ITP (immune thrombocytopenic purpura) is a rare and dramatic blood disease. Almost 500 children and adults in Sweden develop the disease each year. ITP is a disease that involves the destruction of platelets.
Because the platelets are no longer able to close up wound openings where blood would otherwise coagulate, any bleeding becomes serious, or even fatal.
The disease exists as two variants: acute ITP, which is most common in children and which usually remits spontaneously within a few months, and chronic ITP, which is a life-long condition. Four out of five children are found to have the temporary variant, but every fifth child who develops ITP will have to live with the risk of bleeding for his or her entire life.
“At present only time can tell which variant of ITP it is. If a patient is still ill after one year, it is considered to be chronic ITP,” says Margareta Jernås, who is a researcher at the Sahlgrenska Academy, Gothenburg’s university.
Disease caused by own blood cells
ITP is an autoimmune disease, which means that the body’s immune defence system attacks the body’s own cells. The researchers in Gothenburg were the first research team in the world to show that in some people the disease is caused by the body’s own white blood cells attacking the platelets.
Different genetic functions
The researchers have analysed all the genes in T-cells, which are a type of white blood cell, in children who were recently diagnosed with ITP and in children who have been found to have chronic ITP. When the genes that were affected in the sick children were sorted into groups, it was found that the regulated genes in acute and chronic ITP had completely different functions.
“Our results indicate that with recently-diagnosed ITP there is a non-specific and broader inflammatory response, whereas the chronic form is associated with traditional pathological mechanisms such as the production of antibodies and T-cells targeted at the body’s own platelets,” says Bob Olsson, another of the researchers behind the discovery at the Sahlgrenska Academy.
New blood test
The research team at the Sahlgrenska Academy is now working to come up with a blood test that can quickly identify which form of the disease is involved. Such test would ease the psychological burden of parents of a sick child, and also allow for earlier planning of long-term treatment for those children who have the chronic variant. However it will take several more years of research before a blood test could start to be used in hospitals.
“Even though the results may not lead to new diagnosis of the different forms of ITP in the immediate future, we now have a better understanding of the underlying causes. It is one step closer to explaining how the disease comes about,” says Margareta Jernås.
The research was conducted in collaboration with research teams at Chalmers and at Shandong University in China.
The article Differences in gene expression and cytokine levels between newly diagnosed and chronic pediatric ITP (Jernås M, Hou Y, Strömberg Celind F, Shao L, Nookaew I, Wang Q, Ju X, Mellgren K, Wadenvik H, Hou M, Olsson B) was published in the scientific journal Blood.
Margareta Jernås, forskare vid Sahlgrenska akademin, Göteborgs universitet
+4631 342 9433
Bob Olsson, forskare vid Sahlgrenska akademin, Göteborgs universitet
+4631 343 1124