Increased plasma and brain immunoglobulin A in Alzheimer’s disease is lost in apolipoprotein E ε4 carriers

Table 4 Correlations between the plasma IgA levels and neuropathology as well as hippocampal IgA area fraction and IgA-positive cell number in cohort II

Variables	All groups	NC	AD	−APOEε4	+APOEε4
Aβ (score)	ns	ns	ns	0.741**	ns
LB (score)	ns	ns	ns	0.702*	ns
NFT (score)	ns	ns	ns	0.840***	ns
IgA+ cells (no.)	0.560**	ns	ns	0.893***	ns
IgA area fraction (%)	0.688***	ns	0.564*	0.918***	0.618*

Data were analysed using Spearman’s correlation test
Aβ amyloid beta, AD Alzheimer’s disease, APOE4 apolipoprotein 4, −APOEε4 APOEε4 non-carrier, +APOEε4 APOEε4 carrier, IgA immunoglobulin A, IgA+ immunoglobulin A-positive, LB Lewy body, NC non-demented control, NFT neurofibrillary tangle, no. number, ns not significant
*Significant correlation at p ≤ 0.05 level
**Significant correlation at p ≤ 0.01 level
***Significant correlation at p ≤ 0.001 level

ISSN: 1758-9193