Risk factors for Non-Hodgkin's lymphoma in autoimmune disease: a large database analysis.

Immune dysregulation in autoimmune diseases (ADs) is a risk factor for the development of Non-Hodgkin's lymphoma (NHL). However, the underlying mechanisms are not well understood. Hence, this retrospective study aims to describe the clinical and demographic factors that increase the risk of NHL development in patients with ADs. Our study utilised data from National Inpatient Sample (NIS) for the duration of 2016-2020 on all adult patients aged > 18 years who had NHL. We divided them into two cohorts: one with underlying ADs and one without underlying ADs. We then compared the adjusted odds ratios (aOR) of various risk factors. It was found that 0.9% of autoimmune cases had NHL, while 0.7% of non-autoimmune cases had NHL. Among those with autoimmune conditions, various factors influenced the presence of lymphoma, such as personal history of chemotherapy or radiation, family history of lymphoid malignancy, HIV infection, advanced age of 60-69 years, Asian and Pacific Islander ethnicity and viral hepatitis. The increased risk of NHL with autoimmune conditions is well established. Studies have also shown that these patients can overall have a poor prognosis from their NHL when compared to patients without autoimmune diseases. However, there is limited literature regarding the interplay of traditional NHL risk factors with underlying autoimmunity. Hence, our study sheds light on the lesser studied risk factors, such as patient characteristics and comorbidities.