Concentration of anti-pneumococcal capsular polysaccharide IgM, IgG and IgA specific antibodies in adult blood donors

Antony R Parker,Syreeta Allen,Stephen Harding

doi:10.1016/j.plabm.2016.02.004

Abstract

ObjectivesAnti-pneumococcal capsular polysaccharide (PCP) IgM, IgG and IgA ELISAs have been developed to aid assessment of the adaptive immune system. The relationship between the concentrations of PCP IgM, IgG, and IgA was investigated. Design and methodsThe concentrations of PCP IgM, IgG, and IgA were measured in sera obtained from 231 adult blood donors. ResultsConcentrations of each isotype were not normally distributed. The median concentration for PCP IgM was 54U/mL (range 37–75U/mL), IgG 40mg/L (range 26–79mg/L) and IgA 21U/mL (range 13–44U/mL). The median PCP IgM titres decreased with age and were significantly lower in patients aged 81–90 years compared to those aged 18–80 years. By contrast, there was a significantly higher median serum PCP IgG titre in the 61–90 years group compared to those aged 18–60 years and a significantly higher median serum PCP IgA titre in the 51–90 years group compared to those aged 18–50 years. The correlation between PCP IgG and IgA was more significant than between IgM and IgA and between IgM and IgG. Correlation of PCP IgA and IgM concentrations identified four phenotypes: high PCP IgM and IgA; high PCP IgM only; high PCP IgA only; and low PCP IgM and IgA. A significant number of individuals with a PCP IgG concentration >50mg/L had low PCP IgA and IgM concentrations. ConclusionThe additional measurement of PCP IgA and PCP IgM, alongside PCP IgG, in individuals investigated for a compromised immune system may provide a more detailed antibody profile.

Highlights

Serum antibody measurements are used to assess immune system competence and recovery, and are included in guidelines for the assessment of antibody deficiencies [1,5,7]
In this study we report the concentration of, and correlation between, pneumococcal capsular polysaccharide (PCP) IgM, IgG, and IgA antibodies in a large cohort of blood donor samples
The Shapiro–Wilk test for Gaussian distribution demonstrated that PCP IgM, IgG and IgA concentrations from adult blood donors were not normally distributed (p o0.0001)

Summary

Introduction

Serum antibody measurements are used to assess immune system competence and recovery, and are included in guidelines for the assessment of antibody deficiencies [1,5,7]. Measured antibodies include those raised in response to tetanus, haemophilus and pneumococcal capsular polysaccharide (PCP). The measurement of PCP IgM and IgA has been reported in patients with common variable immunodeficiency (CVID) [3]. Cavaliere et al identified four PCP IgM and IgA phenotypes and assessed their concentrations retrospectively to stratify the risk of pneumonia and bronchiectasis. The measurement of antigen-specific IgA and IgM is not routinely performed for the assessment of immunocompetence or risk of infection. In this study we report the concentration of, and correlation between, PCP IgM, IgG, and IgA antibodies in a large cohort of blood donor samples. We hypothesise that the simultaneous measurement IgA and IgM in addition to PCP IgG may give the clinician a more detailed antibody profile for the assessment of immunocompetence

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Conclusion