Previous studies suggested that multiple sclerosis (MS) and Hodgkin lymphoma might share underlying causes, including exposure to microorganisms in childhood, such as Epstein-Barr virus (EBV) infection. In the study “Multiple sclerosis and risk of young-adult-onset Hodgkin lymphoma,” published in the journal Neurology: Neuroimmunology and Neuroinflammation, researchers suggested that common inherited or acquired risks for these conditions do exist.
Hodgkin lymphoma has three age-defined phenotypes, but it was the specific stage of young adult-onset Hodgkin lymphoma (YAHL) that was reported to be associated with a pattern of childhood markers of infectious exposure, and linked to MS.
The research team investigated if MS is associated with YAHL but not with the other Hodgkin lymphoma phenotypes. A cohort of 29,617 Swedish patients with an MS diagnosis (between 1968 and 2012) , and a control group of 296,164 people without MS, were used.
After being adjusted for participants’ age/period, sex, county of residence, and education level, results suggested that the association between MS and YAHL does exist, and most notably in female patients. Specifically, researchers found four patients with YAHL among the MS cohort, and 16 in the non-MS cohort. All four diagnoses of YAHL in MS occurred in women. The researchers, however, noted this may be due to the fact that most MS patients in the cohort were women, or because of sex-specific differences in susceptibility to a risk for both diseases.
A major study limitation was the inability to identify specific childhood exposures that underlie the association between MS and YAHL, the researchers said. Moreover, they had no access to potentially relevant personal characteristics that may influence disease association. Despite the large cohort number, the number of people with both MS and YAHL was found to be very small. This reflects the rarity of Hodgkin lymphoma in MS, and how the underlying risks for both diseases are not likely to be identical, though common factors are involved.
Researchers concluded that YAHL and MS may share common risks. Although unable to identify the risks, the team believes they may include the previously reported pattern of exposure to microorganisms in childhood.