Are Farming and Animal Exposure Risk Factors for the Development of Granulomatosis With Polyangiitis? Environmental Risk Factors Revisited: A Case-control Study.

Objective: To investigate the possible association between animal exposure and risk for granulomatosis with polyangiitis (GPA).

Methods: Patients with GPA at the Department of Rheumatology, Uppsala University Hospital, between January 1, 2011, and December 31, 2018, were consecutively included. All patients filled in a questionnaire on possible environmental exposures: occupation, hobbies, and animal contact.

Are dietary vitamin D, omega-3 fatty acids and folate associated with treatment results in patients with early rheumatoid arthritis? Data from a Swedish population-based prospective study.

Background: Dietary intake of vitamin D and omega-3 fatty acids (FA) may be associated with superior response to antirheumatic treatments. In addition, dietary folate intake may be associated with worse response to methotrexate (MTX). The aim of this study was to investigate the association between dietary vitamin D, omega-3 FA, folate and treatment results of disease-modifying antirheumatic drugs (DMARDs) in patients with rheumatoid arthritis (RA).

Prevalence of Periodontitis in Patients with Established Rheumatoid Arthritis: A Swedish Population Based Case-Control Study.

Introduction: The possible hypothesis of a link between periodontitis and rheumatoid arthritis (RA), specifically anti-citrullinated protein antibody (ACPA) positive RA, prompted us to investigate the prevalence of periodontitis in the Swedish Epidemiological Investigation of RA (EIRA), a well-characterised population-based RA case-control cohort.

Methods: Periodontal status of 2,740 RA cases and 3,942 matched controls was retrieved through linking EIRA with the National Dental Health Registry (DHR), where dental diagnostic- and treatment codes on the adult Swedish population have been registered. Dental records from 100 cases and controls were reviewed to validate the periodontal diagnostic codes in DHR.