440–1461. doi: 10.3390/ejihpe11040103. - DOI - PMC - PubMed