Psoriasis Help Organisation - Online Psoriasis Forum

Then, they tried knocking out the same genes in mice with weakened immune systems to see if the body's defense system plays a role in the disease. They found that even without certain immune cells, mice developed symptoms of psoriasis. 

 
BOTTOM LINE: The study resolves a longstanding controversy over the origins of psoriasis. Some scientists thought the disease started inside the body, as an immune system problem that caused skin cells to turn over too quickly, forcing layers of skin to build up in itchy lesions. The new study shows that the disease is more likely a skin disorder that also has immune effects.
 
CAUTIONS: ''Nothing is black and white in biology," said study co-author Erwin F. Wagner of the Research Institute of Molecular Pathology in Austria. The study shows that psoriasis is primarily a skin disease, but the immune system can't be taken out of the picture completely. Mice with a weakened immune system fared better, not suffering the bone destruction, joint inflammation, and arthritic lesions that struck the mice with normal immune systems. This suggests that psoriasis, though largely a skin disorder, is influenced by a complex interplay of genes and immune cells.
 
WHAT'S NEXT: Scientists will study the gene that they used to trigger the disease in the lab mice as a possible target for medications. They will also use their mouse model -- the first one to replicate many of the symptoms of the disease -- to study possible therapies and learn more about the disease.
 
WHERE TO FIND IT: Nature, Sept. 15, 2005