The number of fluid-containing cell compartments called vacuoles within immune cells could help predict the severity of Batten disease, a new study suggests.
The study, “The quantification of lymphocyte vacuolation serves as a measure of the severity of CLN3 disease,Â»Was published in JIMD Reports.
Vacuoles are compartments inside cells that are filled with fluid, often looking like bubbles under a microscope. The process of forming vacuoles is called vacuolation. Lymphocytes – a class of immune cells important in fighting infection – vacuolate in response to infection.
Abnormally high lymphocyte vacuolation has been observed in people with Batten disease. However, it has not been clear whether there is diagnostic or prognostic relevance to this observation.
In the new study, researchers collected 67 blood samples from 19 people with CLN3 disease, also known as juvenile Batten disease. Those included covered a wide range of disease severity. For comparison, samples were also taken from individuals without Batten disease (controls). Lymphocyte vacuolation was analyzed by a battery of different tests.
“We hypothesized that quantifying lymphocyte vacuolation would provide an objective diagnostic marker that would simultaneously assess disease severity,” the researchers wrote.
The degree of vacuolation was not significantly associated with age or duration of follow-up. Therefore, according to the researchers, measuring lymphocyte vacuolation is probably not a good way to assess disease progression.
In general, greater vacuolation – both in terms of more lymphocytes with vacuoles and the number of vacuoles in individual cells – was seen in samples from people with Batten disease, compared to those from people with Batten disease. witnesses.
Increased vacuolation was also associated with more severe forms of the disease. For example, there was less vacuolation observed in individuals with later onset of disease. In addition, people with more serious (larger) mutations in the CLN3 gene, which are usually associated with more severe disease, tended to have more vacuolation.
The researchers also measured the levels of the LAMP-1 protein in the cells; this protein is associated with the formation of vacuoles. LAMP-1 levels were higher in lymphocytes from people with Batten disease and also in associated metabolic conditions (eg, sialidosis). However, the increase in LAMP-1 was seen in cells that had a lot of vacuolation, and also in cells with relatively little.
“Taken together, these results indicate that the expression of LAMP-1 can be used to aid in the diagnosis of diseases associated with lymphocyte vacuolation and further imply that its distribution within lymphocyte subsets may represent a ‘signature’. disease-specific, âthe researchers wrote.
Collectively, these results indicate that lymphocyte vacuolation is increased in CLN3 disease and is associated with more severe disease, suggesting that measurement of lymphocyte vacuolation may have diagnostic or prognostic value for Batten disease.
The researchers noted that this may be particularly useful for people who have a variant of uncertain significance – that is, a mutation in CLN3 which has not been definitively linked to Batten disease. Measurement of lymphocyte vacuolation can also be a useful measurement in clinical trials.