The researchers looked at a post-mortem cohort of pathologically confirmed cases with multiple sclerosis with fresh frozen material for genetic analysis and fixed material for pathology.
HLA-DRB1 alleles were genotyped to select a subset of age- and sex- matched HLA-DRB1*15-positive (n=21) and negative (n=26) cases for pathological analysis. Three spinal cord levels (cervical, thoracic and lumbar) were stained for myelin, axons and inflammation.
The researchers then looked at the influence of HLA-DRB1*15 on pathological outcome measures. They found that carrying HLA-DRB1*15 significantly increased the extent of demyelination, parenchymal and lesional inflammation in the spinal cord. Meningeal inflammation correlated significantly with small fibre axonal loss in the lumbar spinal cord only in the HLA-DRB1*15 positive cases. Therefore, HLA-DRB1*15 influences spinal cord pathology in MS. This highlights how genes and clinical phenotypes can be linked using microscopic pathology.
Authors: Deluca GC, Alterman R, Martin JL,
Source: Brain. 2013 Mar 12. [Epub ahead of print]