Resumen
The invention relates to the use of an expression product of the VIP gene as a prognostic marker of an autoimmune disease, preferably autoimmune spondyloarthritis, in patients that have previously been diagnosed with said autoimmune disease. The invention also relates to a method for the prognosis of an autoimmune disease, preferably autoimmune spondyloarthritis, said method being characterised by the determination of the quantity of an expression product of the VIP gene.