The discovery might seem like a double-edged sword. The study funded in part by the Luxembourg National Research Fund (FNR), found, by comparing patients with the disease (the index patient) and two of their healthy siblings--that were of the same gender and comparable age--, that the index patient showed signs of reduced immunoageing.

Indeed, the deficiency of DJ-1 is found in people suffering from early onset familial Parkingson’s disease. In Luxembourg, 1,200 cases of this neurodegenerative condition have been identified, according to the university of Luxembourg.

Immunoageing occurs as the network of cells and proteins that make up the immune system becomes weaker. This leads to an increased vulnerability towards illnesses such as cancer or infectious diseases. However, those suffering from early onset familial Parkinson’s disease had a more juvenile immune system than their siblings, making them less vulnerable to infection.

“DJ-1 might be the key Yin-Yang point balancing natural ageing and immune ageing. The next stage in targeting such age related illnesses is to further explore and understand the various complex mechanisms that underpin the immunoageing process and their relationships to DJ-1,” the LIH said in a press release.

Though a DJ-1 deficiency causes neuronal cells to die, which leads to early onset Parkinson’s, as the LIH explains, the protein also dictates the ageing pace of one’s immune system.

The study was performed in collaboration with the university of Luxembourg, the Luxembourg Centre for Systems Biomedicine, the Japanese Agency for Medical Research and Development, the Odense University Hospital of the Southern Denmark University (SDU) and University Hospital Essen (UHE).

For the LIH, its findings are a sign of hope for a continuously ageing global population.