Study finds link between enzyme and arthritis caused by chikungunya virus

A study led by QIMR Berghofer Medical Research Institute has found further evidence that an enzyme in the immune system promotes arthritis following infection with chikungunya virus.

The findings mean the enzyme could become a target for new treatments.

Chikungunya is a mosquito-borne disease related to Ross River virus. It can cause severe, chronic polyarthritis (inflammation in multiple joints) and/or polyarthralgia (pain in multiple joints). Standard anti-inflammatory drugs are usually not very effective in reducing the inflammation or pain.

The study was led by the head of the Inflammation Biology Laboratory at QIMR Berghofer, Professor Andreas Suhrbier.

Professor Suhrbier said the researchers used RNA-sequencing technology to examine inflammatory responses following infection with chikungunya.

“In laboratory experiments we found that when the gene for a particular enzyme – known as granzyme A – was missing, chikungunya virus caused far less swelling and arthritis,” Professor Suhrbier said.

“We also found that when we inhibited the enzyme, there was far less swelling and arthritis.”

The researchers also tested blood samples taken from chikungunya patients and found that they had higher levels of the enzyme.

“More research is needed to confirm these findings, but our study strongly suggests that this enzyme plays a part in promoting arthritis in chikungunya patients,” Professor Suhrbier said.

“If this is correct, the enzyme granzyme A could be a target for new anti-inflammatory drugs for chikungunya, and possibly also other inflammatory diseases, such as Ross River virus.”

The study involved Australian and international collaborators from a range of institutions including Monash University, Griffith University, The University of Sydney and CEA, Paris. The findings have been published in the journal PLOS Pathogens.