TNF-α -308 G allele and G/G genotype had higher frequency among MS patients than control subjects (G vs. A: OR=1.26, P<0.05); G/G vs. A/A: OR=4.59, P=0.0003).
A longitudinal analysis carried out monthly in eight MS patients (four untreated and four treated) revealed a transient increase in TNF-alpha mRNA expression in MNCs of all four treated patients in the first 3 months, supporting previous findings of an early immunoenhancing effect of IFN-beta 1a.
The difference could largely be attributed to increases in the TNFa 118 bp allele and the TNFb 127 bp allele in MS patients, with a conserved MS associated haplotype (130:118:127 TNF d:a:b).